Risk factor analysis for stillbirth and mummification in a Guangdong swine herd

Stillbirth and mummification have a profound negative effect on the number of piglets born alive. Both infectious and noninfectious factors can cause stillbirth and mummification in pigs. The data of a swine farm in Guangdong was used to analyze the effects of noninfectious factors on the probabilities of stillbirth and mummification under subtropical climatic condition. The results showed that higher parity and shorter gestation length could increase the probability of stillbirth, and larger litters were associated with shorter gestation length and higher probabilities of stillbirth and mummification. The parturition season was significantly related the probabilities of stillbirth and mummification; piglets born in January, February, March and December had a lower rate of stillbirth, and those born in February, March, May, October, November and December were less possible to be mummified.