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

Abstract

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.