Italian Journal of Animal Science (Oct 2011)
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 (Pvs 36%; Pvs 1.25; Pvs 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.
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