Effects of isoflavones on reproductive functions of ram lambs

A study was conducted to determine if the isoflavones found in soybean‐based proteins were a detriment to ram lamb production and/or rate to puberty. New born Rambouillet and Suffolk ram lambs were randomly assigned either to the treatment (n=20) or control group (n=19). Treatment received soybean based feed from creep to finishing, while the control received cottonseed meal based feed. At weaning, serum samples and weights were collected to evaluate estradiol and testosterone levels. At an average of seven months of age, blood samples, final weights, semen samples and scrotal circumference measurements were taken. Scrotal circumference and weaning weight were decreased (p<0.05) and in general no other aspect was affected (p>0.05). However, numerically semen counts tended to be reduced. Additionally, estradiol was found to be higher at weaning (p>0.05) in the treatment and lower at final collection, testosterone acted inversely.