Vol 107, No 3 (2024)

In recent years, the increased interest in genetic mechanisms influencing the elemental composition of milk and blood in cows has led to the necessity for a deeper study of this topic. The aim of this research was to evaluate the impact of the K232A polymorphism of the DGAT1 gene on the elemental composition of hair, blood serum, and milk productivity in Black-and-White cows from three regions. Samples were collected from dairy cows in the Leningrad, Vologda, and Orenburg regions. The elemental composition was analyzed for 25 elements (Al, As, B, Ca, Cd, Co, Cr, Cu, Fe, I, K, Li, Mg, Mn, Na, Ni, P, Pb, Se, Si, Sn, Hg, Sr, V, Zn) using inductively coupled plasma mass spectrometry. Genotyping was performed using high-throughput sequencing facilitated by the MiSeq sequencer (Illumina, USA). The results showed that in cows with the AA genotype from the Vologda region, the manganese content in the hair was 31.10% higher, and in the Leningrad region - 55.82% higher than in animals with the KK genotype; the iron concentration exceeded the indicators of this group by 136.17% and 178.43% (p=0.02), respectively. In the blood serum of animals with the KK genotype from Vologda region, the highest concentrations of nickel were recorded, exceeding levels in animals with the AA genotype by 60.81%, and in Leningrad region by 37.88%. Cows with the KK genotype in Vologda region showed higher milk yield, exceeding that of the AA genotype by 25.99% (p=0.03); in Leningrad region, the AA genotype showed 49.14% better results compared to KK, and in Orenburg region by 18.63% compared to AK. The conducted research confirms the significance of the K232A polymorphism of the DGAT1 gene for breeding work.

The article presents the conclusions of tests of the Kazakh white-headed bulls on their own productivity, carried out on the Aisulu farm (Ankatinsky LLP, West Kazakhstan region). The results showed that the increase in the size of calves correlates with an increase in their live weight throughout the entire growing period. Analyzing the exterior dynamics of bulls, it is noted that young animals at a young age largely correspond to the beef type of cattle. The study of growth intensity was carried out on the basis of monthly individual weighing of bulls raised under the same housing and feeding conditions. The weighing results made it possible to determine the productivity indicators of young animals, such as live weight and average daily gain. The feed consumption of bulls was taken into account for the entire test herd, and their consumption was determined monthly for two adjacent days by weighing a given amount of feed and residues. Classification and index assessments of bulls aged from 8 to 12 months and from 12 to 15 months indicate an increase in the number of animals with a high complex class, mainly due to high live weight and meat forms. The results of the classification assessment at different stages of age (up to 12 months and up to 15 months) do not coincide, which indicates different characteristics of bulls at these stages. Therefore, assessing the breeding value of a bull based on a classification assessment at an early age, namely at 12 months, may be unreliable.

Measuring the body size of an animal is the basis for assessing its development and optimal expression of economically useful traits. The development of dairy goats depends on many factors, including the month of birth. The aim of the study was to assess the development of goats born in different months in connection with reproductive rates and milk yield in the first lactation. On a farm with industrial technology for keeping dairy goats, two groups of animals were formed, obtained in different months of lambing: Group I – January (n=22) and Group II – March (n=20). At 3 and 6 months, the following measurements were taken from the goats: height at the withers, oblique body length, depth and width of the chest behind the shoulder blades. At 15 months, the height at the sacrum, chest and metacarpus girth were additionally measured. It was determined that in goats born in January (group I), all morphometric indices of the body at 3, 6 and 15 months were higher than in animals born in March (group II) (P≤0.05-0.001). Animals of groups I and II did not have statistically significant differences in milk yield for the first and second 100 days of lactation and age at first lambing, but the litter size was larger in group I compared to group II: 2.07±0.20 and 1.50±0.13, respectively (P≤0.05). In goats of group II, a positive linear correlation was found between milk yield for the first and second 100 days of lactation and chest width and metacarpus girth (P≤0.05 - P≤0.01). Low morphometric indices at 3, 6 and 15 months of age in animals of group II indicate insufficient development of animals, which negatively affects reproductive capacity and prevents the manifestation of the potential for milk productivity in goats.

This study investigates the genetic diversity of the Evenskaya breed of domestic reindeer using microsatellite DNA markers. The research was conducted on reindeer bred in the APC (F) “Tompo” of the Tomponsky district of the Sakha Republic (Yakutia). The article presents the allele frequencies of 16 microsatellite markers in Evenskaya reindeer, providing valuable data for future research, including comparisons of allele frequencies and genetic diversity indices with other reindeer populations (e.g., from different regions or breeds). The study confirmed the high genetic diversity of the Evenskaya breed. A minimal difference was observed between expected and observed heterozygosity, indicating the absence of significant inbreeding within the studied population. Furthermore, the article compares the genetic diversity of Evenskaya reindeer from the Tomponsky and Oymyakonsky districts of Yakutia. The comparison of allele frequencies revealed notable differences between the populations, particularly in the loci Rt6, BMS1788, Rt30, Rt7, FCB193, and C276. The Tomponsky population exhibited 13 alleles that absent in the Oymyakonsky population, with most occurring at low frequencies except for allele 144 bp in the FCB193 locus. Both Nei's genetic distance (0.086) and F_st analysis (0.017) indicated a relatively small genetic differentiation between the populations.

Complete and balanced feeding, in terms of both nutrients and macro-microelement composition is the main task in increasing animal productivity. The purpose of the study was to determine the effect of feed additives Plexomin Zn 29 and Plexomin Se 2000, containing organic zinc and selenium, on the stressful state of the body of bulls, studying them according to productive and hematological indicators. The scientific experiment was carried out on Black Spotted bulls; for this purpose, two groups (control and experimental) were formed with 20 heads in each, with an average live weight of 328.8-329.3 kg. The bulls of the experimental group received a daily diet supplement in the amount of 460 mg, which contained Zn (zinc) and Se (selenium) in organic form. For a comparative assessment of the metabolic processes occurring in the body of bull calves that consumed a feed additive with and without the diet, morphological and biochemical blood tests were carried out. The research results indicate a positive effect of the studied feed additives on productive and hematological parameters. It was found that live weight of bulls in the experimental group at the end of the experiment was 2.5% greater than in the control. Intergroup morphological and biochemical blood parameters of experimental bulls had some differences, but were within the physiological standard.

The development of an optimal technology for growing and fattening in a specific region, taking into account the forage base and pasture productivity is a topical issue in beef cattle breeding in the issue of how to increase its profitability and competitiveness compared to other livestock industries. In this regard, the aim of the study was to investigate the effect of different periods of keeping on pasture on the productive and economic indicators of Kazakh white-headed bulls. For this purpose, a scientific and economic experiment was conducted at Novoiletskoye LLC in the Sol-Iletsk District of the Orenburg Region on 8-month-old bulls (n=100). They were divided into 2 groups after weaning: Group 1 - from 8 to 18 months of age were kept on a fattening site, Group 2 - from 8 to 11 months of age fattening on natural pastures, and from 12 to 18 months - a fattening site. The experiment lasted 304 days. The results of the experiment showed that from 10 to 14 months of age, the best growth rate was demonstrated by the Group I bulls, their superiority over their peers in Group II in live weight during this period was 3.1-5.8%. After transferring the Group II bulls from the pasture to the feedlot, they demonstrated the best growth rate, which led to a reduction in intergroup differences in live weight to 1.0%. The control slaughter conducted at the age of 18 months under the conditions of the slaughterhouse of JSC Sputnik showed that all carcasses obtained from the experimental animals were classified as Extra, class A. Group II was characterized by the best yield of fresh carcasses, their superiority over their peers in Group I was 0.75%, with less internal fat deposition by 7.9%. The use of a technological operation in the form of extending the grazing period to 11 months of age is economically advantageous; it allows to reduce production costs by 3.0%, increase profits by 14.4%, and the level of profitability by 2.32%.

The main objective of egg farming is the active development of industry through the use of highly productive hybrid poultry breeds and ensuring proper nutrition of the herd. A high-quality and balanced diet is the basis of poultry health, its rapid growth and development. To achieve the best results, it is necessary to use additional medications that will help balance the feeding diet. Currently, feed antibiotics are widely used in poultry farming. However, the use of antibiotics in bird feeding also raises concerns about the development of bacterial resistance to antibiotics and the emergence of resistance to them. Organic agriculture is becoming the preferred choice for modern developed countries that have already abandoned the use of antibiotics in poultry farming. Plant-based additives are now used in poultry feeding instead of antibiotics. Phytobiotics are natural feed additives that are environmentally safe when used in modern animal husbandry technologies. Phytobiotics have antiviral, antimicrobial, antifungal, immunomodulatory, anti-inflammatory and many other properties. The use of phytobiotics helps to increase the production of digestive enzymes, improves the assimilation of feed, increases the digestibility and absorption of nutrients from feed, and also reduces the cost of poultry production. The use of herbal additives in poultry farming is relevant, among other things, because of their safety for the health of birds and people who are the end consumers of products obtained using these feeds.

The article presents data on stress reactions common in the livestock sector as destructive processes that reduce the overall productivity of cattle, poultry and other animals, and as a result, the overall profitability of production. The history of research is outlined, morphophysiological and biochemical reactions that occur in the body under adverse conditions, some types of stress, including the most common thermal, transport and withdrawal, as well as the basic principles of combating and preventing the negative effects of stress reactions are described.

It is impossible to imagine the diet of a modern person without the use of fish and seafood - a tasty and healthy alternative to animal meat. The high content of vitamins, trace elements, fatty acids in which provides strong immunity, the health of the nervous system, high-quality work of internal organs and a high rate of metabolic processes of the organism. In conditions of limited global fisheries, aquaculture products are becoming more accessible to the population due to the development of technology and the active growth of the sector. However, scaling up and expanding production increase the risks of epizootics among the farmed livestock, which, in turn, can reduce the quality of the products produced. Infection with particularly dangerous viral and or bacterial diseases is dangerous with the death of up to 90% of the livestock and the formation of economic damage to antiepizootic measures to stop the disease. Therefore, the most important way to control epizootic processes in aquatic organisms is the use of immunobiological drugs, the development and mass use of which will reduce the use of chemotherapeutic agents, thereby ensuring veterinary well-being. Inactivated mono- and polyvalent vaccines for immersion, intraperitoneal and oral administration (for revaccination) have been developed at the Federal State Budget Scientific Institution “Federal Scientific Centre VIEV”. Effectively combined antigens in the composition made it possible, without overloading the fish's immune system, to form protection against specific diseases in a certain region and to improve the health of the largest aquaculture enterprises in the Northwestern and Southern Federal Districts from bacterial pathogens that hindered the development of production.

The effectiveness of the breeding process is ensured by a set of techniques for evaluating the source material. The recombination potential of the parent forms is an important feature that must be taken into account when involving cultivars in hybridization. The object of the study was 36 varieties of millet. The recombination ability was calculated for each variety as the ratio of the number of combinations created to the number of varieties that reached the competitive variety testing. As a result of the analysis, varieties were identified that are better included in hybridization as a maternal line, since their recombination potential coefficient (RPC) is higher in direct crosses, and varieties with high RPC in reverse crosses, the inclusion of which in the breeding process is advisable only in paternal line.