Oral administration of rumen-protected choline to ewes during the periconceptional period skews the sex ratio of lambs

Modification of the mother's environment early in pregnancy has been reported to alter characteristics of the resultant offspring. Here, it was shown that feeding a form of the nutrient choline that escapes destruction in a ewe's stomach influenced the sex ratio of the lambs (increasing the fraction that were female) and increased the cross-sectional area of a major muscle in the lab. Results provide further evidence for environmental modification of sex ratio in mammals and illustrate the impact specific nutrients early in development can have on the characteristics of the offspring after birth.