Liliane Moreira Silva

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

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.

Embryo production and gene expression in superovulated goats supplemented with de-oiled castor cake before and after detoxification treatment

The use of alternative protein sources that do not impair animal performance is a feasible option to reduce costs associated with animal supplementation. Previous studies indicate that castor cake has a high protein value and good ruminal degradability, making it an attractive alternative dietary source for ruminants. Thus, the aim of this study was to evaluate the effects from ingestion of castor cake (treatment CC) or detoxified castor cake (treatment DCC) on serum IgG levels, in vivo production of goat embryos, and the expression profile of genes related to embryonic development, metabolism, and oxidative stress. The results showed the presence of IgG against ricin only in animals of the CC group. The ovulation rate and the production of transferable embryos in animals of the CC group were lower (P < 0.05) than in the animals fed without castor cake (WCC), but neither group differed significantly from the DCC group. There was no effect of type of diet on the expression of the IGF-IR, IGF-II, and GLUT-1 genes in goat embryos produced in vivo. However, the relative expression of mRNA for the HSP 70.1 gene was significantly higher (P < 0.05) in the CC group than in the WCC group, but did not differ from that of the DCC group. In conclusion, this study showed that supplementation with detoxified castor cake can be used for goat feeding, but caution is necessary when providing castor bean meal in the feed of superovulated breeding females, because ricin in the diet, even at low concentrations, altered IgG levels and the expression of mRNA for HSP 70.1, effects that were accompanied by a lower rate of transferable embryos.

Reproductive responses and productive characteristics in ewes supplemented with detoxified castor meal for a long period

The objective of the present study was to evaluate the effects of supplementation with detoxified castor meal (DCM) in the diet of ewes during pregnancy, partum, and post-partum on the weight development of their offspring and at slaughter. The study included 56 ewes with synchronized estrus that were naturally mated. At the beginning of pregnancy and in post-partum, hepatic and renal function-related parameters and progesterone levels were measured. At slaughter, the proximate composition and fatty acid profile were determined in the loin of ewes. There was no effect of diet on reproductive response after estrus synchronization. At the beginning of pregnancy, albumin and creatinine levels were lower in the DCM group. Supplementation with DCM did not alter the weight or body condition of ewes at partum. However, at weaning, the DCM group showed a higher loin-eye area (LEA) in relation to the group fed diets without detoxified castor meal (WDCM). At partum, as well as at weaning, the offspring of the ewes supplemented with DCM had a larger LEA than the WDCM group. In post-partum, levels of glucose, urea, protein, and cholesterol were lower in the DCM group. The return to cyclicity was similar in both groups, with an average of 47 days after partum. At slaughter, neither anatomical and carcass components nor the results of the proximate analysis were affected by the type of diet, except for an increase in heptadecanoic acid in the DCM group. Supplementation with detoxified castor meal in the diet of ewes does not affect lambing, pregnancy, prolificacy, return to cyclicity, milk production, blood biochemical parameters, or carcass characteristics.