УПРАВЛІННЯ ВІДТВОРЕННЯМ ДІЙНОГО СТАДА

Abstract

В статті розкривається проблемні питання відтворення молочного стада великої рогатої худоби. Досліджуавався вплив рівня молочної продуктивності корів на час їх продуктивного використання в стаді, Вивчався зв'язок між надоєм молока і кількістю отелень у корів. Визначався коефіцієнт відтворення стада, який вказує на необхідну кількість нетелів у господарстві для заміни вибулих зі стада корів. Проведено аналіз і розглядався вплив на коефіцієнт відтворення стада деяких технологічних параметрів виробництва.

В статье раскрываются проблемные вопросы воспроизводства молочного стада крупного рогатого скота. Исследовалось влияние уровня молочной продуктивности коров на время их продуктивного использования в стаде, Изучалось связь между надоем молока и количеством отелов у коров. Определялся коэффициент воспроизводства стада, который указывает на необходимое количество нетелей в хозяйстве, для замены выбывших из стада коров. Проведен анализ и рассматривалось влияние на коэффициент воспроизводства стада некоторых технологических параметров производства.

The study was conducted using herds on the neighbouring farms in the North of Ukraine, namely Zorya Ltd in Krasnograd sub-region of Kharkiv region, Ryasnyanske Ltd in Krasnopillya sub-region and Mayak Ltd in Trostyanets sub-region of Sumy region. The following factors were examined: the impact of cows’ milk productivity on their longevity in dairy herds; number of calvings per cow per lifetime; number of heifer-calves born per 100 cows; heifer retention rate on herd level. The relationship between cows’ milk yields and calvings per lifetime was also explored. The effect of several technological parameters on the herd-replacement rate was examined in depth. The herd-replacement rate which is the number of heifers required to replace productive cows in the herd was determined. The analysis of the obtained results shows the negative relation between milk yield per lactation of a cow and the number of calvings over the cow’s productive life. It was found that cows with milk yields higher than 9,000 kg per lactation were culled from the herd at the age of 6-7 years with 3.6 successful calvings. Cows with milk yields of 5,000 kg per lactation and lower calved successfully 5-6 times. The herd-replacement rate reflects the reproductive ability of the herd quite well. If the rate is higher than 1, the herd size is to increase; if the rate is lower than 1, there are some reproductive issues and the farm should consider improvement of the number of calvings per cow lifetime, as well as the heifer retention rate. In the herds on farms which were evaluated the number of calvings in high-yielding cows averaged 3.6 that corresponded to the herd-replacement rate of 1.2, which is indicative of the fact that the process of the herd replacement is under control. We have examined the effect of the heifer retention rate on the process of herd replacement. It was found that with this rate increasing on herd level, there is a positive response of the herd-replacement rate. For example, with the heifer retention rate of up to 85% we produce extra 50 replacement heifers. Implementation of modern techniques for the reproductive management using sexed semen that allows of producing up to 90% heifer calves born per 100 cows enables to control the reproductive performance of the herd. As a case in point, with unchanged number of calvings and heifer retention rate it is feasible to produce extra up to 130 heifers. Sexed semen has been still used on Zorya farm in Krasnograd sub-region of Kharkiv region for some period already.