Calf coronavirus (viral diarrhea) is an endemic disease that is mainly spread by maternal infectivity, cold, wet conditions and crowded housing conditions. Feces were sampled from the rectum of 50 newborn, 3-35-day-old calves. The samples were examined by microbiological, hemagglutination and Bovine enterichek accelerated test (antibody strips) in the ANAU Research Center of Veterinary Medicine and Veterinary Sanitary Examination. Epidemiological data, manifestations of clinical symptoms, patho-anatomical changes, hemagglutination reaction and Bovine enterichek test were used to identify the infection of 3-35-day-old calves. Feces with mucus content from the rectum of calves with diarrhea (50 samples), internal organs (spleen, liver, etc.) and affected small intestines of fallen 3-7-day-old animals (3 heads) were examined.During epidemiological studies, an increase in body temperature (42 0C), anorexia, exhaustion, depression and watery-slimy diarrhea were observed in sick calves. Clots were found on the walls of the arteries of dead animals, inflammation and hemorrages were found in the lymph nods and kidneys. According to epidemiological, clinical symptoms, patho-anatomical changes, microbiological research, as well as hemagglutination reaction and Bovine enterichek rapid test data, both coronavirus and enterobacterial diseases were detected in animals at the same time. As a result, farmers and villagers suffered economic losses due to newborn calf falls. The disease was diagnosed according to hemagglutination reaction, Bovine enterichek test and microbiological methods. Morbidity and mortality rates were respectively 0.1 (10 %), 0.6 (60 %), economic loss – AMD 209 400. Based on the effectiveness of the “BolsheVac” (“БольшеВАК”) vaccine, we propose to carry out preventive vaccinations in vulnerable farms.

One of the current issues of small poultry farms is the prevalence of Eimeriosis infection (especially in floor housing conditions). The research activities were conducted throughout 2021-2022 years in the small rural poultry farms of some communities at the RA Armavir and Ararat marzes. Eimeria infection of chickens was identified on the basis of the results of laboratory tests performed throughout the year. Two species of Eimeria were detected: Eimeria acervulina and Eimeria tenella. Infected samples made up 36% of the overall examined ones. Heat and humidity are among the factors of external environment contributing to the Eimeria propagation. During the year, one or two outbreaks of epidemic nature of invasion may be recorded. The intensity of invasion in Armavir and Ararat marzes was 33 % and 39 %, respectively. Weather conditions favor the preservation and sporulation of Eimeria oocysts in the outdoor environment, leading to spring outbreaks of infection. During the research, as a result of the monitoring carried out in the permanently insecure areas against the disease, high indicators of the extensity and intensity of the invasion were recorded from the beginning of April until the first ten days of June. Lack of precipitation in the summer contributed to a sharp decline in the extensity and intensity of the invasion. And in the long and warm autumn, due to heat and humidity, a certain increase in the mentioned indices was registered, which, anyhow, did not lead to autumn outbreaks of the invasion.

Reproduction of farm animals is one of the main indicators determining their biological and economic value. Highly efficient reproduction promotes the increase of livestock number and improvement of animal breeding technique. The reproductive qualities of goats depend on genetic factors and environmental conditions: age, fatness, live weight of queens, feeding level before mating and during pregnancy, daylight hours, etc. A goal has been set to study the fertility of goats and the live weight of newborn Saanen goats, bred in the goat farm of Krashen village, in the Shirak region. To analyze the goat fertility, 40 queens were taken into consideration depending on their lactation age, among which 47.5% were first-born, 5.0 % - second-born, 45.0 % were the third lambing and one doe was the fourth lambing. The studies were carried out on the queens of 2-4 years. In our opinion, it is this age, that is optimal for characterizing the queens in terms of fertility, since the first mating of goats is carried out at the age of 10 months, provided that the live weight of the young is 70-75 % of the mother's weight, but not less than 30-32 kg. Such a new approach to the technological solution makes it possible to obtain one lamb more from each queen during economic use than with conventional technology. The data obtained can be used in breeding farms for the production and sale of young animals, and the development of goat breeding in the republic.

During the research aimed at reducing the cost price of poultry feed and increasing their productivity lysofort bio­emulator and L­carnitine supplement were used. 4 groups of ROSS­308 broilers were made (100 heads each). The control group received feed portion corresponding to the nutrition value of ROSS­308 cross boiler feed, containing defined content of exchange energy (in the initial phase­3050 kcal/kg, in the growth period­3100 kcal/kg, and in the final stage­3200 kcal/kg). In the experimental groups, the efficiency of the exchange energy was artificially reduced, mostly due to low content of vegetable oil. Feed conversion, head maintenance, live broiler chickens of different ages, growth dynamics, average daily weight growth, meat qualities of slaughtered poultry were studied in all groups. According to the research results, compared with the control group, the indicators of feed conversion and average daily weight growth of broiler chicken fed by portions containing bio­emulator and L­carnitine were improved, which testifies to the increase in the availability of energy. Due to the synergy of joint application of bio­emulators and L­carnitine, feed conversion is improved, production costs and cost price are reduced, the productivity of broilers is increased, as well as the profitability of poultry production (not at the cost of increasing the consumer prices) and meat quality is improved (as a result of increasing the amount of protein and reducing fat). As an efficient and safe means to increase the profitability of poultry production, the bio­emulators and L­carnitine can be used in the feed of meat poultry.

The aim of the study was to prevent latent mastitis in cows by sanitizing the udder teats with amyloyodin solution (blue iodine). Research work on prevention of mastitis in cows was carried out during 2022 in the Balahovit teaching and experimental farm of ANAU, as well as in the laboratories of the ANAU Research Center for Veterinary Medicine and Veterinary Sanitary Examination on 14 Caucasian brown cows, with seven heads in each group. In the experimental group, the treatment of teats after milking with an interval of 12 hours was carried out by applying amyloyodin to the teats of the udder by dipping them into small plastic cups filled with a solution of blue iodine to three­ quarters of the dish. The teats of cows in the control group were not treated with blue iodine, but were washed with warm clean water immediately after milking. To study the microbial contamination of the cow udder, swabs were taken from the teat skin in animals of the experimental and control groups. A microbiological study of swabs indicates that after milking the number of colonies of microorganisms in the experimental and control groups is approximately the same – 139 and 143, respectively. However, the use of amyloyodin showed preventive efficacy and longer hygienic protection of the teats skin in animals, i.e. the number of colonies in the experimental group decreased after 30 minutes (from 139 to 8), and in the control group, confluent growth of colonies was observed after the same period of time.

In the current work, a comprehensive methodology for the soil and climatic conditions of the Republic of Armenia has been developed to justify the water requirement/demand of plants in the case of drip irrigation. The proposed methodology enables to calculate the values of the individual components of the drip irrigation regime, and in practical terms, it was used to determine the water requirement of perennial plantations in the soil and climatic conditions of the Armavir and Kotayk marzes. Based on the obtained results, the crops drip irrigation norms/rates were mapped in the GIS environment. They can serve as a background for practical planning and justification of the drip irrigation water demand for various crops and contribute to the development of introduction rates of water-saving technologies in this field.

Thearticle considers theproblem of providingconstant or almost constant values of the blade cutting angles during one rotation of the tiller rotor with a vertical rotation axis. Analytical expressions were obtained by analyzing the trajectory of the tiller knife/blade, which enable to determine the change of the blade cutting angles at a constant location and to fine the patterns of this change in the ranges of (0...π) and (π...2π). The derived expressions and conclusions make it possible to adjust the location angle of the knife, using a pattern, in case of which the cutting angles of the knife will remain unchanged during one rotation of the rotor. This circumstance is important from the prospect of ensuring a uniform working mode of the rotary tiller.

This paper presents an overview of a novel approach to spirulina microalgae cultivation. The most optimal design of a photobioreactor with compact dimensions and, at the same time, a large production area is proposed. The research areas that can significantly impact increasing spirulina cultivation productivity are outlined. Results of studies confirm the relatively high productivity of spirulina cultivation, which is more than 30 g/l of dry biomass per 1 sq. m per a day.

Using DNA banks or gene libraries is the most efficient method of protecting and managing valuable, endangered, and rare gene pools. Genomic libraries are collections of bacteria colonies with restriction sites on their genomic DNA that contain desired genes from a specific organism. The “Scientific Center of AgroBiotechnology” branch of ANAU has created gene libraries of 34 plant species, which are preserved in the National Genebank of Crops and their Wild Relatives, which forms a basis for genomic selection. This allows genetic identification, barcoding, DNA formula decoding, and, most importantly, is the basis for genome identification. Based on the results, plasmids can incorporate restriction segments of genomic DNA and be efficiently transformed. The high level of correlation between the number of necessary clones and the efficiency of transformation of all studied plant species proves the completeness of the gene pool.

This study assessed potential risks associated with antibiotic residues in Armenian honey. Honey sample analysis revealed multiple antibiotics, in varying concentrations. Estimated daily intakes of antibiotics were calculated for different consumer clusters. The margin of exposure was determined based on acceptable daily intake values. The findings indicate that there are no risks to consumers regarding antibiotic residues in honey. However, it highlights the importance of controlling antibiotics in beekeeping practices to ensure honey safety.