DEVELOPING MEAT PRODUCTIVITY IN BULL CALVES OF DIFFERENT DGAT1 GENOTYPES

The given research aims to study the way meat productivity in special-purpose beef bull calves of different DGAT1 genotypes is developed. The scientific novelty of the research lies in the fact that an assessment of the meat productivity of Hereford and Limousin bulls of different DGAT1 genotypes was conducted for the first time. Calves were cultivated using elements of resource-saving technology. The research subject was Hereford male young stock (91 heads) and Limousin bull calves (109 heads), which were genotyped by SNP DGAT1-K232A. Live weight, average daily gains, and body size and conformation indices were analyzed. Hematological values and carcass quality of bull calves of different genotypes were studied. As a result of genotyping, young animals of both breeds had a similar distribution of genotypes (DGAT1KK>DGAT1KA>DGAT1AA) and alleles (DGAT1K>DGAT1A). There was no effect of the studied gene polymorphism on growth, body development, and hematological parameters, as bull calves of different DGAT1 genotypes did not show a significant difference between weight and linear growth, blood morphological parameters, the content of protein, and its fractions. SNP DGAT1-K232A was found to affect fat deposition. Thus, carcasses of both studied breeds of DGAT1K genotype had a significantly higher content of internal raw fat, and fat yield was (P<0.05) than carcasses of DGAT1AA genotype bull calves. Therefore, genotyping by SNP DGAT1-K232A can be used in the selection of special-purpose beef cattle as an additional criterion to produce meat of a higher energy value

The effect of holstein bulls’kappa-casein gene genotype on the productive longevity of their female offspring in the republic of Bashkortostan

Increased productivity in the industry can be achieved by breeding for productive longevity through searching and using genetic markers. The study analysed the data of 1476 animals with at least one completed lactation. Depending on the linear affiliation and kappa-casein gene genotype of servicing bulls, their female offspring were divided into 4 groups. The CSN3 A allele frequency in the studied bulls was 81.91%, the CSN3 B allele was 18.09%. The highest frequency of the desired CSN3 B allele in the servicing bulls-producers of the Reflection Sovering line was 20.83%, which is 3.69% more than in the bulls of the Vis Back Ideal line. The animal life length analysis showed that the female progeny of bulls from the Reflection Sovering line (2.46 lactation), especially those with the CSN3 AB genotype (2.59 lactation), had the longest life. The offspring of CSN3AB genotype bulls of the Reflection Sovering line had the highest lifetime milk yield (18490 kg). The CSN3AB genotype cows of the Reflection Sovering line had the highest average milk yield on the 1st day of a cow’s life of 9.05 kg

Slaughter qualities and by-product yield in Limousin bull calves of different genotypes

The study aimed to provide a comparative analysis of post- slaughter performance and by-product yield obtained from purebred Limousin bull calves of different genotypes. The purposes of the study were to fatten bull calves, offspring of mothers of different origin, as well as carcasses and by-products obtained as a result of their control slaughter. The bull calves were raised according to the technology of beef cattle breeding with elements of resource saving. The control slaughter of the bull calves was carried out when they reached the required meat condition at the age of 18 months. In the course of the research, it was established that the bull calves obtained from mothers of French selection significantly exceeded (p˂0.01) the peers obtained from mothers of Australian origin in live pre- slaughter weight of 34.6 kg (6.5%), in carcass weight of 30.8 kg (9.8%); in slaughter weight of 30,6 kg (9.4%). Bulls derived from local selection mothers had significantly (p˂0.05) higher slaughter weight by 16.3 kg (4.4%) compared to peers whose mothers were of Australian origin. Significant differences between groups in weight and yield of byproducts were not revealed; however, there was a tendency to increase the weight of organs in the groups of animals with high preslaughter live weight (bull calves of the first and third experimental groups). Based on the obtained data, it can be assumed that breeding of the ancestors of the studied animals for a long period of time under conditions of different breeding, housing and feeding technologies influences the meat qualities of carcasses obtained by their offspring, Limousin bull calves, which are descendants of mothers of different origin

Nutritional and energy value of muscle tissue of Limousine bulls of different genotypes

The article presents the results of a comparative study of the nutritional and energy value of beef obtained from bull calves of different genotypes. The aim of the study was to evaluate the nutritional and energy value of beef obtained from Limousin bulls of different genotypes. The research objects were half carcasses obtained as a result of control slaughter of Limousin breed bull calves, descendants of mothers of different origin, bred in the Kuyurgazinsky district of the Republic of Bashkortostan in the "Meat Union of Bashkir producers" Ltd. The bull calves were raised according to the cow-calf system, weaning from mothers was carried out at the age of 8 months before stabling, then growing up, the first and second periods of fattening were carried out. Control slaughter of bull calves was carried out when they reached the required meat condition at the age of 18 months. In the course of the studies of dry matter, protein, extracted fat and energy value of carcass muscle tissue, a significant increase in the dry matter, protein, extracted fat, and energy content was observed (p≤0.05) 8.8kg higher performance of bull calves with mothers of French origin compared to carcasses of bull calves from mothers of Australian origin (11.8%), at 5.3kg (12.8%), at 3.1 kg (10.1%) and at 248.6 MJ (12.8%) accordingly. Based on the data obtained, it can be assumed that the breeding of animals for a long period of time under conditions of different housing and feeding technologies influences the chemical composition characteristics and the energy value of the meat of the representatives of the Limousin cattle breed studied

The effect of different suckling feeding modes on the growth and development of calves in postnatal ontogenesis

One of the key areas of development of the cattle breeding industry in Russia is the creation of effective technological methods. They allow to carry out the improvement and establishment of new resource-saving systems for breeding young animals at an accelerated pace. It is essential to meet the modern requirements of meat production as an ecologically safe product. The aim of the research was to enhance the fattening qualities of Hereford bull calves while using mode-setting suckling of various ratios as an element of resource saving. The study was performed on "SAVA-Agro-Yapryk" OOO of the Tuymazinsky district of the Republic of Bashkortostan. The determination of the efficiency of the use of free and mode-setting suckling of various ratios made it possible to identify an effective method of raising young meat cattle. A three-fold mode suckling is used with separate keeping of young animals and mother cows. This makes it possible to keep the optimal microclimate parameters in the calf house, contributes to the rapid early adaptation of calves to the consumption of coarse feed and concentrates. It has a positive effect on the growth and development of calves and their meat productivity at the age of 18 months according to the parameters of removable fat mass, carcass mass and interior fat mass. All this promotes an increase in the sale of beef and an improvement in the level of production profitability to 13.93%