Effect of Discarded Date (Phoenix dactylifera L.) Inclusion, with or without Multienzymes, on the Growth Performance, Carcass Characteristics, and Blood Metabolites of Broiler Chickens

ABSTRACT

This study investigated the effects of discarded date (DD) inclusion in broiler diets, with or without multi-enzymes (MZ) supplementation, on the growth performance, carcass characteristics, and blood metabolites. In a completely randomized design, 480 one-day-old Ross 308 unsexed broiler chicks (average body weight, 42.23 ± 1.84 g) were divided into 8 experimental groups in a 4×2 factorial arrangement comprising four inclusion levels of DD (0%, 10%, 20%, and 30%) and two levels of MZ (0.0 and 1.0 g). Each group included 6 replicates with 10 birds in each replicate, over 35 days. The results of this study showed that including up to 30% of DD did not affect (p>0.05) growth, feed intake, feed conversion ratio, or carcass characteristics. No interaction (p>0.05) was observed between DD levels and MZ supplementation on growth, feed intake, feed conversion ratio, carcass characteristics, or serum biochemical parameters. Supplementation with EZ improved growth (p<0.05) during days 28-35 and 0-35. Glucose concentration increased with rising DD levels, with diets containing 20% and 30% DD yielding higher (p=0.035) values than the 0% DD diet. In conclusion, this study demonstrated that the inclusion of up to 30% of discarded dates in broiler diets is effective and sustainable, without adversely affecting performance or carcass traits. Furthermore, multi-enzymes supplementation enhances the growth of broilers in diets containing discarded dates.

Keywords:
Blood biochemistry; broilers; carcass traits; discarded dates; enzyme; performance

INTRODUCTION

The primary ingredients in poultry feed are yellow corn and soybean meal. In recent years, the poultry industry has been greatly affected by the soaring prices of these feed ingredients. Consequently, using agricultural industrial wastes as less expensive non-traditional feeds to replace traditional sources provides an economical and sustainable alternative. According to the Food and Agriculture Organization (FAOSTAT) (2023), approximately 5.2 billion tons of agricultural by-products were produced globally in 2021. These by-products are mainly generated during the processing of vegetables and fruit crops. Utilizing them is crucial to promote sustainability from both economic and environmental standpoints. Date by-products are particularly abundant in arid and semi-arid regions, and play a significant role in animal systems for livestock and poultry (Khattab et al., 2014; Khattab & Anele, 2022; Raza et al., 2023). Date palm (Phoenix dactylifera L.) trees thrive in such regions, where other crops may struggle to grow, making them a crucial food source. Global production, utilization, and processing of date fruit are increasing due to its growing importance in human nutrition, as date fruits are rich in essential nutrients (Chandrasekaran & Bahkali, 2013). However, date fruit processing industries generate tons of discarded dates daily, leading to environmental problems. In Saudi Arabia, the date palm is a significant crop that greatly contributes to agroecosystems. There are over 400 varieties of palm trees, with the most economically significant ones being Ajwa, Sukkari, Saqi, Anbara, Ikhlas, Barhi, Anbara, Safawi, Ruthana, Khadri, and Rashudi (Yao & Al-Redhaiman, 2014). Discarded dates include the pits and other inedible parts of the fruit for humans. Therefore, the chemical composition percentages vary widely across components: dry matter from 87.7% to 95.2%, crude protein (CP) from 4.4% to 8.1%, ether extract (EE) from 2.0% to 3.5%, crude fiber (CF) from 9.1% to 21.8%, nitrogen free extract (NFE) from 55.3% to 76.4%, and ash from 0.98% to 9.08% (Attia et al., 2021; Khattab and Anele, 2022; Raza et al., 2023).The use of agricultural co-products has increased to leverage the nutrients in these low-cost ingredients, but this increases dietary fiber content (Tejeda & Kim, 2021). Poultry diets typically contain 2-3% crude fiber (Choct, 2015), which plays a crucial role in digestive function (Jimenez-Moreno et al., 2009). At moderate level, dietary fiber promotes digestive tract development, enhances nutrient digestibility, enzyme activity, and improves growth performance (Mateos et al., 2012; Tejeda & Kim, 2021). Advances in feed milling, formulation, and processing of these non-conventional ingredients, combined with exogenous enzymes, have been essential for improving their digestibility and global utilization (Singh & Kim, 2021). The most commonly used enzymes in poultry nutrition are xylanase, glucanase, cellulase, protease, amylase, pectinase, phytase, and galactosidase. These enzymes improve the nutrition utilization efficiency of raw materials (Wenk, 2000) by mitigating the anti-nutritional effects of non-starch polysaccharides in grains and co-products (Al-Harthi et al., 2018; Alqhtani et al., 2022; Al-Harthi et al., 2023), which otherwise reduce digestion and absorption of all nutrients, particularly protein and fat (Khattak et al., 2006).

Several studies have shown that incorporating discarded dates into broiler diets can improve their performance, such as body weight and feed conversion rate. For example, research by Al-Homidan (2003), Al-Harthi (2006), and Al-Harthi et al. (2009) have demonstrated positive effects on these metrics. Raza et al. (2023) found that including dried date waste exhibited improved growth performance, enhanced carcass quality, greater nutrient digestibility, elevated fecal Lactobacillus counts, reduced E. coli counts, and led to better economic performance. Moreover, discarded dates can be included at high levels in poultry diets without adversely affecting growth. Attia & Al-Harthi (2015) reported that up to 20% of waste dates did not impair broiler growth. Similarly, El-Deek et al. (2010) found no negative impact on growth performance when including up to 30% of whole Zahdi dates with corn, while Najafi et al. (2020) observed the same in ostrich diets with waste dates up to 30%. We hypothesized that adding enzymes to broiler diets containing up to 30% discarded dates would improve their utilization as a non-traditional feed ingredient, reduce feed formulation costs, and promote environmental sustainability. Therefore, this study aimed to evaluate the effects of including discarded dates at 0%, 10%, 20%, and 30%, with or without 1.0 g/kg of multi-enzymes supplementation, on growth performance, carcass characteristics, and blood metabolites.

MATERIALS AND METHODS

Ethical Approval

The study was conducted at the Hada Al-Sham Research Station, Faculty of Environmental Sciences, King Abdulaziz University, Jeddah, Saudi Arabia. All experimental procedures were approved by the Agriculture Department Committee at King Abdulaziz University (approval number: ACUC-22-1-2), in accordance with ethical standards for scientific research involving animals, as established by Royal Decree No. M/59 of 24/8/2010.

Ingredients and Chemical Analysis

Discarded whole fruits unsuitable for packing and human consumption were collected from a local market. These fruits were sun-dried and crushed to a maximum size of about 1mm using heavy hammer mills. The chemical composition of the discarded dates and diets was determined for moisture (method 934.01), CP (method 954.01), CF (method 978.10), EE (method 920.39), and ash (method 942.05), according to the methods established by the Association of Official Analytical Chemists (AOAC, 2006). Nitrogen-free extract is calculated as % NFE = 100% - (% EE + % CP + % Ash + % CF).

Birds, Diets and Management

In a completely randomized design, 480 one-day-old Ross 308 broiler chicks (average body weight, 42.23 ± 1.84 g) were randomly assigned to eight treatments (60 chicks/treatment) in a 4×2 factorial arrangement comprising four inclusion levels of DD (0%, 10%, 20%, and 30%) and two levels of multi-enzymes (0.0 and 1.0 g/kg) over 35 days. Each treatment consisted of six replicates with 10 birds per replicate, housed in separate pens (2.0 m x 2.0 m). Experimental diets were formulated to be isonitrogenous (23.2% CP) and isocaloric (3026 kcal/kg metabolizable energy), meeting the nutrient requirements for broiler chickens as specified by the National Research Council (1994). The multi-enzymes used in this study was Growzym, which contains the following per kg: 1.0×10⁵, 1.0×10⁸, 1.0×10⁴, 4.0×10⁵, 1.0×10⁴, 1.5×10⁵, 5.0×10⁵ and 3.0×10⁴ units of α-amylase, cellulase, β-glucanase, protease, lipase, xylanase, phytase and pectinase, respectively. The chemical composition of DD is presented in Table 1, while the ingredients and the composition of the diets are shown in Table 2.

Table 1
Composition of the discarded dates included in broiler diet.

Items	Composition, %
Moisture	8.25
Crude protein	7.83
Crude fibre	8.47
Ether extract	2.56
Ash	4.38
Nitrogen free extract	68.5

Table 2
Ingredients and composition of broiler diets containing different levels of discarded dates.

Items	Discarded dates levels, %
	0	10	20	30
Ingredients, %
Yellow Corn	59.5	40.0	35.0	31.0
Discarded dates	0.00	20.0	25.0	30.0
Soybean meal, 44%	21.4	16.9	16.0	12.9
Gluten corn 60%	10.0	13.0	13.9	16.0
Concentrate 48%	5.00	5.00	5.00	5.00
Salt (NaCl)	0.25	0.25	0.25	0.25
Vitamin + minerals premix1	0.30	0.30	0.30	0.30
Limestone	1.35	1.35	1.35	1.35
Dicalcium phosphate	1.00	1.00	1.00	1.00
DL-Methionine	0.10	0.10	0.10	0.10
Lysine	0.10	0.10	0.10	0.10
Plant oil	1.00	2.00	2.00	2.00
Total	100.0	100.0	100.0	100.0
Calculated and determined composition
Metabolizable energy, kcal/kg2	3057	3030	3007	3012
Crude protein, %3	23.07	23.14	23.34	23.39
Crude Fibre, %3	3.01	4.11	4.37	4.52
Ether extract, %3	3.01	2.87	2.84	2.85
Calcium, %2	1.20	1.19	1.18	1.17
Total potassium, %2	0.70	0.63	0.62	0.60
Lysine, %2	1.05	1.01	1.01	0.97
Methionine, %2	0.49	0.48	0.48	0.49
Methionine + Cysteine, %2	0.67	0.54	0.51	0.45

• ¹
  Each 3 Kg of premix contain: Vitamin A 12,000 IU, vitamin B12 0.02 mg, vitamin D3 3000 IU, vitamin E 40 mg, vitamin K3 3 mg, vitamin B2 6 mg, vitamin B1 2 mg, vitamin B6 5 mg, biotin 0.075 mg, niacin 45 mg, folic acid 2 mg, pantothenic acid 12 mg, manganese 100 mg, zinc 600 mg, iron 30 mg, selenium 0.2 mg, copper 10 mg, iodine1 mg, cobalt 0.1 mg. ²Calculated according to NRC (1994). ³Analysed values.

Chicks had access to water and pellet diets throughout the trial. Broiler chickens were raised according to standard veterinary recommendations and husbandry practices. During the first week, chicks were provided with 24 h of continuous light per day. Thereafter, lighting was reduced to 22 h per day and maintained at this level until the end of the experiment. Room temperature was maintained at 32.0 ± 0.5 °C during the first three days. From day 4 onward, it was gradually reduced, reaching 28 °C by the end of week two, and 21 °C by the end of the experimental period, with a relative humidity of 60%. The vaccination program for all experimental groups included protection against Newcastle disease (ND), infectious bursal disease (IBD, Gumboro), and infectious bronchitis (IB).

Growth Performance and Carcass Traits

The body weight and feed intake (FI) of the birds were recorded weekly, from which body weight gain (BWG) and feed conversion ratio (FCR) were calculated. On the 35th day, two chickens from each experimental replicate were selected, fasted for 8 hours, slaughtered using a sharp knife, and subsequently bled out. After manual plucking, the carcasses were gutted, washed, allowed to drip dry, and weighed. The weights of the viscera and abdominal fat, spleen and the bursa of Fabricius were recorded.

Blood Biochemistry

On the 35th day, following the slaughter, blood samples were drawn (two chickens from each experimental replicate) from the jugular vein and placed in tube without anticoagulant. The blood was then centrifuged at 3000xg for 15 min to separate the serum, which was stored at - 20 °C until analysis. Serum parameters - including total protein, albumin, uric acid, creatinine, triglycerides, cholesterol, glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) - were measured calorimetrically using colorimetric kits (Milton Roy, Ivyland, PA, USA). The globulin value was calculated by subtracting the albumin value from the total protein value.

Statistical Analysis

The study used a fully randomized design with a 4×2 factorial arrangement, including four levels of DD (0%, 10%, 20% and 30%) and two levels of EC supplementation (0 and 1.0 g). Data were analyzed using two-way analysis of variance with General Linear Model (GLM) procedures of SAS Institute (2003), according to the model:

$Y_{ijk}=\mu +X_i+Z_j+{(XZ)}_{ij}+e_{ijk};$

where: Y_ijk = observation; µ = overall mean; X_i = DD effect; Z_j = α-cellulase enzyme effect; (XZ)_ij = interaction between DD and EC level; e_ijk = experimental errors. Treatment means were compared using Duncan’s post hoc multiple range test, with statistically significant declared at p<0.05. When necessary to meet parametric assumptions, data were transformed for normality of residuals: percentages using the arcsine function and other values using the logarithm function (x+1).

RESULTS

Growth Performance

The effect of including DD levels with or without MZ supplementation on BWG is presented in Table 3. Discarded date levels did not affect BWG (p>0.05) across all experimental periods. Multi-enzymes supplementation positively influenced (p<0.05) body weight in the periods between 28-35 and 0-30 of age but showed no significant effects (p>0.05) in earlier age periods (0-14 and 15-28). No significant interaction (p>0.05) between DD levels and MZ supplementation was observed for BWG in any period.

Table 3
Body weight gain (g) of broilers fed discarded dates (DD), with or without multi-enzymes supplementation (MZ).

Items	0 - 14 d of age	15 - 28 d of age	28 - 35 d of age	0 - 35 d of age
Inclusion levels of DD, %
0	445.6	962.8	741.5	2149.9
10	445.7	914.8	734.1	2093
20	441.9	916.4	729.9	2088.2
30	440.7	890.9	697.8	2029.4
Without MZ	437.8	893.3	715.7	2046.8
With MZ	449.1	949.1	535.9	2134.1
SEM	8.35	15.29	12.17	35.32
Main effects
Levels	0.903	0.104	0.272	0.176
MZ	0.079	0.011	0.227	0.019
Levels x MZ	0.929	0.919	0.076	0.553

• SEM: standard error of the mean.

The effect of different levels of DD with or without MZ supplementation on feed intake is shown in Table 4. No level of DD inclusion nor MZ supplementation affected feed intake (p>0.05) throughout the experimental period. Additionally, no interaction (p>0.05) was observed between DD levels and MZ supplementation on feed intake.

Table 4
Feed intake (g) of broilers fed discarded dates (DD) with or without multi-enzymes supplementation (MZ).

Items	0 - 14 d of age	15 - 28 d of age	28 - 35 d of age	0 - 35 d of age
Inclusion levels of DD, %
0	539.3	1207.8	1255.8	3002.9
10	511.0	1184.1	1153.3	2821.2
20	464.2	1179.5	1181.7	2824.4
30	481.2	1191.6	1160.8	2833.6
Without MZ	469.9	1142.5	1182.5	2794.9
With MZ	527.9	5189.0	1193.3	2910.2
SEM	43.55	41.78	51.92	91.61
Main effects
Levels	0.360	0.068	0.228	0.067
MZ	0.081	0.138	0.772	0.097
Levels x MZ	0.884	0.346	0.204	0.922

The effect of various DD levels with or without MZ supplementation on FCR is detailed in Table 5. No DD inclusion level nor MZ supplementation affected FCR (p>0.05) during the experimental periods. Moreover, no interaction (p>0.05) was observed between DD inclusion levels and MZ supplementation on FCR.

Table 5
Feed conversion ratio (g feed / g gain) of broilers fed discarded dates (DD) with or without multi-enzymes supplementation (MZ).

Items	0 - 14 d of age	15 - 28 d of age	28 - 35 d of age	0 - 35 d of age
Inclusion levels of DD, %
0	1.210	1. 254	1.694	1.397
10	1.151	1.294	1.571	1.361
20	1.050	1.287	1.618	1.353
30	1.092	1.338	1.664	1.396
Without MZ	1.073	1.279	1.652	1.365
With MZ	1.175	1.253	1.622	1.364
SEM	0.140	0.106	0.059	0.065
Main effects
Levels	0.541	0.724	0.837	0.946
MZ	0.253	0.676	0.078	0.618
Levels x MZ	0.871	0.640	0.464	0.897

• SEM: standard error of the mean.

Carcass Characteristics

The effect of different levels of DD with or without MZ supplementation on carcass characteristics is presented in Table 6. The percentages of carcass, heart, gizzard, liver, abdominal fat, total edible part, spleen, and bursa were not significantly affected (p>0.05) by increasing levels of DD or MZ supplementation. Additionally, no significant interaction (p>0.05) was observed between DD levels and MZ supplementation on these carcass characteristic parameters.

Table 6
Carcass characteristics of broilers fed discarded dates (DD) with or without multi-enzymes supplementation (MZ).

Items	Carcass weight (%)	Heart weight (%)	Gizzard weight (%)	Liver weight (%)	Abdominal fat (%)	Total edible part (%)	Spleen weight (%)	Bursa weight (%)
Inclusion levels of DD, %
0	63.53	0.99	3.61	4.69	1.22	9.27	0.26	0.28
10	64.35	0.94	3.37	4.86	1.72	8.94	0.22	0.27
20	64.81	1.01	3.16	4.57	1.73	8.83	0.23	0.27
30	63.64	1.01	3.77	4.71	0.86	9.47	0.27	0.35
Without MZ	63.78	1.04	3.50	4.58	1.40	9.16	0.24	0.29
With MZ	64.39	0.93	3.45	4.82	1.36	9.09	0.25	0.30
SEM	5.54	0.078	0.342	0.405	0.457	0.644	0.031	0.030
Main effects
Levels	0.756	0.791	0.473	0.987	0.205	0.741	0.348	0.078
MZ	0.537	0.051	0.725	0.649	0.892	0.877	0.904	0.713
Levels x MZ	0.620	0.345	0.603	0.689	0.916	0.811	0.809	0.192

• SEM: standard error of the mean.

Serum Biochemical Parameters

The effect of different levels of DD inclusion, with or without MZ supplementation, on serum biochemical parameters is shown in Table 7. Glucose concentration increased with increasing DD inclusion levels; specifically, diets containing 20% and 30% DD resulted in significantly higher (p=0.035) concentrations compared to the 0% DD diet, while other parameters remained unaffected. Multi-enzymes supplementation had no effect (p>0.05) on these parameters, nor was there any interaction between DD levels and MZ supplementation.

Table 7
Serum biochemical parameters of broilers fed discarded dates (DD) with or without multi-enzymes supplementation (MZ).

Items	Total protein, g/dl	Albumin, g/dl	Globulin, g/dl	Triglyceride, mg/dl	Cholesterol, mg/dl	Glucose, mg/dl	AST, U/L	ALT, U/L
Inclusion levels of DD, %
0	5.53	2.56	2.97	241	166	236b	60.6	46.3
10	6.00	2.51	3.49	235	163	249ab	64.1	41.4
20	5.97	2.52	3.45	267	172	262a	65.6	42.0
30	5.82	2.42	3.40	263	177	260a	63.2	44.3
Without MZ	5.73	2.48	3.25	265	175	223	64.4	44.5
With MZ	5.92	2.52	3.40	238	163	229	62.3	43.4
SEM	0.081	0.035	0.085	6.712	0.042	3.691	3.283	0.209
Main effects
Levels	0.382	0.854	0.338	0.120	0.086	0.035	0.257	0.326
MZ	0.206	0.369	0.429	0.659	0.742	0.876	0.334	0.719
Levels x MZ	0.871	0.948	0.846	0.546	0.564	0.358	0.584	0.745

• ^a
  ^{, b} Means in the same column bearing different letters significantly (p≤0.05). AST, aspartate aminotransferase; ALT, alanine transaminase; LDL, low-density lipoprotein; HDL, high-density lipoprotein; SEM, standard error of the mean.

DISCUSSION

The primary objective of this experiment was to evaluate the effects of incorporating high levels of DD as an alternative energy source on broiler performance, carcass characteristics, and serum biochemical parameters. Our findings showed that discarded dates contain higher levels of CP, fat, and carbohydrates compared to corn grains, consistent with previous studies (Khattab et al., 2014; Attia et al., 2021). However, their gross energy content is 4335 kcal/kg, which is slightly lower than that of corn grains at 4493 kcal/kg, due primarily to the high nitrogen-free extract content (72.8%) in dates (Najafy et al., 2021). Their soluble carbohydrates are rich in monosaccharides (44% glucose, 50% fructose, and a minor amount of sucrose) (Khattab and Anele et al., 2022). Additionally, discarded dates provide elevated levels of calcium, phosphorus, and trace minerals compared to corn (Najafi et al., 2021). Thus, discarded dates represent a sustainable, practical alternative for poultry nutrition, potentially reducing diet formulation costs.

Results of this study show that including DD at levels ranging from 0% to 30% resulted in a numerical decrease in BWI, feed intake, and feed FCR. However, this inclusion did not significantly affect WG, feed intake, and FCR in broiler chickens from 1 to 35 days of age. Notably, feed intake showed a slight increase at higher substitution levels up to 30%. These findings suggest that DD can replace corn grains as the primary ingredient in poultry feeds, given its higher nutrient density and availability. Previous studies support including DD at high levels in poultry diets. For instance, Attia and Al-Harthi (2015) reported no negative effect on growth performance from up to 20% waste dates in broiler diets during the growing-finishing period. Similarly, El-Deek et al. (2010) found that up to 30% whole Zahdi dates replacing corn had no adverse impact on growth performance. In a recent study, Recentaly, Najafi et al. (2020) concluded that up to 30% waste dates could be included in ostrich chick diets without negatively affecting growth performance.

The second objective of this study was to study potential strategies to enhance the digestion process and maximize the benefit of DD. The high fiber content in DD (10.46%) poses the main challenge to its utilization. Incorporating agricultural by-products high in dietary fiber into poultry feed results in low digestibility and poor poultry growth (Singh and Kim 2021). In poultry, dietary fiber digestibility is inherently low, which reduces the diet’s metabolic energy, increases digesta viscosity, and negatively affects nutrient digestibility (Aftab & Bedford, 2018). Therefore, crushing DD to a maximum size of about 1mm using heavy hammer mills may improve its utilization. De Vries et al. (2001) reported that processing fibrous feed ingredients using hammer and roller milling can improve solubility and enhance digestibility in poultry. In addition, multi-enzymes supplementation was used to further enhance DD utilization. The findings demonstrate that enzyme supplementation positively impacted BWC, feed intake, and FCR from day 1 to 35. The favorable effects can be attributed to the specific enzymes in the mixture, such as xylanase, cellulase, and β-glucanase, which partially degrade fiber components, thereby increasing nutrient availability and improving live body weight (Wang et al., 2005; Zhang et al., 2014; Aftab & Bedford, 2018). Multi-enzymes use significant affected bird BWG between 14 and 28 days, as well as in subsequent periods, when birds have a more developed digestive system and a greater capacity to digest and absorb nutrients (Sklan, 2001). These findings align with those of Berwanger et al. (2017), who observed similar results when adding an enzyme complex to broiler diets containing sunflower cake.

The study showed that incorporating discarded dates or multi-enzymes into the broiler diet did not affect the percentages of carcass weight, heart weight, gizzard weight, liver weight, abdominal fat, total edible part, spleen weight, and bursa weight. These findings align with previous studies by Al-Homidan (2003), Al-Harthi (2006), El-Deek et al. (2010), and Youssef & Al-Harthi (2015), who reported that dates did not adversely impact dressed carcass weight, total edible parts, liver, and gizzard percentages. Furthermore, El-Faham et al. (2017) found that adding date waste to broiler diets did not affect carcass yield.

The levels of serum biochemical parameters can indicate the nutritional status, metabolism, and health status of birds. In this study, including DD in broiler diets at levels up to 30% had no negative effects, consistent with the findings of Attia and Al-Harthi (2015), who reported no adverse effects from the inclusion of up to 20% date waste in broiler diets, and Najafi et al. (2021), who observed no negative impacts from up to 30% date waste in ostrich diets. Furthermore, the inclusion of DD resulted in higher serum glucose concentrations, aligning with Najafi et al. (2021), who linked increased serum glucose to greater waste dates inclusion in ostrich diets. This increase in broiler chickens fed 10 or 30% DD may be attributed to higher consumption of non-starch carbohydrates in DD.

CONCLUSION

In conclusion, this study demonstrates that discarded dates represent a valuable and sustainable feed ingredient for broiler chickens. The findings indicate that incorporating discarded dates into broiler chicken diets at levels up to 30% had no adverse effects on growth performance, carcass characteristics, or blood biochemical markers. In addition, adding multi-enzymes to these diets further enhanced growth performance.

ACKNOWLEDGEMENTS

The authors gratefully acknowledge Deanship of Scientific Research (DSR) at King Abdulaziz University for its technical and financial support.

REFERENCES

• Aftab U, Bedford MR. The use of NSP enzymes in poultry nutrition: myths and realities. Journal of World's Poultry Science 2018;74:277-86. https://doi.org/10.1017/S0043933918000272
  » https://doi.org/10.1017/S0043933918000272
• AOAC - Association of Official Analytical Chemists. Official methods of analysis. 16th ed. Washington: AOAC; 2006.
• Al-Harthi MA. The influence of date waste meal supplemented with enzymes, probiotics or their combination on broiler performance. Egyptian Poultry Science 2006;26:1031-55.
• Al-Harthi MA, Attia YA, Al-Sagan AA, et al. Effects of autoclaving and/or multi-enzyme complex supplementation on performance, egg quality and profitability of laying hens fed whole Prosopis juliflora pods meal in the diet. European Poultry Science 2018;82:248. https://doi.org/10.1399/eps.2018.248
  » https://doi.org/10.1399/eps.2018.248
• Al-Harthi MA, Attia YA, Elgandy MF, et al. The effects of Moringa peregrina seed meal, autoclaving, and/or exogenous enzyme cocktail on performance, carcass traits, meat quality, and blood lipids of broilers. Frontiers Veterinary Science 2023;10. https://doi.org/10.3389/fvets.2023.1158468
  » https://doi.org/10.3389/fvets.2023.1158468
• Al-Harthi MA, El-Deek AA, Yakout HM, et al. The nutritive value of date waste meal as a feedstuff for Lohmann Brown pullets and layers. Journal of Poultry Science 2009;46:303-12. https://doi.org/10.2141/jpsa.46.303
  » https://doi.org/10.2141/jpsa.46.303
• Al-Homidan AH. Date waste (whole dates and date pits) as ingredients in broiler diets. Egyptian Poultry Science 2003;23:15-35.
• Alqtani AH, Al Sulaiman AR, Al-Harthi AS, et al. Effect of exogenous enzymes cocktail on performance, carcass traits, biochemical metabolites, intestinal morphology, and nutrient digestibility of broilers fed normal and low-energy corn-soybean diets. Animals 2022;12:1094. https://doi.org/10.3390/ani12091094
  » https://doi.org/10.3390/ani12091094
• Attia AI, Reda FM, Patra AK, Elnesr SS, et al. Date by-products: Chemical composition, nutritive value and applications in poultry nutrition, an updating review. Animals 2021;11:1133. https://doi.org/10.3390/ani11041133
  » https://doi.org/10.3390/ani11041133
• Attia YA, Al-Harthi MA. Effect of supplementation of date waste to broiler diets on performance, nutrient digestibility, carcass characteristics and physiological parameters. European Poultry Science 2015;79:91. https://doi.org/10.1399/eps.2015.91
  » https://doi.org/10.1399/eps.2015.91
• Berwanger E, Nunes RV, Pasquetti TJ, et al. Sunflower cake with or without enzymatic complex for broiler chickens feeding. Asian-Australasian Journal of Animal Science 2017;30:410-6. https://doi.org/10.5713/ajas.15.0644
  » https://doi.org/10.5713/ajas.15.0644
• Cao BH, Zhang XP, Guo YM, et al. Effects of dietary cellulose levels on growth, nitrogen utilization, retention time of diets in digestive tract and caecal microflora of chickens. Asian-Australasian Journal of Animal Science 2003;16:863-6. https://doi.org/10.5713/AJAS.2003.863
  » https://doi.org/10.5713/AJAS.2003.863
• Chandrasekaran M, Bahkali AH. Valorization of date palm fruit processing by-products and wastes using bioprocess technology-Review. Saudi J Biol Sci. 2013;20:105-20. https://doi.org/10.1016/j.sjbs.2012.12.004
  » https://doi.org/10.1016/j.sjbs.2012.12.004
• Choct M. Fibre-chemistry and functions in poultry nutrition. Proceedings of the 52º Simposio Científico de Avicultura; 2015 oct 28-30; Málaga: Asociación Española de Ciência Avicola; 2015 p.113-9.
• De Vries S, Pustjens AM, Schols HA, et al. Improving digestive utilization of fiber-rich feedstuffs in pigs and poultry by processing and enzyme technologies: a review. Animal Feed Science and Technology 2012;178(3-4):123-38. https://doi.org/10.1016/j.anifeedsci.2012.10.004
  » https://doi.org/10.1016/j.anifeedsci.2012.10.004
• Duncan DB. Multiple Range and Multiple F-test. Biometrics 1955;11:1-42.
• El-Deek AA, Attia AA, Al-Harthi MA. Whole inedible date in the grower-finisher broiler diets and the impact on productive performance, nutrient digestibility and meat quality. Animal 2010;4:1047-52. https://doi.org/10.1017/S1751731110000820
  » https://doi.org/10.1017/S1751731110000820
• El-Faham AI, Nematallah GM, Ali Reham AM, et al. Date palm waste in starter-grower diets and impact on productive and physiological performance of broilers. Egyptian Journal of Nutrition and Feeds 2017;20:299-308. https://doi.org/10.21608/ejnf.2017.75214
  » https://doi.org/10.21608/ejnf.2017.75214
• FAOSTAT. Food and Agriculture Organization Corporate Statistical Database. Rome: FAOSTAT; 2023.
• Hetland H, Svihus B, Krogdahl A. Effects of oat hulls and wood shavings on digestion in broilers and layers fed diets based on whole or ground wheat. British Poultry Science 2003;44:275-82. https://doi.org/10.1080/0007166031000124595
  » https://doi.org/10.1080/0007166031000124595
• Hussein AS, Alhadrami GA, Khalil YA. The use of dates and date pits in broiler starter and finisher diets. Bioresource Technology 1998;66:219-23. https://doi.org/10.1016/S0960-8524(98)00054-6
  » https://doi.org/10.1016/S0960-8524(98)00054-6
• Jiménez-Moreno E, González-Alvarado JM, González-Serrano A, et al. Effect of dietary fiber and fat on performance and digestive traits of broilers from one to twenty-one days of age. Poultry Science 2009;88:2562-74. https://doi.org/10.3382/ps.2009-00179
  » https://doi.org/10.3382/ps.2009-00179
• Khattab IM, Anele UY. Dry matter intake, digestibility, nitrogen utilization and fermentation characteristics of sheep fed Atriplex hay-based diet supplemented with discarded dates as a replacement for barley grain. Journal of Animal Physiology and Animal Nutrition 2022;106:229-38. https://doi.org/10.1111/jpn.13577
  » https://doi.org/10.1111/jpn.13577
• Khattab IM, Salem AZM, Camacho LM, et al. Azzawi dates as a substitute for corn as an energy source in sheep diet: in vitro gas production and fermentation. Anim Nutr Feed Technol. 2014;14:41-9.
• Khattak FM, Pasha TN, Hayat Z, et al. Enzymes in poultry nutrition. Journal of Animal Plant Science 2006;16(1-2):1-7.
• Mateos GG, Jiménez-Moreno E, Serrano MP, et al. Poultry response to high levels of dietary fiber sources varying in physical and chemical characteristics. Journal of Applied Poultry Research 2012;21:156-74. https://doi.org/10.3382/japr.2011-00477
  » https://doi.org/10.3382/japr.2011-00477
• Najafi S, Ghasemi HA, Hajkhodadadi I, Khodaei-Motlagh M. Nutritional value of whole date waste and evaluating its application in ostrich diets. Animal 2021;15:100165. https://doi.org/10.1016/j.animal.2020.100165
  » https://doi.org/10.1016/j.animal.2020.100165
• NRC - National Research Council. Nutrient requirements of poultry. 9th rev. ed. Washington: National Academic Science; 1994.
• Raza MH, Tahir M, Naz S, et al. Dried date meal inclusion in the diets of broilers affects growth performance, carcass traits, nutrients digestibility, fecal microbiota and economics. Agriculture 2023;13:1978. https://doi.org/10.3390/agriculture13101978
  » https://doi.org/10.3390/agriculture13101978
• SAS Institute. SAS user's guide: statistics. Version 9.2. Cary: SAS Institute; 2003.
• Sawaya WN, Khalil JK, Safi WN, et al. Physical and chemical characterization of three Saudi date cultivars at various stages of development. Canadian Institute Food Technology Journal 1983;16:87-92. https://doi.org/10.1016/S0315-546372065-1
  » https://doi.org/10.1016/S0315-546372065-1
• Singh AK, Kim WK. Effects of dietary fiber on nutrients utilization and gut health of poultry: a review of challenges and opportunities. Animals 2021;11:181. https://doi.org/10.3390/ani11010181
  » https://doi.org/10.3390/ani11010181
• Sklan D. Development of the digestive tract of poultry. Journal of World's Poultry Science 2001;57:415-28. https://doi.org/10.1079/WPS20010030
  » https://doi.org/10.1079/WPS20010030
• Sklan D, Smirnov A, Plavnik I. The effect of dietary fibre on the small intestines and apparent digestion in the turkey. Br Poult Sci. 2003;44:735-40. https://doi.org/10.1080/00071660310001643750
  » https://doi.org/10.1080/00071660310001643750
• Tejeda JO, Kim KW. Role of dietary fiber in poultry nutrition. Animals 2021;11:461. https://doi.org/10.3390/ani11020461
  » https://doi.org/10.3390/ani11020461
• Wang ZR, Qiao SY, Lu WQ, et al. Effects of enzyme supplementation on performance, nutrient digestibility, gastrointestinal morphology, and volatile fatty acid profiles in the hindgut of broilers fed wheat-based diets. Poultry Science 2005;84:875-81. https://doi.org/10.1093/ps/84.6.875
  » https://doi.org/10.1093/ps/84.6.875
• Wenk C. Recent advances in animal feed additives such as metabolic modifiers, antimicrobial agents, probiotics, enzymes and highly available minerals-review. Asian-Australasian Journal Animal Science 2000;13:86-95. https://doi.org/10.5713/ajas.2000.86
  » https://doi.org/10.5713/ajas.2000.86
• Yao S, Al-Redhaiman K. Date palm cultivation in Saudi Arabia: current status and future prospects for development. Proceedings of the ASHS Annual Conference; 2014 Jul 27-Aug 1; Orlando, FL, USA. 2014.
• Zhang L, Xu J, Lei L, et al. Effects of xylanase supplementation on growth performance, nutrient digestibility and non-starch polysaccharide degradation in different sections of the gastrointestinal tract of broilers fed wheat-based diets. Asian-Australasian Journal of Animal Science 2014;27:855-61. https://doi.org/10.5713/ajas.2014.14006
  » https://doi.org/10.5713/ajas.2014.14006

• FUNDING
  This project was funded by the Deanship of Scientific Research (DSR) at King Abdulaziz University, Jeddah, under grant G: 649-155-1441.
• DATA AVAILABILITY STATEMENT
  The data that support the findings of this study are available from the corresponding author upon reasonable request.
• DISCLAIMER/PUBLISHER’S NOTE
  The published papers’ statements, opinions, and data are those of the individual author(s) and contributor(s). The editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions, or products referred to in the content.

Edited by

• Section Editor:
  Rodrigo Garófallo Garcia

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Publication Dates

• Publication in this collection
  27 July 2026
• Date of issue
  2026

History

• Received
  09 Apr 2026
• Accepted
  20 May 2026