Effect of litter birth weight standardization before first suckling on colostrum intake, passive immunization, pre-weaning survival, and growth of the piglets

Within-litter variation in birth weight is a relevant factor in pig production. This study aimed at comparing pre-weaning mortality, colostrum intake (CI), passive immunization, and growth of piglets from litters of uniform (UN) or heterogeneous (HET) birth weights. The study included 52 multiparous sows (Large White × Landrace) and their litters. Two types of litters were constituted based on birth weight, namely: UN or HET, the control group, using piglets from two to three sows farrowing approximately at the same time. At birth, piglets were weighed, identified, and placed in a box under an IR lamp. At the end of farrowing, piglets were re-weighed and allotted to groups UN or HET (12 per litter) with average weights of 1394 and 1390 g, respectively, and allowed to suckle (time 0). They were re-weighed 24 h later to estimate CI and sows' colostrum yield. At time 0, the average intra-litter CV (%) in weight of experimental litters were 9.3 ± 0.8 (SEM) and 27.8 ± 0.7 in groups UN and HET, respectively (P