Studies on the age of sexual maturity of swine with special reference to the early maturity of Chinese breed

摘要

The speed of sexual maturity is an important factor in the economy of swine industry and in the improvement of swine. In this report observations were made of sexual maturities of males and females of Chinese breed, which is of Asian origin, and known as a descendant of Sus vittatus, and has been useful for establishment of various breeds of swine. The results were compared with those of four improved breeds, originated from Sus scrofa. Total 528 swine (84 Chinese, 237 Middle Whites, 106 Berkshires,66 Large Whites and 35 Poland Chinas) were used. Anatomical, histological and physiological investigations were carried out on the male reproductive organs, epididymal spermatozoa and ejaculates. In the females, age of appearance of first estrus (with ovulation) was determined.