The influence of exploitation on the involution of reproductive organsin highproducing dairy cows

Abstract

The purpose of this work is to determine the effect of lactation duration (240 and 340 days), and subsequently the level of feeding ("moderate" and "forced" feeding) in the postpartum period on the involution of the genitals, the timing and quality of the first stage of sexual cycle arousal in highly productive cows. The work was carried out on a breeding farm, cows of the Kholmogorsky breed, aged from 3 to 6 years, with an average weight of 550 kg, after the first and second lactation. It was found that 240-day lactation, moderate lactation from 15 to 32 days after calving, allow a favorable effect on the body, the completion of genital involution (23.3±0.87 days) and the quality of formation of the 1st stage of ovarian cycle arousal (80 %) after calving. 340-day lactation, forced lactation from 15 days after delivery, where the diet contains up to 54.2% of the total nutritional content of concentrates, i.e. they are consumed up to 478 g per 1 kg of milk, leads to an increase in the respiratory rate and pulse, a decrease in the number of scar contractions, a decrease in serum total calcium, carotene, alkaline reserve and sugar, an increase in inorganic phosphorus and total protein (compared to the experimental groups), a delay in the completion of genital involution (44.9±1.20 days), a decrease in the quality of formation of the 1st stage sexual cycle (10 %), culling (90 %).