Vol 107, No 4 (2024)

A series of studies were performed to evaluate the biological properties and productive action of a silicon dioxide nanoparticle preparation (NPS SiO₂) on a carp model. The NPS SiO₂ preparation obtained by plasma-chemical synthesis was used (d=126.5±9.7 nm, Z-potential - 29±0.1 mV). The NPS SiO₂ preparation was characterized by the absence of toxicity in the range from 1.5•10^-5 to 5•10^-1 g/l (Escherichia coli K12 TG1 biosensor model). The effect of NPS SiO₂ in three dosages (100, 200, 300 mg/kg of feed) on the productivity and metabolism in the carp body was studied. The optimal dosage of NPS SiO₂ was established, amounting to 200 mg/kg. When including NPS SiO₂ in a complete feed with a crude protein content of 23%, the fact of increasing the intensity of carp growth by 10.2 - 14.1% was established. At the same time, an increase in the content of total protein in the blood serum of fish and an increase in the content of a number of amino acids in the liver of carp were established. In the second experiment, the productivity and metabolism of mineral substances in carp were studied with joint feeding of NPS SiO₂ and amino acids (lysine, mytheonine, arginine).

In order to study the influence of ambient temperature on the productive qualities and elemental[1] status of Black Spotted bulls in the conditions of the Krasnogorsky collective farm of the Orenburg region, a scientific and economic experiment was conducted. For this purpose, 2 groups were formed: I (n=20) – the spring season of birth (March), II (n=20) summer (June). The duration of the experiment was 90 days. The ambient temperature for group I averaged +13.1°C during the daytime, +6.3°C at night, +28.3°C during the daytime and +22.1°C at night for group II. An assessment of the impact of the season on productive qualities showed that bulls of group II were inferior to their peers from group I in terms of live weight at the age of 1 month – by 2.7%, 2 months – 5.3 %, 3 months – 6.0%, average daily gains, at the age of 0-1 months – by 7.5%, 1-2 months – 12.4%, 2-3 months – 8.5%. Assessment of the activity of the antioxidant system protection showed a decrease in catalase levels by 17.6% in summer, SOD by 11.0%, and an increase in malondialdehyde by 115.4% compared to spring. High temperatures in the summer affected the elemental status of the bulls. Thus, the concentrations of Hg, V, Cr, Pb, As in the hair of group II gobies were higher and Mg, P, K, Ca, Sr, Na, B, Mn, I were lower compared to I. Thus, the ambient temperature affects both the productive qualities and the elemental status an animal estimated by the concentration of chemical elements in the hair. The data obtained should be taken into account when compiling feeding rations for young animals in the summer period of the year.

The article discusses the possibility of using calpain 1 (CAPN1) and calpastatin (CAST) genes for the prediction of beef tenderness and selection of the most perspective in this property animals. The aim of the research was the study of the CAPN1 and CAST gene polymorphisms in association with the chemical composition and histological structure of the meat in cattle. Samples from the longest muscle of the back (M. longissimus dorsum) of Aberdeen-Angus bulls (n=9) with known genotypes for the CAPN1_316, CAPN1_4751, CAST_282 and CAST_2959 polymorphisms were collected after slaughter and analyzed for protein, fat, dry matter and mineral content, as well as muscle, connective and adipose tissue content and muscle fiber diameter. It was found that meat from bulls with the GG-CAPN1_316 and GG-CAST_2959 genotypes contained 14.5-15.8% more protein and 11.4-13.3% less fat compared to other genotypes, and meat from animals with the ST-CAPN1_4751 and AA-CAST_2959 genotypes had lower connective tissue content (by 7.5-7.7 and 9.6-10.2%, respectively). The largest myofibril diameter was observed in samples from steers with genotypes CC-CAPN1_316 (111.2 μm), TT-CAPN1_4751 (116.2 μm) and AA-CAST_2959 (111.7 μm). With respect to the CAST_282 polymorphism, animals with the GC genotype showed advantages in all studied parameters.

One of the methods for preventing the spread of subclinical mastitis in herds is the selection of animals with natural resistance to this disease. This approach is based on genetic predisposition, which determines the individual resistance of cows to various forms of mastitis. The aim of the study was to identify and analyze genomic regions and SNPs presumably associated with the somatic cell count, taking into account their differentiation in the Russian population of Ayrshire cows. The study included 5828 milk and DNA samples from 600 Ayrshire cows from six farms in the Leningrad and Moscow regions. On average, the SCC value was 184.1±12.1 thousand units/ml with fluctuations from 107.6±6.4 thousand units/ml to 272.5±49.4 thousand units/ml. A similar picture was observed in relation to the DSCC indicator with an average value of 31.8±0.7%, a minimum of 25.9±0.8% and a maximum of 47.9±4.2%. The heritability coefficients were calculated for the SCC – 0.207, for the DSCC – 0.085. A significant influence of the factors “Farm”, “Father” and “Lactation period” (p˂0.001) on the level of SCC and DSCC in cows’ milk was revealed. In the course of the study, using the Illumina BovineSNP50 BeadChip DNA chip, SNP profiles of animals were obtained and functional candidate genes were identified. GWAS analysis revealed three SNPs in BTA12 (MYO16, rs42775315), BTA17 (NELL1, rs43178042) and BTA29 (the closest region of the SCLT gene, rs43178042) significantly associated with the number of somatic cells in cows' milk (p < 0.00001). Animals with homozygous genotypes for rs42775315 GG (90.3%, 163.1±9.8 thousand units/ml), rs109897445 GG (44.17%, 137.5±11.6 thousand units/ml) and rs43178042 CC (85.0%, 162.6±9.5 thousand units/ml) had lower SCC values. The results obtained provide important information on the genetic mechanisms that determine the predisposition to mastitis in Ayrshire cows.

The aim of the study was to search for SNPs and identify candidate genes associated with color characteristics of chicken meat. The object of the research was F2 chickens of the resource population obtained through interbreeding of two breeds with contrasting meat productivity indicators - Russian White and Cornish. The obtaining resource population of chickens was phenotyped at the age of 42 days for breast and thigh meat color according to the a*, b* and L* color scale using a spectrophotometer, and genotyped using the Illumina Chicken iSelect BeadChip 60k DNA chip. The GWAS identified 30 significant SNPs (P≤0.0001) associated with meat color in F2 chickens of the resource population, including 12 SNPs associated with breast muscle color traits and 18 SNPs associated with thigh color parameters. The 214 genes were identified in the SNPs region, including 10 genes at the positions of these SNPs - BRAF, ENO2, UBE3D, RGS6, ATP13A3, RHBDD1, MB21D2, BHLHE23, PIAS4, and MLLT1, localized on chromosomes GGA1, GGA3, GGA5, GGA9, GGA20 and GGA28. The results have practical significance for understanding the molecular genetic mechanisms in the formation and manifestation of traits that determine the color characteristics of chicken meat and can be used in subsequent studies in genomic selection of chickens to improve the quality of meat.

The study of the formation of the composition and quality of livestock products is of scientific and practical importance. In this regard, the aim of the research was to determine the biological markers characterizing the quality indicators of muscle tissue of the Angus cattle. The object of the study was muscle samples of the rib eye of the Angus bulls (n = 157). The indicators of chemical, mineral, amino acid composition, quality indicators of meat were determined and correlations between them were calculated. pH 24 positively correlated with the content of chromium in meat. Positive correlations of water-holding capacity of meat (WHC) with the content of moisture, protein, ash, calcium, phosphorus, chromium, phenylalanine and negative ones with the content of fat and arginine were noted. Total amount of water-soluble antioxidants (TAWSA) positively correlates with the content of moisture, ash, macro- and microelements, cysteine, proline and negatively with the content of fat and some amino acids. The obtained results allow us to draw a conclusion about the formation of quality indicators of raw materials, which will help in developing methods for regulating and intravital formation of high-quality products of domestic cattle breeding.

As is known, complete balanced feeding of animals is one of the fundamental moments in increasing the production of livestock products and their quality indicators. The use of special feed additives in feeding rations plays an undoubted role in this. The article presents the results of studies on establishing the dosage of a new prebiotic feed additive based on starch polysaccharide in the diet of red steppe cows, its effect on milk productivity and the quality of the obtained milk. According to the research results, the most optimal dosage of the additive was chosen in the amount of 80 g per head per day. When feeding this additive, an increase in milk productivity of animals, as well as milk quality indicators (fat, protein and carbohydrates) was established. Better organoleptic indicators and higher nutritional value indicators distinguished the fermented milk product produced from the milk of the experimental group of animals.

The paper presents the results of a comparative assessment of the effect of compound feeds with adjusted mineral nutrition according to various standards on milk productivity of cows. According to the 2021 standards, we increased the input of a number of microelements: zinc by 9.4%, manganese by 125%, cobalt by 67%, iron by 9.1% and chromium by 33.3% compared to the 2001 standards. According to the tabular data, the average values ​​in 2022 increased for compound feed consumption by 24.4%, milking speed by 0.32 l/min; milk yield per head per month by 4.54%. Observing the experimental herd, we registered an increase in the frequency of visits to the milking robot, as evidenced by the increase in compound feed consumption. Due to the correction of the diet for minerals according to the 2021 standards, the strength of the hoof horn has significantly improved, which is confirmed by specialists during hoof treatment.

The paper presents data regarding the impact of some trace mineral supplementation on milk minerals content of glycine chelated mineral supplemented dairy cows. The study was made on thirty Holstein multiparous dairy cows, aging arround 62 ± 4.5 months that were divided randomly in two groups: C – Control receiving normal diet without glycine mineral supplementation and one experimental group (E) that received supplement of glycine chelated Cu, Zn, Mn and Fe as follows: 15 mg/kg Cu, 20 mg/kg Mn, 60 mg/kg Zn and, 100 mg/kg Fe, added in concentrate feed. The experiment was designed from day 30 of lactation until day 100 of lactation, and were assesed the milk levels of zinc (Zn), selenium (Se), iron (Fe), manganese (Mn) and copper (Cu). In the experimental group we observed significant (p<0.05) increase of milk concentration of Se, Mn and Cu at day 65 of lactation and highly significant (p<0.01) increase of Zn, Se, Mn and Cu in the day 100 of lactation. The Fe content was increased in all period of study, but the increase was not statisticaly significant (p>0,05). We conclude that supplementing the dairy cows whit chelated minerals will be followed by a increase of milk mineral content that could be beneficial for health.

The results of the research obtained from the results of the experiment conducted on two groups of Holstein cows (n=20) indicate a positive effect from increasing the indigestible fraction of crude protein (NDP) in the diet of lactating cows during the milking period from 35 to 40.0%, when replacing sunflower meal (1.2 kg) with soy protein concentrate (1.0 kg), which manifested itself in an increase in milk yield by 259 kg (P≤0.05) during the first third of lactation and an increase in fat and protein yield by 11.0 kg and 9.4 kg (P≤0.05), with a decrease in urea content by 6.7% (P≤0.05). Dynamic milk yield of cows receiving protein concentrate affected the increase in milk yield per lactation by 6.5% (p≤0.01). The obtained effect was also supported by biochemical blood tests, which showed that the use of soy protein concentrate to balance the diet according to the NDP had a positive effect on the state of protein metabolism, with an established trend of increasing the concentration of total protein by 3.2% and a reliable decrease in the concentration of urea by 13.6% (P≤0.05). Optimization of protein nutrition indicators of high-yielding cows in the first third of lactation using soy protein concentrate had a positive effect on the cost of milk, which decreased in relation to the control by 1.6%, against the background of receiving additional income per 1 head in the amount of 3885.4 rubles.

The current situation in the Russian economy and international politics is very difficult, the problem of import substitution is acute. Therefore, the purposes of our research are to develop a functional full-ration concentrated feed for the lagomorphs based on the local low-budget environmentally friendly natural raw materials as well as biologically active ingredients, to elaborate a method of its manufacture and use, to test and to study its impact on biological and economically positive indicators of rabbits. The article presents the results of studies conducted on the rabbits of the Soviet chinchilla breed. Chemical composition and nutritional value of a traditional and a functional concentrated feed has been studied, a comparative analysis has been done. The effect of a functional concentrated feed use on the weight of some internal organs of rabbits as well as on the main exterior indicators, zootechnical indicators, and the quality of rabbit meat has been defined.

Reducing economic losses, improving feed utilization, maintaining health and improving the quality of finished products in the livestock industry are the main tasks that need to be solved. Scientists around the world are already proposing to use animals based on their genetic selection, which characterizes high-quality phenotypic traits. Methods are used to measure the external data and meat qualities of cattle using advanced systems for recognizing live animal bodies, including depth cameras and soft reconstruction of three-dimensional shape. However, one of the criteria for assessing animals can be the analysis of the genetic bank of microorganisms, closely related to the functional activity of the animal's digestive system. A comprehensive assessment of gene expression, taxonomic structure of the microbiome, exterior characteristics and meat productivity in combination will provide more accurate forecasts for the use and selection of animals. Our study presents the results of metagenomic sequencing (NGS) of the intestinal contents of young animals (n=40) raised in a feedlot, and annotates the association of the microbiome with their live weight and marbling degree, predicting the metabolic pathways with which these genes were associated. The analysis (LEfSe) revealed a taxonomic difference in the intestinal contents of animals with high and low live weight, the genera Clostridium sensu stricto, Clostridium XlVa, Treponema were predominant in animals with lower live weight.

Microelements such as iron, manganese, copper, cobalt, selenium and zinc are vital and play an important role in the growth and productivity of farm animals. Excess or deficiency of essential elements leads to deviations in the development of animals and a general deterioration in health and metabolic processes. The microbiome of the gastrointestinal tract of ruminants is a participant in many metabolic processes in the body and will also respond to changes in mineral metabolism. The aim of the work was to study the relationship between the elemental composition of hair, milk and the state of the colon microbiome. According to the elemental composition of hair, the animals were divided into 2 groups (n = 15): Group I (control) - the level of microelements (Cu, Zn, Co, Se, Mn, Fe) within the reference values, Group II - the level of microelements is below or within the lower limit of the reference values. The level of Se, Cu, Co, Zn, Fe and Mn was significantly (P≤0.05) lower by 21.4; 20; 30.1; 17.9; 40.3 and 30.2% in animals of group II relative to I. Also, in the hair of cows of group II, a lower content of calcium (-7.3%, P≤0.05) and chromium (-5.67%, P≤0.05) and a higher concentration of silicon (+36.4%, P≤0.05), mercury (+6.73%, P≤0.05) and nickel (+11.6%, P≤0.05) were noted in comparison with group I. Similarly, in milk from animals of group II, the content of copper (-23.3%, P≤0.05), calcium (-3.19%, P≤0.05) and selenium (-7.96%, P≤0.05) was lower than in I. The microbiome of the large intestine of cows of group II in comparison with I was characterized by lower biodiversity. In the taxonomic composition of the intestinal microbiota of cows of group II, a lower relative abundance of bacteria of the taxa Lachnospiraceae, Alistipes, Prevotella, which are active producers of short-chain fatty acids, was noted. The obtained data show the importance of studying the myrobiota of the gastrointestinal tract against the background of an imbalance of trace elements in the animal body and the prospects for managing metabolic processes in the intestine by correcting elementoses.

In recent years in connection with the extension of Alfalfa (Medicago) spreading area and promotion to the northern regions. It is necessary to introduce new generation varieties that are resistant to abiotic environmental factors and capable of growing in conditions of long daylight hours, limited heat resources, and increased soil acidity to increase the efficiency of its cultivation. Considering that previously alfalfa did not grow in the conditions of Karelia, there are no native strains of nodule bacteria in the soil that can enter into productive relationships with this legume crop, it is necessary to inoculate seeds with Sinorhizobium meliloti and at the same time select the most adaptive variety-microbial systems to the conditions of the region. In this regard, three-year studies were carried out on the ecological variety testing of variable alfalfa varieties Taisiya, Agniya VIK, Pastbischnaya 88 and variety samples SGP-387 and 506 (Lyusya variety), and when inoculated with strains of nodule bacteria Sinorhizobium meliloti (SKhM-1-105, 415, A-1, A-5, and variant without application). It was found that among the studied varietal-microbial systems the most adapted to the conditions of the North-West region are variety 506 (Lyusya variety) inoculated with strain SKhM-1-105, capable of providing yield on average for two years of use up to 7.45 tonnes/ha dry weight, as well as Agniya VIK in combination with the same strain (7.25 tonnes/ha), strains A-1 and A-5 also provided yield increase over the control in 1.8-2.2 times. In terms of varieties, these strains can be characterised as universal.

The article contains an analysis of the prevalence of spring durum wheat crops in the world and in the Orenburg region, and yields over a long period. There is a tendency to decrease the productivity of this crop over the studied period, primarily due to the increasing aridity of the growing season. The results of a correlation and regression analysis of the dependence of its yield on the main weather indicators are presented, while identifying their optimal values for the formation of highly productive crops of this crop. Analyzing the obtained dependencies, attention is focused on the intensity of the growing conditions of spring durum wheat in recent years in the arid zone, which do not allow realizing the potential of this crop. The calculated coefficients of the relationship between the yield of this crop and weather factors show reliable dependences on the temperature regime of May, July, the amount of precipitation in May and the relative humidity of the entire growing season. The results of the mathematical dependence of durum wheat grain quality indicators on the weather characteristics of the growing season are presented. At the same time, the optimal air temperature values in May were 13.4 °C, in June 15.0 °C, in July 23.3 °C, according to the amount of precipitation, the optimal amount for the months of vegetation was 30 mm in May and June and 36 mm in July. The above–mentioned optimal values of weather factors in May corresponded to the theoretical yield of durum wheat up to 30.0 c from 1 ha, the optimal values in June - 22.6 c from 1 ha and the optimal values in July – 18.9 c from 1 ha. Correlation coefficients and actual data on grain quality indicators allow us to note their significant variability from the conditions of the growing season and varietal specificity. A high correlation (r = 0,827-0,926) was established for the studied grain quality indicators with average relative humidity and with an average daily humidity deficit. The average relationship (r = 0.635-0.745) was obtained for the average air temperature, maximum air temperature and average daily humidity deficit. Grain quality is subject to variability from the conditions of the growing season: in harvest years, there is an increase in the vitreous content of grain to 92-93%, and in years with an increase in the temperature regime of the air, there is an improvement in the quality of gluten to the level of class II.