육용종웅계의 사양방법이 체성장 및 성 성숙에 미치는 영향

Effects of the Feeding Methods on Body Growth and Sexual Maturity in Broiler Breeder Males

본 시험은 6가지 다른 사양방법이 White Plymouth Rock 육용종 웅계의 생체중, 정소, 계관 그리고 뇌하수체의 발육 및 성성숙에 미치는 영향을 구명하기 위하여 부화후부터 22주령까지 2주간격으로 생체중, 정소, 계관 그리고 뇌하수체의 중량이 조사되었으며, 또한 정소조직과 정액성상이 조사되었다. 그 얻어진 결과를 요약하면 다음과 같다. 1. 생체중, 정소, 계관의 발육은 10주령 이후부터 무제한급이군들이 제한급이군들(무제한급이군들의 70%급이)보다 2주 더 빠름을 나타내었다. 정소 및 계관의 급증시기는 무제한급이군들에서 20주령이었고, 제한급이군들에서 22주령이었다. 2. 뇌하수체의 무게는 부화후부터 22주령까지 4주령, 14주령, 16주령을 제외하고 각 주령별, 각 처리군간에 유의성이 나타나지 않았다. 뇌하수체의 중량은 주령이 경과하면서 완만한 증가를 나타내었다. 3. 22주령까지에서 주령, 생체중, 정소, 계관 및 뇌하수체간에는 고도의 유의적인 상관관계를 나타내었다. 4. 세정관의 관경과 강경은 부화후부터 10주령까지 점진적으로 증가되다가 무제한 급이군들에서는 12주령부터 제한급이군들에서는 14주령부터 급증하기 시작하였고, 그 후에도 22주령까지 계속증가되었다.

This experiment was conducted to find out the effects of the six different feeding methods on the development of body weight, testis, comb and pituitary gland, and the sexual maturity of White Plymouth Rock cockerels. From hatching to 22 weeks of age, the weights of whole body, testis, comb and pituitary gland, and the histological changes of testis and the semen characteristics were checked every other week. The results obtained in this expeniment were as follows: 1. The growth rates of the self-feeding groups were faster than those of the limited feeding groups (70 percent of the self-feeding) by about 2 weeks. The weights of testis and comb showed the most marked increase at 20 weeks of age in the self-feeding groups and at 22 weeks of age in the limited feeding groups, respectively. 2. The weights of pituitary gland from hatching to 22 weeks of age at all observation weeks were not recognised significantly among the compared groups except 4, 14 and 16 weeks of age. 3. Correlations between week of age, body weight, testis, comb and pituitary gland, in the course of 22 weeks, were highly significant. 4. The diameters of lumina and tubules in the seminiferous tubules increased very slowly until 10 weeks of age. They showed the most marked increase at 12 weeks of age in the self-feeding groups and at 14 weeks of age in the limited feeding groups, and then continuously increased until 32 weeks of. age. 5. Primary spermatocytes appeared at first at 8 weeks in the all treatment groups, Secondary spermatocytes appeared at first at 10 weeks in the self-feeding groups and at 12 weeks in the limited feeding groups. At 14 weeks of age spermatids and spermatozoa were found at first in the self-feeding groups but spermatids were found in the limited feeding groups. 6. Age of the first ejaculation was between 14 and 16 weeks of age in the all treatment groups. The Average semen. volume and sperm concentration ranged from 0.1-0.2$m\ell$/ ejaculate and 5.6-9.8${\times}$10$\^$8/ sperm/$m\ell$ at the age of the first ejaculation but 0.30-0.35$m\ell$/ ejaculate and 22.4-42.7${\times}$10$\^$8/ sperm int at the 20 weeks of age in the all treatment groups.