Изучили репродуктивные функции коров в зависимости от молочной продуктивности и количества лактаций путем регулярных гинекологических обследований, а так же причины и характер нарушений. Установлено, что нарушения воспроизводительной функции коров увеличиваются с ростом молочной продуктивности, максимально осложняясь у 43 коров 6 и более лактаций, а продолжительность сервиспериода достигает 145 дней при средних значениях индекса осеменения 3,2. У коров по 1 и 2 лактации частота репродуктивных осложнений составляет в среднем 21. Анализ материалов исследований по состоянию репродуктивной активности обследованных коров чернопестрой породы в условиях Республики Башкортостан показывает, что основной причиной снижения плодовитости является наличие гипофункции яичников, которая может составлять до 37,1, кист 15,2 в высокопродуктивных стадах и 34,5 персистентных желтых тел в низкопродуктивных. Применение комплекса биорегуляторов позволяет получать достаточно высокие показатели прихода коров в охоту от 74 до 91 животных от общего их числа. Наибольшие значения показателя плодотворного осеменения (до 75) были установлены у коров по 3 и 4 лактациям. Обследование выявило, что увеличение молочной продуктивности приводит к увеличению нарушений воспроизводительной функции. По нашим данным, в высокопродуктивных стадах диагностировано гинекологически больных коров в 2,1 раз больше, чем в низкопродуктивных.Reproductive functions of cows depending on milk productivity and the number of lactation periods, as well as the reasons of reproductive impairments, were studied using regular gynecological examinations. It was found that reproductive function impairment in cows is increased with the growth of milk productivity with the complication reaching maximum in 43 of cows for 6 and more lactation, and the length of the service period amounts to 145 days with the average value of insemination index being equal to 3.2. During lactation periods up to 1 and 2 the average frequency of reproductive impairment in cows is 21. The analysis of research materials concerning reproductive activity of examined cows of blackandwhite breed in the conditions of the Republic of Bashkortostan shows that the main reason of decrease in breeding performance lies in the presence of ovary hypofunction which can amount to 37.1, cysts 15.2 in highly productive herds, and 34.5 of persistent yellow bodies in those with low productivity. The use of bioregulator complexes allows achieving rather high values of cows coming in heat from 74 to 91 of animals from the total quantity. The highest values of successful insemination (up to 75) were registered in cows during lactation periods 3 and 4. Examination found that improvement of milk productivity leads to the increase in reproductive function impairment rate. According to our information, the number of cows with gynecological diseases in highly productive herds was higher than in those with low productivity by 2.1 times.

A method for improving the reproductive performance of first-calf heifers using a complex mineraland vitamin feed additive is presented to the production. The animals of the control group were fed according to the main diet accepted in the farm and mineral matters. The animals from group I were fed the main ration with 120 g of the complex mineraland vitamin feed additiv per head according to recipe No.1. The animals from group II received the main ration with 120 g of the feed additive per head according to recipe No.2. The cow mating index of the first heifers of the control group is 2.1, which is0.48 and 0.60 times higher than in groups I and II. The highest rate of fecundation showed the cows of the experimental group II. It made up 63%, 7% higher than the experimental group I(56 %) and 18% higher than the control group (45 %). After the second fecundation, the conception rate in group II was 37%, which is 18% higher than in the control group and 7% higher than in animalsof group I. The calf crop in all groups was 100%.

Relevance. The most important condition for increasing the competitiveness and profitability of dairy cattle breeding is to increase the duration of productive use of the breeding stock and, especially, highly productive cows. It is known that the more intensively animals are used, the less costs per unit of production, the more profitable and profitable milk production becomes.Methods. The research was carried out based on the materials of the primary zootechnical accounting of the SELEX program of retired Holstein cows from 2017 to 2019 in the herd of LLC «A7 Agro-RB» of the Zianchurinsky district of the Republic of Bashkortostan. To study the effect of the level of productivity of mothers on the duration of use and lifetime productivity of cows-daughters, the animals were divided into groups depending on the level of milk yield of mothers for the first lactation with a class interval of 1000 kg: group I — up to 5000 kg, II — 5001–6000 kg, III — 6001–7000 kg, IV — 7001–8000 kg, V — 8001 and more.Results. The longest period of economic use was distinguished by daughters with mothers' milk yield for the first lactation up to 5000 kg — 3,30 lactations, which significantly exceeds the average values for the herd (2,58 lactations). The greatest lifetime milk yield (21 003 kg) was characterized by daughters from group IV. Their superiority over the animals of group I was 154 kg, group II — 391 kg, group III — 1639 kg and group V — 4303 kg. The highest average milk yield on the 1st day of the daughterʼs life was in animals of group IV — 12,01 kg, surpassing peers from group I by 2,46 kg, group II — by 1,84 kg, group III — by 1,54 kg and group V — by 0,93 kg.

No abstract

One of the key areas of development of the cattle breeding industry in Russia is the creation of effective technological methods. They allow to carry out the improvement and establishment of new resource-saving systems for breeding young animals at an accelerated pace. It is essential to meet the modern requirements of meat production as an ecologically safe product. The aim of the research was to enhance the fattening qualities of Hereford bull calves while using mode-setting suckling of various ratios as an element of resource saving. The study was performed on "SAVA-Agro-Yapryk" OOO of the Tuymazinsky district of the Republic of Bashkortostan. The determination of the efficiency of the use of free and mode-setting suckling of various ratios made it possible to identify an effective method of raising young meat cattle. A three-fold mode suckling is used with separate keeping of young animals and mother cows. This makes it possible to keep the optimal microclimate parameters in the calf house, contributes to the rapid early adaptation of calves to the consumption of coarse feed and concentrates. It has a positive effect on the growth and development of calves and their meat productivity at the age of 18 months according to the parameters of removable fat mass, carcass mass and interior fat mass. All this promotes an increase in the sale of beef and an improvement in the level of production profitability to 13.93%.