Effects of flunixin meglumine, recombinant bovine somatotropin and/or human chorionic gonadotropin on pregnancy rates in Nelore cows

Abstract

The objective was to compare pharmacological strategies aiming to inhibit prostaglandin F2 alpha (PGF(2α)) synthesis (flunixin meglumine; FM), stimulate growth of the conceptus (recombinant bovine somatotropin; bST) and progesterone (P(4)) synthesis (human chorionic gonadotropin; hCG), as well as their combinations, regarding their ability to improve pregnancy rates in beef cattle. Lactating Nelore cows (N = 975), 35 to 70 days postpartum, were synchronized and inseminated by timed artificial insemination (TAI) on Day 0. On Day 7, cattle were allocated into eight groups and received one of the following treatments: saline (S) on Days 7 and 16 (Group Control); S on Day 7 and FM on Day 16 (Group FM); bST on Day 7 and S on Day 16 (Group bST); bST on Day 7 and FM on Day 16 (Group bST + FM); hCG on Day 7 and S on Day 16 (Group hCG); hCG on Day 7 and FM on Day 16 (Group hCG + FM); bST and hCG on Day 7 and S on Day 16 (Group bST + hCG), or bST and hCG on Day 7 and FM on Day 16 (Group bST + hCG + FM). The aforementioned treatments were administered at the following doses: 2.2 mg/kg FM (Banamine®; Intervet Schering-Plough, Cotia, SP, Brazil), 500 mg bST (Boostin®; Intervet Schering-Plough), and 2500 IU hCG (Chorulon®; Intervet Schering-Plough). Pregnancy diagnosis was performed 40 days after TAI by transrectal ultrasonography. Pregnancy rates were not significantly different among treatments. However, there was a main effect of hCG treatment to increase pregnancy rates (63.0 vs. 55.4%; P = 0.001). Concentrations of P(4) did not differ significantly among groups on Day 7 or on Day 16. However, consistent with the higher pregnancy rates, hCG increased P(4) concentrations on Day 16 (10.6 vs. 9.6 ng/mL, respectively; P = 0.05). We concluded that hCG treatment 7 days after TAI improved pregnancy rates of lactating Nelore cows, possibly via a mechanism leading to induction of higher P(4) concentrations, or by reducing the luteolytic stimulus during maternal recognition of pregnancy.

Corpus Luteum Development and Function after Supplementation of Long‐Acting Progesterone During the Early Luteal Phase in Beef Cattle

“…; Rossetti et al. ); (ii) increased luteal tissue area in response to hCG treatment 2 or 5 days after oestrus (Howard et al. ; Maillo et al.…”

Pregnancy rates and serum 13,14-dihydro-15-keto-PGF2α concentrations in recipient Nelore heifers treated with meloxicam after the transfer of in vitro–produced embryos

“…Recently, the effects of flunixin meglumine, recombinant bovine somatotropin, and/or hCG on the pregnancy rates in Nelore cows were evaluated [23]. Regarding flunixin meglumine, the authors observed that an injection of 2.2 mg/kg on Day 16 after insemination did not significantly affect the pregnancy rates compared to nontreated cows and heifers (57.3% vs. 47.5%) or progesterone concentrations.…”

Nonsteroid Anti-Inflammatory Drugs to Improve Fertility in Cows

“…1 st group constitutes the control and given saline on 7 th and 16 th days; to the 2 nd group, saline on the 7 th day and flunixin meglumine on the 16 th day; to the 3 rd group, bST on the 7 th day and saline on the 16 th day, to the 4 th group, bST on the 7 th day and flunixin meglumine on the 16 th day, to the 5 th group, hCG on the 7 th day and saline on the 16 th day, to the 6 th group, hCG on the 7 th day and flunixin meglumine on the 16 th day, to the 7 th group, bST + hCG on the 7 th day and saline on the 16 th day, to the last group, bST + hCG on the 7 th day and flunixin meglumine on the 16 th day were administered. It was found out that the group only cured with hCG on the 7 th day showed a higher rate of pregnancy [85].…”