Animal Husbandry and Fodder Production

The prospects for the use of ultrafine particles (UFP) Co₃O₄ and Mn₂O₃ in feeding farm animals are outlined. The digestibility of wheat bran in vitro and the dynamics of volatile fatty acids and nitrogen in the rumen fluid with the introduction of various dosages of the studied substances was assessed. It has been established that UFP Co₃O₄ and Mn₂O₃ at concentrations of 0.6 and 38.6 mg/kg of feed dry matter increase the digestibility coefficient by 4.49 and 5.05%, respectively (P ≤ 0.01); simultaneously stimulate the formation of acetic, propionic and butyric acids, and increase the concentration of total and protein nitrogen, with an increase in the number of protozoa in 1 ml of ruminal contents.

Organic forms and, in particular, chromium picolinate are used to increase the bioavailability of chemical elements from diets due to its effective impact on the productivity of farm animals and low toxicity. The metabolism of chromium in the body has not been fully studied, and the question of its effect on the mechanisms of transformation and metabolism of elements remains open. The aim of the work was to evaluate the effect of chromium picolinate in the diet on the concentration of chemical elements and biochemical parameters of blood serum of Kazakh White–Headed bulls aged 12-13 months, with an average weight of 324 kg. In the experiment, a group of control bulls (n=3) received the main diet, chromium picolinate was included in the diet for I group (n=3) of bulls at a dose of 7.2 mg / kg of dry matter (DM), and for II group (n=3) of animals at a dose of 8 mg / kg of DM. According to the results of an experimental study, the optimal dose of chromium picolinate in the diet was determined – 8 mg / kg of DM, which was accompanied by stimulation of protein and lipid metabolism, as well as an increase in the bioavailability of the main macro- and microelements. In particular, an increase in total protein by 6.0 %, urea – by 154.5% (P≤0.001) and creatinine – by 2.2%, as well as cholesterol – by 28.7% (P≤0.05), with a decrease in triglycerides by 73% (P≤0.01) and 40% (P≤0.001) in blood serum, an increase in the concentration of As – by 158.1% (P≤0.001), Cu – by 6.2% (P≤0.01), Se – by 9.1 % (P≤0.01), Zn – by 6.3% (P≤0.05), Na – by 3.4% (P≤0.05).

The conducted studies were aimed at identification of genetic markers that affect the tenderness of beef as the most important characteristic that determines taste. In the course of works, the test systems for the identification of the allele variants of polymorphism of CAPN1 genes – CAPN1_530 and CAPN1_4751, based on PCR-RFLP and RT-PCR methods were created. Genotyping of Aberdeen-Angus cattle populations (n pop No. 1=140, n pop No. 2=20) and Galloway (n=100) breeds according to the studied polymorphisms showed the presence of pop No. 1 in Aberdeen cattle genotypes of the preferred allele C-CAPN1_4751 at a frequency of 0.44. It is noteworthy that in this population, there were no animals homozygous for the C-CAPN1_4751 allele with a sufficiently high proportion of heterozygotes (122 animals out of 140, which was 87.1%). No animals carrying the C-CAPN1_4751 allele were found in the Galloway breed population. The G-CAPN1_530 allele, which is desirable for meat tenderness, was not identified in any of the studied populations. Due to the large influence of the CAPN1 gene on the tenderness of meat, as well as the revealing of the genetic variability for CAPN1_4751 among the Russian populations of beef cattle, we consider it advisable to conduct further research on a larger number of animals. This will contribute to the search for additional genetic markers of meat productivity with the prospect of their introduction into genomic selection systems to increase the accuracy of genomic forecasting in beef cattle breeding.

Due to the intensification of dairy cattle breeding, the problem of accumulation of harmful LOF-mutations in cattle appeared, which reduced the quality of production, fertility of animals, as well as led to various anomalies. This study aimed to establish the frequency of mutant alleles accumulation in three genes UBE3B, CHRNB1, FMO3, associated with fertility (PIRM syndrome), multiple arthrogryposis (AM - Arthrogryposis Multiplex), and the appearance of a fishy odor in cow's milk, respectively. Genotyping of 135 heads of Ayrshire cattle was conducted in Leningrad region, which revealed the presence of undesirable haplotypes: AH1 in the UBE3B gene with a frequency of 17.0%, AHC in CHRNB1 with a frequency of 2.2%, in the FMO3 gene with a frequency of the homozygous genotype by mutation 1.5% and heterozygous – 3.0%. Thus, the occurrence of LOF mutations carriers in the population of Ayrshire cows was 23.7%. To eliminate harmful mutations, breeding work is required aimed at further identifying mutation carriers, primarily sires and cows, their culling and correction of the parental pairs selection.

The quality of dairy food products directly depends on the quality of the raw material base. Feed additives are becoming widely used to improve the quality of raw materials. The purpose of the work was to study the influence of the new feed additive KD-Bish on the quality of raw milk from Holstein cows and the cheese produced. The object of the study was milk obtained from cows of two studied groups, one of which was fed a diet enriched with the additive. The quality of cheeses made from this milk was also studied. The resulting milk was studied according to all quality criteria. The cheese suitability of milk from two groups was determined. The raw materials were used to produce cheese samples. Laboratory analysis showed that the feed additive had a positive effect on the quality composition of milk and cheeses.

The results of studies on the influence of different dosages of the complex mineral feed additive ToxiNon on the quality indicators of laying hen eggs from the industrial herd of the Hisex Brown cross are presented. The studies were conducted in the conditions of Bogotolsk Poultry Farm LLC, Krasnoyarsk Territory, on four groups of chickens (control and three experimental) at the age of 21 weeks, 50 birds in each group. The duration of the experiment was 133 days. The birds of the experimental groups, in contrast to the control group, were given the feed additive ToxiNon in the diet in dosages of 0.15; 0.25; 0.35% by weight of the feed mixture. As a result of the research, it was found that the dosage of the additive 0.25% of the weight of the feed mixture had the most positive effect on the quality of chicken eggs: compared with analogues in the control group, the average egg weight increased by 2.9%, yolk weight – by 3.6%, shell weight - by 8.0%, shell thickness – by 3.7%, yolk index – by 0.9 percentage points, and feed costs per 10 eggs decreased by 7.3%, per 1 kg of egg mass – by 9.2%.

The paper presents the results of a comparative assessment of the effect of the feed additive «Silaccess» based on flaxseed cake (group I) and zeolite (group II) on the digestibility of nutrients in the starting and growth diet of broiler chickens. There is an increase in the digestibility coefficient of crude fat during the starting period in the experimental groups receiving the feed additive. Moreover, according to this indicator, experimental group I exceeds the control by 5.12%, group II – by 7.83%. There is also an increase in the digestibility of carbohydrates in the starting diet in both experimental groups by 0.22% and 1.90%. During the growth period, a feed additive, both containing flaxseed cake and zeolite, specifically promotes the best digestibility of dry matter, organic matter, crude fat, crude protein, crude fiber, nitrogen-free extractives and carbohydrates. Due to the characteristic blood picture, the birds of experimental group I, which received a feed additive based on flaxseed cake, had the best performance.

The development of antibiotic resistance leads to the search for new solutions in the field of improving the quality of finished products and reducing the negative impact on the end user. Aquaculture being an actively developing industry imposes serious requirements on products, including reducing the incidence of diseases among farmed fish and reducing the use of antibiotics. Among the alternative drugs, there are various feed additives (pro-, prebiotics, phytogenic drugs) that can replace antibiotics without harm to the body of hydrobionts. A new branch is the study of quorum sensing bacteria and its effect on pathogenic organisms. Recent studies have shown that the use of quorum inhibitors can become a promising replacement for antibiotics without harm to the body and the end user. The main action of inhibitors is aimed at blocking the interaction of N-Acyl homoserine lactone with signaling receptors, which leads to inhibition of the expression of virulence-related genes. Scientists from different countries have conducted research on the effect of inhibitors on pathogenic bacteria for hydrobionts. The review presents information about quorum sensing of bacteria and general data on the study of quorum inhibitors that can become promising components in the feeding of hydrobionts.

Weather conditions, soil moisture, nutrient content, both plant and microbial, precursors and weediness of agrocenoses affect the productivity of crop rotations and permanent crops. The purpose of the study was to determine the yield of agricultural crops grown on rainfed soils in 2023 and to evaluate the impact of different crop rotations on the yield of spring wheat and barley under drought conditions. The research was carried out by researchers of the Department of Agriculture and Resource-Saving Technologies of the Federal Research Centre of Biological Systems and Agrotechnologies RAS between 1990 and 2023 on a stationary site located near the Nezhinka village, Orenburg Region (51.7756125°N and 55.306547°E). The soil of the experimental plot belongs to southern carbonate, low-humus, heavy-loamy black soils with a humus content in the arable layer of 3.2-4.0%. The experimental design explores options for cultivating spring durum wheat (Orenburgskaya 21), spring soft wheat (Uchitel’) and barley (Anna) in six-field, two-field and permanent crops. A feature of the early spring drought of 2023 is the negative impact of the use of mineral fertilizers, which is expressed by a decrease in the yield of grain crops against a fertilized background. The decrease in the yield of spring durum wheat in 2023 when using mineral fertilizers in crop rotations ranged from 1.31 centners (in crop rotation with green manure) to 2.46 centners (in crop rotation with winter crops). The experiment noted a decrease in the yield of spring wheat on a fertilized background after peas by 0.6 centners and after corn by 2.0 centners per 1 ha. Cultivation of barley using mineral fertilizers is accompanied by a positive effect and the highest crop yield is in a six-field with green manure, in the aftereffect of peas (11.34 c), millet (10.85 c) and corn (9.3 c per 1 ha). Mono-cultivation of barley is accompanied by a decrease in crop yield compared to cultivation in crop rotation (8.27 centners), and it increases to 9.23 centners per 1 ha in double-field durum wheat.