Reproductive responses and progesterone levels of postpartum oestrus synchronization in goats with different body reserves

Abstract

Thirty adult goats were classified at parturition into two body condition score (BCS) groups: BCI (n=16) with a score of 2.7 and BCII (n=14) with a score of 2.0. On the fiftieth day postpartum, oestrus was synchronized by CIDR for 5 days. Upon CIDR removal (Day 0), they received 1 mL of PGF2α IM and mated for 72 hours. Kids were kept with does and weaned at 40 days of age. Blood samples were taken at 0, 1, 4, 8 and 21 days after CIDR removal for progesterone assay. The BCI group showed a greater weight loss compared to the BCII group, and BCS before synchronization was 1.9±0.08 and 1.6±0.07 for the BCI and BCII groups, respectively (P<0.05). The weaning weight of BCI kids was greater when compared to BCII (P<0.001). After CIDR removal, all females were marked and mated. Pregnancy rate was higher in BCI goats (87% vs 36%; P<0.05), as well as prolificacy (1.65 vs 1.25; P<0.05) and twinning rate (0.62 vs 0.25; P<0.05). Progesterone concentration was higher in pregnant does in BCI. A positive relationship was found between progesterone level at CIDR removal and BCS at parturition (0.57; P<0.01), also between progesterone level at 21 days after CIDR removal and BCS at parturition (0.47; P<0.05), or BCS before synchronization (0.51; P<0.05). We conclude that oestrus response to postpartum CIDR synchronization appeared to be slightly dependent on BCS. However, goats with low BCS at oestrus synchronization exhibited a reduction in pregnancy rate.

Use of castor meal (Ricinus communis L.) as a source of dietary protein in goats during the mating period: impact on reproductive and metabolic responses

“…In pregnant goats, there was a significant decrease in urea and LDH levels in goats fed DCM and CM, while GGT levels increased only in females fed with CM when compared to goats fed WCM. These results are not in agreement with Silva et al (2010), who reported that plasma urea levels in sheep with detoxified castor meal were unaltered by the end of the supplementation. In another study, also did not observe alterations in plasma levels of ALT and AST in sheep fed or castor meal detoxified for 21 days.…”

“…In previous studies by our group, we observed that the inclusion of 50% cashew bagasse in the diet of sheep during the post-partum period also did not influence the response to estrous synchronization (RODRIGUES et al, 2011). Thus, it is believed that the expression of estrous is directly related to the levels of the animal's body reserves (SILVA et al, 2011a), but not to the intake of alternative dietary sources. Besides, studies with goats (OLIVEIRA; GUIDO; LIMA, 2001) and cows (FLORES et al, 2006) demonstrated that the utilization of CIDR in estrous synchronization protocols is a highly efficient treatment.…”

“…These observations are in accordance with the findings of Kerbler et al (1997), who reported that the luteal secretion of P 4 is essential for the production of oocytes of good quality, as well as for embryonic survival in sheep. In addition, P 4 levels have been successfully utilized for the evaluation of ovarian function in goats (SILVA et al, 2011a) and sheep (RODRIGUES et al, 2011).…”

“…Upon removal of the CIDR, the goats received an application of 1 mL of prostaglandin F2α (Lutalyse ® , Pfizer, Kalamazoo, USA), as described by Silva et al (2011a). Next, males of proven fertility and marked in the sternal region were placed together with the females for a period of 72 h, allowing the mated females to be identified by the presence of the marker paint in the region of the croup.…”

Impact of body condition on postpartum features in morada nova sheep

“…The intense loss of body mass in ewes with a high BCS is the main reason for the increased performance of their lambs (SILVA et al, 2011). During the first weeks postpartum, the female responds to a negative energy balance through the mobilization of fat and muscle tissue to meet the energy demand during milk production (LAGO et al, 2001).…”