Conception failure in swine: importance of the sex ratio of a female's birth litter and tests of other factors.

摘要: Failure of gilts and sows to conceive when they are mated is a potentially serious economic cost for swine producers. In Exp. 1, we determined that anogenital distance newborn related the proportion males in litter (P < .001). Gilts from litters with more have larger distances (mean = 8.0 +/- .2 mm); those low proportions smaller 5.7 .1 mm). 2, examined effect birth sex ratio on reproductive performance using 13-yr database breeding data. failed become pregnant first attempt came significantly higher than successfully conceived attempt. Overall, female were likely exhibit lower rates successful during their four attempts if had been born male-biased litter. These results implications producers deciding which keep market. Given probability problems 12 or pigs 67% males, these females should market hogs. Sow's age, mode insemination, number insemination at an estrus period, but not season, can affect breeding.