Abstract
This study investigated the effects of prenatal herbal methionine supplementation on growth, puberty onset, reproductive efficiency, and blood metabolites in first-generation G1 Alpine doelings. Sixty pregnant multiparous goats (G0), each with at least three parturitions, were assigned during the last trimester of pregnancy to either herbal methionine (H-MET-G0; 1% Optimethione(®); n = 30) or a control group (CTL-G0; n = 30). Only female offspring (G1 doelings) were studied (H-MET-G1:19; CTL-G1:25) from weaning (45 days old) to 10 months (first breeding). G1 doelings were weighed and monitored weekly for metabolites, IGF-1, insulin, and progesterone. Ovulation of the G1 doelings was induced using vasectomized bucks, followed by breeding with intact bucks. Postweaning growth, age at puberty (H-MET-G1:216 vs. CTL-G1:229 days), and live weight at puberty (H-MET-G1:20.5 vs. CTL-G1:21.0 kg) did not significantly differ (p > 0.05). Age at puberty and conception were negatively correlated with live weight (p < 0.001). First-cycle conception rates were 81% in CTL-G1 and 66% in H-MET-G1, with similar days to conception (p > 0.05). The number of pregnant doelings and the number of kids in utero did not significantly differ (p > 0.05) between treatments. Plasma IGF-1 and insulin levels were significantly higher (p < 0.001) in H-MET-G1 doelings, whereas plasma metabolites related to nutrition showed no differences between groups (p > 0.05). Prenatal herbal methionine supplementation had no carry-over effect on growth, puberty onset, or reproductive efficiency. Age at puberty and conception were negatively correlated with live weight and positively correlated with IGF-1 and insulin levels.