Purpose: comparative characterization of sterlet (Acipenser ruthenus) microsatellite loci described in the scientific literature and identification of the most promising of them.

Materials and methods. Electronic libraries and databases: https://elibrary.ru/, https://www.ncbi.nlm.nih.gov/pmc/, https://pubmed.ncbi.nlm.nih.gov/.

Results. A search and analysis of scientific publications on the polymorphism of STR loci in sterlet was carried out. Descriptions of 45 microsatellite markers tested for testing sterlet have been found in the scientific literature. Their polymorphism is compared.

Conclusion. An analysis of the literature data made it possible to identify 45 STR markers tested for work with sterlet. A comparison was made of the key characteristics of the polymorphism of these loci, among which conservative and polymorphic ones were identified.

Materials and methods. The semen of 53 bulls was collected at OJSC Nevskoe. A total of 110 bull semen samples were analyzed. Sperm quality was determined using Argus-CASA (ArgusSoft, Russia). Membrane integrity was determined by staining the samples with nigrosine-eosin dye (Diam, Russia) and a Motic BA 410 microscope. Spermatozoa respiration was determined using an Expert-001 instrument. The functional state of the energy system was assessed by the reaction of respiration to the addition of the uncoupler of respiration and phosphorylation, 2,4 dinitrophenol (2,4-DNF). DNA for genetic analysis was isolated from semen by the phenol-chloroform method. Sanger sequencing was performed on an Applied Biosystems 3500 Genetic Analyzer using commercial BigDye® Terminator v3.1 Sequencing Standard Kits (Applied Biosystems) according to the manufacturer's protocol.

Results. Sperm quality were characterized by high individual variability. Thus, the volume of the ejaculate was from 2 to 15 ml, the concentration of spermatozoa was from 0.6 to 1.7 billion/ml, the total number of spermatozoa in the ejaculate was from 1.6 to 15 billion, and progressive motility was from 0 to 85%. Four SNPs were identified for the ESR1 gene. No significant associations of ESR1 gene polymorphism were found, except for a significant association of ESR1 665 G>C with spermatozoa concentration and the number of swollen acrosomes

Purpose: assessment of the dynamics of the growth of the red fox in the process of its ontogenetic development.

Materials and methods. The article describes and analyzes the body weight and linear body measurements of females and males of the red fox of the Ognivka Vyatskaya type in postnatal ontogenesis. The research was carried out in the Vyatka farm (Kirov region). The animals were kept in the same conditions, fed in accordance with age and physiological condition. Linear measurements and weighting were performed at 3, 4, 5, 6 and 7 months of age. Growth indicators were fox body weight, body length, snout, head and tail, girth and height of the chest, snout width, length and girth of the front and hind legs.

Results. As a result of the studies, periods of intensive puppy growth were identified. The maximum increase in body weight and linear measurements is observed from 3 to 4 months of age, when intensive growth and development of the animal organism is observed. Throughout the study, the coefficient of body weight variation (CV) was maximal compared to linear body measurements and ranged from 6% in 3-month-old puppies to 17% in 6-month-old animals, which makes it possible to consider body weight as an individual indicator of puppy development. All linear measurements at all study timelines had a coefficient of variation (CV) below 10% (ranged from 1 to 8%), that is, one can judge the weak degree of variability of the studied features. Also, during all study periods, sexual dimorphism is visible, males significantly exceeded the size and body weight of females in all studied parameters (p < 0.005).

Conclusion. The dynamics of the growth and development of red fox puppies of the Ognivka Vyatskaya type were revealed. Age-related changes in the exterior parameters of young red foxes have been studied.

An assessment of the Estimation Breeding Value (EBV) of Ayrshire first-calving cows was carried out using the BLUP Animal Model, followed by the modeling of breeding indices and the calculation of weight coefficients, taking into account the segmentation of animal groups by breeding regions. As a result of the assessment of breeding value, differences were established for certain economically useful traits in the studied populations of first-calving cows. In the group of cows from the Republic of Karelia (KRL), estimates for milk yield for 305 days (MY) were +263 kg, fat yield (FAT) +9.2 kg, protein yield (PROT) +8.7 kg. Animals from the Leningrad region (LO) had the most desirable reproduction scores: days open (DO) and Intercalving period (ICP) were at the level of -0.15 and +0.08 days, respectively. The fertility index (FI) turned out to be at the level of +0.19, yielding in value only to first-calving cows from the KRL, whose estimates were +0.31. A negative genetic relationship between MY and the percentage of fat and protein (rg = -0.100, rg = -0.096) and a low phenotypic relationship (rp = +0.013, rp = +0.168, respectively), were revealed. The phenotypic correlation of MY with live weight at 10 months (W10) was +0.351, which is higher compared to other signs of development. The heritability coefficients of developmental indicators, such as W10, live weight at the first insemination (W1INS) and after the first calving (W1C) had insignificant differences between themselves and amounted to: 0.17, 0.20 and 0.18, respectively.  On the basis of phenotypic and genetic correlation coefficients and heritability coefficients of the studied traits, on average for the population, a general index was used, and taking into account differences in regions, regional indices were developed. The main difference between the presented indices is the values of weight coefficients. In the Republic of Komi, in comparison with other regions, MY for 305 days (+54.94) and FI (+0.90) take more weight, in the Siberian Federal District (SFO) - FAT (+12.98), in the Southern Federal District (SFO) - PROT (+26.9), and in the index for the LO - the indicator W10 (+0.50). The values of weight coefficients for W10 differ between regions not only in terms of values, but also in direction. According to this indicator, negative weighting coefficients were noted in the Vologda (-0.30), Kirov regions (-0.10) and the Southern Federal Districts (-0.10). In the KRL, there is a greater need to work with the reproductive qualities of animals, as indicated by the weight coefficient for the fertility index equal to +0.25.

Purpose: make a comparative assessment of indicators of reproduction and productive longevity of cows of meat breeds.

Materials and methods. The goal set in the study was studied using special scientific literature on the analyzed problem, the annual work on the tribal work in meat cattle breeding in the farms of the Russian Federation for 2021 (VNIILO), and periodicals.

Results. The most common meat breeds on the territory of the Russian Federation – Aberdeen Angus, Hereford, Kalmyk and Kazakh white–headed - are characterized by significant differences in production use. Thus, representatives of the Aberdeen Angus breed differ from the listed breeds at an earlier age at the first insemination, and the most late-maturing ones were individuals of the Kalmyk breed (differences of 7 months). At the same time, cows of these breeds, unlike Hereford and Kazakh white-headed cows, were used in herds for a longer time (on average for 2.2-2.8 calving). According to the output of calves from 100 Kalmyk cows, only 71 heads were obtained, which is significantly lower than from the breeding stock of Hereford, Aberdeen Angus and Kazakh white–headed breeds - on average by 9-14 heads. Analysis of the yield of calves per 100 cows in the context of the most common breeds of beef cattle, low values of the indicator are observed in individuals of the Kalmyk breed, at the same time they are much higher in the types available in the breed – 77-91 heads. Of all the studied breeds and types of beef cattle of the Russian Federation, only individuals of the Aberdeen Angus breed, the Andrianovsky and Dmitrievsky types of the Hereford breed, the Zavolzhsky type of the Kazakh white–headed breed exceeded in both indicators - the age of retirement and the yield of calves per 100 cows – the average values for all meat breeds and types of the country.

Purpose: the study of the breeding and genetic aspects of the bull-producers of the Kholmogorsk breed in the conditions of the Arkhangelsk region, taking into account their bloodiness in improving breeds (Golsteinskaya).

Materials and methods. Individual reproductive abilities of bull-free bulls with the productivity of their daughters in comparison with peers, dairy productivity of ancestors on the maternal line (M-mother, ⅰ-ⅴ lactation), the mother of the father, and the mother’s mother were studied. A scientific analysis of the recreation cows of the Kholmogorsk breed of the Arkhangelsk population was carried out in order to establish the potential of the breed for further selection.

Results. It was established that for bulls' bulls of blood, 30-39%, the effectiveness of one insemination is 52-57%, from the first insemination the effectiveness from these bulls was 35-47%. The resulting offspring, depending on the individuality of the bulls, is from 33 to 53% of females. However, the average indicator is almost 50x50 (51%♂ and 49%♀). It was established that the higher the blood producers in the producers in an improvement breed, the higher the dairy productivity, for example, the daughter of purebred bull-fingers, had dairy productivity of 3311 kg of milk for lactation, and with blood cells 63%-5281 kg of milk for lactation.

At all levels, these indicators were higher than that of peers. Analytical indicators were recorded in terms of productivity by 1% fat content of milk. It should be noted that the parents of the manufacturing bulls for mothers had productive periods of operation of more than five lactations with a maximum productivity of more than 11,700 kg of milk with a fat content of 3.85%. This shows the level of potential of mothers of these bullshit. On average for the mother, the productive indicators of these bulls-manufacturers amounted to 10,400 kg of milk per year for one lactation. The productivity of MM and MO on average amounted to 7720 and 7401 kg of milk for lactation, respectively.

It was found that the dairy productivity of the recreation cows of the Kholmogorsk breed of the Arkhangelsk population in the conditions of the Arkhangelsk region, from 13 cows, on average amounted to 12852 kg of milk, with variability of 12340-14859 kg. This indicates the breeding potential of this population, in addition, it should be noted that the milk productivity of the Kholmogorsk breed of cows with each new lactation increases with respect to previous lactations, even the mothers of these bullshit after ⅴ lactation remains at the highest level. For example, in a cow named phytom for ⅳ lactation, milk yield amounted to 14859 kg of milk with a fat content of 3.99 % and a protein of 2.99 %. For comparison, it can be noted that on average, the economic use of the Holstein cows in total is 2.5-2.8 lactations.

The purpose of the work is to study the dynamics of the live weight of reindeer of the Chukchi breed in a number of generations and in connection with the range.

Matherials and methods.For comparative analysis, the live weight of slaughter deer was taken, calculated as the arithmetic mean for 10 years. The study used zootechnical information from the annual reports of reindeer farms in the Chukotka Autonomous Okrug for 1974-1983 and 2009-2018.

Results. 9 generations, the average live weight of females (females over 2 years old) in the whole breed changed from 90.4 kg to 92.7 kg (102.5%); adult bulls - from 118.7 kg to 123 kg (103.6%); bulls - from 77.4 kg to 80 kg (103.3%); 5-6 month old calves - from 50 to 51.8 kg (103.6%). Analysis of the data shows that the live weight of deer of the Chukchi breed is a relatively stable phenotypic trait over time. In favorable natural and climatic conditions, the live weight of deer can exceed the average annual figures by 10-11 kg, or 11.6%, which characterizes the genetic and breeding potential of the Chukchi breed. Interpopulation crossings of deer lead to a significant increase in live weight. Significant differences in the level of average live weight were found in deer populations from areas of the range that differ in ecological conditions. In reindeer herding farms whose pastures go to the Bering Sea (southern regions of the range), the live weight of the reindeer is 9-10 kg (10.4%) more in comparison with analogues grazing on the coast of the seas of the Arctic Ocean. To level the negative impact of the external environment, deer need compensatory feeding with protein-mineral mixtures in the winter-spring period.

Honey bees are an important element of the ecological system. Today the state of the gene pool of honey bees is one of the main causes of the beekeeping crisis in the world. The quality of drone sperm is a significant factor for breeding productive bee colonies. Sperm concentration, motility, and viability of spermatozoa are an expression of sperm fertility. However, a full understanding of fertility can be obtained only by studying the morphology of spermatozoa. The purpose of this study was to describe the morphometric parameters and morphological characteristics of sperm heads of the Caucasian honey bee (A. mellifera caucasica), Bashkir honey bee (A. m. mellifera L.), of the Russian Far East honey bee (A. mellifera from far-eastern Russia) and Carnica honey bee (A. mellifera carnica) in order to determine standard features that could be used in further studies. Diff Quick staining was used to study the morphometric parameters of sperm heads. Sperm images were taken on each of the slides from a Canon 1300D digital cameras with an Altami-LUM 1 LED microscope using oil immersion at a magnification of 2000 × . Sperm images and morphometric parameters were studied using Altami Studio software version 3.5. The morphometric dimensions for area nucleus, perimeter nucleus, nucleus length and acrosome length were acquired for 200 images drone spermatozoa for each A. mellifera. Acquiring 200 images assures that a minimum of 150 properly measured sperm heads are analyses after improperly measured sperm heads are deleted from the analysis . The sperm cells were randomly selected for the morphometric analysis.  A total of 573 spermatozoa were assessed with morphometric parameters of sperm heads. The results of the morphometric analysis of drone spermatozoa show individual differences between the spermatozoa dimensions in each group. Between the A. mellifera groups the differences are not statistically significant. In this study, the min and max values of the acrosome length 3.14-5.02 µm, and nucleus length 4.02 -5.9 µm, perimeter nucleus 10.4-13.4 µm, and area nucleus 3.4-6.73 µm2, of A. mellifera spermatozoa. The morphological analysis of the drone spermatozoa revealed the presence of various abnormalities of the head (including the acrosome) and flagellum of the spermatozoa.

Purpose: the aim is to study the therapeutic efficacy of the macrolide group antibiotic tulatromycin and its effect on the immunological and cytological characteristics of vaginal secretions.

Materials and methods. For the experiment, 2 groups of 8 animals each were formed. The first group - cows without clinical signs of vaginitis with a positive PCR test for Mycoplasma spp.; the second group - clinically healthy cows with a negative PCR test for Mycoplasma spp. The first group of cows, the group for the treatment of genital mycoplasmosis, used the antibiotic traksovet 100 (tulatromycin) at a dose of 2.5 mg per 1 kg of animal body weight, subcutaneously, once 40 days before the expected delivery. Vaginal secretions were collected from both groups of cows, in which the content of Ig G, Ig M, Ig A, sIg A, lysozyme activity and cytological examination of the vaginal smear were determined.

Results. The use of tulatromycin in cows with genital mycoplasmosis leads to a decrease in the content of Ig M and sIg A in vaginal secretions, which reach the values of these indicators in healthy animals. A less pronounced positive effect is observed with respect to the activity of the vaginal secretion lysozyme, which, although significantly increased, remains lower than in healthy cows. Cytological examination of vaginal smears against the background of antibiotic therapy showed a significant decrease in the number of epithelium and leukocytes.

Conclusion. The use of traksovet 100 antibiotic as etiotropic therapy for cows with genital mycoplasmosis leads to the elimination of the pathogen from the vaginal mucosa in 75 % of sick animals and provides partial restoration of cytological and immunological characteristics of vaginal secretions.

Purpose: to study the effect of the mineral feed additive «Helavit C» on hematological blood parameters.

Materials and methods. The experiment was carried out on male white laboratory rats of the Wistar line weighing 402-420 grams. «Helavit C» was used as a mineral feed additive. Animals were bled from the tail vein every two weeks five times and examined for the following parameters: hemoglobin, red blood cell count, color index, hematocrit, and erythrocyte indices were calculated. The hemoglobin content was determined by the photometric hemiglobin cyanide method. The number of formed elements was counted using a Goryaev's camera. The color index of blood and erythrocyte indices were calculated by the formulas. Hematocrit was determined using a special hematocrit centrifuge.

Results. The results of the experiment showed that the feeding of mineral feed additive «Helavit C» in liquid form at a dose of 20 μl per head per day for 8-10 weeks led to a significant increase in hemoglobin concentration by 14.3-15.5%, erythrocyte concentration - by 12.3%, an increase in hematocrit by 13.9-14.0% and an average erythrocyte volume by 1.9%.

Conclusion. The conducted studies indicate that the presence of iron, cobalt, zinc and copper in the composition of the mineral feed additive «Helavit C», their combined action contributes to an increase in the level of hemoglobin, the number of erythrocytes and an increase in the average volume of erythrocytes in laboratory rats. Due to the full consumption of microelements by experimental animals, their erythropoiesis improves, which directly affects the processes of oxidative metabolism, as well as the plastic metabolism of animals.

Purpose: to study the allelofund of blood groups of cattle of different breeds.

Materials and methods. 3117 Holstein cows of the black-and-white breed were studied, 848 cows of the Simmental breed, 555 cows of the Hereford breed and 172 cows of the Aberdeen-Angus breed. Blood groups were determined using a hemolysis reaction using mono-specific serum reagents, a suspension of erythrocytes and rabbit complement. Blood groups consist of alleles – a set of antigens inherited concatenated. In total, 12 systems are isolated in the blood groups of cattle. In this study, the EAV system is used, since it has the greatest variety of alternatives.

Results. It was revealed that the allelofund of the Holstein black-and-white breed is represented by 44 alleles, the Simmental breed – 87 alleles, the Geford breed - 53 alleles, the Aberdeen Angus breed – 38 alleles. The most common alleles of blood groups of cattle of Holstein black-and–white breed are G₂Y₂'E'₁Q' and I₂, Simmental breed – Q', Hereford breed – b and Y₁D'I', Aberdeen-Angus breed O₁Q'. The frequency of occurrence of these alleles exceeds 6% and in some cases reaches 44%. It should be noted that the most common alleles of breeds remain in the leading positions in frequency of occurrence over time and are not replaced by other alleles. It is also established that in each breed there are specific alleles inherent only to it, which can be called markers of the breed. So, in the Holstein black-and–white breed, these are the alleles O₁Y₁G'G" and O₃J'₂K'O', in the Simmental – D'E'₃G'I' and D'G'I'Q', in the Hereford – Y₁D'I' and I₂Y₂G'G", in the Aberdeen-Angus – P₁Y₁ E'₃P'₂Q'G".

Purpose: to study the effect of complex biologically active additives based on a protein hydrolyzate together with an iron-containing preparation on the metabolism of lactating goats of the Saanen breed according to the physiological and biochemical status of blood and the physicochemical properties of milk from animals grown in an industrial complex. 

Materials and methods. In the experiment, 45 Saanen goats were used, of which 15 goats were combined into the control group, 30 equally divided into two experimental groups. Experimental animals in addition to the standard diet received a biological supplement based on protein hydrolyzate, 40 ml/day. and iron-containing preparation "Bio-iron with trace elements" 10 ml / day. An experimental group of 15 heads received the drug "Abiotonic", another group of 15 heads - "Abiopeptide" (hereinafter, the subgroups "ABT + BfM" and "ABP + BfM"). Animals received dietary supplements in the complex, according to the following scheme: 30 days with a break of 5 days after 10 and 20 days, i.e. In general, the experiment lasted 45 days. To assess the condition of the control and experimental goats, blood and milk were taken (before the start of the experiment and at the end of the experiment). Physiological and biochemical blood parameters of goats were determined, which characterize protein metabolism - the level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total protein (OB), albumin (A), globulins and urea (M); lipid metabolism - the level of cholesterol (X) and triglycerides; carbohydrate metabolism - glucose level (G); energy metabolism - creatinine level (K); mineral metabolism - the level of phosphorus (P), chlorine (Cl) and iron (Fe). Milk was taken in the morning milking, examined for physical and chemical parameters: fat, protein, dry skimmed milk residue (SOMO), somatic cells and density. 

Results. It is shown that the use of these dietary supplements in lactating goats affects the physiological and biochemical status of blood and the physicochemical properties of milk. It is noted that the beneficial properties of additives are aimed at enhancing the catabolic processes of the body of goats, they are most effective in combination with vitamins and microelements, contributing to an increase in productivity while maintaining the internal reserves of the body. It should also be noted the effectiveness of the iron-containing preparation "Bio-iron with microelements", used in feeding lactating goats.

Purpose: to determine the values of the macruse index in the clinically healthy cows of the Jersey breed with different vegetative tones. 

Materials and methods. The characteristics of the ECG and the variability of the rhythm of the heart were learned in 103 goals of the Jersey breed. For the analysis and record of the Jersey cattle ECG, the Conan-4.5 program was used on the frontal diverting system according to the method of M. P. Roshchevsky. ECG was recorded two to three hours before eating. Clinical studies included palpation, percussion and auscultation in strict accordance with the methodology of clinical examination of animals according to B. V. The work was calculated in the work of the macrose index, it is the ratio of the duration of the tooth P to the duration of the PQ segment (the difference between the duration of the Ruz P and the PQ interval) or is the fraction of the time of the cardiopulse by atrium to the total time of the atrioventricular conduct 

Results. The obtained electrophysiological indicator of the Jersey breed cows - the macruse index in a state of relative rest, characterizes the normal functioning of cardiac activity, and when they change their pathological conditions. This indicator was 0,29-0,81, its change is associated with an increase in the time of atrioventricular conduction and the expansion of the P-Q interval as a result of this interval. On the ECG, the clinically healthy cows of the Jersey breed with the alleged initial vegetative tone of “Varoidony” the Macruse index was 0.29 ± 0.01. In this group, the parasympathetic department of the autonomic nervous system prevails. For healthy studied animals with the proposed initial vegetative tone of Normotonia, the macruse index was 0.38 ± 0.01. This group is characterized by the equilibrium state of homeostasis between CO and the autonomic nervous system. For animals with the alleged initial vegetative tone of the “sympathycotony”, the macruse index was 0,59±0,01. In this group, the vegetative balance takes place towards the sympathetic department of the autonomic nervous system. And for "hypercimpaticotonics" the macruse index was 0,81±0,01. In this group there is a “goature” of the sympathetic department of the autonomic nervous system. 

Purpose: assessment of vegetative tone in clinically healthy dogs in the absence of irritants. 

Materials and methods. Studies were conducted in a group of 11 clinically healthy dogs, a breed of husky with a live weight of 19 to 25 kg. ECG recording was conducted on the Conan hardware and software complex. By the method of variational heart rate measurement, an assessment of vegetative tone was carried out. The ECG was recorded first standing, then by the classical method on the right side for 5 minutes, in I, II, III leads; the data obtained were processed by mathematical and statistical methods 

Results. Differences in vegetative tone were distributed as follows: 1 individual (9%) was a versympathotonic, the value of the IN range of 301-600 c.u.; 4 individuals (37 %);  were normotonics, IN from 31-120 c.u.; 6 individuals (55%) were sympathotonic, IN in the range of 121-300. The method of determining the autonomic tone of an individual can be developed and applied to the qualitative selection of dogs with more stable psychophysiological parameters, where necessary. However, it is worth considering that this method should be supplemented with various additional tests and registration conditions, in order to develop a clear understanding of the correlation of variational heart rate measurement indicators with mental and emotional stability.