Sow efficiency and early piglet mortality in two local pig breeds on smallholder farms in northern Vietnam-a longitudinal study.

In the recent past, pig performance and sow management on smallholder farms in the Southeast Asian Massif have been extensively researched. But the objective of this study was to investigate the lifetime efficiency of breeding sows of the local Vietnamese Ban (n = 89) and Mong Cai (n = 131) breeds in a production system context. The impact of sow longevity was considered in particular. In addition, predictors of early pre-weaning mortality in piglets were investigated. In total, nine villages of Son La province, situated in the uplands of north-western Vietnam, were selected, differing in access to markets, production intensity, and pig management level. Data was collected over a period of 10 years through an on-farm performance testing system. It was shown that sows of both breeds that achieved five or more parities farrowed and weaned significantly more piglets per life year compared to sows with only one or two parities. The conception rate (Spearman's rho = 0.374) and age at first farrowing (Spearman's rho = -0.424) were significantly correlated with the number of weaned piglets per life year of stayable (≥4 parities) Mong Cai sows. The risk of early pre-weaning death of piglets born to Mong Cai sows was affected more by litter size, while for piglets born to Ban sows, the risk was influenced more by the season. Therefore, interventions to improve the sow lifetime efficiency and piglet survivability must match the sow breed and management level.