Effect of peripartum nutritional management on plasma profile of steroid hormones, metabolites, and postpartum fertility in buffaloes

Aim: The aim of this study was to evaluate the influence of peripartum protein and minerals supplementation on plasma profile of steroid hormones, metabolites, and fertility in rural buffaloes.

Material and methods: A total of 85 advanced pregnant (~8 months) pluriparous buffaloes selected at farmers' doorstep in three tribal villages of Middle Gujarat were randomly divided into two groups, viz., control (n=45) and nutrients treatment (40). The buffaloes of treatment group (n=40), in addition to farmers feeding schedule/control, received daily 1.5 kg compound concentrate mixture (22% CP) and 50 g of chelated ASMM for 2 months each pre- and post-partum. Further, 15 buffaloes, each of control and treatment group, were injected parentrally (deep i/m) with 5 ml of micro-minerals (each ml containing Se, Zn, Cu and Mn at 5, 40, 15 and 10 mg, respectively), twice 2 months before and on the day of calving, keeping rest of the animals (control, n=30 and treatment, n=25) as controls. Blood sampling was done on days -60, -30, -15, 0, 15, 30, 45, and 60 peripartum for estimation of plasma progesterone and estradiol by standard RIA techniques and other metabolites using assay kits on biochemistry analyzer. The puerperal events and postpartum fertility were monitored through history and by fortnightly palpation per rectum till day 45 and then again at 120 days postpartum for both the groups and subgroups.

Results: The mean plasma progesterone concentrations in all groups declined significantly (p<0.05) from day 60 to day 15 prepartum, reached to the basal levels (<0.5 ng/ml) on the day of parturition, and subsequently, reduced nonsignificantly till day 15 postpartum and then showed a rising trend from day 30 to 60 postpartum with significantly higher values at day 45 and/or 60. The mean plasma estradiol values increased with approaching parturition and were at its peak on the day of calving (p<0.01). Thereafter, there was a rapid fall in the levels by day 15 and it remained low till day 45-60 postpartum. The blood glucose values showed an increasing trend with advancing gestation, reaching the highest on the day of calving, dropped significantly (p<0.01) within 15 days postpartum, and thereafter showed consistent values. The buffaloes supplemented with peripartum nutrients maintained significantly (p<0.05) higher blood glucose concentrations than the control during the peak lactation. The plasma protein levels varied significantly (p<0.05) between days within the group with the lowest values on the day of calving, as well as between groups with higher (p<0.05) values on day 30 and 60 postpartum in treated group. Micro-minerals injected did not reveal significant influence on steroid hormones, blood glucose, or plasma protein. The mean plasma total cholesterol was significantly lower (p<0.05) in treatment than the control group. The mean values in micro-minerals injected subgroup were higher than the non-injected control subgroup during postpartum phase. The mean plasma triglyceride values in the pregnant buffaloes under both the groups and subgroups gradually decreased as parturition approached with significantly lowest values on the day of calving. The values increased nonsignificantly by day 15 and then remained steady throughout postpartum period without influence of nutrient supplementation or micro-minerals injection. The incidence of retained fetal membranes (RFMs) was 5.00 and 13.33% in treatment and control groups, respectively, with placental expulsion time of 3.27±0.37 and 4.44±0.53 h (p>0.05). The micro-minerals injection appreciably reduced the incidence of RFMs and significantly (p<0.05) reduced the placental expulsion time over non-injected controls. In treatment group, the period for involution of uterus was significantly shorter (29.39±0.50 vs. 32.12±0.82 days, p<0.05), with early onset of first postpartum estrus (67.65±1.67 vs. 79.43±3.06 days, p<0.01), shorter service period (90.89±4.41 vs. 105.09±4.76 days, p<0.05) and higher conception rate (55.00 vs. 40.00%) than in control group. The micro-minerals injection apparently and/or significantly improved all these traits in both the groups. Thus, the postpartum reproductive performance was significantly improved in treated than control groups and subgroups.

Conclusion: The results showed that nutrient supplementation in terms of high protein concentrate, ASMM and injection of sustained release micro-minerals (Se, Zn, Cu, and Mn) during transition period minutely altered the plasma steroid hormones and blood metabolites though it significantly improved the postpartum reproductive performance in buffaloes under field conditions.