Important health and management reasons of early sow removal

Abstract

Gilt and sow management practices are key factors for the reproduction and production efficiency of any production system. In Poland, the number of piglets born alive per sow per year and the number born alive per sow per lifetime are relatively low. This may have a number of causes. One of them is an unsuitable parity distribution. According to some data, most females are removed from the herd after the first or second parity. As a consequence, the number of piglets born alive per sow per lifetime is small. In some countries, the number of litters per sow per lifetime varies from 3.3 to 5.6, with a total number of 32 to 73 piglets weaned. The average longevity of a sow in various countries ranges from 467 to 969 days. For Poland, precise data are unfortunately lacking, but unpublished data suggest that the number of litters per statistic sow does not exceed 5, although in particular farms this parameter ranges from 3 to 7. According to data available from different farms, early sow culling takes place mostly after the first or second parity. The causes include errors in gilt’s rearing and introduction into the herd, stall acclimatization, and boar exposure. A gilt’s longevity and performance are also determined by her body weight and age at first breeding, feed intake in the lactation period, as well as body weight gained during gestation and 1st lactation. If properly developed and managed, a gilt with high immunity will perform well as a P1 and will continue to be highly productive throughout her lifetime. Otherwise, she will perform poorly in her first parity, after which her longevity is likely to be short. This paper also reviews health-related causes of early sow culling in Polish farms. The most important ones are infertility, embryonic death, stillbirth, mastitis, and MMA (mastitis, metritis, agalactia), as well as infectious pathogens (viruses), such as IAV-S, PRRSV, PCV2, PPV, ECMV, ADV, CSF, or bacteria: Leptospira spp., Brucella suis, and Erysipelothrix rhusiopathiae.