https://dspace.mnau.edu.ua/jspui/handle/123456789/24813 2026-04-22T14:18:38Z https://dspace.mnau.edu.ua/jspui/handle/123456789/24383 Назва: Analysis of the calving-to-conception interval variation and it relation to milk production traits of dairy cows Автори: Крамаренко, Олександр Сергійович; Kramarenko, Alexander; Крамаренко, Сергій Сергійович; Kramarenko Sergej Короткий огляд (реферат): Intensive selection for milk production has resulted in unfavorable genetic correlations with fertility, contributing to longer calving intervals, increased insemination rates, higher culling levels, and rising costs of reproductive management. This study e x amined the effects of genetic and environmental factors on the calving-to-conception interval and its relationship with milk produ c tivity traits in Holstein cows. The analysis was based on data from cows that calved at PJSC ‘Plemzavod Stepnoy’ in Zaporizhzhia region , Ukraine , between 2014 and 2017. For each animal, 305-d milk yield, milk fat percentage, and the calving-to-conception interval were recorded and analyzed using the General Linear Model. The results showed that parity, year and season of calving significantly influenced the calving-to-conception interval, whereas the effect of sire was not significant. Younger cows generally conceived sooner after calving than older cows. Over the study period, there was a clear tendency toward shorter calving-to-conception intervals, suggesting improvement in reproductive performance. Cows calving in summer and autumn also had shorter intervals than those calving in winter or spring. The joint analysis of parity and the calving-to-conception interval indicated that reproductive efficiency was closely related to milk yield and composition. Cows with moderate calving-to-conception intervals (91–120 d) produced more milk of slightly higher quality than those with shorter or longer intervals. Overall, the findings highlight the importance of managing reproductive cycles to optimize both fertility and milk productivity in Holstein herds under the produ c tion conditions of southern Ukraine. 2025-01-01T00:00:00Z https://dspace.mnau.edu.ua/jspui/handle/123456789/24123 Назва: Economic efficiency of feeding piglets with milk replacer Автори: Moisei, I.; Povod, M.; Mykhalko, O.; Lykhach, M.; Gutyj, B.; Zlamaniuk, L.; Гиль, Михайло Іванович; Gill, Mikhail; Tsereniuk, O.; Shuplyk, V.; Shkurko, M.; Ovdiienko, K. Короткий огляд (реферат): The study aimed to assess the impact of additional milk replacer feeding in the first week after weaning on growth, survival, feed efficiency, and economic indicators of piglets' growth. The reduction of weaning age and high multiparity of modern sows cause stratification of piglet litter by weight. This reduces their adaptability to housing and feeding conditions during growth. The inclusion of 130 g of liquid milk replacer per day in the first week after weaning provided 27.4% weight gain, 21.1% weight gain at the time of transfer to fattening, 10.3% improvement in feed conversion, 21.1% increase in piglet market value and 12.2% increase in profitability. At the same time, there was a 3.0% decrease in the cost of feed per 1 kg of gain, a 13.1% reduction in treatment costs, a 3.1% decrease in the price of 1 kg of gain, which contributed to a 2.7% increase in profitability and 6.9% higher profitability. Along with the positive results, a 13.9% increase in daily feed consumption, a 23.1% increase in its cost, 10.3% higher treatment costs, a 23.0% increase in the price of growing a piglet, and a 4.1% lower profitability of growing a piglet was recorded. Therefore, using milk replacer improves piglet productivity but requires additional costs to be considered. 2025-01-01T00:00:00Z https://dspace.mnau.edu.ua/jspui/handle/123456789/21449 Назва: The influence of the castration method and the weight before slaughter on the indicators of the meat cuts of pig carcasses Автори: Mykhalko, O.; Povod, M.; Gutyj, B.; Гиль, Михайло Іванович; Gill, Mikhail; Verbelchuk, T.; Verbelchuk, S.; Луговий, Сергій Іванович; Lugovoy, Sergey; Shuplyk, V.; Kovalchuk, Y.; Koberniuk, V. Короткий огляд (реферат): The aim of the article was to investigate the dependence of the slaughter characteristics of boars and the method of their castration on the weight before slaughter. To carry out the experiment, 30 surgically and 30 immunocastrated male pigs weighing 100, 110 and 120 kg were taken and reared under the same conditions in an industrial pig complex. After completion, the pigs were slaughtered and the carcasses were cut into cuts. The weight and content of the cuts were examined separately in the shoulder-scapular third, back-loin third and pelvis-femoral third of all groups of experimental pigs. According to the experimental results, the influence of the castration method on the weight and content of meat cuts, bacon pieces and bones in the shoulder-scapular third was found to be in favour of the immunocastrated boars. The weight and content of meat pieces in the posterior lumbar third were the same in surgically and immunocastrated boars, with the exception of bones. Meat pieces, bacon and bones in the pelvic femoral third of the pelvis did not differ between surgically and immunocastrated male pigs. Increasing the weight before slaughter from 100 to 120 kg had a positive effect on the weight and meat piece content of the piglets in both castration methods. 2025-01-01T00:00:00Z https://dspace.mnau.edu.ua/jspui/handle/123456789/21131 Назва: Changes in the prooxidant-antioxidant system of rat hearts under the complex influence of food additives and their correction with melatonin Автори: Пшиченко, Вікторія Вікторівна; Pshychenko, Viktoriia; Cherno, V.; Larycheva, O.; Chebotar, L.; Петрова, Олена Іванівна; Petrova, Olena Короткий огляд (реферат): This study presents the results of research on changes in the prooxidant-antioxidant system of rat hearts under the combined effect of food additives and the correction of pathological shifts with melatonin. It was established that the complex influence of sodium glutamate, the synthetic dye Ponceau 4R, and sodium nitrite leads to an increase in lipid peroxidation products in heart homogenates and multidirectional changes in the antioxidant defence system. Initially, these changes manifest as an increase in enzyme activity, followed by a decrease, indicating the development of oxidative stress and the depletion of the enzymatic component of the antioxidant system, with damage mechanisms prevailing over protective mechanisms. The administration of melatonin during the last ten days of the study contributed to a reduction in lipid peroxidation processes and improved the balance of the prooxidant-antioxidant system. Thus, exogenous melatonin is a potentially useful agent for correcting oxidative stress in the myocardium. The study is a fragment of the research project “The influence of environmentally hazardous factors on the mechanisms of development of diseases of civilization and their correction with physiologically active substances”, state registration No. 0124U002163.; -; У роботі представлені результати дослідження змін прооксидантно-антиоксидантної системи серця щурів при комплексній дії харчових добавок та корекції патологічних зрушень мелатоніном. Встановлено, що комплексний вплив глутамату натрію, синтетичного барвника понсо 4R та нітриту натрію призводить до підвищення у гомогенаті серця рівнів продуктів ліпопероксидації та різноспрямованих змін системи антиоксидантного захисту, що спочатку проявляються зростанням активності ферментів, а потім їхнім зниженням, що свідчить про розвиток оксидативного стресу і вказує на виснаження ферментативної ланки антиоксидантної системи та переважання механізмів пошкодження над механізмами захисту. Введення мелатоніну протягом останніх десяти діб дослідження сприяло зменшенню інтенсивності процесів перикисного окиснення ліпідів та покращенню балансу ланок прооксидантно-антиоксидантної системи. Таким чином, екзогенний мелатонін є потенційно корисним засобом для корекції окислювального стресу у міокарді. 2025-01-01T00:00:00Z