A note on the effect of contact with male goats on occurrence of puberty in female goat kids

Abstract

ABSTRACTTwelve British Saanen female kids were exposed to male goats for 1 h daily on 29 July (Ml), 12 on 12 August (M2) and 12 on 27 October (M3), when the kids were, on average, (± s.d.) 136·4 (± 12·2), 150·2 (± 12·8) and 225·4 (± 3·5) days of age, respectively. Blood samples were collected to determine plasma progesterone concentrations from 17 July onwards. By 27 October, 11 and 12 kids from treatments Ml and M2 had attained puberty, compared with no kids from treatment M3. Ten kids from treatment M3 attained puberty after male introduction. The mean ages and dates at puberty for treatments Ml, M2 and M3, respectively, were as follows: 205·5, 215·3 and 233·0 days (P < 0·001); and 7 October, 17 October and 3 November (P < 0·001). The mean reaction interval to male introduction for treatments Ml, M2 and M3 was 69, 66 and 7 days (P < 0·001), respectively. The variances for the date of attainment of puberty showed differences in the degree of synchronization of the event between all three treatments.