Piglet preweaning mortality in a commercial swine herd in Thailand.

In the modern swine industry, the number of piglets born alive per litter is dramatically increasing due to genetic improvement of litter traits. However, knowledge on post-partum management is inadequate to reduce piglet preweaning mortality. The present study aimed to investigate piglet preweaning mortality in a commercial swine herd in Thailand in relation to the number of littermate pigs and piglet birth weight. Data included 11,154 litters from 3574 sows farrowed from January 2009 to December 2012. Littermate pig was defined as the number of piglets after cross-fostering. Number of littermate pigs was classified as 1-7, 8-10, 11-12, and 13-15 piglets per litter. Mean birth weight of the piglets was classified as low (<1.30 kg), medium (1.30-1.79 kg), and high (≥1.80 kg). Piglet preweaning mortality was calculated, logged transformed, and analyzed by general linear mixed models. On average, piglet preweaning mortality was 14.5 % (median = 10.0 %). Piglet preweaning mortality in the litter with 13-15 littermate pigs (24.1 %) was significantly higher than the litter with 1-7 (11.9 %, P < 0.001), 8-10 (11.8 %, P < 0.001), and 11-12 (14.6 %, P < 0.001) littermate pigs. The litters with a low piglet birth weight had a higher piglet preweaning mortality rate (18.8 %) than the litters with a medium (15.7 %, P < 0.001) and a high piglet birth weight (12.1 %, P < 0.001). In conclusion, to reduce piglet preweaning mortality in commercial swine herds, special care needs to be taken in litters with more than 13 littermate pigs and with piglets with birth weight below 1.30 kg.