Romanov Breed Research Articles

Distribution of genotypes by the growth diferential factor 9 (GDF-9) gene locus in the romanov breed sheep population

The FecG gene, also known as GDF-9 (growth factor differentiation factor 9), plays an important role in regulating reproductive function in mammals. This paper presents the results of a study of a point mutation in the differential growth factor gene in Romanov breed sheep. Mutations in exon 1 of the GDF-9 gene can lead to disturbances in ovarian development and ovulation, resulting in infertility or reduced reproductive capacity in animals. The object of the study was Romanov breed sheep in a sample of 30 individuals. For DNA extraction, venous blood samples were taken from the jugular vein. In Romanov breed sheep for the GDF-9 gene, it was found that at the G1 locus of this gene there are two alleles – G and A. Three genotypes were also identified: GG (254 bp/117 bp), AG (410bp/254/117 bp) and AA (410 bp/410 bp). The observed χ2 criterion was less than expected, therefore, the empirical and theoretical frequencies do not differ significantly, and deviations from the distribution according to the Hardy-Weinberg law are not observed. The observed heterozygosity index (Ho) was 0.27. Allele frequencies were 0,8 for G and 0,2 for A. For genotypes the following were obtained: GG – 0,66, GA – 0,27 and AA – 0,07.It can be noted that the data on the frequencies of alleles and genotypes in the population of Romanov breed sheep differ from the results for the Kulunda fine-wool, Dagestan mountain, Salsk, Lacaune and Merino breeds. The research results can be used to monitor changes in allele frequencies and genotypes in sheep during the selection process.

Assessment of the hormonal and antioxidant status of the sheep of different age groups

The purpose of the research was to study some indicators of antioxidant and hormonal status in the body of ewes and young sheep of the Romanov breed, as well as to identify correlations between the studied indicators. The experiment was carried out in the physiological yard of the L.K. Ernst Federal Research Center for Animal Husbandry in spring of 2022 with stall housing, on 2 groups of ewes (30 days, n = 15 and 90 days after lambing, n = 14) and 3 groups of young Romanov breed (aged 1, n = 15, 3, n = 14 and 4 months, n = 13). Indicators of antioxidant and hormonal status were determined in the blood. Mathematical and statistical processing of the results was carried out using methods of descriptive statistics, one-way analysis of variance, and correlation analysis. The high level of total antioxidant status in the blood of ewes 3 months after lambing (2.38 mmol/l) indicates successful adaptation to oxidative stress and LPO accumulation through the use of enzymatic and non-enzymatic antioxidants. In the blood of lambs upon weaning, the maximum accumulation of TBA-AP is observed compared to animals at one month of age (3.49 versus 3.21 μM/l at p≤0.05), which is compensated by the body by increasing the level of ceruloplasmin and catalase number. At an older age, the body shows adequate adaptation to post-weaning stress, which is manifested in a decrease in the level of TBA-AP by 24.93 % (p≤0.05), an increase in the concentration of ceruloplasmin, a decrease in peroxidase activity (by 28.47 % at p≤0.001 and 8.13 %, compared with the age of 1 and 3 months, respectively), increasing the TBA-AP/CP ratio. The acquired knowledge about age-related and physiological changes in LPO, AOD and hormonal status will be useful in assessing the health status and will help to provide timely preventive measures that increase the adaptive capabilities of the sheep’s body and the fullest realization of the genetic potential of productivity.

ЭФФЕКТИВНОСТЬ БИОКОНВЕРСИИ ПИТАТЕЛЬНЫХ ВЕЩЕСТВ И ЭНЕРГИИ КОРМА В МЯСНУЮ ПРОДУКЦИЮ БАРАНЧИКАМИ РАЗНОГО ГЕНОТИПА

The purpose of the study is to determine the influence of the genotype of rams on the efficiency of transformation of protein and energy of the feed ration by purebred young animals of the Romanov breed (Group I), its crosses with the Edilbaevskaya breed of the first generation 1/2 Romanovskaya × 1/2 Edilbay (II group) and the second generation 1/4 Romanovskaya × 1/4 Edilbay – ( Group III) in food protein and energy of meat products. Crossbreeds of groups II and III were distinguished by less crude protein consumption per 1 kg of live weight gain than peers of group I – by 15.9 (1.62 %) and 33.5 g (3.48 %) and energy by 3.64 (4.23 %) and 4.89 mJ (5.77 %). An advantage was noted for crosses of groups II and III in terms of the weight of edible parts of the carcass, which amounted to 5.05 (36.89 %) and 6.79 kg (49.60 %). Purebred rams of group I were inferior to crossbred young animals of groups II and III in terms of protein content in the edible part of the carcass by 0.86 (31.62 %) and 1.15 kg (42.28 %), respectively, extractable fat – by 0.82 (66.13 %) and 1.25 kg (100.8 %), energy – by 46.54 (49.01 %) and 68.30 mJ (71.93 %). All this determined the advantage of crossbred rams of groups II and III in terms of the yield of nutrients, edible parts of the carcass and energy per 1 kg of pre-slaughter live weight. For protein, this advantage was 2.49 (3.53 %) and 4.32 g (6.12 %), extractable fat – 9.86 (30.65 %) and 16.01 g (49.77 %), energy – 0.59 (23.98 %) and 0.70 mJ (28.45 %). The advantage of crossbred young animals of groups II and III in terms of the protein bioconversion coefficient was established, which was 0.26 and 0.65 % for protein, 0.21 and 0.40 % for energy, respectively. The leading position in all indicators was noted for crossbreeds of the second generation of group III.

Characteristic of allele pool of sheep of the southern meat breed using microsatellite markers

Purpose: to characterize the allele pool of sheep of the southern beef breed using microsatellites.Materials and methods. The biomaterial was ear’s plucks from 80 sheep of the southern meat breed, selected from the Ladozhsky Breeding Plant. 20 East Friesian sheep, 33 Dorset sheep and 63 Romanov sheep were used for comparison. Nine microsatellite loci (INRA005, SPS113, INRA23, MAF65, McM527, OarCP49, HSC, OarAE129, MAF214) were selected as DNA markers. Microsatellite variability was analyzed using the ABI3130x1 Genetic Analyzer. The results were processed in the GenAIEx 6.503 program, with the help of which the main indicators characterizing the state of the allele pool and genetic diversity were calculated.Results. Analysis of the population genetic parameters of sheep of the southern meat breed showed that the average number of alleles per locus (Na) and the effective number of alleles per locus (Ne) exceed the sample average by 1,72 and 0,58 alleles, respectively. The expected heterozygosity (He) was 0,766, while the observed heterozygosity (Ho) was 0,741. The coefficient of inbreeding (Fis) was 0,03. The analysis of the principal components, carried out for the studied breeds in the planes of the first and third principal components, did not fundamentally change the nature of the spatial clustering of the studied groups of sheep. Analysis of the principal coordinates, performed on the basis of calculation of pairwise Fst values, showed that the southern meat breed is located in the upper left quadrant and is isolated from other breeds. The values of the Fst indicator indicate that there is moderate genetic differentiation between the southern meat and dorset breeds (Fst=0,116), and significant genetic differentiation between the southern meat and romanov breeds (Fst=0,161).Conclusion. An analysis of the population genetic parameters of sheep of the southern meat breed, in comparison with the east friesian, dorset and romanov breeds, showed that, in general, in terms of the total number of alleles per locus and the number of effective alleles per locus, it is characterized by a high level of genetic diversity. The presence of a tendency towards a deficiency of heterozygotes is probably explained by the limited population, represented by the only relict gene pool in Russia.

Digestive processes and microbiocenosis of intestinal contents in sheep when using a «protected» form of betaine in nutrition

In the process of maintaining the metabolic processes of the gastrointestinal tract of ruminants, an important link is to ensure a complete feeding diet. The study of the use of betaine supplements in a form "protected" from the indirect effects of the microflora of the rumen showed positive dynamics in relation to the digestive processes, the microbial composition of the rumen and the intestines of sheep. In the conditions of the physiological yard of the Federal Science Center for Animal Husbandry named after Academy Member L.K. Ernst conducted a physiological experiment on ramshanks of crossbreeds of the Romanov breed and katadins, aged 8-9 months, with chronic scar fistulas according to Basov (n=3). In the control period, the animals received the main diet, in the experimental 1 – the main diet + unprotected betaine at a dosage of 0.05 g / kg of live weight, in the 2nd experimental period a "protected" betaine supplement at a dosage of 0.05 g / kg of live weight. The duration of each period was 30 days. During the accounting period, average daily stool samples were taken according to the generally accepted method. To study cicatricial digestion, at the end of each period, samples of the contents were taken from animals through the fistula of the scar by Basov. As a result of the use of both the "protected" and native forms of betaine, the mass of microorganisms of the scar content became higher than in the control period. When the "protected" form of betaine was added to the diet of animals, the overall digestibility of feed nutrients tended to improve. In the 2nd experimental period, compared with the control, the level of bifidobacteria in the large intestine of sheep increased by 1.63 CFU/g, the level of pathogenic yeast fungi decreased several times.

Применение иммуногенетического метода и статистического анализа в характеристике популяций овец романовской породы

The article is devoted to the development and application of a combined method for determining genotypes and alleles in complex blood group systems in sheep (A, B, C, M). To establish genotypes and alleles in complex systems, we used the combined method we developed with the implementation of the formula of Bernstain F. (1924) in the Microsoft Office Excel (2003) computer program. In total, the experiment used materials obtained from 586 Romanov breed sheep from 5 regions of the Russian Federation (Republic of Bashkortostan, Voronezh region, Smolensk region, Tambov region, Yaroslavl region). In diallelic loci (R, D, I), the determination of genetic structures was carried out using a formula obtained on the basis of the Hardy–Weinberg law. It has been established that 7 blood group systems in Romanov breed sheep (A, B, C, M, D) are open. The exception were two diallelic loci (R, I), in which the study of the allele type was carried out based on the phenomenon of epistasis, when the recessive Ii/i genotype of the I system suppresses the manifestation of antigens, genotypes and alleles of the R system. Based on the data obtained, the level of heterozygosity was determined, which is a measure of assessing biodiversity in the studied populations of Romanov breed sheep. A cluster analysis of 12 blood group systems in 7 populations of the Romanov breed of sheep showed the relationships between them. The resulting dendrogram is a reflection of the results of the research. The possibilities of using the statistical method in order to identify specific characteristics in VII blood group systems in Romanov breed sheep are revealed.

Линейный рост молодняка романовской породы и ее помесей с эдильбаевской

The article presents the results of studying the linear growth of lambs and gelded lambs of the Romanov breed (group I), its first generation crossbreeds with Edilbai - ½ Romanov × ½ Edilbai (group II) and the second generation ¼ Romanov × ¾ Edilbai (group III). It was found that due to the manifestation of the crossing effect, the crossbreed gelded lambs of groups II and III exceeded in size all measurements of the body articles of purebred peers of group I. At the same time, the circumference of the chest behind the shoulder blades, the oblique length of the trunk, the width and depth of the chest were characterized by the highest intensity of height measurements, as well as the circumference of the pastern increased less intensively with age.

Эффективность применения защищенной формы метионина в рационах молодняка овец

The effectiveness of using the developed protected form of betaine in the diets of young sheep of the Romanov breed was studied and the effect on biochemical and clinical blood parameters, resistance, and productive qualities was established.

Changes in peripheral blood parameters of lambs with spontaneous eimeriosis

In order to study the morphological and biochemical parameters of the blood of lambs affected by the causative agent of eimeria, an experimental group of animals of the Romanov breed, two months old, was formed. The lambs were spontaneously infected with the causative agent of eimeria, which was confirmed by laboratory and clinical studies. The second group of animals was free from eimeria and was kept separately. According to the results of blood tests of sick lambs, a decrease in the number of peripheral blood erythrocytes by 29.66 %, an increase in the total number of leukocytes by 47.12 % compared to the blood parameters of the control group of animals was revealed. A change in leukogram parameters was also noted: an increase in the number of eosinophils by 55.43 %, young neutrophils by 75 %. At the same time, there was a decrease in the number of rod-shaped neutrophils and an increase in the number of segmented neutrophils by 8.7 and 29.51 %, respectively. A decrease in the number of lymphocytes and monocytes by 31.68 and 12 %, respectively, was registered. Biochemical changes in the blood serum of sick lambs also underwent changes. A decrease in the content of total protein by 36.06 %, albumin by 13.09 % was established. An increase in the content of globulins and dysproteinemia was noted. Hemoglobin content was also reduced compared to blood parameters of healthy lambs by 32.25 %, as well as glucose content by 27.83 %. The activity level of ALT and AST increased by 43.43 and 33.15 %, respectively, as well as a slight decrease in GGT activity. The difference was statistically significant (Р < 0.01 and Р < 0.05). Differences in the blood parameters of sick lambs have been established and indicate a syndrome of the body's general inflammatory reaction, anemia, damage to the alimentary canal by the causative agent of eimeria and intoxication.

Study of the specific features in the histological structure of the longissimus muscle dorsi in animals of the genus <i>Ovis</i>

Relevance. Interspecific hybridization of domestic animals with wild related species is considered as one of the promising directions in animal husbandry in the framework of improving the quality and nutrient biodiversity of livestock products. The article shows the research results of the specific features in the histological structure of the longissimus muscle dorsi in animals of the genus Ovis with different genotypes.Methods. The object of research was sheep of the Romanov breed and interspecific hybrids of domestic sheep (Romanov breed) with argali. Histological studies of the longissimus dorsi muscle of purebred and hybrid animals at the age of 12 months were carried out in a comparative aspect. The thickness and area of muscle fibers, muscle bundles, the number of muscle fibers per unit cross-sectional areas were studied.Results. Differences in a number of morphometric parameters in the main structural units of the longissimus dorsi muscle in hybrid animals depending on the genotype were revealed. In hybrid animals, in comparison with purebred sheep, a decrease in the thickness and area of muscle fibers by 12% and 25% was found (p < 0.01). An increase in the number of muscle fibers per 1 mm2 of the cut and a decrease in the proportion of connective tissue in the structure of the longissimus dorsi muscle in interspecific hybrids were shown in comparison with those in sheep of the Romanov breed (p < 0.01). These biological features of hybrid animals should be taken into account when breeding, selecting and using them to obtain meat and meat products.

Polymorphism of the BMP-15 locus in Romanov sheep in Western Siberia

Currently, selective selection takes into account gene polymorphisms associated not only with multiple pregnancies (growth differentiation factor 9 (GDF-9), bone morphogenetic protein receptor (BMPR-IB), etc.) but also with milk parameters (β-lactoglobulin (β-lg), αS1-casein) and meat (myostatin (MSTN), calpastatin (CAST), calpain (CAPN1)) productivity. Thus, genes associated with the transforming growth factor began to be monitored to improve reproductive performance in sheep breeding: BMP-15, GDF-9, and BMPR-IB. Genetic markers related to animal reproduction are exciting, with several productive indicators and other evaluation criteria that have not been previously studied. Work on the relationship of animal gene inheritance with biochemical, haematological, environmental and zootechnical indicators is particularly relevant. In this paper, we consider genotypic variability in Romanov sheep for the BMP-15 gene locus, which belongs to the genes of the β-growth factor family. The distribution of genotypes in sheep of the Romanov breed in the conditions of Western Siberia was as follows: for ewes, the frequencies of genotypes WW–25%, WM–75, and MM–0%; for sheep - 0, 80 and 20%, respectively. All three genotypes (WW, WM, and MM) were identified in the studied sheep. The results differ from the data obtained in several other works on foreign sheep breeds (short-tailed sheep Khan, Awassi, Barki, Ossimi, Rahmani, etc.). It is interesting to study the BMP-15 locus further to establish its associations with biochemical and haematological parameters and the hormonal status of sheep.

Anatomical and topographic substantiation of mandibular anesthesia in sheep

This study presents an anatomical and topographic justification for performing mandibular anesthesia in sheep. The study was conducted on the basis of the Department of Anatomy and Histology of Animals named after Professor A. F. Klimov of the Moscow State Academy of Veterinary Medicine and Biotechnology – MBA named after K. I. Scriabin. The object of the study was sheep of the Romanov breed (n=20) aged 1-2 years without pronounced signs of pathology of the dental apparatus. The material for the study was the lower jaws (n=20) and survey radiographs of the head area (n=20). To achieve this goal, a comprehensive methodological approach was used, including: anatomical dissection and macromorphometry with the determination of skeletotopic and linear parameters of the mandible. Mandibular anesthesia is one of the most common manipulations in animal dentistry. For high-quality anesthesia of the mandibular branch of the trigeminal nerve, it is important to take into account the topical landmarks of the structures forming the mandibular canal. Based on the results of macromorphometry and rengenogrammetry, skeletotopic landmarks of the holes forming the mandibular canal are presented, which are important to take into account when performing anesthesia of the lower alveolar nerve. Comparative analysis of morphometric and rengenogrammetric parameters of the upper and lower jaws did not reveal significant differences in their linear parameters, which indicates the high informative value of the X-ray diagnostic method in assessing the morphofunctional state of the jaw bones and the channels located on them. The results obtained can be used in the development of new approaches to the mandibular branch of the trigeminal nerve during local anesthesia in veterinary and experimental dentistry.

The Significance of a Multilocus Analysis for Assessing the Biodiversity of the Romanov Sheep Breed in a Comparative Aspect.

The Romanov breed was evaluated using immunological and genetic markers. The seven blood group systems were characterized with a greater accuracy than in previous works on sheep in the Russian Federation, and were compared to eight ruminant species. Unlike other breeds, Romanov sheep shows a higher frequency of HBA than HBB alleles. There are 3-4 genotypes at the transferrin locus whereas in other breeds 6-11 genotypes have been found. At the albumin locus, the majority of the identified genotypes were heterozygotes, unlike in the other breeds studied. In the prealbumin locus, the Romanov breed was the only one where all the genotypes were heterozygous. We speculate that polymorphism at two loci (BMP-15 and BMPR1B) could effect on the high ovulation rates of Romanov sheep. Based on different genetic markers, the prevalence of heterozygotes in the Romanov sheep could determine their higher viability. A cluster analysis showed the close proximity of 12 populations of the Romanov breed, as the breeding stock come from the Yaroslavl region.

O-013 Influence of gender on carcass traits and meat quality of Romanov breed

O-013 Influence of gender on carcass traits and meat quality of Romanov breed

The influence of biotic factors on the parameters of the nucleolus

Relevance. The nucleolus regulates many aspects of cell physiology, including genome organization, stress response, aging, and lifespan. The number of visible nucleoli per cell varies depending on the cell cycle, cellular activity, or differentiation status. The aim of the study was to study the influence of abiotic factors on the parameters of animal nucleoli depending on their species (genus Ovis and genus Capra) and type of crossing (interspecific hybrids). Materials and methods. The studies were carried out at the Federal Research Center for Animal Husbandry named after Academy Member L. K. Ernst. The object of the study were domestic sheep (Romanov breed) and its hybrids (½ Romanov sheep x ½ mouflon), as well as goats of the Karachay breed and their hybrids (¾ Karachay goat x ¼ caucasian tur). The material of the study was preparations obtained from venous blood and prepared according to the Havell – Blake method. For microscopy and visualization of preparations, a “Nikon Eclipse Ni” microscope equipped with a “DS-Qi2” digital video camera was used. The processing of photo- and videomaterials was carried out using the “NIS-Elements BR4.30” and “Image Scope 1.0” software. Results. It has been established that in interspecific hybrids of goats (¾ Karachai goat x ¼ caucasian tur) the number of nucleolar-organizing regions (NOR) is 17 % more than in purebred individuals, while individual of interspecific hybrids of sheep (½ Romanov sheep x ½ mouflon) exceeded their purebred counterparts in this indicator by 47 %. The kurtosis and asymmetry of NOR in the population of purebred goats and their hybrids with the caucasian tur have the same directions. The results of the analysis of variance indicate that the effect of species on the size of the nucleoli in the studied populations is not statistically significant. The average value of the nucleolus diameter in representatives of the genus Capra was 6.17 ± 0.45 μm, genus Ovis – 6.63 ± 0.32 μm.

Testosterone content and variability in adult and young Romanov sheep

In the article, the authors conducted a comprehensive study of the interior, including biochemical, physiological, physicochemical, cytogenetic, and other indicators in sheep of the Romanov breed of Western Siberia. For the study, blood serum samples were taken from 10 rams-producers and 30 lambs at four months. Conventional methods took blood samples. Analyses were performed in the biochemistry laboratory of Novosibirsk State Agrarian University using the technique of competitive enzyme immunoassay with the reagent kit “SteroidIFAtestosterone” for the quantitative determination of testosterone concentration in blood serum. In the sheep breeding area, the authors constantly monitored the content of heavy metals in water, soil, feed, organs, and tissues. The concentration of chemical elements did not exceed the permissible exposure limit. Enzyme-linked immunosorbent assay was performed on a Thermo Scientific Multiskan FC analyzer. The authors performed statistical processing of experimental data using standard methods of descriptive statistics, the statistical programming language, or the RStudio data analysis environment (using the functions DescrStats, Summary, Sd, Read. Table, Write. Table, Aes). The authors established the influence of the age of ontogenesis on the testosterone content in Romanov rams. Presented figure with two variation curves with high transgression. The average testosterone level was 1.8 times higher in lambs (0.774 mmol/l) than in lambs. Testosterone concentration was characterized by high phenotypic variability. The authors have identified reference intervals for testosterone in blood serum depending on environmental conditions in sheep of the Romanov breed of Western Siberia.

Гистологическая структура длиннейшей мышцы спины у межвидовых гибридов домашних овец и муфлона

The histological studies results of the longissimus dorsi muscle structure in interspecific hybrids of domestic sheep with mouflon are presented in a comparative aspect with the original parental form - purebred sheep of the Romanov breed.

Рентгеноанатомические параллели в структурном оформлении костных челюстных каналов у овец

The article presents X-ray anatomical parallels of the structural design of the bone jaw canals of sheep. The studies were carried out at the Department of Anatomy and Histology of Animals named after. Professor A. F. Klimov of Moscow State Academy of Veterinary Medicine and Biotechnology – MVA named after K. I. Skryabin. The object of research was sexually mature sheep of the Romanov breed (n=20) without pronounced signs of pathology. Skulls and plain radiographs (n=20) served as the material for the study. The study used a set of methods, including: anatomical macroand micro-preparation and macromorphometry, also performed a survey radiography of the bone skeleton of the head in the studied sheep on the apparatus, followed by decoding of the information received and morphometry, followed by statistical processing of the obtained digital data according to generally accepted methods. Analysis of the obtained linear morphometric parameters of the jaw bones made it possible to conclude that the parameters of the upper jaw are inferior in terms of their numerical values to those of the lower one, while there were no significant differences between their right and left halves. In a comparative analysis of the morphometric and X-ray parameters of the skull, no significant differences were found, which indicates the high information content of X-ray diagnostic methods in assessing the morphological and functional components of the head organs. The results obtained are the basis for the development of new methods of treatment strategy and tactics for extirpation of teeth, as well as for local anesthesia of the trigeminal nerve during surgical interventions in veterinary and experimental dentistry.

ВЛИЯНИЕ ГЕНОТИПА БАРАНЧИКОВ НА КАЧЕСТВО МЯСНОЙ ТУШИ

The article presents the results of assessing the quality of meat carcasses of purebred and crossbred sheep. The object of the study was the carcasses of purebred sheep of the Romanov breed (group I), its crossbreeds of the first generation with the Edilbay (½ Edilbay × ½ Romanov II group) and the second generation (¾ Edilbay × ¼ Romanov – III group). The advantage of crossbred young animals of groups II and III over purebred peers of group I in terms of absolute and relative most valuable in food in relation to the posterior third of the trunk was established. This superiority in the value of the first indicator was 2.00 kg (34.30 %, P < 0.01) and 2.67 kg (45.80 %, P < 0.001), respectively, the second – 0.52 % and 0.78 %. The leading position in terms of the analyzed indicator was occupied by crossbreeds of the second generation of group III. When analyzing the indicators of varietal carcass cutting according to the trade classification, it was found that crossbred youngsters of groups II and III, due to the manifestation of the crossing effect, surpassed purebred peers of group I in absolute weight of meat of grade I by 5.58 kg (34.36 %, P < 0.01) and 7.25 kg (44.64 %, P < 0.001), relative – by 1.30 % and 1.49 %. At the same time, the crossbreeds of the second generation of group III outperformed the crossbreeds of the first generation of group II in terms of the analyzed indicators by 1.67 kg (7.65 %, P < 0.05) and 0.19 %, respectively. As for the meat of the second grade, in terms of its absolute mass, the advantage was on the side of the mixed young animals of groups II and III, and the relative – the leading position was occupied by purebred sheep of group I.

МОРФОЛОГИЧЕСКИЙ СОСТАВ И СООТНОШЕНИЕ ТКАНЕЙ В ТУШЕ БАРАНЧИКОВ РОМАНОВСКОЙ ПОРОДЫ И ЕЕ ПОМЕСЕЙ С ЭДИЛЬБАЕВСКОЙ ПОРОДОЙ

The article presents the results of crossing Romanov sheep with Edilbaev sheep in the production of young mutton. It was found that due to the eff ect of crossing, the crossbreeds of the fi rst generation (½ Romanovskaya × ½ edilbai) and the second generation (¼ Romanovskaya × ¾ edilbai) were distinguished by a higher yield of the edible part of the carcass, the meat content coeffi cient, the yield of carcass pulp per 1 kg of pre-slaughter live weight, a better ratio of edible and inedible parts and a muscle-fat ratio in compared with purebred youngsters of the Romanov breed.