Effect of anti-stressor nutritional supplement in combination with progesterone implant on estrus induction and conception rate in summer anestrus Murrah buffaloes

The present study was carried out to determine the effect of an anti-stressor nutritional supplement in combination with a progesterone implant on estrus induction and conception rates in summer anestrus Murrah buffaloes. In this study, 33 anovular lactating buffaloes (> 90 days postpartum) were monitored for one month and adjudged anovular through transrectal ultrasonography at 10-day intervals. Subsequently, buffaloes were divided into treatment (n=16) and control groups (n=17), and the treatment group buffaloes were given an anti-stressor feed supplement (a preparation consisting of sodium bicarbonate and additional minerals and vitamins ~ 100g daily) for 40 days, while the control group animals received no feed supplement and were fed the normal diet as per the farm schedule. A controlled internal drug-releasing device (CIDR, 1.38g progesterone, Pfizer Pharmaceuticals Ltd.) was administered intravaginally 15 days prior to the start of the feeding trial and was left in place. After 7 days, implants were removed, and 400 IU PMSG (Folligon, MSD Animal Health, i.m) and 500 ug Cloprostenol (Injection Vetmate, 2 ml, i.m) were administered at the time of implant removal. Fixed-time insemination using frozen-thawed semen was carried out at 48 and 60 h after implant removal. The feeding trial was continued until 15 days post-artificial insemination (AI), and CIDR was inserted intravaginally simultaneously in the control group and kept in place for 7 days, similar to the treatment group. Within 15 days of feed supplementation, 37.5% (6/16) buffaloes in the treatment group resumed cyclicity as compared to 11.8% (2/17) in the control group. In response to hormonal treatment, the overall estrus induction rate was 100% for both the treatment and control groups. No difference in estrus intensity was observed between the groups. Following fixed-time AI, the conception rate was lower in the treatment group (37.5%) as compared to the control group (64.7%). However, approximately 70% of buffaloes became pregnant within two AIs in both groups. Furthermore, no significant difference (P = 0.60) in overall conception rates was found between the treatment (93.7%) and control groups (87.4%) within 90 days of CIDR removal. However, a significant difference (P = 0.03) in conception rates was noticed between 30–90 days of CIDR removal between the two groups (56.2% vs 17.7%). In conclusion, the inclusion of anti-stress supplements along with CIDR supplementation may enhance estrus induction in postpartum anestrus buffaloes during the summer season.