Effects of Transition Period Nutrition on Lactation Performance, Metabolic Profiles and Reproductive Efficiency in Indigenous Dairy Cattle

A study was conducted to evaluate the effect of Bypass Fat and Vitamin E supplementation on milk production, composition, plasma metabolites, and reproductive performance in postpartum cows during the periparturient period. Twenty-one transition indigenous cows were divided into three groups: T1 (control, n=6), T2 (BF, n=8) and T3 (BF+Vit E, n=7).  The Control group received a basal ration as per ICAR (2013) guidelines, while T1 was additionally supplemented with Bypass Fat @ 50 g/animal/day and T2 with Bypass Fat @ 50 g + Vitamin E @ 3000 IU/animal/day, from 21 days prepartum to 21 days postpartum. Blood samples were collected on days -21, -14, -7, 0, 7, 14, and 21, and milk yield and composition were recorded during the first 21 days of lactation. Uterine involution and ovarian activity were assessed via ultrasonography on days 15, 25, 35, and 45 postpartum, with pregnancy confirmation on days 28-30 and 50 post-AI. Plasma glucose and cholesterol levels were significantly higher (P<0.05), and NEFA concentrations were significantly lower (P<0.05) in both treatment groups compared to the Control. No significant differences (P>0.05) were observed in dry matter intake (DMI), body weight (BW), milk yield, and milk composition, except for a significant reduction (P<0.05) in somatic cell count (SCC) in the T2 group. Uterine horn diameter was significantly larger (P<0.01) in the Control group on day 45 postpartum. No significant differences (P>0.05) were found in the total number and size of antral follicles, calving to first estrus interval, calving to conception interval, or number of services per conception. Pregnancy rates were 50% in the Control group and 66.66% in both T1 and T2 groups. It can be concluded that Bypass Fat supplementation, alone or with Vitamin E, improved energy balance, uterine involution, and conception rates, but did not significantly affect milk yield and composition, except for a reduction in SCC in the T2 group.