Previous segregation between sexes is not a requisite to succesful male effect in anestrous goats

Abstract

THIS STUDY WAS PERFORMED TO DETERMINE WHETHER PREVIOUS SEPARATION BETWEEN SEXES IS NECESSARY TO STIMULATE THE SEXUAL ACTIVITY OF ANESTRUS FEMALE GOATS BY THE MALE EFFECT. FIFTY CREOLE FEMALE GOATS FROM SUBTROPICAL MEXICO (26°23' N AND 104°47' W) IN PERMANENT CONTACT WITH TWO MALE GOATS FROM DECEMBER WERE USED. ON MARCH 15TH, DOES WERE ALLOCATED IN TWO GROUPS (N = 25 EACH, ONE MALE PER GROUP). ON MARCH 16TH, THE MALES IN CONTACT WITH FEMALES WERE REMOVED, AND IMMEDIATELY, ONE GROUP OF DOES WAS PUT IN CONTACT WITH ANOTHER THREE BUCKS IN REST SEASON, WHILE THE OTHER GROUP WAS EXPOSED TO THREE BUCKS PREVIOUSLY TREATED WITH 2.5 MONTHS OF LONG DAYS TO STIMULATE THEIR SEXUAL ACTIVITY. THE FREQUENCY OF SELF URINATION, ANO-GENITAL SNIFFING, NUDGING, MOUNTING ATTEMPTS AND MOUNTS OF THE MALES DURING THE FIRST FIVE DAYS FOLLOWING THEIR INTRODUCTION WAS LOWER IN CONTROL THAN IN TREATED MALES (P < 0.05). IN THE FIRST 10 DAYS, MORE THAN 95% OF FEMALES IN CONTACT WITH CONTROL AND TREATED BUCKS SHOWED AT LEAST ONE ESTRUS BEHAVIOR (P > 0.05). THESE RESULTS INDICATE THAT THE PREVIOUS ISOLATION OF THE TWO SEXES IS NOT NECESSARY TO STIMULATE THE SEXUAL ACTIVITY OF THE ANESTROUS FEMALE GOATS BY THE MALE EFFECT, AT LEAST WHEN THE ANESTROUS CONDITION OF THE FEMALES IS MODERATELY EXPRESSED.