The dynamics of livestock production in Russia was analyzed. The decrease in the breed diversity of animals was noted, which creates risks of loss of sustainability of agricultural production systems. Critical factors in the preservation of the domestic gene pool of large species of farm animals have been identified. The possibility of preservation of genetic resources outside agricultural production systems (ex situ) for the preservation of domestic gene pool of animal species and breeds is discussed. The stages of development of assisted reproductive technologies and biotechnological methods of reproduction as a basis for the introduction of innovative production technologies in livestock breeding, which are the main direction in modern breeding to obtain individuals with outstanding hereditary traits, are considered.

Passive immunity obtained with colostrum is of critical importance for the health and well-being of newborn calves. There are a large number of factors that can influence the absorption of immunoglobulins (IgG) by calves, which are important to consider from the preparation of pregnant animals for calving to the technology of preparation, collection and feeding of colostrum itself. Direct and indirect methods allow us to evaluate the quality and quantity of IgG, as well as the quality of the procedure for transferring passive immunity to the calf. Thus, the technology of working with colostrum is a key part of the prevention of diseases and mortality in young dairy calves.

The study and conservation of agricultural genetic biodiversity represent a pressing challenge in modern biological science. Agricultural genetic resources constitute both a national and global biological asset, essential for the future development of production systems. In this regard, genomic analysis and molecular genetic methods have become integral to contemporary animal breeding. These techniques enable more precise evaluation of animals' genetic potential and the selection of the most promising individuals for reproduction. This approach significantly accelerates the breeding process and enhances the efficiency of selective breeding programs.

In Russia and Kazakhstan, as in many other countries, genomic analysis is being progressively implemented in livestock farming practices. This method allows for the identification of genetic traits in animals that may not be adequately assessed through traditional progeny testing. Additionally, it helps prevent hereditary diseases and improve breeding quality.

The development and application of genomic selection in livestock breeding are of particular importance for Russia and Kazakhstan. This technology can enhance the genetic potential of herds, increase productivity, improve animal adaptation to local conditions, promote health and longevity, and ultimately boost the overall efficiency of agricultural production.

Thus, research and advancements in genomic selection in Russia and Kazakhstan hold significant promise for improving agricultural output, enhancing industry competitiveness, and ensuring food security.

In the presented work, as a result of an analytical study, the main reasons for low results in the practice of transplantation of preimplantation embryos were studied to optimize the management of processes to improve the efficiency of applied use of reproductive technologies in cattle breeding. The significance of such factors as the readiness of the morphophysiological state of the recipient's reproductive system for embryo implantation at the time of transplantation and the efficiency of estrous cycle synchronization systems was determined. Particular importance was given to the results of transplantation depending on the place of embryo application in the uterine horn, which is associated with the need for professional experience among specialists and is a significant threshold for limiting the level of embryo engraftment. In this regard, the effectiveness of using modified instruments for deep embryo application was noted. The dependence of the engraftment of depreserved embryos on the methods of cryo- and depreservation during non-surgical transfer to recipients was determined.

In the overall analysis of our own research, morphological quality assessment was carried out on more than 12,000 embryos, of which about 8,000 underwent cryo- and deconservation procedures, and the total number of transplants of freshly obtained and frozen-thawed embryos amounted to more than 9,000, which together indicates the high significance of the results obtained.

The study of gas formation in the animal body is an important stage of physiological research. The methods of study have undergone significant changes over time. Initially, the purpose of studying gas formation was the fundamental principles of energy metabolism in the body. With the development of scientific and technological progress and climate change in the world, environmental reasons for studying the emission of greenhouse gases by animals were added. Methods for measuring gas emission depend on the purpose, equipment, knowledge, time and budget available to assist researchers and manufacturers in development and monitoring. The purpose of this review is to summarize information on modern methods for determining greenhouse gas emissions in the body of ruminants in Russia and the world. The methods are divided into 3 large groups: the study of gas emission from animals, from objects and global gas emissions into the atmosphere. The most popular research method according to publications for 2022-2025 in Russian are in vitro laboratory experiments, which is due to their low cost, availability and speed of studying a large number of options in a relatively short time. There is no universal method for quantifying gases from animals. Some methods are expensive, require highly qualified staff, others have accompanying factors that affect the results. The "gold" standard of research is the use of respiration chambers. To obtain reliable results, it is advisable to combine laboratory studies in vitro and on animals in vivo. The use of modern methods allows not only to screen greenhouse gas emissions in the body of ruminants, but also to develop regulation methods in order to reduce the negative impact on the environment and increase the economic component of livestock industries.