Eggs are one of the most sought-after sources of available animal protein. Eggshell quality is of particular biological interest and economic importance to the poultry industry. Huge losses caused by eggshell quality deterioration have become an urgent problem in the production of breeding and food eggs. Deterioration of eggshell quality causes the risk of foodborne diseases in consumers. This review analyzes the literature data on molecular and genetic mechanisms of eggshell formation. Transcriptome analysis of the eggshell gland in laying hens differing in age showed differential expression of FGF14, COL25A1, GPX8 and GRXCR1 genes. Functional annotation analysis showed their involvement in processes related to eggshell calcification and cuticularization. Examination of the transcriptome of 49-week-old hens divided into groups according to eggshell quality showed that the KRT14 gene was one of the genes with the largest difference between groups with strong and fragile eggshells. Following KRT14 overexpression in uterine epithelial cells, the expression of OC-116, CALB1 and BST1 increases significantly, while OC-17 expression decreases significantly. Comparison of differentially expressed genes in two independent studies performed on chickens with different shell quality traits revealed 16 genes whose expression patterns were similar. The identified genes are involved in various biological processes and perform a variety of functions. Thus, the protein encoded by the TTYH3 gene functions as a calcium(2+)-activated chloride(-) channel of large conductance. The ITPKA gene regulates the metabolism of inositol phosphate, which is a substrate for cyclic AMP-dependent protein kinase, calcium/ calmodulin-dependent protein kinase II, and protein kinase C in vitro. ITPKA is one of the genes that bind to eggshell speckles. Thus, the performed analysis of literature data showed that molecular genetic mechanisms of eggshell formation are complex and not fully understood. The studies demonstrate the role of differentially expressed genes in various processes, including their potential participation in the calcification process.

In a fundamental aspect, farm animals can be considered as "physiological models" (or rather "physiological-biochemical models") for research in biology and medicine of humans and animals. The author proposes innovative approaches to the creation and study of supramolecular "enzyme" systems (SES) by various levels of their structural organization: from the 1st level (SES-1) enzyme-substrate complexes "pre-organized" in monolayers to SES of the 4th level (SES-4) three-component complexes based on biopolymers with immobilized lipases. This review considers such SES based on lipase "from the pancreas of pigs" in comparison with other lipases of various origins. The results obtained in the study of SES allow us to develop new approaches to the structural and functional study of many processes in the organs and tissues of the body, for example, for modeling physiological and biochemical processes in the gastrointestinal tract, blood and other tissues of animals, and also allow us to create innovative “bionanomaterials with specified properties”.

Currently, the most common method for long-term storage of reproductive cells for farm animals and birds is cryopreservation technology, which involves storing samples at ultra-low temperatures. However, significant costs for sample’s preservation and their transportation reduce economic efficiency of method. Lyophilized sperm can be stored at temperatures above zero and does not require special equipment for this. It is now known that lyophilization protocols make it possible to preserve the integrity of sperm chromatin and factors that determine oocyte activation in rodents and mammals, and method of intracytoplasmic sperm injection into the oocyte (ICSI) opens up possibility and prospects for using “lyophilized” male gametes in reproductive technologies. The article provides a literature review on problem of preserving farm animal’s sperm in a state of anhydrobiosis. Described history of the beginning freeze-drying method of biological samples, problems previous technological stages in different types of farm animals, summarized achievements and trends in technology of lyophilization of male animal gametes.

Obtaining in vitro embryos (IVP-embryos) by using oocytes obtained by ultrasound-assisted follicle puncture is a widely used practice in the current bovine genetic improvement system. The number of IVP- embryos has increased significantly over the past 10 years, exceeding 1521.0 thousand in 2021. The share of IVP embryos in total production has increased from 39.5% to 79.7% in 2021. This demonstrates the superiority of IVP over the traditional MOET method for cattle. MOET technology was introduced into sheep production practices more than two decades ago. However, high individual differences between donors in superovulation response and variability in the efficiency of embryo retrieval and transplantation methods (22% to 80%) have been limiting factors for widespread use of this technology. In the 1990s, techniques for obtaining IVP embryos from ewes were optimized and are still being used successfully with minor modifications. The efficiency of this process is estimated at approximately the same level in most studies: embryo maturation from prophase I to metaphase II is 70-90%, fertilization and first division - fragmentation - from 50 to 80%, blastocyst yield - from 20 to 50%. However, the main limitation for the wide practical application of this technology is the use of oocytes from ovaries extracted after the death of the animal. Laparoscopic oocyte retrieval in sheep is considered to be one of the most minimally invasive methods in animal reproductive biotechnology. This method allows the operation to be performed on a live donor quickly and efficiently, minimizing the trauma of the procedure and preserving the excellent condition of the animals. Thanks to laparoscopy, it is possible to extract high quality eggs suitable for subsequent maturation and fertilization in vitro. However, there are disadvantages to using this method in sheep, such as inconsistent efficacy, lack of repeatability of results and different variants of the technique with varying efficacy. In this review, we analyzed the statistical and technological features of the technique in order to identify the main directions of its improvement and to choose the optimal strategy for the development of this technology in Russia.

The study of the process of methanogenesis in the body of ruminants and the possibility of its regulation is associated not only with the environmental factor of the impact of greenhouse gases on the environment, but also pursues the goal of reducing the energy consumption of the body for the formation of methane. Many methods of influencing the process of methanogenesis related to nutritional and genetic factors are proposed for use. Nutritional strategies that exclude negative effects on feed intake, digestion processes, and digestibility of feed nutrients are relevant. The purpose of this review is to summarize current data on the influence of lipid nutrition factors on methane formation in ruminants. Unlike chemical compounds, fats are of natural origin, are a source of energy and affect the fatty acid profile of meat and milk, enhance the palatability of feed, which makes their inclusion in the diet of animals not only safe, but also an effective way to influence the formation of methane. The effects of fat on methanogenesis occur through a variety of mechanisms, including effects on rumen archaea and protozoa, decreased digestibility of diets, and competition for hydrogen for hydrogenation. Methane formation is affected by the degree of saturation, acid chain length, dosage included in the diet, duration of feeding, composition and quality of the main diet. A promising direction is the use of insect fat in the diets of ruminants in order to influence methanogenesis. Despite the study of the issue of using fats in the diet of ruminants in order to reduce methanogenesis, the role of lipids on the process of methane formation with different compositions of diets, information on the influence of some fats in in vivo experiments, and the need for a more in-depth study of the mechanisms of influence of strategies on the productivity and health of animals remain poorly understood.