Results of industrial crossbreeding of meat-wool sheep with specialized foreign meat breedsAbstract
This study presents the results of evaluating the meat productivity of crossbred ram lambs obtained through industrial crossbreeding of ewes of the Kazakh meat-wool and Kazakh fine-wool breeds with rams of the Ile de France, Romney Marsh, and Hampshire breeds. The primary objectives of the research were to assess the growth and development of crossbred lambs, evaluate the slaughter and meat characteristics of first-generation (F1) crossbreds, and analyze the effectiveness of different mating and crossbreeding combinations based on key productive traits. The dynamics of live weight from birth to 2-2.5 and 3.5-4 months of age were studied, and average daily gain was calculated. To determine slaughter and meat characteristics, ram lambs from experimental and control groups were slaughtered at 3.5-4 months of age, and economic performance indicators were estimated. The results indicate that crossbreeding schemes involving stud rams of the Ile de France and Hampshire breeds were the most promising. Increased meat production can be achieved through marketing lambs within the year of birth, thereby reducing production costs and improving the profitability of sheep farming. Accordingly, studies focused on meat productivity are of considerable scientific and practical importance.
Keywords:
crossbred lambs; industrial crossbreeding; live weight; meat coefficient; meat productivity; morphological composition; slaughter yield
Resumo
Esta pesquisa apresenta os resultados da avaliação da produtividade de carne de cordeiros machos mestiços obtidos por meio do cruzamento industrial de ovelhas das raças Cazaque de lã e carne e Cazaque de lã fina com carneiros das raças Ile de France, Romney Marsh e Hampshire. Os principais objetivos da pesquisa foram avaliar o crescimento e o desenvolvimento dos cordeiros mestiços, avaliar as características de abate e de carne dos mestiços de primeira geração (F1) e analisar a eficácia de diferentes combinações de acasalamento e cruzamento com base em características produtivas-chave. A dinâmica do peso vivo do nascimento aos 2-2,5 e 3,5-4 meses de idade foi estudada, e o ganho médio diário foi calculado. Para determinar as características de abate e de carne, os cordeiros machos dos grupos experimental e controle foram abatidos aos 3,5-4 meses de idade, e os indicadores de desempenho econômico foram estimados. Os resultados indicam que os esquemas de cruzamento envolvendo cordeiros das raças Ile de France e Hampshire foram os mais promissores. O aumento da produção de carne pode ser alcançado por meio da comercialização de cordeiros no mesmo ano de nascimento, reduzindo assim os custos de produção e melhorando a rentabilidade da ovinocultura. Desse modo, estudos focados na produtividade da carne são de considerável importância científica e prática.
Palavras-chave:
cordeiros mestiços; cruzamento industrial; peso vivo; coeficiente de carne; produtividade de carne; composição morfológica; rendimento de abate
1. Introduction
Under current global trends in sheep production, lamb has become the dominant commodity. This specialization is driven by international market demand and enables more efficient sector management. The same trend is highly relevant to sheep farming in Kazakhstan, where current lamb production meets domestic demand. Consequently, one of the strategic priorities of the national sheep industry is to restructure breed composition toward increasing the proportion of meat and meat-wool sheep, alongside the introduction of high-performance imported meat breeds.
Owing to its unique geographical position and vast territory (280 million ha), with a predominance of natural pastures (up to 69%, or 187 million ha), Kazakhstan has substantial potential for livestock expansion without compromising ecological stability or pasture ecosystem integrity. The estimated carrying capacity allows for an increase in sheep numbers to 49.2 million head, goats to 6.8 million head, cattle to 21.5 million head, horses to 7.9 million head, and camels to 0.6 million head (Shopan Ata, 2020). This resource base creates opportunities for the country to secure a competitive position in international markets by offering diversified, export-oriented livestock products independent of oil, gas, and mineral resources.
Sheep are raised throughout Kazakhstan, with the highest concentrations in the southern, southeastern, central, eastern, and western regions. The principal determinants of success in sheep production include large-scale operations, specialization, and cost reduction.
Kazakhstan exports lamb to Russia, Iran, China, Bahrain, the United Arab Emirates, Oman, Qatar, and Kuwait. In 2018, exports amounted to 3028 tonnes valued at USD 15 452 thousand, while in 2019 exports totaled 2 503.5 tonnes valued at USD 12 318.8 thousand. Among livestock products, Kazakh lamb commands the highest export price (Shopan Ata, 2020).
Sustainable development of the sheep industry depends on improving efficiency through increased animal productivity, reduced production costs, and enhanced product quality.
In addressing these objectives, particular emphasis should be placed on improving early maturity, fattening performance, and meat traits of young stock. A major reserve for increasing lamb production is the implementation of industrial crossbreeding systems. When optimal combinations of parental breeds are used, industrial crossbreeding promotes accelerated growth and development due to heterosis. Enhanced viability of offspring resulting from heterosis in interbreed crosses has long been recognized. However, the magnitude and expression of heterosis in sheep crossbreeding vary considerably. In some cases, heterosis is strongly expressed for certain traits, weakly expressed or absent for others, or may result in intermediate inheritance of economically important traits (Mukhamedgaliev et al., 1975).
Many researchers define heterosis as the superiority of crossbred animals over the average performance of both purebred parents. At the same time, prominent breeders (Ovsyanikov, 1968; Balmont, 1968) interpret heterosis more broadly, including cases where crossbred progeny outperform the improved maternal breed for traits of interest. At present, early-maturing meat and meat-wool breeds are considered the most competitive and economically valuable (Podkorytov et al., 2019; Chamurliev et al., 2019). Meat productivity in sheep depends on production type, age at weaning, and other factors (Khamiruev et al., 2016). In a market economy, the genetic potential for meat production has become particularly important, as the most economically advantageous strategy for increasing sheep output is the production of lamb within the year of birth. The justification for slaughtering lambs at this age is based not only on the high nutritional and dietary value of lamb meat but also on its direct economic benefits (Murzina and Khvostova, 2016).
2. Materials and Methods
The development of effective industrial crossbreeding systems in sheep production is aimed at maximizing heterosis effects (Zlobin et al., 2023), thereby substantially improving the productive performance of offspring. Lamb quality is influenced by multiple factors. It is well established that increasing both the quantity and quality of lamb production requires the use of specialized meat-type breeds and their appropriate genetic deployment.
When optimal parental breed combinations are selected, industrial crossbreeding promotes enhanced growth and development attributable to heterosis.
Crossbreeding designed to combine the most valuable traits of different breeds contributes to improved survival rate, fertility, and overall health status. The effective utilization of heterosis in sheep breeding provides new opportunities for improving agricultural efficiency and meat production quality (Quan et al., 2025).
According to Hutt (1969), heterosis is defined as “an increase in vigor and constitutional strength whereby interspecific, interbreed, and interline hybrids (crossbreds) surpass both parents.” Thus, heterosis may be expressed through accelerated growth rate, increased body size, higher productivity, and related traits.
To implement a simple industrial crossbreeding system, promising foreign meat breeds were identified for the subsequent use of their breeding stock and/or frozen semen. Imported breeds such as Hampshire, Dorper, Texel, and Suffolk are known for their high genetic potential for early maturity and superior meat traits (Fuerst-Waltl and Fuerst, 2021).
The research conducted in 2018-2020 focused on developing an effective crossbreeding technology using rams of the Ile de France, Romney Marsh, and Hampshire breeds, as well as their frozen semen, with the objective of improving lamb quality and reducing production costs.
2.1. Ile de France
The Ile de France is a long-tailed, meat-wool breed characterized by large body size and early maturity. The breed was developed by crossing Dishley rams with Rambouillet ewes, followed by inter se breeding of animals of the desired type. Animals exhibit well-developed meat conformation, including a broad head, short and wide neck, rounded ribs, and well-muscled hindquarters. Average live weight is approximately 100 kg for rams and 65 kg for ewes. Lambs intended for slaughter are typically raised indoors, whereas adult animals are pasture-grazed. Carcass weight of lambs at 3-4 months of age ranges from 17 to 20 kg. The productive lifespan of ewes is 9-10 years. Ewe lambs are first mated at 7-8 or 10-12 months of age upon reaching a minimum live weight of 45 kg. Average prolificacy is 130 lambs per 100 ewes. Average daily gain (ADG) ranges from 320 to 380 g. At one year of age, live weight reaches 47-50 kg in females and 65-70 kg in males.
2.2. Hampshire
The Hampshire breed was developed in the early nineteenth century in Hampshire County (England) by crossing local sheep with Southdown rams. The foundation flock was established in the 1840s. Modern Hampshire sheep are characterized by large body size and strong skeletal development. The body is wide and low-set, with a deep, rounded chest; the withers, back, and loin are level and broad; and the hindquarters are well developed. Average live weight of rams ranges from 90 to 110 kg and of ewes from 70 to 75 kg. In leading breeding farms, prolificacy reaches 130-150 lambs per 100 ewes. Under adequate feeding conditions, lambs at 4 months of age may produce carcasses weighing up to 25 kg. When maintained on high-quality pastures, average daily gain may reach 400 g.
2.3. Romney Marsh
A semi-fine-wool, meat-wool breed developed in Kent (England) through crossing local sheep with Leicester longwool sheep. Animals are large-framed, constitutionally strong, and well adapted to humid climatic conditions. The body is wide and deep, with strong, relatively short legs. Romney Marsh sheep are polled. Live weight of rams reaches 100-120 kg and of ewes 80-90 kg. The fleece is white, uniform, and semi-fine to medium in fiber type. Annual fleece weight ranges from 7 to 13 kg in rams and 4 to 6 kg in ewes. Lambs are early maturing and reach a live weight of 35-40 kg by 4 months of age.
2.4. Methodology
The experimental component of the industrial crossbreeding study was conducted at the following farms: Kazakh fine-wool breed – “Kazakh Research Institute of Animal Husbandry and Forage Production” LLP (Zhambyl District) and “Alakol-Agro” LLP (Alakol District), Almaty Region; Kazakh meat-wool breed – “Bala-Zhaisan” farm (Shu District), Zhambyl Region (Table 1).
3. Results and Discussion
Growth and development patterns of purebred and crossbred lambs obtained from different mating and crossbreeding combinations (Karimi et al., 2022) were evaluated based on live weight at birth, at 2-2.5 months, and at 3.5-4 months of age (Yaman et al., 2024). Meat formation was assessed through control slaughter at 3.5-4 months of age by determining carcass weight, slaughter weight, slaughter yield, and the proportions of muscle, fat, and bone tissues in the carcass.
In the first crossbreeding variant, rams of the Hampshire, Ile de France, and Romney Marsh breeds were mated with ewes of the Kazakh meat-wool breed.
The dynamics of live weight in crossbred and purebred lambs from birth to 2-2.5 and 3.5-4 months of age revealed noticeable differences in growth rate during the compared periods (Table 2).
Average daily gain over the evaluated growth periods was consistently higher in crossbred lambs than in purebred contemporaries. From birth to 2-2.5 months of age, ADG ranged from 353-374 g, 345-366 g, and 360-379 g in the respective crossbred groups, compared with 332-348 g in purebred lambs. From birth to 3.5-4 months, ADG ranged from 286-290 g, 257-284 g, and 268-289 g in crossbreds, whereas in purebred lambs it ranged from 251-263 g. The superiority of crossbred lambs over purebred peers in live weight at birth, at 2-2.5 months, and at 3.5-4 months of age, together with their higher growth intensity during the suckling period, indicates the manifestation of heterosis. Live weight in young sheep is the principal trait determining carcass quality and overall meat productivity (Yerokhin et al., 2016) (Figure 1).
To evaluate slaughter and meat traits, ram lambs from experimental and control groups were slaughtered at 3.5 months of age.
Crossbred lambs had slightly higher pre-slaughter live weight (34.4, 35.2, and 35.8 kg) compared with 32.2 kg in purebred Kazakh meat-wool ram lambs. In terms of carcass yield, crossbred ram lambs (H×KMW; RM×KMW; IDF×KMW) exceeded purebred contemporaries by 14.1%, 8.2%, and 16.7%, respectively. Slaughter yield was also higher in crossbreds (51.22%, 50.43%, and 51.76%, respectively) compared with purebred animals (Table 3, Figure 2).
Slaughter and meat characteristics of purebred and crossbred ram lambs at 3.5 months of age (n = 3).
Muscle tissue constitutes the principal component of the carcass, and the degree of its development largely determines the assessment of meat productivity as well as the nutritional value of meat and meat products.
The morphological composition of carcasses was determined by deboning individual wholesale cuts and primal joints, with separation of muscle and bone tissues. Total muscle and bone weights per carcass were then calculated based on their summed values (Jerónimo et al., 2026).
In the present study, at 3.5 months of age, crossbred ram lambs exhibited a higher proportion of muscle tissue in the carcass compared with purebred contemporaries (Alshamiry et al., 2023). The meatiness coefficient (muscle-to-bone ratio) was also superior in crossbreds, reaching 4.27, 4.15, and 4.09, whereas in purebred animals it was 3.69.
Thus, the results obtained from mating Kazakh meat-wool ewes with rams of the semi-fine-wool meat breed Hampshire indicate that this industrial crossbreeding variant positively affects the increase in muscle proportion and overall meat productivity. Crossbred lambs were characterized by high dressing percentage, elevated muscle yield (80.34%, 80.61%, and 81.03%), high meatiness coefficient (4.09-4.27), and increased caloric value of the carcass (Figure 3).
The second crossbreeding scheme involved the use of Hampshire and Ile de France rams mated with ewes of the Kazakh fine-wool breed.
Prior to initiating the industrial crossbreeding experiment, baseline live weight of the parental breeds selected for mating was determined. The average live weight of mature Kazakh fine-wool rams at “Alakol-Agro” LLP and “Kazakh Research Institute of Animal Husbandry and Forage Production” LLP (Almaty Region) was 74.6 kg and 81.7 kg, respectively. The average live weight of Kazakh fine-wool ewes was 55.0 kg. The average live weight of Hampshire rams was 83.4 kg, and that of Ile de France rams was 87 kg.
Evaluation of live weight dynamics from birth to 2-2.5 and 3.5-4 months of age demonstrated noticeable differences in growth performance between crossbred and purebred lambs (Table 4).
Crossbred lambs outperformed purebred Kazakh Fine-Wool contemporaries at birth, at 2-2.5 months, and at 3.5-4 months of age. Ram lambs obtained from the IDF × KF cross exceeded purebred counterparts by 14.5% at birth, 22.8% at 2-2.5 months, and 15.9% at 3.5-4 months of age. Similarly, H × KF crossbred ram lambs exceeded purebred animals by 7.5% at birth, 18.7% at 2-2.5 months, and 10.4% at 3.5-4 months of age (Figure 4).
Average daily gain during the evaluated growth periods was higher in crossbred lambs than in purebred contemporaries. In the IDF × KF cross, average daily gain ranged from 338-377 g, and in the H × KF cross from 330-365 g, compared with 271-307 g in purebred lambs from birth to 2-2.5 months of age. From birth to 3.5-4 months, average daily gain ranged from 292-316 g and 284-305 g in the respective crossbred groups, versus 244-271 g in purebred Kazakh fine-wool lambs. The superiority of crossbred lambs over purebred contemporaries in live weight at birth, 2-2.5 months, and 3.5-4 months of age, together with their higher growth intensity during the suckling period, indicates the presence of a heterosis effect in the studied crossbreeding combinations involving Ile de France and Hampshire rams mated with Kazakh fine-wool ewes (Kao et al., 2022).
To assess slaughter and meat traits, ram lambs from experimental and control groups were slaughtered at 3.5-4 months of age (Table 5).
Slaughter and meat characteristics of purebred and crossbred ram lambs at 3.5-4 months of age (n = 3).
In terms of carcass yield, crossbred ram lambs of the first and second groups exceeded purebred contemporaries by 20.4% and 17.2%, respectively. Dressing percentage was also higher in crossbred lambs, surpassing purebred animals by 20.5% and 15.7%, respectively. At 3.5-4 months of age, crossbred ram lambs demonstrated a higher proportion of muscle tissue in the carcass compared with purebred animals. The superiority in muscle yield ranged from 24.1% to 22.3% in the respective crossbreeding groups (Table 5).
The meatiness coefficient (muscle-to-bone ratio) was also higher in crossbred lambs, reaching 3.85 and 4.11 in the first and second groups, respectively, compared with purebred counterparts (Figure 5).
The morphological composition of carcasses was determined by deboning individual wholesale cuts and separating muscle and bone tissues, after which total muscle and bone mass per carcass were calculated.
The results obtained from mating Kazakh fine-wool ewes with rams of the Ile de France and Hampshire breeds demonstrate that these industrial crossbreeding systems positively influence carcass muscle proportion and overall meat productivity. Crossbred lambs were characterized by higher carcass yield, increased muscle content, and improved caloric value of the meat compared with purebred animals (Figure 6).
4. Conclusion
The applied research conducted using rams of the Hampshire, Île-de-France, and Romney Marsh breeds (in the Almaty and Zhambyl regions) demonstrated that:
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Industrial crossbreeding of Kazakh fine-wool ewes with Hampshire and Île-de-France rams results in a substantial improvement in lamb meat characteristics. An increase in carcass yield, a higher proportion of lean meat (80.4% and 79.4%, respectively), and an improved meatiness coefficient (4.11 and 3.85) were established. Enhanced carcass conformation due to more uniform fat distribution was also observed.
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The use of Hampshire, Romney Marsh, and Île-de-France rams for crossbreeding with Kazakh meat-wool ewes produced a pronounced heterosis effect. The crossbred lambs exhibited high slaughter yield, a substantial lean meat proportion (81.03%, 80.61%, and 80.34%, respectively), and elevated meatiness coefficients (4.27, 4.16, and 4.09), positively affecting carcass marketability.
The results obtained from the use of Île-de-France, Romney Marsh, and Hampshire rams on ewes of different productivity types indicate that these industrial crossbreeding strategies positively influence the increase in lean tissue proportion and overall meat productivity of lambs, characterized by high slaughter yield and improved meatiness coefficients.
The practical significance of the study lies in the fact that crossbreeding ewes of different production types with stud rams of specialized meat and dual-purpose breeds (Île-de-France, Hampshire, Romney Marsh) ensures, through heterosis in the crossbred offspring, a 10-15% increase in live weight and enables the production of commercial lamb with reduced fat content and a higher proportion of muscle fibers in the carcass lean. The extensive breeding areas of the maternal breeds facilitate the implementation of the proposed industrial crossbreeding schemes in the southern and southeastern regions of Kazakhstan, thereby contributing to an increase in the commercial sheep population with improved meat productivity.
The research findings may serve as a basis for the development of new approaches to improving the productivity of existing breeds and for the creation of new breeds, types, and lines of sheep using superior foreign genetic resources.
Abbreviations
H – Hampshire
IDF – Ile de France
KF – Kazakh fine-wool
RM – Romney Marsh
KMW – Kazakh meat-wool
Acknowledgements
This research has been funded by the Ministry of Agriculture of the Republic of Kazakhstan (Grant No. BR22885692 “Development modern selectional-technological and molecular-genetic methods for improving, preserving and rationally using genetic resources sheep the different areas of productivity”).
Data Availability Statement
The entire data set that supports the results of this study will be published in the article itself.
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