Characterization of Piglet Losses in Regard to Boar Genetics and Management Factors

Losses of piglets within the first five days are still very high. Reductions of piglet losses require more information about the dead piglets. The aim of the study was to characterize lost piglets and investigate how reason recordings by the farmer are related to valid measurable criteria on the dead piglet.

On two different farms in North Rhine-Westphalia (Germany) with comparable sow genetics, but different management systems piglets were produced in a two by two Latin square design from the two boar genetics PIC408 and GerPi (German Pietrain). Approximately the first 100 dead piglets (n =383) of each boar genetic on each farm that were lost during the first five days of life were bagged and deep frozen. For dissection, piglets were thawed, abdominal girth, crown-rump length (CRL), total and organ weights were specified as well as external signs of injury, deformities and fractures recorded. Effects of fixed factors sex, farm and boar line were identified using a Mixed Model of SAS and post hoc Tukey test (P < 0.05). Valid measurable parameters were related to recordings from the farms by Spearman Rank correlation.

Farmer’s recordings identified underweight with 29 % on farm A and 40 % on farm B as the most common causes of death. On both farms the offspring of GerPi boars get older, than the offspring of the PIC408 (P < 0.01). CRL was about 3 cm longer in PIC408 piglets than in GerPi (P < 0.05). Total and organ weights remained on a comparable level between birth and day 3, but increased to day 4 and 5 (P < 0.05, respectively), whereby PIC408 offspring showed a higher proportion of organ weights per total weight. Death (or total) weights correlated closely with recordings of underweight as cause of death within the same age (P < 0.05; 0.5 < r < 1). The rigidity of the cranial bone was negatively related to low death weights (P < 0.05; -0.5 > r > -1) and might be a proper indicator for ontogenic age. Different management on the two farms affect age at death, whereby results indicate that the closer invasions e.g. castration were scheduled after birth the less likely piglets survive. Boar Genetic seemed to be responsible for differences in anatomy: PIC408 offspring may die earlier because of less muscle and fat storages.