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According to the International Embryo Technology Society, the number of bovine embryos produced by in vitro fertilization technology is increasing every year. However, despite the large volumes of their production, the effectiveness of this method is still low and needs to be improved. Therefore, the purpose of this study was to compare the effectiveness of two commercial media -- Origio Sequential Series (Origio, Denmark) and a panel of products manufactured by Minitube (Germany) in terms of oocyte maturation and development of bovine embryos in vitro. At the first stage of the study, a comparative evaluation of oocyte maturation media was performed: based on TCM 199 (Minitube) and Universal (Origio) culture media. At the second stage, the protocols for culturing bovine embryos were compared: Minitube and the two-stage Origio culture protocol with changing media. Therewith, it was found that the use of TCM 199 medium for oocyte maturation is more effective compared to Universal. Thus, at 48 hours of cultivation (the initial stage of embryo development), 64.3 ± 1.0 and 60.3 ± 1.4% of 2-8 cell embryos were obtained, and on Day 8 -- 25.3 ± 1.0 and 20.0 ± 0.6% of blastocysts, respectively. The results of a comparison of bovine embryo culture protocols showed that when using both Minitube and Origio media, the percentage of division and the percentage of resulting embryos corresponded to their known values. It was found that the Minitube cultivation protocol is more effective than Origio. At 48 hours, the number of embryos obtained using the Minitube culture protocol was 1.3% higher compared to Origio, on Day 6 -- by 7.8%, and on Day 8 -- by 3.8%. The results obtained are a necessary component of the development of successful processes to produce bovine embryos in vitro with further implementation in the ruminant reproduction biotechnology [ABSTRACT FROM AUTHOR]

The use of biotechnological reproduction methods is a relevant issue since the embryo transfer, obtained after stimulating superovulation, can accelerate reproduction and improve the number of cattle. The purpose of the study was to evaluate the effectiveness of various schemes for stimulating superovulation in cows of the Ukrainian black-pock dairy breed. Therewith, the study analysed the ovarian response to the drug "FSH-Super" under different introduction schemes: Step-up (gradual increase in the dose) and Step-down (gradual dose reduction) and recorded the number of embryos suitable for transplantation. Donor cows were administered the drug "Estrofan" to synchronise the sexual cycle. After 7 days, the drug "Ovarelin" was injected, and after another 7 days, the injection of the drug "Estrofan" was repeated in the same dose. Stimulation of superovulation began on the 10th day of the sexual cycle with the drug "FSH-super" in the form of eight gradually increasing (Step-up) and gradually decreasing (Step-down) doses within 4 days. Artificial insemination was performed 12 and 24 hours after the start of oestrus. During the study, it was discovered that in the group of cows with gradual dose reduction of the drug "FSH-Super", 83.3% reacted with superovulation, and in the group with the gradual increase - only 71.4%. Therewith, the number of yellow bodies on two ovaries in a donor cow averages 15.6 and 9.2, respectively. An average of 12.4 and 7.8 embryos (Step-down and Step-up) were obtained from the donor, of which 7.8 and 4.2 are suitable for transplantation, respectively. However, in the group of cows with gradually decreasing doses, a higher number of embryos unsuitable for transplantation was obtained - 4.6 and unfertilised oocytes - 2.6, compared with the group of donors with gradually increasing doses, where these indicators are 3.6 and 1.0, respectively. Thus, the use of the drug "FSH-super" to donor cows according to the step-down introduction scheme allows getting more embryos suitable for transplantation. This will allow managing the biotechnological aspects of cattle reproduction and effectively and in a controlled manner accelerate the breeding process in farms of various forms of ownership, fixing the desired genotype in the herd [ABSTRACT FROM AUTHOR]

Mastitis is one of the most common diseases on dairy farms. It causes significant economic damage associated with the cost of treating sick cows, reduced milk yield and quality indicators of dairy products, and the risk of premature culling of animals. Treatment of cows with mastitis on dairy farms is carried out mainly with antimicrobial drugs, which are usually used without a preliminary test to identify the causative agent of the disease and determine its sensitivity to antimicrobial substances, which is an important part of the effectiveness of therapy. Increasing the resistance of bacteria to antimicrobial substances poses a threat not only to the animal but also to humans, as a consumer of dairy products. The availability of data on the sensitivity of mastitis pathogens to antimicrobial drugs makes it possible for veterinary doctors to choose the most effective antibiotic for treating animals with the shortest duration of treatment. The presented results of studies of breast secret samples taken from cows indicate that in 57.5% of cases, contagious pathogens of mastitis were identified. In particular, Streptococcus agalactiae made 24.1%, Staphylococcus aureus -- 18.4%, Corynebacterium spp. -- 7.2%, Streptococcus dysgalactiae-- 5.6%, Streptococcus uberis -- 2.2%. Environmental pathogens accounted for 42.5% of the total number of isolated isolates, among which Streptococci represented gram-positive microflora at 11.5 Streptococcuscus spp. (6.2% Streptococcuscus parauberis (4.4% Streptococcuscus Bovis (0.9%) and Staphylococcus spp. -- 10.3%. Gram-negative microflora is 20.6%, among which the largest percentage belongs to E. coli -- 8.4% and Klebsiella pneumonia -- 1.9%. Mastitis caused by yeast accounted for 1.4% of all diagnosed pathogens. Antimicrobial sensitivity was evaluated using the disk diffusion method (Kirby-Bauer). According to the results of determining the sensitivity of mastitis pathogens to antimicrobial substances, it was found that the highest sensitivity of the isolated isolates was to Ceftiofur, Amoxicillin/clavulanic acid, Rifampicin, Amoxicillin, Gentamicin, Ampicillin, Bacitracin, Cephalexin, Cloxacillin, Enrofloxacin, Trimethoprim/sulfamethoxazole, Oxytetracycline, Lincomycin. The least sensitive -- to Spiramycin, Tylosin, streptomycin, neomycin, Marbofloxacin, Tilmicosin, and Danofloxacin. [ABSTRACT FROM AUTHOR]