摘要在生猪繁育体系中，繁殖性能是母猪最重要的生产性能，会直接影响到养猪

Abstract <br>In the pig breeding system, reproductive performance is the most important production performance of sows, which will directly affect the economic benefits of the pig industry. Because the heritability of reproductive traits of sows is low, it is more affected by non-genetic factors. Therefore, it is necessary to deeply explore the effects of non-genetic factors such as the farrowing season on the reproductive performance of sows. <br>In this study, based on the reproductive performance data of 388 binary sows (L Landrace and Y Large White hybrids) of an agricultural and animal husbandry food company from December 2018 to December 2019, the reproductive performance of different farrowing seasons was analyzed. The results showed that the number of live piglets in the first parity of the binary sow was the lowest, and the number of piglets alive in the second to ninth parities was higher, indicating that the effective use life of the binary sow was longer; the second to eighth parity Jinhua The pig's birth weight, newborn litter weight, 21-day-old litter weight, weaning weight, and weaning litter weight all performed well, but the production level decreased after the 9th litter; the reproductive performance of sows bred in winter was better than other seasons. <br> <br>Keywords: reproductive performance; farrowing season; binary sow<br> 

summary<br>In the pig breeding system, breeding performance is the most important production performance of sows, which will directly affect the economic benefits of pig farming. Also because the genetic strength of sow reproductive traits is low, the influence of non-genetic factors is greater. Therefore, it is necessary to explore in depth the effect of non-genetic factors such as delivery season on sow reproductive performance.<br>The study analyzed the reproductive performance of 388 binary sows (L-long white and Y-white hybridization) from December 2018 to December 2019. The results showed that the number of live births in the first birth of binary sows was the lowest, and the number of live births in the 2nd to 9th births was higher, indicating that the effective use of binary sows was longer;<br> <br>Keywords: breeding performance; delivery season; binary sows<br> 

abstract<br>In the breeding system of pig, reproductive performance is the most important performance of sow, which will directly affect the economic benefits of pig industry. Because of the low heritability of sow reproductive traits, it is influenced by non genetic factors. Therefore, it is necessary to study the effect of non genetic factors such as delivery season on sow reproductive performance.<br>This study analyzed the reproductive performance of 388 binary sows (L-long white and y-white hybrid) from December 2018 to December 2019 of a certain agricultural and animal husbandry Food Co., Ltd. The results showed that the first birth live piglets were the lowest in the second to the 9th stage, indicating that the effective utilization of the two-stage sows was longer; the first weight, the first litter weight, the 21 day old nest weight, the weaning weight and the weaning nest weight of the second to 8th Jinhua pigs were all good, while the 9th was better The reproduction performance of sows in winter was better than that of other seasons.<br> <br>Keywords: reproductive performance; delivery season; dual sow<br>