The main objective of this study was to determine if administration of meloxicam, a cyclooxygenase (COX) two inhibitor, to heifers in which embryo transfer (ET) is more difficult and requires a greater manipulation of the tract, would be beneficial. Nulliparous recipient heifers were divided in two groups: CON (n = 102), in which animals received 10 ml of saline IM (the same volume of meloxicam) and MEL (n = 105) animals that were treated with meloxicam. According to the degree in passing the catheter, recipients from both groups were classified as Grade I, easy (< 60 s), and Grade II (more than 80 s), difficult. Immediately after embryo transfer, MEL recipients received an injection of 200 mg of meloxicam (10 ml).There was no difference in the pregnancy rates on Day 35 considering animals which presented Grade I cervix independently whether the treatment was performed or not (p = 0.22). There was a statistical difference in the pregnancy rates (p < 0.01) between both groups (49.0% and 66.7% for CON and MEL, respectively) when cervical grade was not considered, on Day 35. Considering the animals that presented Grade II cervix, the pregnancy rate was higher for MEL (21.15% and 78.84%, respectively) in both examinations (p < 0.01).The authors concluded that meloxicam had a positive influence on general pregnancy rate of treated heifers in comparison to non-treated heifers. It was also observed that pregnancy rate was not influenced by meloxicam administration in Grade I heifers. Treatment increased the pregnancy rate of Grade II heifers.

The aim of this study was to establish a comparison between heterospermic and monospermic semen on the pregnancy rate of fixed-time AI Bos indicus cows. The experiment was conducted in the state of Mato Grosso, Brazil, during December 2010 and February 2011. Multiparous (n = 173) and primiparous (n = 204) Nelore cows, 45 ± 15 days postpartum, were evaluated on body condition score (BCS; score 1 to 9), and those that presented BCS between 5 and 8 were selected. Two protocols of estrous cycle synchronization were performed (PeCG and Pshang). Synchronization of the estrous cycle was achieved with the aid of the following protocol: on Day 0, all animals were treated with a progesterone vaginal implant with 1.9 g of progesterone combined with an IM injection of 2 mg of estradiol benzoate. On Day 7, an IM injection of 12.5 mg of dinoprost was administered. On Day 9, implants were withdrawn and the animals received an IM injection of 0.5 mg of estradiol cypionate. On Day 9, part of the animals (n = 222) received an IM injection of 300 IU mg of eCG (PeCG) and the other part (n = 155) had their calves removed for 48 hours (Pshang). All animals were inseminated 46 to 52 h after the end of the protocol. Cows were allocated randomly in 4 groups according to the donor male sample in the semen straw and groups were designated as MA (monospermic straw from bull A; n = 110), MB (monospermic straw from bull B; n = 102), MC (monospermic straw from bull C; n = 108), and HT (heterospermic sample from bulls A, B, and C; n = 57). Commercially available semen straws from Aberdeen Angus donors were used (ABS Pecplan, Brazil). Pregnancy diagnosis was performed 35 days after AI using real-time ultrasonography. Results are summarized in Table 1. There was no statistical difference between MA, MB, MC, and HT in any group according to the chi-square test (P > 0.05). However, there was a remarkable difference in pregnancy rates among the 3 bulls tested considering both protocols, probably due to the variation in the ovulation moment. Table 1.Pregnancy rates of Nelore cows submitted to FTAI protocol inseminated with monospermic (bull A, B, or C) or heterospermic (HT) semen