The incidence of female genital abnormalities in swine.

PPROXIMATELY one-fifth of the females in a swine herd fail to conceive during a breeding season and about one-third of all matings are infertile (Phillips and Zeller, 194i ). Warn/&, Grummer and Casida (1949) reported that in a group of 63 "repeat-breeders" bilateral barriers to fertilization were present in 5o.o~o of the nonparous females (gilts) and i5.8~ of the sows. In addition, unilateral abnormalities were present in 13.7% of the gilts and I5.8~o of the sows. In a similar study of 79 animals Wilson, Nalbandov and Krider (I949) found that 35.3% of the gilts and io.7% of the sows had gross abnormalities which made fertilization unlikely, and i7.6~o of the gilts and zi .4% of the sows had other gross abnormalities although fertilization was judged possible. Tubal abnormalities, cystic ovaries and missing parts of the genital tract were the most common abnormalities found in both studies. The "repeat-breeder" studies necessarily involved small, selected groups of animals. The study reported here was made to estimate the incidence of various gross abnormalities in a much larger, less selected group of females