Vol 107, No 2 (2024)

Organic acids and ultrafine particles (UFPs), especially of a metallic nature, are increasingly being used in agriculture as fertilizers and components of feed additives. At the moment, detailed studies are in demand to confirm the safety and relevance of their use in animal feeding. The purpose of this study was to determine the effect of an organomineral complex based on SiO₂ UDP and succinic acid (SA) on the characteristics of the rumen and intestinal microbiome and morphobiochemical blood parameters. The analysis of β-diversity showed the presence of a significant effect of the use of UFP SiO₂ and SA in the diet on the organization of bacterial communities in the microbiome of rumen fluid, in comparison with the control. An increase in the phylum Bacteroidota, Pseudomonadota and Bacillota in the microbiome of the rumen has been shown. The microbiome of the large intestine of bulls was inhabited mostly by the phylum Bacteroidota (40.8%), Bacillota (49.3%) and Verrucomicrobiota (4.41%). At the genus level, the following taxa were numerous: Bacteroides, Phocaeicola, Paludibacter. Comparison of α-diversity indices showed that the use of UFP SiO₂ and SA leads to an increase in the values of the Chao-1 index, which may indicate a greater number of species in the microbiota of the large intestine, compared with the control. The value of morpho-biochemical parameters of blood serum in the experiment demonstrates the presence of fluctuations within the physiological framework.

The study of the elemental status of fish is due to the need for a comprehensive study of the effect of various feed additives on the animal body. The purpose of the research was to study the effect of activated carbon (AC) on the concentration of chemical elements in the muscle tissue of rainbow trout (Oncorhynchus mykiss). The paper presents the results of the effect of AC in dosages of 1 g/kg, 2 and 3 g/kg of feed on the elemental status of rainbow trout. During the research, it was found that the inclusion of activated carbon in the trout diet at a dosage of 1 g/kg of feed contributed to an increase in Pb by 144.4% (P≤0.001) and Cu by 11.92% (P≤0.05) and a decrease in the level of macro- and microelements. When using a dosage of 2 g / kg of compound feed, the level of Na, Ca, P decreased. Among the trace elements, the level of Pb increased by 77.77% (Р≤0.001), while the following decreased: Co, Se, Ni, Mn, Zn, Fe, Ag, Cd, As, Sr, Al , In, Ba, Tl. The use of AC in fish feeding at a dosage of 3 g/kg of feed contributed to an increase in the macronutrients Na and Ca by 18.52% (P≤0.05) and 14.05% (P≤0.05), respectively. Among the trace elements, a significant increase of Pb by 127.77% (Р≤0.001) and decrease of Co, Ni, Mn, Cr, Zn, Fe, Ag, Cd, Sr, Al, In, Ba, Tl, Bi were observed. Thus, during the experiment, the fact of direct effect of AC on the level of macro- and microelements in fish muscle tissue was established. The dosage of AC in 2 g/kg of feed is the most optimal and has a positive effect on the dynamics of live weight of fish, while providing acceptable deviations in the elemental profile of rainbow trout.

The improvement of beef cattle breeds involves the use of modern tools in livestock breeding. The purpose of the study was to study the exterior characteristics of the Angus cows using the linear assessment technique. The exterior features of the Angus cattle in the conditions of the Northern Trans-Urals have been studied. The assessment of the exterior was carried out according to the method of linear assessment of the exterior of livestock in the meat production area developed by the authors, and cows were also measured. The results obtained were compared with the parameters recommended for the Angus breed. Animals of the controlled herd have a harmonious physique and good meat forms. The estimates for the exterior features are at the level of optimal values. The average rating of the exterior of cows according to the "B" system corresponds to the "good" type. The conducted studies did not allow us to identify a reliable influence of the exterior assessment of cows on their productive qualities and weight growth. Linear assessment makes it possible to rank animals according to exterior characteristics. Additional testing of the developed methodology on a larger number of livestock is required.

Establishment of objective methods for evaluation and improvement of quantitative and qualitative indicators of meat productivity of farm animals should be based on comprehensive genetic, physiological and biochemical analysis of the organism. The aim of the research was to study the peculiarities of the formation of meat productivity and beef quality in Hereford bulls of various genotypes for growth hormone and thyroglobulin genes. Hereford bulls (n=9) were reared under the same feeding and housing conditions until 21 months of age. PCR-PDRF was performed for genotyping by polymorphisms of GH L127V growth hormone and TG5 C422T thyroglobulin genes. Slaughter indices, chemical, fatty acid and amino acid composition of meat were determined in experimental animals. A significant effect of GH L127V polymorphism was observed on carcass weight (P≤0.05) and amino acid composition of meat. TG5 C422T polymorphism had a significant (P≤0.05) effect on differentiation of bulls in terms of the ratio of polyunsaturated to saturated fatty acids. Thus, genetic variability of bulls on growth hormone and thyroglobulin genes can be used to improve both quantitative and qualitative indicators of meat productivity of Hereford cattle at marker-assisted selection.

The purpose of the research was to study the influence of genotype on growth and development of purebred and crossbred bulls and the economic efficiency of beef production. Newborn bulls were split into 4 groups: I - purebred Simmental breed (control), II - Salers × Simmental crosses, III - Charolais × Simmental crosses, IV - Kazakh white-headed × Simmental crosses. It was found that the greatest average daily weight gain from birth to 6 months of age was observed in bulls of group III and amounted to 1177.2 g, which is 23.0% higher than in crossbred bulls of group IV; from 6 to 10 months such an increase was 1008.3 g, and by the end of the experiment - 1100.9 g. The results of the control slaughter showed that the heaviest carcasses were obtained from bulls of group III, which is higher than that of peers from group I in terms of pre-slaughter weight by 25.7%, carcass weight by 28.0%, slaughter weight by 27.4% and slaughter yield by 1.4%. Assessing the economic efficiency of introducing industrial crossing, it was found that group III bulls showed the highest level of profitability (48.62%), exceeding the control group by 31.29 percentage points. And crossbred animals of groups II and III were superior to their peers of group I by 5.1 and 22.41%. The results of the research confirm the effectiveness of using industrial crossing to improve production performance in livestock breeding.

The article discusses the biological and economic characteristics of Black Spotted cows with different levels of milk productivity in the conditions of the Tyumen region. For the research, cows that had been removed from the herd for three years were selected. They were divided into three groups depending on the amount of milk yield in maximum lactation. It was found that cows with record milk yields for the herd were characterized by greater early maturity; their advantage in live weight at the age of 10 and 12 months was 7.9 (P≤0.05) and 8.9 kg (P≤0.05) compared with animals with the lowest milk yield, respectively. In the first lactation, cows with maximum milk productivity were distinguished by deeper, but less voluminous chest; their long leg, chest and bone indexes had the lowest values. Analysis of the main signs of longevity showed that highly productive cows had the longest duration of economic use (+206 – 565 days; P≤0.001), lifetime milk yield (+6904 – 15792 kg; P≤0.001) and the amount of milk fat and protein (+478 – 1104 kg; P≤0.001), and the number of calves obtained per cow averaged 4.28 heads, which is 16-35% more compared to other groups (P≤0.001).

Breeding meat sheep in a large-scale farm using Romanov breedis important to have high levels of safety of young animals and slaughter yield. The purpose of our study was to study the effect of multiple births on the safety and slaughter yield of Romanov breed rams during meat sheep farming. The study was conducted on rams obtained at different levels of multiple births from birth to slaughter at the age of 8 months. The study showed that at the birth of a single lamb, safety by the age of 8 months reaches 100%, while the slaughter yield is at the level of 48%. Lambs born in twins show a safety level of around 93% for slaughter, while the slaughter yield is 47.44%. Under similar feeding and housing conditions lambs survival in singles was 92%, while the slaughter yield rate decreases slightly, to 46.25%. An increase in the level of multiple births of ewes significantly reduces the level of production, so rams born in quads showed an extremely low level of safety at slaughter, which amounted to 62%, while the slaughter yield also decreased to 46.28%. Breeding meat sheep using the Romanov breed, it is advisable to conduct breeding work aimed at improving the safety of the resulting young by increasing the milk productivity of mothers and a competent approach to artificial feeding of young animals from multiple lambs.

The successful development of agricultural sectors, such as livestock farming, poultry farming and aquaculture, depends on the availability of feed. Alternative technologies include microbiological synthesis. New uses are driven by the recognition that yeast derivatives contain specific bioactive compounds that have functional properties - from improving feed efficiency to being used as an alternative to growth-promoting antibiotics and maintaining intestinal health and immunity while reducing pathogen release. The results of scientific research presented in this article emphasize the important role of carotene-synthesizing yeast as a functional feed additive for the nutrition of farm animals and poultry. Red yeast is capable of synthesizing carotenoids from inexpensive carbon sources; carotenoids are important due to their activity as precursors of vitamin A, dyes, and antioxidants. Carotenoids can be easily produced by chemical synthesis, although their biotechnological production is rapidly becoming an attractive alternative to chemical processes. They also participate in molecular processes, which leads to possible beneficial effects on the body as a whole. Biosynthesis of carotenoids is a specific feature of the genera Rhodotorula, Rhodosporidium and Phaffia. The main carotenoid pigments produced by the yeasts Rhodotorula and Rhodosporidium are β-carotene, torulen and torulorhodine in varying proportions, as well as astaxanthin produced by Phaffia rhodozyma.

Fibrolytic enzyme complexes are widely used in the feeding of farm animals in order to increase the digestibility and effectiveness of nutrients through their use in the preparation of feed. The article presents the results of research on the enrichment of grain feeds by fermentation of substrates using various doses of fibrolytic enzymes. The purpose of the research is to study the effects of fibrolytic enzyme preparations on changes in the chemical composition of grain forage. Fungal alpha-Amylase (Amilorizin), an enzyme derived from Aspergillus oryzae strain, was used as an enzyme preparation. The study used different varieties of barley cultivated in our center with different nutrient contents. The enzyme preparation was used in doses of 25 and 50 mg / kg of vegetable raw materials. Barley grain was hung 200 g each in sealed plastic containers, the required volume of enzyme preparation was introduced and placed in a thermostat for incubation at a temperature of 39 °C for 24 hours. The degradation of barley nutrients was recorded after 3, 6, 9, 12 and 24 hours. The studies of the digestibility of dry matter (DM) of barley were carried out by the in vitro method using the incubator "ANKOM Daisy II" (modifications D200 and D200I). The use of a fibrolytic enzyme in the fermentation of a grain substrate contributes to the decomposition of raw fiber of barley up to 6%, an increase in fat content and an improvement in the digestibility of dry matter by 5.4-6.8% in the "artificial rumen" system.

The research was conducted in stationary experiment in the period from 1991 to 2023 on southern black soil of the Orenburg Cis-Urals in the Orenburg State Agrarian University. The purpose of the research was to study the dynamics of soil density during long-term use of soil cultivation methods and systems that differ in the level of minimization. For the present work, from 16 systems studied, the 4 most contrasting in terms of intensity and depth of impact on the soil were selected: 1 – plowing at 20-22 and 28-30 cm (intensive); 2 – non-mouldboard loosening at 20-22 and 28-30 cm (multi-depth, non-mouldboard); 3 – shallow at 12-14 cm, normal at 20-22 cm and deep at 28-30 cm flat-cutting (minimal), 4 – zero alternating with shallow and deep loosening, while for grain crops it was carried out for two years in a row and in total 14 times in 35 years (soil-saving). The moldboard cultivation system ensures the most loose soil composition. With multi-depth, non-moldboard, minimal and soil-saving systems, the volumetric mass of the soil increases by 0.10 g/cm³, 0.11 g/cm³ and 0.12 g/cm³, respectively, at the beginning of research and by 0.08 g/cm³, 0.10 g /cm³ and 0.09 g/cm³ at the end. Reducing the depth of tillage, regardless of the method, contributes to the formation of a “plow sole” in the layer lying below the horizon loosened by the working part of the tool: with conventional plowing and moldless loosening in a layer of 20-22 cm, with shallow tillage - 10-20 cm. With all methods and soil cultivation systems, the soil density remains in the zone of optimal values, with the exception of the option with shallow tillage, where in a layer of 10-20 cm it goes beyond the upper limit of the optimum.