Resumo

MARIN-AGUILAR, Alejandra M et al. Resumption of ovarian activity and lipid metabolites in lactating cows supplemented with vegetal oil during early postpartum. INCI [online]. 2007, vol.32, n.3, pp.180-184. ISSN 0378-1844.

To evaluate the resumption of ovarian activity (RAO) and lipid metabolite serum concentrations in lactating cows supplemented with vegetal oil during early postpartum, 18 Holstein Friesian cows of third parity; 597.3 ±50.2kg and body condition of 3.5 ±0.6 were randomly distributed in two groups. Nine cows were supplemented with 500g of vegetable oil in the diet (CAV) and nine cows were not supplemented (SAV, control group). The CAV group received the supplementation during eight weeks starting from the second week postpartum. RAO was determined when P₄ concentrations were maintained ³1ng/ml by two consecutive weeks. To measure P₄ concentrations and lipid metabolites (cholesterol, high and low density lipoproteins, triglycerides and total lipids), blood samples were collected weekly during the supplementation period. P4 concentration was determined by radioimmunoessay and lipid metabolites by enzyme methods and spectrophotometry. The CAV group began RAO seven days before than SAV group (23.3 ±12.8 vs 29.6 ±12.4 days, P<0.05). P₄ concentration was not affected by supplementation (1.48 ±0.31 vs 1.15 ±0.31 ng/ml for SAV and CAV, respectively); however, a significant effect (P<0.05) was observed between 28 and 56 days for the CAV group. Cholesterol, triglycerides and total lipids concentrations were different between treatments (109.3 ±9.9 vs 135.7 ±9.9; 29.3 ±7.9 vs 41.3 ±7.9 and 366.2 ±50.3 vs 434.2 ±50.3mg/dl for SAV and CAV, respectively; P<0.05). The vegetable oil supplementation reduces the resumption of postpartum ovarian activity interval and increases serum concentrations of cholesterol, triglycerides and total lipids in lactating cows.