Risk factors for high sow mortality in French swine herds

Episodes of high sow mortality rates affect profitability of swine farms. However, relevant control actions are difficult to implement. The objective of this study was to identify the risk factors for high levels of sow mortality rate (HM) in French swine herds. A case-control study was carried out in 102 swine herds located in Brittany (western France). Level of sow mortality of a herd was quantified by the annual mortality rate using sow-days as denominator. Fifty-five (53.9%) herds which experienced a sow mortality rate over 5% were classified as HM herds. Logistic regression was used to assess associations of managerial practices and disease prevalence with the odds of HM. High prevalence of urinary tract infections, metritis or lameness were significantly associated with a HM herd status (P < 0.10, OR ranging from 3.4 to 5.2). Multiplying herds were herds at higher risk for sow mortality than commercial farrow-to-finish herds. Providing three meals per day instead of two to dry sows decreased the odds of HM. Feeding plans where the maximum daily amount of feed provided to lactating sows was lower than 8 kg and was reached before 15 d in lactation were related to lower odds of HM (P < 0.10). Average age at weaning of 28 d or more and/or small average litter size at birth (12 piglets or less) were associated with higher odds of experiencing HM.