14 ENHANCEMENT OF THE EARLY RECOVERY OF OVARY AND UTERUS FUNCTIONS BY TREATMENT OF eCG AND POVIDONE-IODINE IN POSTPARTUM JAPANESE BLACK CATTLE

The aim of this study was to evaluate the effect of administration of eCG and intrauterine infusion of povidone-iodine to promote the early recovery of ovary and uterus functions in early stage after delivery on postpartum beef cows. Thirty-three postpartum Japanese Black cows without retention of placenta were used for this investigation. After delivery, cows nursed colostrums to calves for several hours in a pen, and then were separated from calves and returned into a barn managed in a group. In experimental group (n = 14), on Day 10 (Day 0 = day of parturition), an intramuscular administration of 500 IU of eCG and infusion of 30 mL of 2% povidone-iodine into the uterus body were conducted. The untreated cows delivered in the same period were compared as a control group (n = 19). Cows were inseminated artificially using commercial Japanese Black frozen–thawed semen when standing oestrus was detected until Day 90. Pregnancy diagnosis was performed 30 days after insemination by ultrasonography. For all of the experimental group and 8 cows in the control group, the diameter of follicles >8 mm and the diameter of cross-section between endometrium in uterus of the implanted side at the point of ~2 cm from bifurcation of the uterus were measured using an ultrasound scanning machine connected to a 7.5-MHz convex probe. This monitoring was carried out every 10 days from Day 10 until the day of first oestrus (= insemination) or until Day 80 for non-returned oestrus cows. Data were analysed using Fisher’s exact test and ANOVA. The ratio of returned oestrus by Day 90 was 100% (14/14) in experimental group and 89.5% (17/19) in control group. The first oestrus day postpartum in the experimental group and the control group was the almost same: 52.9 ± 12.1 (24–88) days and 57.2 ± 19.9 (29–78) days, respectively. The conception rate until Day 90 tended to be higher (P = 0.07) in the experimental group (78.6%, 11/14) than in the control group (47.4%, 9/19). The days inseminated to cows that were conceived, was almost same between the experimental group (57.5 ± 18.6, 24–87 d) and the control group (55.4 ± 12.9, 36–78 d). The ratio of cows observed follicles more than 8 mm, was higher in the experimental group than control group on Day 50 (90.9% v. 50.0%; P = 0.09) and Day 60 (66.7% v. 0%; P < 0.05), respectively. The diameter of uterus tended to be lesser in the experimental group than in the control group on Day 30 (16.9 ± 2.8 mm v. 19.2 ± 2.8 mm; P = 0.09), and that regressed linearly to Day 30 in the experimental group however that was prolonged until Day 40 (16.4 ± 1.7 mm) in the control group. These results indicate that administration of eCG and uterus infusion of povidone-iodine at an early stage postpartum may promote the early recovery of ovary and uterus functions in beef cows. This research was supported by a grant from the Research Program of MAFF, (REP1004) Development of Innovative Technology for Animal Reproduction.