Resumo em Inglês:

ABSTRACT We investigated the impact of weaning at 30, 75, and 180 days of age on performance, body measurements, and rumen development (using the β-hydroxybutyrate biomarker) of beef calves until 190 days of age. A total of 64 Brangus calves were assigned to three treatments: hyper-early (W30), weaned at 32±0.89 days of age (n = 22, 10 males and 12 females); early (W75), weaned at 77±0.95 days of age (n = 20, 12 males and eight females); and conventional (W180), weaned at 183±0.82 days of age (n = 22, 13 males and nine females). Body weight (BW), average daily gain (ADG), β-hydroxybutyrate (βHBA), and morphometric measurements were evaluated. These variables were influenced by an interaction between treatment and days and were not affected by the sex of calves. The W30 calves experienced weight loss from 30 to 40 days of age compared with the W75 and W180 calves. Consequently, at day 75, W30 animals were lighter and had lower body length, thoracic circumference, withers height, and croup height compared with the W75 and W180 calves. However, no significant differences in BW were observed among treatments at 85 days of age. Additionally, W30 calves exhibited higher ADG and a moderate correlation with βHBA levels. Weaning calves at 30 days of age may negatively affect their performance until the sixth week after weaning, but there is no impairment in performance at 190 days of age.

Resumo em Inglês:

ABSTRACT The relationship between animal products and agricultural gross domestic product (AGDP) in Türkiye was investigated in this study. We used data of eight animal products (cow milk, sheep milk, beef, mutton, poultry meat, eggs, wool, and honey) from 1980 to 2020. After checking the stationarity of the series by the Augmented Dickey-Fuller (ADF) test, the Johansen cointegration test was used to establish the existence of a long-term relationship between animal products and AGDP, and the results were interpreted using The Fully Modified Ordinary Least Squares (FMOLS) analysis. According to the findings, honey, beef, poultry meat, mutton, eggs, and wool had a positive and significant relationship with AGDP in Türkiye, whereas sheep milk and cow milk and AGDP was not significant. The total effect of the examined animal products on AGDP was 0.61%. The results showed that wool was the most important contributor to AGDP among the products analyzed. Therefore, it is suggested that policymakers develop funding strategies to expand the production of these products.

Resumo em Inglês:

ABSTRACT This study aimed to analyze the economic viability of the implementation of a mechanized harvesting of broilers where the activity is carried out entirely manually. The viability indicators used were net present value (NPV), net future value (NFV), net uniform value (NUV), discounted payback (DP), and internal rate of return (IRR). Scenario analysis, sensitivity, and Monte Carlo simulation were performed in the present study. The results showed that the initial investment was US$ 1,868,302.76. The average price paid by the slaughterhouse to third-party manual harvesting companies was US$ 18.17 per thousand broilers, which was converted into revenue in the cash flow of the project. The cash flow result was positive at US$ 22,256.14 over the entire study period considering a daily catch of 144 thousand broilers. The results of the economic viability analysis were NPV of US$ 64,786.23, NFV of US$ 333,382.11, NUV of US$ 735.19, DP of 13.82 years, IRR of 0.965 monthly, and modified IRR of 0.933 monthly. These values prove the economic viability of implementing the project considering the market conditions at the time of the study. The analysis of scenarios showed great sensitivity to the exchange rate and the price of fuels. The Monte Carlo simulation highlighted a moderate risk of negative NPV, emphasizing the importance of considering this variable when making decisions. Despite these challenges, the potential benefits of mechanized harvesting, such as increased efficiency and reduced labor costs, make it a promising alternative to manual harvesting, even for small to medium-sized poultry industries.

Resumo em Inglês:

ABSTRACT This study aimed to assess the antimicrobial susceptibility of 52 Staphylococcus aureus (S. aureus) bovine mastitis isolates obtained from 37 dairy herds from the northwest of Portugal against antibiotics belonging to the β-lactam family, evaluate the detection of blaZ and mecA resistance genes, and study the diversity of positive isolates. The antimicrobial susceptibility tests were performed by the disk diffusion method. The detection of blaZ and mecA genes was performed using specific polymerase chain reaction (PCR) and the diversity of blaZ was evaluated by phylogenetic analysis. The antimicrobial susceptibility test showed a prevalence of phenotypic resistance by S. aureus of 52.0% against penicillin and ampicillin, 34.6% against oxacillin, 17.3% against amoxicillin plus clavulanic acid, and 21.1% against cefazolin. A prevalence of phenotypic intermediate resistance of 5.7% against penicillin, 9.6% against amoxicillin plus clavulanic acid, and 1.9% against ampicillin and cefazolin, respectively, was demonstrated. A 100.0% phenotypic susceptibility was found against piperacillin. Of the 52 S. aureus isolates, 35 (67.3%) were PCR positive for blaZ gene, and isolate 25 was positive for mecA gene. The phylogenetic analysis of partial blaZ gene S. aureus isolates consensus sequences were placed in two different clades, clade A (cluster A, A.1) and B (cluster B), all closely related to animal and/or human S. aureus strains. Isolate 2 appeared in the phylogenetic tree as the most divergent. This study indicates that blaZ resistance gene plays a role in β-lactam resistance in the tested bovine mastitis S. aureus isolates within dairy herds in the northwest of Portugal, especially in case of penicillin and ampicillin antibiotics that have shown a high phenotypic prevalence. Indeed, the proportion of bovine mastitis isolates with phenotypic resistance did not agree with the proportion of those identified for blaZ, as isolates with 100.0% of phenotypic susceptibility for all tested antibiotics also harbored blaZ. BlaZ phylogenetic analysis from S. aureus isolates showed diversity inside or between different herds in the northwest of Portugal. Piperacillin, as a suggestion, could be tested for S. aureus bovine mastitis treatment in the future to evaluate this new possibility of therapy.

Resumo em Inglês:

ABSTRACT We investigated the influence of poultry rearing factors, including strain, type of ventilation, and sex on the slaughter characteristics of broiler chickens. Factorial analysis of mixed data was employed to analyze the data from broiler flocks slaughtered between 2018 and 2020 in Mato Grosso do Sul, comprising 2,684 flocks and 82,486,500 birds. The characterization information considered included age at slaughter, average weight, date of slaughter, percentage of pododermatitis, percentage of scratches, percentage of pre-slaughter condemnations, percentage of slaughter condemnations, percentage of total condemnation, percentage of field mortality, type of ventilation, strain, and sex. The factorial analysis of mixed data aimed to identify the relationships between pre-slaughter factors and slaughter characteristics. Five main components, explaining 85.5% of the total data variance, were derived from the analysis. Age, generated value per kilo of product, and percentage of pre-slaughter condemnations exhibited positive correlations. Negative pressure ventilation was found to be more closely associated with the percentage of pododermatitis, while the dark house system showed a stronger association with the percentage of total condemnation and percentage of pre-slaughter condemnation. The Cobb strain and female sex were found to be more strongly related to the generated value of the product. Strain, sex, and type of ventilation were identified as decisive factors influencing the characteristics of meat yields and the economic results of poultry activity in slaughterhouses. Moreover, it was observed that percentages of scratches and pododermatitis were negatively correlated with the value generated ($/kg) by broiler flocks, and they were more closely associated with positive pressure ventilation systems, Ross strain, mixtures of strains within the same flock, and male chickens. It was possible to prove the strong interdependence between the rearing stage of broiler chickens and the slaughterhouse, which needs to be considered in decision making by agroindustry to achieve an ideal rearing model.

Resumo em Inglês:

ABSTRACT The objective of this study was to examine the physicochemical composition and sensory properties of Boursin cheese made from the milk of goats fed diets with increasing levels of cassava chips replacing corn. Eight lactating Alpine goats were distributed into two 4 × 4 Latin squares, where they were subjected to diets in which 0, 33, 66, and 100% of corn was replaced with cassava chips. The cheeses were prepared with individual milk of each goat for physicochemical, yield, and texture analyses. Sensory analysis consisted of flavor and texture appraisal by 50 untrained tasters, using the difference-from-control test and the acceptance test. The cheeses from the four treatments did not differ in their fat, protein, and total solid contents; acidity; moisture; ash; pH; yield; or the texture parameters of gumminess, cohesiveness, hardness, and chewiness. They also showed no difference in the sensory acceptance of flavor and texture, indicating that the panelists did not perceive the replacement of corn with cassava chips.

Resumo em Inglês:

ABSTRACT This study aimed to develop and assess a deterministic mathematical model for predicting the impacts of varying sow replacement rates on the performance of farms producing weaned piglets. Initially, the influence of replacement rate on herd structure was examined using two equations, which accounted for the percentage of sows replaced (55, 45, and 35%), retention rates between parities (13, 9, and 5%), and number of last parities in the herd (6, 7, and 8). The model then estimated sow development throughout the reproductive cycle, starting with an initial weight of 140 kg at first mating and adjusting for weight gains during gestation and losses during lactation, influenced by the varying number of live-born piglets across parities. Energy requirements were calculated using the factorial method, which included maintenance, protein and fat gains, and milk production. The generated data formed various scenarios to derive productive values. These scenarios were analyzed using analysis of variance with the general linear model procedure, treating each scenario as a separate treatment. Early parities (up to P3) contributed 42% in SC-35, 51% in SC-45, and 60% in SC-55. Significant differences were noted in variables such as average parity, birth weight, feed intake during gestation, and average piglet weight gain. The developed model, incorporating replacement gilt modules, gestation, and lactation, can effectively predict herd structure by parity and assess the impact of annual sow replacement rates on the productivity of farms rearing weaned piglets.

Resumo em Inglês:

ABSTRACT This research aimed to compare statistical methods (random forest, RIDGE, LASSO, and elastic net regression) for the prediction of body weight in purebred and crossbred pigs reared in Brazil. This prediction was based on dorsal-view images obtained from video image processing. The study involved 69 animals belonging to breeds such as Large White, Piau, Duroc × Large White, and Piau × Large White. The data collection spanned 144 days, with measurements taken at approximately 20-day intervals, totaling eight measurements for each animal throughout their growth stages. Image acquisition was carried out in individual pens using an Intel RealSense Depth D435 digital camera. The features back area, back perimeter, back width, and body depth were extracted from the images. Pearson’s correlation analysis was conducted to assess the relationship between live weight and these features. The dataset was randomly divided into a training dataset (65%) and a test dataset (35%), and model training was performed by five-fold cross-validation balanced according to the growth stage, which was divided into three groups. This procedure was repeated 100 times, and the resulting metrics were taken as the average of the 100 repetitions. Although with a slight difference, the random forest method outperformed the others with the highest average R2 value (0.87), as well as the lowest average RMSE (14.32) and average MAE (10.13) values. Consequently, the random forest algorithm proved to be the most effective in predicting body weight. The back area, back width, and back perimeter were the most important variables in the model.

Resumo em Inglês:

ABSTRACT This study aimed to assess the growth performance of bullfrog (Aquarana catesbeiana) tadpoles subjected to different management practices and diets. Two distinct feeding management strategies were evaluated: broadcast feeding and the use of a trough. Regarding the diet, two formulations were tested: the first involved feed with 28% crude protein (CP) for the initial 30 days, followed by feed with 36% CP for the subsequent 30 days; the second treatment consisted of a commercial feed designed for tropical carnivorous fish, containing 40% CP, administered throughout the experimental period (60 days). The experiment was conducted in sixteen 30-L containers, each undergoing a daily water renewal of 200% of its volume, and tadpoles were stocked at a density of one tadpole/L (0.081±0.075 g initial weight). Growth performance was evaluated. The experimental design was factorial (2 × 2) with four replicates. Data were analyzed using analysis of variance and Tukey’s test (α = 0.05). Tadpoles fed the commercial feed outperformed (final weight of 3.329 g (FW), feed conversion (FC) of 1.423 g/g, and protein efficiency rate (PER) of 1.578 g/g) those fed the experimental diets in all growth performance parameters except for PER, whose best results were achieved with the experimental diets (FW of 2.708 g; FC of 1.579 g/g, and PER of 1.880 g/g). Regarding management practices, the use of a trough yielded (FC of 1.409 g/g) superior outcomes compared with the traditional method (FC of 1.579 g/g); therefore, the combination of a trough and the commercial feed regimen demonstrated the best results.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate, through principal component analysis, the effect of different feedlot structures on climatic conditions, nutrient intake, and performance of Nellore bulls during the feeding period in the semi-arid region. Data from 225 non-castrated Nellore bulls with initial mean body weight (BW) of 294 ± 19 kg and age of 24 months were used. This was done in a completely randomized design with three feedlot structures (no shading, natural shade, and artificial shade with 50% light interception), resulting in 75 repetitions (each animal serving as an experimental unit). The feeding period for the animals in the feedlot was 107 days. The first two components explained 99.65 (no shade), 97.32 (artificial shade), and 99.89 (natural shade) of total data variation. The variables, namely the black globe temperature index (0.88), radiant heat load (0.96, 0.99, 0.76), black globe temperature (0.96), and hot carcass weight (0.64) exerted the greatest influence on the feedlot structures. Climatic and intake variables were identified as having the most significant impact on feedlot structures. Artificial shade with 50% light interception shade cloth positively contributes to the hot carcass weight of feedlot Nellore cattle.

Resumo em Inglês:

ABSTRACT This study evaluated the effects of housing in the last month of gestation on hoof health in postpartum dairy heifers. The hooves of the heifers were evaluated during functional claw trimming and lameness scoring at 30 days before the expected calving date, and only heifers without any hoof lesions and lameness were included in the study. The heifers were kept in cubicle housing systems with mats (MAT, n = 12), mattresses (MATR, n = 12) and solid concrete floors, and on a straw yard (SY, n = 12) without exposure to concrete during the last month of gestation. The effects of housing systems on hoof lesions and lameness were evaluated during functional claw trimming and locomotion scoring at 60 and 90 days in milk (DIM). The evaluation of hoof lesions with respect to the study group, time, and their interaction was performed with the general linear mixed model for repeated measures. All heifers displayed sole hemorrhages (SH), white-line hemorrhages (WLH), and heel horn erosion in the postpartum period, but none of the heifers displayed lameness. The mean SH severity score was significantly higher in groups MAT and MATR than in group SY (2.25, 1.92, 0.75, respectively) at 60 DIM, and significantly higher in group MAT than in groups MATR and SY (1.92, 0.92, 0.92, respectively) at 90 DIM. The mean WLH severity score was higher in group MAT than groups MATR and SY (1.92, 1.17, 0.92, respectively) at 60 DIM, and similar (0.83, 0.75, 0.50, respectively) at 90 DIM. Heel horn erosion did not differ in severity among the groups. Improving housing comfort during the last month of pregnancy significantly decreases the severity of postpartum SH and WLH.

Resumo em Inglês:

ABSTRACT Data from 83,088 Hereford and Braford cattle were used to compare parameters and breeding values obtained using linear and threshold models for visual scores of limb conformation (LCW and LCY), breed traits (BTW and BTY), sexual traits (STW and STY), eye pigmentation (EPW and EPY), and navel size (NSW and NSY) at weaning and yearling, respectively. Additionally, principal component analysis was applied to investigate the relationship among the estimated breeding values. Higher direct heritability were estimated using the threshold model (ranging from 0.134±0.021 to 0.194±0.023) compared with the linear model (ranging from 0.085±0.008 to 0.120±0.009). Rank correlations between breeding values predicted using linear and threshold models ranged from 0.61 to 0.88 (LCW), 0.53 to 0.91 (BTW), 0.66 to 0.87 (STW), 0.80 to 0.96 (EPW), 0.87 to 0.95 (NSW), 0.70 to 0.92 (LCY), 0.49 to 0.93 (BTY), 0.56 to 0.95 (STY), 0.88 to 0.97 (EPY), and 0.80 to 0.95 (NSY). The low genetic variability of the studied traits suggests a small genetic gain in the morphology and adaptation. According to the results obtained in the rank correlation, the percentage of coincident animals and the cross-validation analyses, it is recommended to use the threshold model for limb conformation, breed, and sexual traits. For eye pigmentation and navel size scores, both models can be used. In practical terms, the producer will be able to carry out his own selection, considering other traits that are not currently incorporated in the selection indexes, but that can lead to simultaneous gains in the morphology and adaptation of Hereford and Braford cattle.

Resumo em Inglês:

ABSTRACT The objective of this study was to estimate the genetic parameters and predict selection of genetic gains and genetic diversity of 12 Andropogon lateralis ecotypes collected in the State of Rio Grande do Sul, Brazil. To estimate genetic parameters and predict selection gains, the REML/BLUP technique was applied. Genetic diversity among the ecotypes was evaluated by two clustering methods (optimization and hierarchical) and principal component (PC) analysis, the latter method also used to discard variables. The genetic parameters studied showed high potential for selection of important agronomic forage traits for livestock production. Results showed that the 12 A. lateralis Nees ecotypes exhibited high genetic variability for the studied forage characters and indicated parental prosperity for crosses within the genetic breeding program. Principal component analysis showed that number of total vegetative tillers, leaf:stem ratio, number of reproductive tillers, and leaf dry matter yield accounted for 80.6% of the observed variation in PC1. These variables are important characteristics for quantifying the dry matter production and nutritional value of forage plants, and they can help to discriminate amongst ecotypes. Ecotypes sourced from the Pelotas, Piratini, Passo Fundo, Bagé, and Montenegro regions showed superior forage production when evaluated by the BLUP methodology. Therefore, this group was identified as the most suitable for selection and crossing purposes. Tocher’s cluster analysis grouped the ecotypes into five divergent groups. Principal component and UPGMA hierarchical methods were also efficient at separating the ecotypes.

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ABSTRACT This study was conducted to investigate the polymorphism of the silence information regulator 5 (SIRT5) gene in 103 Congjiang Xiang pigs from Southwest China. We searched for SNP (single nucleotide polymorphism) loci of SIRT5 gene through sequence alignment and PCR. We obtained nine SNP loci: g.14135 A>C (intron 6), g.14247 C>A (intron 6), g.14305 C>T (exon 7), g.14335 C>T (exon 7), g.16603 T>C (intron 7), g.16613 T>C (intron 7), g.16800 G>A (intron 7), g.16812 C>G (intron 7), and g.16916 A>G (exon 8). Further analysis of SNP genotypes associated with the carcass traits of skin thickness, backfat thickness, and eye muscle area was carried out in pigs. We found that the genotypes g.14305 C>T (CC) and g.16812 C>G (CG) had certain advantages for improving the carcass traits of Congjiang Xiang pigs. The haplotype combination of the SIRT5 gene that improved skin thickness was H2H3:CCGGCTCA. These results may provide empirical support for molecular-based breeding of carcass traits in Congjiang Xiang pigs.

Resumo em Inglês:

ABSTRACT This study used a pedigree analysis to monitor trends in the genetic structure of the Mangalarga breed and identify factors that could impact its genetic variability. For this, genealogical information was used from the Associação Brasileira dos Criadores de Cavalo da Raça Mangalarga, considering as total population (TP) the animals born between 1919 and 2018 (n = 206,426) and as reference population (RP) those born between 2009 and 2018 (n = 20,539), which is the most recent generation according to the average generation interval calculated for the breed of 9.37 years. We evaluated the number of male and female births per year, foals produced by Mangalarga breeding animals, using the ENDOG 4.8, generation interval, proportion of known ancestors per parental generation, number of equivalent generations known per animal, inbreeding coefficient, increase in inbreeding, average relatedness (AR), effective population size, effective number of founders, effective number of ancestors, and founder genome equivalent. The number of equivalent generations known per animal increased over time, reaching an average of 2.75 in TP and 4.88 in RP. The calculated F was 2.26% for TP and 5.57% for RP, while AR was 2.41% for TP and 4.10% for RP. The effective population size was 40.85 for TP and 38.89 for RP. The 206,426 registered Mangalarga horses (TP) were derived from the genetic contribution of 9,011 founders and 8,908 ancestors, whereas those registered in or after 2009 (RP) originated from 2,662 founders and 2,193 ancestors. The effective number of founders represented 1.11 and 1.35% of the total number of founders in TP and RP, respectively. For RP, 11 animals accounted for 29.21% of the genetic pool of the breed. The analysis of population parameters estimated in the present study indicates that the Mangalarga horse population was formed through uneven contributions from founders and ancestors; therefore, genetic management of the breed is required to restrict average inbreeding from increasing over generations.

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ABSTRACT This study aimed to optimize a reliable and rapid genotyping assay to detect the carriers of bovine citrullinemia (BC), bovine leukocyte adhesion deficiency (BLAD), complex vertebral malformation (CVM), and deficiency of uridine monophosphate synthase (DUMPS) in cattle populations. We developed real-time polymerase chain reaction (RT-PCR)-based assays to distinguish wild-type and defective alleles of BLAD, CVM, BC, and DUMPS. Twenty-four bulls in the International Center for Livestock Research and Training were genotyped. At the same time, genotyping was performed for DUMPS and BC using PCR-RFLP, and sequencing was performed for all diseases and compared with the RT-PCR kit we developed. None of the bulls carried mutant alleles of these hereditary autosomal recessive lethal defects. It takes only 2 h for the assay to be completed, including DNA extraction from the sample. These consequences indicate that RT-PCR is an easy, reliable, and rapid method for detecting BLAD, CVM, BC, and DUMPS carriers. Studies show a high frequency of mutant alleles of these genetic defects that cause genetic diseases, and this requires routine test systems to eradicate genetic diseases of economic importance.

Resumo em Inglês:

ABSTRACT The objective of this study was to assess the genetic structure and diversity of six Santa Inês sheep flocks from the Central-Northern Brazil. A panel of 20 highly polymorphic and informative microsatellite loci was selected and amplified. The following parameters were obtained: overall mean of number of alleles = 15.4; expected heterozygosity (He) = 0.89; polymorphism information content (PIC) = 0.88; discriminatory capacity = 0.95; combined probability of identity = 1.50 × 10−34; and probability of exclusion = 1.00. The flocks with the lowest and the highest degrees of genetic variability were Farm 6 (He = 0.70, PIC = 0.653, and allelic richness [Ar] = 3.76) and Farm 1 (He = 0.89, PIC = 0.882, and Ar = 4.39), respectively. Indications of genetic bottleneck were observed in all flocks, as well as moderate genetic differentiation, with FST = 0.053, RST = 0.096, and Dest = 0.169. The migration rate in all flocks was high, with a trend towards Farm 1. This finding was not in agreement with the substructure found with the Bayesian admixture analysis and corroborated the array obtained with the principal component analysis and the clustering analysis. The results revealed moderate structuring and high genetic diversity in the flocks. However, management strategies should be reviewed, as evidence of bottleneck and genetic erosion was observed.

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ABSTRACT We evaluated the reproductive losses in three periods: period I - starting from the time the cows were exposed to the bulls to pregnancy diagnoses (PD, number of cows diagnosed as non-pregnant/total exposed cows × 100); period II - from the time of PD to calving (number of calving cows/number of cows diagnosed as pregnant × 100); and period III - from calving to weaning (number of weaned calves/number of calving cows × 100) in purebred Hereford (HH) and Angus (AA) cows and their crosses in beef cows under extensive production systems. Likewise, the effect of parity (nulliparous, primiparous, and multiparous) and the interaction between both factors were studied. A thirteen-year data set (2505 record) of an experimental breeding herd, maintained in an extensive production system based on natural grassland, was used. The dataset was under a complete diallel design between HH and AA breeds. Both the genetic group and parity of the cow affected the reproductive losses, but only in period I. No interaction was found. Purebred cows had higher reproductive losses than the crossbred cows, without differences between the purebred (HH and AA) or between the crossbred (AH and HA). The greatest losses were observed rather in primiparous than in nulliparous and multiparous cows without difference between the latter two. The use of crossbred cows in extensive production systems is an alternative to reduce reproductive losses and to increase calf harvest.

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ABSTRACT The objective was to explore publications on the effects of genotype × environment interaction (GEI) in livestock farming. The dataset used for this analysis came from the Web of Science (WOS) database, and the search was carried out from the first article identified in the WOS database until the search date (August 17, 2023). A set of minimum parameters was defined, and then the data was processed using the VOSviewer® software. To generate visual representations in VOSviewer, fractional counting was used, in which the contribution of each article is divided proportionally based on the number of co-authors. Consequently, if an article has three authors, the weight of each author is calculated as 1/3. Brazil and the United States lead research on GEI, while India, China, and Uruguay are emerging countries on the subject. The most cited journals on GEI include the Journal of Animal Science, Journal of Dairy Science, Animal, Livestock Science, Journal of Animal Breeding and Genetics, and Revista Brasileira de Zootecnia. In Brazil, the research groups are at the forefront of publications related to GEI. Ongoing climate changes over the years have likely led to further investigations into this matter. In the Brazilian context, research groups from the São Paulo State University (UNESP), College of Agricultural and Veterinary Sciences - Jaboticabal, and the Faculty of Veterinary Medicine and Animal Science at the University of São Paulo (FZEA/USP, Campus Pirassununga) have played a prominent role in advancing this area of study. Furthermore, our bibliometric analysis revealed future trends in GEI publications, including an increasing integration of genomic information into research.

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ABSTRACT The objective was to verify the existence of lineages in the Mangalarga Marchador breed using microsatellites and to phenotypically characterize the lineages found using linear morphometric measurements taken at the time the animals were registered to be used as a tool for selecting individuals according to each breeder’s selection objective. The genotyping database contained 255,257 Mangalarga Marchador horses born between 2005 and 2021. In addition, a database was used with pedigree information on 622,299 animals born between 1952 and 2020 and a database of phenotypes assessed at the time of definitive registration of these animals, containing 303,248 animals born between 1950 and 2018. The databases used came from the Associação Brasileira dos Criadores do Cavalo Mangalarga Marchador. To verify the existence of genetic differences according to the lineages of the breed, a discriminant analysis of principal components (DAPC) and the Kruskall Wallis test were carried out to perform phenotypic characterization to compare the means of the morphometric measurements, both using the R software. The DAPC analysis showed the genetic differentiation of the Angaí and Herdade lineages in relation to the others. The Herdade lineage showed greater phenotypic differentiation when compared with the three separate genetic groups in this study, demonstrating that the animals of this lineage are smaller and more gathered and have higher scores for gait and morphology. When compared to the historically described Mangalarga Marchador lineages, the breed does not have so many genetic groups, separating it into just three groups (Angaí, Herdade, and General), and when compared to phenotypic characteristics, only the Herdade lineage stood out.

Resumo em Inglês:

ABSTRACT The present study aimed to evaluate the growth of Criollo foals from birth to 800 days of age using Brody, Gompertz, Logistic, and Von Bertalanffy nonlinear models. The data utilized consisted of weight, height, chest circumference, and shin circumference taken from 75 foals kept in southern Brazil. Morphometric traits analyzed showed mean values ranging from 63 to 325 kg for weight, 0.92 to 1.32 m for height, 0.88 to 1.58 m for chest circumference, and 0.12 to 0.18 m for shin circumference. For the evaluated traits, all applied nonlinear models achieved convergence. The results indicated that the Brody model provided the best adjustments for weight, height, and chest circumference. Gompertz model was found to be the most suitable for describing the growth curve of shin circumference. The animals exhibited an increase in weight during the evaluated period. Height showed the most rapid increase until approximately 365 days of age, followed by a decrease, and a more homogeneous growth pattern thereafter. Chest circumference exhibited more uniform growth in animals from 365 days of age onwards, with slower growth and greater variability observed from 400 days of age. Shin circumference showed greater growth in the first months of age, remaining stable thereafter. We observed that 94 and 5% of the animals in the studied population did not meet the minimum values for height and chest circumference, respectively, according to the breed standards from 24 months of age. Our results can assist in selection and future studies with the Criollo breed.

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ABSTRACT This study was conducted to identify the key volatile compounds that characterize whether silage has deteriorated and to investigate the intrinsic link between the key compounds and silage odor. First, silages with different aerobic exposure durations were sampled, and sensory evaluation integrating aerobic stability monitoring was used to distinguish whether the silage had deteriorated. Subsequently, headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) was utilized to determine the relative content of the compounds. Using the relative content of the compounds in each silage as input, relative odor activity value (ROAV) calculations and orthogonal partial least squares discriminant analysis (OPLS-DA) were performed to determine the odor contribution of the compounds and the compounds with significant differences in relative content (based on variable importance for the projection, VIP) between the deteriorated and non-deteriorated silages. Next, the key compounds were identified by combining the conditions of average ROAV (aROAV) ≥ 1 and VIP > 1. Finally, the OPLS algorithm was used to analyze the intrinsic link of key compounds with the silage odor. The results showed that three out of 63 compounds—4-ethyl phenol, eugenol, and ethyl linoleate—were key compounds to characterize whether the silages deteriorated or not. In addition, ortho-guaiacol, 4-ethyl guaiacol, and 2-methoxy-4-vinyl phenol were the specific key compounds for deteriorated silage. Eugenol and ethyl linoleate were correlated with fruity, sour, and spicy odors. In addition, guaiacol, 4-ethylphenol, 4-ethyl guaiacol and 2-methoxy-4-vinyl phenol contributed to roasted, musty, and putrid odors.

Resumo em Inglês:

ABSTRACT This trial was designed to evaluate the effect of processing method of rehydrated corn grain silage (RCGS) on feed intake, performance, carcass traits, feeding behavior, rumen morphology, and blood metabolites of cattle in the finishing phase. Thirty-eight F1 Angus × Nellore bulls (365±22 kg) raised under grazing conditions were housed in individual pens (2 × 4 m) for the feeding trial. At the end of the adaptation period, animals were weighed after a 16-h fast, blocked by shrunk body weight, and randomly assigned to one of two dietary treatments: GRC, consisting of RCGS that was ground before ensiling using a hammer mill with a uniform 8-mm screen (1.52 mm geometric mean particle size); and RRC, consisting of RCGS that was rolled before ensiling in a roller mill mounted in a bagging machine (2.18 mm geometric mean particle size). Diet ingredients were mixed manually twice daily, at 09:00 and 15:00 h, and offered as total mixed rations in amounts approximately 50 g/kg in excess of daily intake. The experimental diets contained a forage:concentrate ratio of 130:870 g/kg, with 644 g/kg of RCGS. The GRC resulted in greater daily variation in dry matter intake, total-tract digestibility (dry and organic matter), fecal pH, rumen papillae width, and lower first meal duration, meal length, fecal starch, and rumen papillae height than the RRC. However, grinding or rolling RCGS did not affect dry matter intake, growth performance, carcass traits, or health (liver abscesses, ruminitis, serum D-lactate) of finishing beef cattle. Therefore, the processing equipment to make RCGS might be preferable based on equipment availability, milling yield, energy consumption, and diet composition.

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ABSTRACT This study aimed to evaluate the effects of two maturity stages of whole-plant corn at harvest (32.1 or 42.5% dry matter (DM)) and a commercial microbial inoculant composed of L. buchneri and L. plantarum at concentration of 110,000 CFU/g of fresh forage (1.1 × 105 CFU/g FF) on fermentation losses, aerobic stability, chemical composition, and digestibility of starch and neutral detergent fiber (NDF). A factorial and randomized design was used (two DM contents, both with or without inoculant), with five replicates per treatment. Dry matter at harvest affected most variables, except lignin, NDF digestibility, ethanol, and lactic and acetic acids. Drier silages differed in total DM losses (−1.7%) and lactic acid bacteria (LAB) population (+1.2 log CFU/g). The use of the inoculant affected the levels of ether extract (+0.27% DM), starch (+2.9% DM), and lignin (−0.17% DM). The LAB (+1.6 log CFU/g) and yeast (−2.82% log CFU/g) populations were also influenced, as well as aerobic stability at six days. The inoculant × DM interaction was observed in the water-soluble carbohydrates content, being higher in silages with 32.1% DM and in those not inoculated for both DM. Crude protein was also higher in these silages, whether inoculated or not. Wetter silages were more prone to gas losses when inoculated (+2.5% DM) and lost more effluent when not inoculated (+4.82 kg/t FF). However, total DM losses during aerobic stability were on average 10.58% DM lower in these silages, with inoculation being preferred (6.72% DM vs 11.60% DM (control)). Under these conditions, harvesting corn for silage at 42.5% DM is indicated to obtain a more energetic silage, as noted both in the increased starch content and the reduced losses associated with fermentation.

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ABSTRACT This study investigated the occurrence of mycotoxins in wet brewers’ grains (WBG) treated with salt (sodium chloride) and the intake, nutrient digestibility, and nitrogen use efficiency in lamb diets. Two experiments were conducted: first, WBG was distributed in plastic boxes and treated with no additive (control), sodium formate (3 g/kg of WBG), or three levels of salt—25, 30, and 35 g/kg of WBG. The WBG were stored at room temperature (17.7±4.6 ℃) for 27 days. In the second experiment, eight six-month-old male lambs were allotted to one of four total mixed ration (TMR) diets in a 4 × 4 double Latin square: 0, 10, 20, and 30% of WBG replacing corn silage and soybean meal. In the first experiment, the concentration of mycotoxins throughout the experiment was lower than the tolerance levels accepted by the European Community and Food and Drug Administration for animal feedstuffs. However, the control and sodium formate groups showed visual fungal development on the WBG surface from the sixth day and presented an unpleasant smell from day 12. In the salt treatments, fungal growth was observed on top of the WBG from day 12 and an unpleasant smell from day 15. Salt-treated WBG showed a lower pH than the control and sodium formate groups and decreased dry matter deterioration. In the second experiment, including up to 30% WBG in the TMR did not affect dry matter, organic matter, neutral detergent fiber, and acid detergent fiber intake or digestibility in lambs. However, the N digestibility and N use efficiency increased with WBG inclusion. These results suggest that salt can be used to increase the storage time of WBG up to 15 days and the inclusion of up to 30% WBG in TMR for lambs can improve N use efficiency without negatively affecting nutrient intake and digestibility.

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ABSTRACT This study aimed to evaluate different proportions of cactus pear in silage with BRS Capiaçu grass, along with a 10% inclusion of ground corn grain, focusing on aerobic stability, fermentative profile, chemical composition, and digestibility. The treatments included cactus pear (Opuntia spp.) at increasing levels of 0, 15, 30, 45, and 60% of the natural matter in the silage with BRS Capiaçu grass, plus 10% ground corn grain. Additionally, a control silage composed of BRS Capiaçu grass without ground corn was used. A completely randomized design was employed with six treatments and eight replications. The BRS Capiaçu grass was harvested after 100 days of regrowth. For ensiling, experimental PVC silos of known weights and of 50 cm long and 10 cm in diameter were used. The breakdown of aerobic stability of the silage without cactus pear (BRS Capiaçu grass with 10% ground corn) occurred 144 h after opening the silo. The inclusion of cactus pear in the silage with BRS Capiaçu grass and 10% ground corn grain resulted in a linear increase in pH value. Among the silages with cactus pear inclusion, there was no significant difference in gas losses (P = 0.46) and dry matter (DM) recovery (P = 0.43). There was no significant difference between the silages in terms of acetic acid content (P = 0.91). The content of DM and total digestible nutrients was lower in the control silage compared with the other silages. For each percentage unit of cactus pear inclusion, there was a reduction of 0.1195% in DM content. Additionally, for every 1% inclusion of cactus pear in silage with BRS Capiaçu grass, there was an increase of 0.2007 percentage units in DM digestibility. The optimal proportion of cactus pear in silage with BRS Capiaçu grass and 10% ground corn is up to 60% of the natural matter.

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ABSTRACT This study aimed to assess an alkaline protease supplemented in diets with and without crude protein (CP) reduction on performance, apparent total tract digestibility (ATTD), blood parameters, and carcass and meat traits in growing-finishing pigs. Forty male pigs (26.2±1.2 kg) were randomly allocated into one of five treatments: negative control (NC, 2% and 1% reduction of CP in grower and finisher phases, respectively, no protease); NC150: NC + 150 mg protease kg−1 diet; NC300: NC + 300 mg protease kg−1 diet; PC: positive control (no CP reduction and protease); and PC300: PC + 300 mg protease kg−1 diet, with eight replicates of one pig/pen. Pigs fed NC showed greater average daily feed intake (ADFI) than pigs fed NC300 or PC and lower ADFI compared to pigs fed NC150. Pigs fed PC had lower ADFI than those fed PC300. Greater average daily gain and gain to feed ratio (G:F) were observed in pigs on NC compared with those on NC300 or NC150 and NC300, respectively. Pigs fed PC showed better G:F than pigs fed PC300. Lower coefficients of ATTD (CTTAD) of dry and organic matter (OM), digestible dry matter (DDM), digestible organic matter (DOM), and digestible protein were observed in growing II pigs fed NC compared with pigs fed NC150 or NC300. Pigs fed NC showed a lower DP compared with PC or NC150. Positive control group showed increased digestible protein compared with NC. Finishing II pigs fed NC showed lower DDM, DOM, CTTAD of OM, and gross energy than pigs fed NC150 or NC300. Pigs fed PC showed greater albumin concentration compared with pigs fed PC300 in finishing II. Pigs fed NC and PC300 showed greater luminosity in the l. thoracis muscle than pigs fed PC. A greater color score was evidenced in the l. thoracis in pigs fed PC compared with pigs fed PC300. The dietary supplementation of isolated alkaline protease and CP-reduced diets improves ATTD without supporting pig performance.

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ABSTRACT A meta-analysis was employed to assess the effects of phytogenic feed additives and antibiotics on the performance and intestinal morphometry of unchallenged weanling pigs. The database included 41 articles published between 2004 and 2017, comprising 5,197 unchallenged nursery piglets. Piglets had 7.7 to 13.8 kg body weight and were assessed at 27.3 to 47.8 days of age, distributed into 156 experimental groups. All treatments were categorized into negative control, phytogenic additive (PA), and antibiotics (ATB) groups. The meta-analysis followed two sequential analyses: graphical and variance-covariance. Age and body weight were the factors that highly influenced the model. Piglets that received antibiotics had a higher (12.2%) daily weight gain than piglets in the control group. Phytogenic additives in diets enhanced intestinal morphometry in unchallenged piglets. Antibiotics increased (by 12.7%) the crypt depth of jejunum in comparison to the control treatment. Animals on PA had an 11.1% increment in villus height:crypt depth ratio than those on antibiotics. Phytogenic additives and antibiotics boost nursery piglet performance. Antibiotics advances the performance of unchallenged nursery piglets, but increases crypt depth in the jejunum. Performance of nursery piglets is better with combined phytogenic additives than with the isolated use of plant extracts.

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ABSTRACT The objective of this study was to evaluate the effects of prebiotics, alone and in combination with antibiotics, on broiler performance, carcass yield, intestinal permeability, and intestinal morphometry. A total of 1440 day-old male Cobb 500 chicks were distributed in a completely randomized design, with four treatments and 10 replications per treatment. The treatments used were a basal diet without prebiotics and antibiotics (BD), a basal diet with antibiotics (AB), a basal diet with prebiotics (PRE), and a basal diet with antibiotics and prebiotics (AB+PRE). To perform the treatment, the antibiotic zinc bacitracin and a prebiotic of S. cerevisiae-derived mannan-oligosaccharides and beta-glucans were used. The treatments did not affect the performance of birds from 1 to 7 and 1 to 21 days of age. From 1 to 35 and 1 to 42 days, birds fed the AB+PRE treatment had higher feed intake than those fed the AB treatment. From 1 to 35 days, birds fed the AB+PRE treatment showed a worse feed conversion ratio. However, there was no difference in carcass yield between treatments. A higher number of goblet cells was observed in the duodenum and ileum of birds fed AB+PRE, but lower counts were obtained in birds fed AB. Intestinal histomorphometry displayed similar responses between both ages regarding antibiotic and prebiotic treatments, except in the ileum at 42 days, in which the antibiotic elicited a better response. Intestinal permeability analysis showed no significant difference between diets. The use of prebiotics, alone or in combination with antibiotics, does not improve the performance of broilers.

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ABSTRACT This experiment was carried out to evaluate the effects of organic acids on the intestinal integrity and productive performance of broiler chickens experimentally inoculated with Salmonella Enteritidis. Additionally, Salmonella colonization levels in internal organs were evaluated. The study included 576 one-day-old CobbTM male broilers, distributed into eight treatment groups and six replicates. A completely randomized experimental design (encapsulated butyric acid × inoculation by Salmonella Enteritidis) was used. Poultry was orally inoculated with Salmonella Enteritidis in the first day (0 or 2.0 × 106 CFU/mL) and after 22 days of age (0 or 1.0 × 109 CFU/ mL). The butyric acid was added to the feed in different concentration (treatments 0.03, 0.075, and 0.15%), and the chickens were raised up to 42 days old. Encapsulated butyric acid at 0.03% increased the body weight gain and the average weight of the chickens up to 21 days old. After 14 days old, the butyric acid had a positive effect on jejunum villus. Encapsulated butyric acid at 0.03% in feed improves the performance and intestinal integrity of chickens.

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ABSTRACT This study aimed to investigate the effects of xylanase (Xyl) individually or in combination with B. subtilis and B. licheniformis associated or not with yeast cell wall in pig diets with a reduction of 100 kcal/kg of metabolizable energy (ME) content. Pig performance, bone parameters, intestinal morphometry, and bioeconomic indices were evaluated. A total of 75 pigs (25 females and 50 barrows; 25.02±3.21 kg) obtained from crossing Large White × Landrace were used. The experimental design consisted of randomized blocks, with five treatments and five blocks, totaling 25 experimental units subjected to treatments: basal diet (B); basal diet with reduction of 100 kcal/kg of ME (BEM); BEM with supplementation of xylanase (0.01%; BX); BX with supplementation of direct-fed microbials (composed of B. subtilis and B. licheniformis; 0.02%; BXM); and BX supplemented with 0.10% of symbiotic (which includes B. subtilis, B. licheniformis, and yeast cell wall; BXS). There were no differences in bone parameters. The BEM diet resulted in a lower villus height:crypt depth ratio in the jejunum than that seen upon using the BXS diet as feed. In the first period, pigs fed BEM diet had a 12% higher average daily feed intake than those fed the BXM diet. There were no differences in the pig performance during the second period. Over the total period, pigs fed BEM diet had greater FCR compared with pigs fed BXM diet. The inclusion of feed additives in diets with reduced ME content contributes to the maintenance of performance and characteristics of the metacarpus and jejunum of growing pigs and provides better bioeconomic indices.

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ABSTRACT In this study, a mixture of estradiol benzoate, progesterone, and testosterone propionate was injected into Diannan small-ear sows to induce estrus. The 16S rRNA technology was used to comparatively analyze the differences in fecal microbial composition and diversity between induced and spontaneous estrus in Diannan small-ear sows. The most abundant phylum in the sows in estrus were Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria. There was a significant negative correlation between Firmicutes and Bacteroide and a significant positive correlation between Bacteroides and Bifidobacterium. The relative abundance of Stenotrophomonas, Neisseria, Anaerofustis, and Terrisporobacter in the sows during induced estrus was significantly higher than that during spontaneous estrus. Taken together, induced estrus affects the relative abundance of specific microbes in the feces of Diannan small-ear sows, but it does not affect the overall composition and diversity. These results provide fundamental knowledge about the gut microbiota of sows with induced estrus.

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ABSTRACT This study aimed to investigate the effects of different levels of vitamin D3 in broiler diets on performance and bone health. A total of 360 one-day old male Cobb500® broiler chicks were subjected to five treatments of different levels of vitamin D3 in diets during two rearing phases: 0 IU/kg in both phases; 625 IU/kg in starter and 500 IU/kg in grower phase (25% of commercial inclusion); 1,250 IU/kg in starter and 1,000 IU/kg in grower phase (50% of commercial inclusion); 1,875 IU/kg in starter and 1,500 IU/kg in grower phase (75% of commercial inclusion); and 2,500 IU/kg in starter and 2,000 IU/kg in grower phase (100% of commercial inclusion). The traits studied weekly were feed intake, body weight, feed conversion, and viability. At 21 and 35 days of age, tibiae and femurs were removed, dissected, and evaluated for dry matter (DM), ash (%MM), calcium (%Ca), phosphorus (%P) and breaking strength. At 35 days of age, the bones were subjected to histopathological analysis for macro- and microscopic morphological evaluation. Data were subjected to regression analysis, using α = 0.05. The variables of percentage %MM, %Ca, %P, and breaking strength experienced a positive linear effect up to the supplementation levels of approximately 25% of inclusion. The histopathological analysis found that the group that received the diet with 100% inclusion of vitamin D3 presented lesions compatible with osteopetrosis and tibial dyschondroplasia. The observed results showed that for isonutritive diets, reduced levels of vitamin D3 guaranteed performance during the evaluated period while the use of 100% of vitamin D3, as commonly used, can cause bone diseases and harm the welfare of broilers.

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ABSTRACT This study aimed to evaluate the effect of including an emulsifier (soybean lecithin) and two lipid sources (soybean oil and chicken fat) on the performance and intestinal morphology of broiler chickens. A total of 576 one-day-old Cobb® 500 male chicks were housed in a completely randomized design, with treatments divided in a 2 × 2 factorial arrangement (with and without emulsifier and two lipid sources – soybean oil or chicken fat), totaling four treatments with eight replications and 18 chicks per plot. The experimental diets were formulated to be isoenergetic and isoproteic. The use of chicken fat improved the live weight at the starter rearing stage. However, the use of the emulsifier improved the live weight at the grower and finisher phases. No interaction effect was observed between treatments for performance. The intestinal morphology showed an increase in duodenal villus height with the use of chicken fat and emulsifier. The ileum had an increase in villus height in chickens fed the diet with soybean oil and emulsifier. Supplementation of the emulsifier resulted in positive results in the live weight of chickens at 35 and 42 days of age, in addition to increasing the villus height in the small intestine.

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ABSTRACT The experiment aimed to evaluate the effects of supplementing a standard broiler diet, formulated based on corn and soybean meal (CSBM), with two levels of an exogenous enzyme (EZ) cocktail (0 and 0.05%), under two dietary metabolizable energy (ME) levels – normal (positive control, PC) and low (negative control, NC). From 0 to 35 d, 288 Ross 308 chicks were distributed across four treatments with 12 replicates of six chicks each. Growth performance was evaluated during the starter, grower, finisher, and cumulative period. At 35 d, blood samples were collected to measure serum metabolite concentrations, and birds were processed to determine carcass traits. Ileum segments were prepared for histological measurements, and excreta were collected to analyze apparent nutrient digestibility. Data were analyzed employing two-way ANOVA and Tukey’s test. The results indicated no significant interaction between ME and EZ for any measured parameter. The EZ supplementation improved feed conversion rate (FCR) during the starter phase, and improved feed intake, body weight gain (BWG), FCR, and production efficiency index (PEI) during the grower phase; PEI during the finisher phase; and BWG, FCR, PEI, and final BW over the cumulative phase. Furthermore, EZ enhanced dressing percentage, breast yield, villi length, retention of crude protein, and nitrogen-corrected ME (AMEn), while also increasing glucose concentration and reducing the relative weight of the gizzard and intestine. Compared with the NC diet, the PC diet enhanced feed efficiency across the grower, finisher, and cumulative phases and increased AMEn and triglyceride levels. Supplementing ME-adequate CSBM diets with an EZ cocktail can boost the nutrient digestibility and growth efficiency of broilers.

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ABSTRACT The study aimed to optimize the processing conditions for hydrolyzed feather meal (HFM) with the addition of coagulated blood. Factorial design and response surface methodology were used to optimize processing conditions in function of protein content (%) and digestibility value (%) of HFM. Higher protein contents were obtained when the upper levels of the variables pressure (kgf.cm−2), hydrolysis time (min), and blood addition (%) were used in the process. Longer hydrolysis time and a higher percentage of blood result in higher digestibility values. Mathematics models can be used to estimate the protein content and digestibility value of HFM with coagulated blood. Hydrolyzed feather meal with higher protein content and digestibility value can be produced by adding coagulated blood and appropriate processing parameters.

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ABSTRACT The objective of this study was to determine the energy values and standardized ileal digestibility (SID) of amino acids of corn, corn protein meal (CPM), corn germ (CG), and dried distillers' grains with solubles (DDGS) in broiler diets. In the first experiment, the apparent metabolizable energy (AME) and nitrogen-corrected apparent metabolizable energy (AMEn) values were determined using the total excreta collection method. A total of 240 14-day-old broiler chicks were randomly distributed in a completely randomized design with five treatments, including four different feed ingredients and a reference diet, each with eight replicates of six birds. In the second experiment, to determine the coefficient values of amino acids, 240 birds aged 14 to 28 days were randomly assigned to five treatments, including four different feed ingredients and a nitrogen-free diet, each with eight replicates of six birds. At 28 days of age, birds were slaughtered, and the digesta were collected to determine the standardized ileal digestibility coefficients and, subsequently, the digestibility of amino acids. The AMEn for corn, CPM, CG, and DDGS is 3178, 2171, 2473, and 3398 kcal/kg, respectively. The metabolizability coefficient of the AMEn percentages are 68.03% for corn, 46.62% for CPM, 44.15% for CG, and 73.39% for DDGS. The average digestibility of essential amino acids in corn, CPM, CG, and DDGS is 92.55, 52.63, 73.07, and 81.51%, respectively. For non-essential amino acids, the average digestibility in corn, CPM, CG, and DDGS is 90.59, 54.36, 70.20, and 79.47%, respectively, with an overall average of 85.21%.

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ABSTRACT This research aimed to evaluate the influence of a commercial prebiotic in different concentrations upon several parameters. To carry out the experiment, 640 male one-day-old broiler chicks were distributed in four treatments (0, 0.5, 1.0, and 1.5 kg/ton of yeast cell wall) with eight replicates of 20 birds per experimental unit, in randomized blocks. Prebiotic effects were assessed on performance, carcass yield and prime cuts, in addition to the litter quality (its content of nitrogen and phosphorus). There were significant improvements for weight gain and feed conversion ratio in experimental growth periods. However, prebiotic level at 1.0 kg/ton is enough to provide improvement in performance and similar yield parameters than the control group. Also, 1.5 kg/ton prebiotic inclusion in the diet promotes environmental benefits by reducing the phosphorus amount in the litter by 51%. Above 1.0 kg/ton prebiotic addition in broiler diets can be safely recommended, because it promotes both performance and environmental benefits.

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ABSTRACT Two experiments were conducted to assess the impact of an enzyme complex (EC) on the metabolizability coefficients of dry matter (MCDM), crude protein (MCCP), and ether extract (MCEE) and on the nitrogen-corrected apparent metabolizable energy (AMEn) of corn gluten meal, soybean protein concentrate, dried bovine plasma, and poultry offal meal. Additionally, the experiments aimed to evaluate how EC affected broiler performance. In experiment I, 720 day-old Cobb 500® broilers were assigned to a completely randomized design using a 4 × 2 factorial arrangement. The main factors considered were the feedstuff (corn gluten meal, soybean protein concentrate, dried bovine plasma, and poultry offal meal) and the presence or absence of EC. The broilers were housed in 45 pens, using five replicates, with ten birds in the pre-starter phase and six birds in the starter phase. This design resulted in eight treatment groups, including one reference diet group. In experiment II, 1140 day-old Cobb 500® chicks were allotted in a completely randomized design, employing a 4 × 2 factorial arrangement, with the same main factors as in experiment I. Birds were housed in 48 pens, using six replicates/30 birds, yielding eight treatments. The use of the EC did not lead to improvements in digestibility of the feedstuffs. However, the addition of EC resulted in enhanced body weight gain and improved feed conversion ratios across all phases of broiler growth. Enzyme complex inclusion did not affect feed intake. While the EC did not enhance the metabolizability of nutrients in feedstuffs individually, broilers fed diets containing these feedstuffs and supplemented with EC exhibited improved performance at 42 days of age. This suggests that the impact of the EC varies depending on whether it is observed at the feedstuff or diet level.

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ABSTRACT The objective of this study was to evaluate the L-arginine supplemental effects for broilers in the final rearing phase (29 and 42 days), during which they were exposed to heat stress and fed diets with different metabolizable energy levels. Performance, carcass parameters, and physiological and biochemical parameters related to lipid metabolism were evaluated. A completely randomized design was used, in a 3 × 2 factorial arrangement, corresponding to three metabolizable energy levels (3000, 3150, and 3300 kcal/kg) in diets supplemented or not with L-arginine (0.66%). Eight replicates composed by eight broilers each (experimental units; boxes) per treatment were evaluated, totaling 48 experimental units. Performance was evaluated in the period from 29 to 42 days old, and carcass and blood parameters were measured at 42 days old. L-arginine supplementation improved feed conversion and blood profile, mainly due to the reduction of total and LDL-cholesterol levels. Broilers that received 3300 kcal/kg of metabolizable energy showed the greatest weight gain, regardless of supplementation or not with arginine. The dietary supplementation with 0.66% of L-arginine for heat-stressed broilers can be recommended, regardless of the feed energy level.

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ABSTRACT This study investigated the effect of yeast on the growth performance and inflammation of yellow-feathered broilers challenged with lipopolysaccharide (LPS). Four hundred and eighty-one-day-old broilers (BW 38.5±1.01 g) were randomly divided into six treatments with eight replicates of 10 birds each and fed a basal diet with or without 0.025% antibiotics and 0.05 and 0.5% yeast (Saccharomyces cerevisiae, 1.0 × 1010 cfu/g), respectively. Broilers from each replication were intra-abdominally injected with LPS (1.0 mg/kg body weight) or saline at 21, 23, 25, and 27 d of age. Samples were obtained after 3 or 12 h of the first injection (d 21) and the last injection (d 27), respectively. The results showed that LPS stimulation resulted in a significant decrease in productive performance (P<0.01) and a significant decrease in splenic index (P<0.05). Lipopolysaccharide injection caused significant (P<0.01) increase in serum α-AGP in the first hour and haptoglobin in the last 3 h (P<0.01), while other acute phase proteins were not significantly affected. All chickens fed diets supplemented with 0.5% yeast had elevated serum levels of IgA (P = 0.094) and lysozyme (P = 0.067) at 12 h of the first injection compared with those fed antibiotic diets. Lipopolysaccharide injection substantially increased the levels of cytokines in serum. A trend toward decreased levels of IL-10 (P = 0.078), transforming growth factor-beta 1 (P = 0.075), and interferon-gamma (P = 0.061) was observed in the LPS-stimulation × diet interaction. There was an LPS-stimulated × diet interaction (P<0.05) for interleukin-1beta transcript levels in the liver 12 h after repeated LPS injections. Chickens fed diets with 0.05 or 0.5% yeast tended to have higher levels of toll-like receptor 4 (P = 0.074) transcripts in the spleen at 3 h and β-defensin 1 (P = 0.065) transcripts at 12 h compared with those fed diets with antibiotics. The addition of 0.05 or 0.5% yeast alleviated the adverse effects caused by LPS injection, and this study provided a reference for the application of yeast in the broiler industry.

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ABSTRACT The objective of this study was to assess the effects of liquid delactosed permeate (DLP) alone or mixed as baby feed with a conventional lactose-containing diet for nursery piglets on growth performance, diarrhea occurrence (DO), blood profile, gastrointestinal tract traits, and bacterial population counts. Ninety male hybrid piglets (7.59±0.63 kg) weaned at 25 days old (day 0) were assigned for 35 days in a complete block design based on body weight (BW) to one of three treatments: control diet (CD) containing lactose via whey permeate powder, supplied in mash and dry form, without DLP; supplemented diet (SD): CD + DLP provided in specific feeders and separated from the mash diet; moist diet (MD): CD moistened with DLP in a 1:1 ratio, 10 replicates, and three piglets per pen. Nursery phases were defined as pre-starter I and II (days 0 to 7, and 8 to 21) and starter (day 22 to 35). Piglets fed MD diet had better feed conversion (FCR) compared with those fed CD in the pre-starter I and II and total period. Piglets in pre-starter I fed MD diet had a higher DO compared with those fed CD, whereas piglets fed SD had intermediate results. Piglets in pre-starter II fed SD had a higher total protein concentration than those fed MD, and CD provided intermediate results. Piglets on MD had higher leukocyte concentrations compared with those fed CD, but piglets fed SD had intermediate results. Piglets fed CD or SD diets had higher colonic content pH than those fed MD. Piglets fed SD or MD diets had longer large intestine lengths than animals fed CD. Delactosed permeate improves FCR in piglets in the pre-starter phases and promotes minor changes in other variables; however, a greater DO is observed in the first few days post-weaning.

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ABSTRACT The objective of this study was to identify parameters, before the start of the breeding season, that affect the conception rate of precocious Nelore heifers through ultrasonographic ovarian evaluation and evaluation of weight and body condition score (BCS). A total of 407 heifers aged 404±69 days (≈14 months old), weighing 267.1±31.2 kg, and with mean BCS of 3.1±0.5, were used. Heifers were subjected to hormone treatment to induce cyclicity and, 30 days later, to a fixed-time artificial insemination (FTAI) program with three managements. Morphometric measurements of ovaries and ovarian structures were performed by transrectal ultrasonographic evaluation, as well as weighing and evaluation of BCS on D −30 and D0. Conception rate was evaluated 30 days after FTAI. The conception rate of heifers did not vary according to ovary diameter, weight, BCS, and age at first calving. However, heifers with the presence of follicle with a diameter > 6 mm at D −30 and D0 had a higher conception rate at the first FTAI. The presence of a dominant follicle greater than 6 mm at D −30 is an efficient complementary criterion to identify 14-month-old Nelore heifers with greater ability to conceive at the first FTAI before the breeding season. Antral follicle count performed on D −30 is not a good tool to predict fertility at the first FTAI, and the weight may not be a limiter to select heifers under good nutritional and health management.

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ABSTRACT This study examined the impact of a 37.5 °C temperature on chick embryos during the hatching period (18-21 days of incubation) and its subsequent effect on hatchery results and the thermotolerance of broiler chicks from 28-40 days of rearing. For hatchery results, the study involved 16 trays per treatment. For performance, the study involved 360 broiler chicks from two distinct hatching temperature conditions: a control group (36.5 °C and 65% relative humidity (RH)) and a thermal manipulation group (37.5 °C/6 h/d from 18 to 21 days of incubation with 65% RH). The chicks were reared in a thermoneutral temperature until day 28. Subsequently, on day 28 post-hatch, the chicks were randomly assigned to a 2 × 2 arrangement to assess the differences in thermotolerance acquisition. The primary factors were embryo thermal manipulation in the hatcher and the thermal environmental rearing from day 28 until day 40 (thermoneutrality (at a constant 23.0 °C) or thermal environmental challenge (30.0 °C/6 h/d)). No effect was observed on hatchability, residual analysis of unhatched eggs, and chick quality. No interaction was observed between treatments for performance or cloacal temperature from day 28 to day 40. However, birds reared in a thermoneutral environment exhibited higher feed intake and body weight gain from day 28 to day 40 and a lower feed conversion ratio than the birds reared in a cyclic heat temperature environment. An increase of 1 °C/6 h/d in the hatcher from day 18-21 does not affect hatchery results or enhance the adaptability of broilers to a heat stress environment during the final rearing period

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ABSTRACT The objective of this research was to determine the influence of heat stress, using the temperature-humidity index (THI), on the production and quality of native sperm of bulls. The effect of heat stress on the quantity of semen (mL), density of ejaculate (number of spermatozoa, 106/mL), gross sperm motility (1-5), number of frozen doses, and motility after freezing was analysed in 1,017 sperm samples taken from 32 Holstein-Friesian bulls, in the 2017-2019 period, at the Centre for Reproduction and Embryo Transfer in Serbia. The lowest amount of ejaculate (4.18±1.95 mL) and the lowest density of ejaculate (1,189.19±668.23 × 106/mL) were recorded under conditions of very strong heat stress on the day of semen collection. The level of heat stress measured on the day of semen collection did not affect sperm gross motility, number of frozen doses, and motility after freezing. The level of heat stress at the beginning of spermatogenesis, measured 60 days before semen collection, did not affect the amount of ejaculate and motility of spermatozoa after freezing, but at very strong stress, the lowest density of ejaculate (1,170.34±680.27 × 106/mL) and gross motility of spermatozoa were found (2.91±0.96). The lowest number of doses per ejaculate was recorded in conditions of moderate heat stress (396.6±157.71). Bulls older than 36 months had the best results according to all tested parameters of native sperm production and quality. The year in which the bulls produced semen did not affect density of ejaculate and sperm motility. The season of semen collection did not significantly affect the production and quality of native sperm, due to the practice of exploiting only bulls with the best sperm quality during the summer.

Resumo em Inglês:

ABSTRACT The objective of the study was to characterize differences in the time to onset of puberty and reproductive variables between East Friesian and Corriedale ewe lambs in an extensive pastoral system. The study was carried out for two consecutive years, and 73 pure-breed ewe lambs were evaluated (35 East Friesian and 38 Corriedale). Plasma progesterone was determined weekly between 4.5±0.5 and 7.2±0.5 months old. The time to onset of puberty was assumed when the progesterone levels were ≥0.6 ng/mL for at least three consecutive blood collections. Body weight and body condition score were also determined. The reproductive variables calculated were fertility (ewe lambs’ pregnancy/ewe lambs mated), prolificacy (lambs born/ewe lambs’ pregnancy), and fecundity (lambs born/ewe lambs mated). We found that 97.1% of East Friesian lambs and 44.7% of Corriedale reached puberty during the blood-sampling period, and there was no significant age difference between breeds. Average body weight at puberty was significantly higher for East Friesian than for Corriedale ewe lambs (44.2±0.8 and 40.6±0.9 kg, respectively). Fertility significantly differed between breeds (85.7 vs 34.2% East Friesian and Corriedale, respectively) and was not affected by year. Of the pregnant ewe lambs, 88.4% carried a single lamb. Prolificacy did not differ with the breed, year, or dam parity but was significantly higher for those lambs born as twins. Fecundity was significantly higher for East Friesian than for Corriedale lambs. Breeding Corriedale and East Friesian ewe lambs in their first year results in different reproductive outcomes.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the performance of Nellore bulls finished in the feedlot and fed high-energy diets containing sodium monensin associated or not with tannins and saponins. Ninety-six Nellore bulls were used with an average initial body weight of 350.6±17.9 kg. The bulls were weight-blocked and randomly allocated to 12 pens, which were considered the experimental units. The treatments were assigned to the pens according to the blocks, as follows: sodium monensin (25 ppm; SM) and sodium monensin (25 ppm) plus tannins (350 ppm) and saponins (3.92 ppm, SM+TS). The bulls received an adaptation diet for the first 19 days, a growing diet from day 20 to day 59, and a finishing diet from day 60 to 98 of the experimental period. The animals were slaughtered after 98 days of study. The addition of tannins and saponins to the diets of feedlot Nellore cattle did not change the dry matter intake, hot carcass weight, and dressing percentage; however, it increased body weight by 2.0% and average daily gain by 5.4% and improved feed conversion by 4.3%. The addition of tannins and saponins to high-concentrate diets containing sodium monensin improves the productive performance of Nellore cattle finished in a feedlot for 98 days.

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ABSTRACT This study evaluated the effects of tannin extract of Acacia mearnsii De Wild. or monensin on intake, digestibility, nitrogen balance, and ruminal variables of lambs. Five rumen cannulated lambs (40.3 ± 2.8 kg) were used in a 5 × 5 Latin square design, with periods of 21 days each. The treatments were: control, without additive; Tan-0.60, Tan-1.20, and Tan-1.80 for the doses of 0.60, 1.20, and 1.80 g kg−1 body weight (BW) of tannin extract, respectively; and ionophore (monensin) at 0.75 mg kg−1 of BW. Tannins reduced the digestibility of dry matter (DM) and the greatest effects were observed for Tan-1.80. Tannins also increased or tended to increase the fecal excretion of DM, and the greatest effects were observed for Tan-1.20 and Tan-1.80. Tannins increased the fecal excretion of N, decreased the amount of N in urine, but did not affect N retained. Furthermore, tannins reduced the concentration of valerate and the acetate:propionate ratio and increased propionate without affecting the amount of total volatile fatty acids, and the greatest effects were observed for Tan-1.80. The use of ionophore only increased the elimination of N in the urine. Thus, monensin does not affect nitrogen retention, and tannin impairs digestibility, but increases propionate production.

Resumo em Inglês:

ABSTRACT The present study presents a comparative evaluation of the transit kinetics of straw briquette in response to the dietary addition of non-protein nitrogen sources in the form of a mineral supplement. Four rumen-cannulated, castrated Holstein-Gir crossbred cattle, weighing an average of 380±22.64 kg, were distributed into a 4 × 4 Latin square design (four supplements with non-protein nitrogen sources × four experimental periods). The following non-protein nitrogen sources were studied: conventional urea, slow-release urea, extruded urea, and monoammonium phosphate. During the experiment, the animals were housed in individual stalls with concrete floors where they received a basal diet consisting of straw briquette, potato starch, and the mineral supplement, the latter whose variation was only in the non-protein nitrogen source, which characterized the treatments. The different non-protein nitrogen sources did not affect the parameters of transit or degradation kinetics of straw fiber briquette. These results can be associated with the low nitrogen content limited by the types of supplements and the particle size of straw briquette, which is smaller due to processing.

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ABSTRACT The objective of this study was to examine the effect of the increasing levels of inclusion of palm kernel cake (PKC) in the diet on the performance of feedlot heifers. Forty-eight Nelore heifers with an initial weight of 274 ± 4.58 kg, at 24 months of age, were confined for 98 days in a feedlot. The animals were allocated to the four treatments in a completely randomized design. Treatments consisted of PKC levels of 0 (control), 10, 20, and 30% in the total dry matter of the diet. The roughage:concentrate ratio in the diets was 30:70. Ether extract intake increased, whereas the intakes of non-fiber carbohydrates and total digestible nutrients decreased with the inclusion of PKC. The apparent digestibility of all nutrients decreased, as well as the amounts of nitrogen digested and retained. Microbial protein synthesis and its efficiency also declined. The inclusion of up to 20% PKC increased feeding time and reduced rumination time of heifers. Intake and rumination efficiencies decreased with the inclusion of PKC in the diet. Final weight and average daily gain did not change, but feed efficiency increased with the inclusion of PKC. The inclusion of up to 30% PKC in the diet of feedlot heifers is recommended.

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ABSTRACT The objective of this study was to evaluate the in vitro fermentation products, digestibility, gas production (GP) kinetics, and enteric greenhouse emissions (CH4 and CO2) of substrates with different forage:concentrate ratios (100F, grass hay only; 100C, concentrate mixture only, and mixture, an equal proportion of them) within non-woven fabric (NWT; 100 g/m2) or F57 (Ankom®) filter bags compared to directly dispersed in the medium (DIS), arranged in a 3 × 3 factorial arrangement. Substrates (0.5 g) were incubated using an AnkomRF GP System. Gas samples were collected during 24 and 48 h of incubation. We observed substrate × dispersion method interactions on GP at 48 h (GP48) and on in vitro organic matter digestibility (IVOMD). The GP48 and IVOMD of the 100C substrate were greatest in DIS, intermediate in NWT, and least in F57. With mixture substrate, there were no differences in GP48 and IVOMD between DIS and NWT, but they were greater than in F57. The GP48 and IVOMD were greater in NWT than in DIS and F57 when 100F was incubated. There were no dispersion method × substrate interactions on molar proportions and total volatile fatty acids. With the increase in forage:concentrate ratio incubated, there was a linear decrease in CH4 and CO2 emission relative to organic matter digested. Overall, CH4 and CO2 emissions and digestibility were lower when substrates were incubated within filter bags. The noteworthy interaction between the incubation method and substrates indicates that the ranking of these variables for substrates with differing fermentabilities changes with the dispersion method employed.

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ABSTRACT The objective of this study was to assess the effects of high-concentrate diets with and without the inclusion of soybean hull (SH; 0 or 500.8 g/kg) plus corn (whole or ground) on the performance, morphometric traits, and nutritional and metabolic parameters of crossbred dairy calves. We also aimed to assess the costs associated with the experimental diets employed. Thirty-six male calves with an average weight of 89±18.6 kg and age of 3.5 months were allocated to four treatments, with nine replicates of one calf/pen, in a completely randomized experimental design for 198 days. The inclusion of the SH and the physical form of corn did not influence animal performance or morphometric measurements; however, SH inclusion increased the digestibility of neutral detergent fiber and the intakes of dry matter and neutral detergent fiber, but did not affect total digestible nutrient intake. The physical form of corn did not influence nutrient intake or digestibility, which resulted in similar performance across the animals. Blood glucose levels as well as alkaline phosphatase and creatinine remained elevated regardless of the diet. The use of SH reduced the total plasma cholesterol content, and there was an interaction between the physical form of corn and SH inclusion in relation to creatinine levels, which were higher when using diets with whole corn and SH. Although the inclusion of up to 500.8 g/kg of SH in the diet reduces feed efficiency, its use decreases the cost per kilogram of weight gain. Dairy calves can exhibit satisfactory production performance when fed alternative ingredients such as whole corn or SH, which have a lower cost than ground corn, traditionally used in diet formulations.

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ABSTRACT Our objective was to compare performance and carcass characteristics of backgrounding steers grazing poor quality pasture, receiving energy or protein supplements during summer, and on subsequent finishing period. Sixty Hereford steers (14 months; 348±33 kg body weight [BW]) were blocked by BW and randomly assigned to one of three treatments (n = 20 per treatment): control (non-supplemented) and supplemented at 0.8% BW with whole grain of corn (CS) or lupin bean (LS) (phase I; 77 days). Over the following 84 days, none of the steers had access to supplement (phase II). During phases I and II, steers grazed together endophyte-infected tall fescue. In the last phase (phase III; 176 days), and until slaughter, steers grazed lucerne and orchard grass and were supplemented at 0.8% BW with high-moisture sorghum grain. Data were evaluated as a complete block randomized design with three treatments. Intake of supplement in CS and LS groups was 1.9 and 2.4 kg DM/d, respectively. Steers supplemented with lupin showed an improvement in the supplement conversion efficiency (5.7:1 vs. 10.0:1). At the end of phase I, BW and average daily gain were different between groups (LS > CS > control). Final body weight in phase II was greater in supplemented steers than in control steers. At slaughter, supplemented groups had greater hot carcass weight than the control group. The advantage obtained by supplementing steers with lupin, compared with corn, was lost in the subsequent phases, as reflected by the absence of differences in carcass weight. Our data illustrate that in similar scenario, energy supplementation is adequate and there is not any extra benefit of adding protein by the use of lupins when considering cattle management and economic factors.

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ABSTRACT This study aimed to evaluate the productive and reproductive performance and the nutritional metabolic condition of ewes supplemented at different stages of gestation in a synchronized reproduction system. Fourty Santa Inês × Dorper crossbreed ewes, pregnant with an average age of ten months and two previous births, were distributed in a completely randomized design, with four treatments: mineral salt, supplementation started 20 days before the estrus synchronization (ES) protocol, supplementation from confirmation of pregnancy (60 days after ES), and supplementation in the final third of gestation (90 days after ES). The adoption of supplementation strategies during the beginning, middle, or end of pregnancy changed the intake and digestibility of dry matter (g/day), with a reduction of 10.53 and 9.14%, respectively, for the mineral salt treatment, in addition to organic matter, crude protein, neutral detergent fiber, acid detergent fiber, non-fibrous carbohydrates, ether extract, and total digestible nutrients, as well as protein, energy, and mineral profiles. There was no difference in the number of ovulations and reproductive and productive performance using supplementation alternatives. Supplementation strategies during the gestation stages influence the intake and digestibility of nutrients, as well as the animal metabolic profiles. However, it does not change reproductive and productive performance.

Resumo em Inglês:

ABSTRACT This study was conducted to evaluate the relationship among digestibility, residual feed intake (RFI), and enteric methane emission in growing Nellore cattle (Bos indicus) divergently classified based on RFI phenotype and breeding value (EBV-RFI). Animals (n = 122) subjected to performance testing (forage:concentrate ratio of 60:40) in two test groups were classified based on RFI. A sample of 80 animals classified as low (−0.748±0.076 kg DM/day) or high (0.775±0.075 kg DM/day) RFI was evaluated regarding feed compounds digestibility, fecal excretion, and methane emission (CH4, g/day). Statistical mixed models included fixed effects of RFI (or EBV-RFI), linear effect of initial age as covariate, and the random effects of the test group. There was no difference in the digestibility of feed compounds between the most and least efficient animals. However, dry matter intake (DMI; 6.92 vs. 8.66 kg DM/day) and feed conversion (7.93 vs. 9.42 kg/kg) were lesser in low RFI animals. On average, low RFI animals emitted 14.3 g less CH4 per day (174 vs. 188 g CH4/day); however, CH4 emission expressed as g/kg DMI (23.1 vs. 20.1) and the percentage of gross energy intake lost as CH4 (8.13 vs. 7.08%) were greater for these animals. These results showed the benefits of using more feed efficient animals in the beef production chain, i.e., animals that exhibit lower feed intake, lower fecal excretion, and lower enteric methane emission without differences in weight gain or body weight. However, the variations in feed efficiency among them cannot be explained by differences in dry matter or feed compounds digestibility. More efficient animals emit less enteric methane than less efficient animals, probably as a result of lower DMI.

Resumo em Inglês:

ABSTRACT This study evaluated the substitution of corn grain with white oat grain in finishing yearling bulls (initial weight of 259.4±31.7 kg and 18.0±0.2 months of age). The experimental design was completely randomized. The substitution levels of corn grain for white oat grain were 0, 25, 50, 75, and 100%. Diets comprised 85% of grains + 15% of a protein-vitamin-mineral pelleted supplement. The adaptation program consisted of ad libitum feeding of five diets over the adaptation period of 14 days, with the concentration level increasing from 60 to 100% of the diet on a dry matter basis. Daily weight gain and carcass gain presented a quadratic behavior with the inclusion of white oat grain. As a result of the differences in average daily gain, the feedlot period varied among groups until the target slaughter weight was reached. Dry matter intake, nutrient intake, feed efficiency, and Kleiber ratio presented a quadratic behavior. Ingestive behavior and rumination patterns were modified by the levels of white oat grain, with longer rumination time observed with the combination of grains. A similar response was observed for the number of regurgitated and chewed bolus. Conversely, the number of chews per bolus and the chewing time per bolus increased linearly with the replacement of corn with white oat grain. Residual intake and body weight gain and the participation of heart, lung, and kidney, heart, and pelvic fat g kg−1 of empty body weight decreases linearly with the inclusion of white oat grain. The partial substitution of corn grain with white oat grain improves the productive performance and rumination patterns yearling bulls in feedlots receiving non-forage diets.

Resumo em Inglês:

ABSTRACT This study was carried out to evaluate the effects of corn dried distillers’ grains (DDG) levels in non-forage diets by in vitro, in situ (0 to 50%), and in vivo (0 to 40%) trials on kinetic parameters of gas production (GP) on rumen-degradable protein (RDP) and rumen-undegradable protein (RUP) as well as on nitrogen (N) metabolism in Nellore cattle. For in vitro and in situ studies, three rumen cannulated Nellore males with body weight of 340.48 ± 22.22 kg were used. For the in vivo study, five non-castrated male Nellore cattle with an initial body weight of 355.20 ± 35.28 kg and 24 ± 3 months old were used to evaluate the effect of increasing DDG levels in non-forage diets on N metabolism by a 5 × 5 Latin square design. Experimental diets were based on ground corn, cottonseed cake, urea, mineral supplement, and increasing levels of DDG replacing ground corn. The DDG levels caused a linear decrease in GP and in vitro dry matter digestibility. The DDG presented a lower dry matter digestibility (DMD) and RDP and higher RUP than corn grain and cottonseed cake, making DDG diets present lower DMD and RDP than control. The DDG levels linearly increased the intake of crude protein, neutral detergent fiber, and ether extract, whereas non-fiber carbohydrates intake decreased and tended to decrease the DMD and organic matter digestibility. The DDG levels caused a linear increase in N intake and in total, fecal, and urinary N excretion, which was the major N excretion route, causing a quadratic drop in retained N and caused a quadratic effect on alanine aminotransferase. In contrast, triglycerides were cubically affected, and total blood protein increased. Thus, DDG levels negatively affect in vitro and in situ digestibility, increasing N intake but increasing urinary N excretion.

Resumo em Inglês:

ABSTRACT The objective of this study was to investigate the influence of snaplage on fecal characteristics, feeding behavior, and performance of finishing bulls. Seventy-two single-sourced Nellore bulls (initial body weight [BW] = 400 ± 27.4 kg; 2.4 years old) were randomly assigned to one of three treatments (three bulls/pen; eight pen replicates/treatment). Treatments consisted of finishing diets with the following sources of fiber and energy: corn silage, reconstituted corn grain silage, and dry-ground corn (control; inclusion of 22.9, 42.1, and 20.0% of dry matter (DM), respectively); snaplage (inclusion of 65% of DM) and dry-ground corn (SNAP65); and snaplage only (inclusion of 85% of DM; SNAP85). Bulls were adapted over a 15-d period and fed for a total of 86 d. Fecal samples were collected on days 42, 65, and 73. Feeding behavior was assessed on days 51 and 69. All data were analyzed as a completely randomized block design. No differences were obtained for initial BW, gain:feed ratio, hot carcass, and dressing. The SNAP85 diet had a greater intake, followed by SNAP65 and control diets (P = 0.02). There was a tendency of greater average daily gain and final BW (P = 0.07 and 0.08, respectively) for SNAP65 diet, followed by SNAP85 and control treatments. A tendency (P = 0.07) was also observed for greater ribeye area in bulls consuming SNAP65 (85 cm2), followed by control (81 cm2) and SNAP85 (80 cm2). Bulls consuming SNAP65 and SNAP85 spent more time chewing (on average, 249 min/d) than those consuming control diet (177 min/d; P = 0.01). Fecal starch was lower, and pH was greater for SNAP85 (P = 0.01 for both variables). Overall, snaplage is a suitable ingredient in high-starch diets for providing energy and physically effective neutral detergent fiber. The inclusion of 65% of snaplage and 20% of dry-ground corn (DM basis) showed a slight superior performance in Nellore bulls.