Nelcio Antonio Tonizza de Carvalho

The objective was to evaluate the influence of nonsteroidal anti-inflammatory drugs on the duration of the luteal phase, progesterone concentrations and pregnancy rates in buffaloes undergoing embryo transfer. Twenty-nine buffaloes were synchronized. After estrus detection, the recipients were divided into three groups: Control (uterine manipulation), Flunixum Meglumine (manipulation + administration) and Firocoxib (manipulation + administration). Ultrasound evaluations and hormonal dosages were performed on days 6, 12 and 18 to determine the plasma concentration of P4 and the functional duration of the corpus luteum. The control group presented a larger CL area on day 0 than the FM group, there was a significant increase in plasma progesterone concentration between D6 and D12 (P < 0.05), and a significant decrease between D6-D18 and D12-D18. Additionally, 8 buffalo cows underwent in vitro embryo transfer and were divided into three groups: CONT (manipulation of the reproductive tract), FM group (manipulation + administration) and FIRO group (manipulation + administration). Pregnancy diagnosis was performed at 30 and 60 days. No statistically significant differences in pregnancy rates were observed between groups. It was concluded that a single application of FM and FIRO at the time of embryo transfer did not significantly increase conception rates.

This study compared the plasma progesterone concentrations from pregnant and non-pregnant buffaloes to identify non-pregnant females and submit cows earlier to oestrous resynchronization. Forty-four multiparous mix-breed Murrah buffaloes were selected for the study. The cows were subjected to hormonal oestrous synchronization and separated into 4 groups, P12 (pregnant, n = 8) and P18 (n = 8) at 12 and 18 days post-insemination; NP12 (non-pregnant, n = 7) and NP18 (n = 7) at 23 and 29 days after the onset of synchronization, respectively. The embryos and blood were collected, and the plasma was separated for centrifugation and used to determine progesterone concentration. Progesterone concentration was higher in P18 than P12 (p = .02) and NP18 groups (p < .001). The steroid was also increased in the P12 group compared with NP12 (p = .031). There was no difference between NP12 and NP18 (p = .906). We conclude that the plasma progesterone concentration can be an alternative to identify earlier non-pregnant buffaloes, advancing the oestrous resynchronization or natural service to improve productivity.

The aim of this study was to evaluate different times for timed artificial insemination (TAI) in buffalo submitted to a P4/E2/eCG-based protocol. In this study, 204 buffaloes were distributed into one of two groups (TAI56, n=103 and TAI64, n=101). At a random stage of the oestrous cycle (Day 0 = D0), in the morning (TAI56, a.m.) or afternoon (TAI64, p.m.), buffaloes received an intravaginal progesterone device (P4; 1.0 g) plus EB (2.0 mg i.m.). On D9 a.m. (TAI56) or p.m. (TAI64), the P4 was removed and buffaloes received PGF2a (0.53 mg i.m. sodium cloprostenol) and eCG (400 IU i.m.). On D10 a.m. (TAI56) or p.m. (TAI64), 24 h after P4 removal, buffaloes were treated with EB (1.0 mg i.m.). Buffaloes from TAI56 and TAI64 were inseminated 56 and 64 h after P4 removal (D11, p.m. and D12, a.m., respectively). Ultrasound examinations were performed on D0 to ascertain ovarian follicular status, at TAI to measure the diameter of the dominant follicle (DF) and D42 for pregnancy diagnosis. The statistical analysis was performed using the GLIMMIX procedure of SAS®. There was no difference between TAI56 and TAI64 for the diameter of the DF at TAI and the pregnancy per TAI. It was concluded that TAI 56 or 64 h after P4 removal did not affect fertility in buffaloes submitted to the induction of ovulation with EB. The present research supports that is possible to perform TAI at any time throughout the day in buffalo synchronized during the non-breeding season.