Sexual maturity in British breeds of goat kids.

Eight male kids of British Sannen and one each of the British Alpine and British Toggenberg breed, born between the last week of February and first week of March 1990, were used. From the age of 12 weeks, they were monitored every week for body and testicular growth and sexual development, until they attained sexual maturity. The development of the sexual behaviour was a gradual process. From 12 weeks of age, the body weight increased at a constant rate. Testicular development, however, showed a biphasic pattern; the testis size increased rapidly between 12 and 20 weeks of age and was followed by a period of slow growth. Sexual maturity occurred at a mean age of 172.7 +/- 4.47 days, and at a mean body weight of 31.25 +/- 1.50 kg when the mean values of scrotal circumference, testis diameter and paired testes width were 24.13 +/- 0.47 mm, 54.01 +/- 1.26 mm and 88.31 +/- 1.61 mm, respectively. In most kids, the quality of the first ejaculate was good, although it varied widely between animals. It appeared that sexual maturity in British goat kids occurs at a younger age than in different breeds in other parts of the world that have been reported in the literature.