Objectives:The study aimed at investigating the porential effexts of growth-
promoting additives im animal feed on the reproductive
function in the adolescence feed on part of re pro of female ra ts and the toxic action.Methods:In ap plied animal experiments,rats were treated with various of grow th-
promoting additive by oral gav age to observe the age of vaginal open ing(VO),estrous cy cle,gland/body weight coefficient and other re pro ductive parame ters and tox ic index.Re sults:①Com pared with the con trol group,rats in the lower dose group weighted apparently more and had higher increase rates of body weight in crease at the end of the experiment(P<0.05).②The VO age of rats in the lower dose group,became sig nificantly younger in comparison to that of the
control group(P<0.05).③Af ter two-week treatment,the num ber of rats which had en tered the first estrous cycle in the lower dose group was remarkably lon ger than that in the control group,while the number of groups rats in the mid-dose and higher dose di f-fered little from that ia the control group.④The uterus/body weight and ovary /body weight coefficients in various groups differed very slightly the coefficients tended to decline with the increase of dosages.Con-clu sion:Growth-pro moting ad di tive showed an estro gen-like effects on rats,which seems to have some corre la tion with the con centra tion of additives.