The effect of maternal and litter factors on piglet mortality rate

This investigation includes a total of 1 O51 piglets, originating from 95 litters, who were offspring of 39 Large White x Landrace sows sired by Pietrain x Duroc boars.The mortality rates at birth and in the period of lactation were 3.2 and 28.3 %, respectively.The number of stillbirths per litter was increased (P < 0.05) by greater heterogeneity, measured as a coefficient of weight variation within the litter.The number of piglets lost during lactation increased (P < 0.05) with litter size, by an increasing coefficient of variation in average weight of liveborn piglets and by a descending aver- age weight of birth.Parity order, season of farrowing and litter male/female class did not affect mor- tality at birth.However, a slightly higher number of deaths occurring during lactation was observed in parity 2 compared with parity 4 litters (3.1 vs. 2.4 %).In addition, mortality at birth was slightly higher for suckling piglets born in summer than for those born in spring and autumn (3.2 % vs. 2.4 and 2.5 %, respectively).Piglet losses increased as the milk yield on day 7 post partum was < 4 kg, but the total milk production during lactation did not affect mortality during the lactation period.A large percentage (69 %) of all piglet losses occurred in the lst week of lactation.Piglet birth weights in the intervals > 1.25 kg, between 1.25 and 1.00 kg and < 1.00 kg resulted in mortality rates of 20, 39 and 61 %, respectively.Piglets lost during the lactation period were observed to have weight losses or low daily weight gains.(© Elsevier / Inra) piglet / mortality rate at birth / preweaning mortality Résumé — Effet des facteurs maternels et de la portée sur le taux de mortalité de porcelets.L'étude a porté sur 7 O51 porcelets, provenant de 95 portées de 39 truies Large White x Landrace accou- plées avec des mâles Piétrain x Duroc.Le taux de mortalité à la naissance et durant la période de lac- tation a été respectivement de 3,2 et de 28,32 %.Le nombre de porcelets mort-nés par portée a augmenté (p < 0,05) avec le coefficient de variation du poids des porcelets à la naissance.Le nombre de porcelets morts pendant la lactation a augmenté (p < 0,05) avec la taille de la portée, et avec l'accrois- * Correspondence and reprints.