Investigation Of The Reproductive Performance And Factors Associated With It In A Swine Breeding Herd In Hunan

To demonstrate reproductive performance and factors associated with it of sows in a Swine Breeding Herd in Hunan, return rate, farrowing rates, litters/sow/year, litter size, piglets born alive/litter, piglets weaned/sow/year were investigated based on the data in2008and2009to evaluate reproductive performance of sows, and breeds, parities, farrowing months, stillbirth and foetal mummification were investigated to evaluate the influencing factors on the reproductive performance of sows. The results are as follow.On the reproductive performance of sows. The return rate, farrowing rates, litters/sow/year, litter size, piglets born alive/litter, piglets weaned/sow/year of the breeding herd in2008and2009are18.49%and13.26%,76.51%and75.40%,2.12and2.11,10.67and10.13,9.62and9.59,17.90and18.72, respectively.On the influencing factors on the reproductive performance of sows. The breeds of boars mated have some influences on litter size. Significantly more piglets were born per litter of Yorkshire sows than that of Duroc sows, and born alive/litter than that of Duroc sows and Landrace sows (P<0.05).Larger litter size and piglets born alive/litter are from sow parity3compared with parity1and10to11(P<0.01) and parity2and9(P<0.05). The incidence of stillbirth and foetal mummification from sows of parity1is higher than that of sows from parities5and7(P<0.05). The piglets underweight and deformed from sows farrowed in June are more than that of in July and August (P<0.05).Stillborn piglets and mummificated foetus from sows farrowed in September are more than that of in February to July (P<0.01). Stillborn piglets and and mummificated foetus were observed in18.22%of the litters with stillbirth and foetal mummification in parity1,The group with stillbirth and foetal mummification had a larger litter size compared with the group without stillbirth and foetal mummification (P<0.01).In conclusion, the reproductive performance in this breeding herd should be improved. The influencing factors are include breeds, parities, farrowing months and stillbirth.