Energy supplementation and its effect on cholesterol levels and preovulatory hormonal profile in cows

摘要

A negative energy balance in cows results in a delayed postpartum ovulation, due to the lack of metabolites for hormone secretion, affecting the profitability of milk production. The aim of this work was to valuate the effect of protected fat supplementation on blood cholesterol concentration, progesterone, estradiol and LH preovulatory hormone in cows of Paipa municipality, Boyacá. Twelve Holstein cows were used; they were kept consuming kikuyu, clover and false poa pasture and water ad libitum. Three randomized groups were formed for the provision of the following diets: Control diet, D1: 200 g of protected fat (Megalac - E ®) and D2: 400 g of protected fat. The supplementation period was 60 days and blood sampling was examined in the preovulatory peak with ultrasound evaluation, approximately 30 to 90 days postpartum. Blood samples were sent to a laboratory for the quantification of each parameter. Protected fat supplemented cows showed an increase in cholesterol, progesterone and estradiol levels, regarding the control group with statistically significant differences (p0,05) between groups; regarding LH, there were differences between D2 and the other two groups (p0,05). The inclusion of supplements such as protected fat in the diet of fresh cows is as an adjuvant for the production of gonadotropic hormones and steroids that are directly related to the next ovulation.