The effect of birth weight and feeding of supplemental milk replacer to piglets during lactation on preweaning and postweaning growth performance and carcass characteristics1

The effects of piglet birth weight and liquid milk replacer supplementation of piglets during lactation on growth performance to slaughter weight was evaluated in a study carried out with 32 sows (PIC C-22) and their piglets (n = 384; progeny of PIC Line 337 sires). A randomized block design with a 2 x 2 factorial arrangement of treatments was used. Treatments were birth weight (Heavy vs Light) and liquid milk replacer (Supplemented vs Unsupplemented). The study was divided into two periods. At the start of period 1 (birth to weaning), pigs were assigned to either Heavy or Light (1.8 SD = 0.09 vs 1.3 kg SD = 0.07 BW, respectively, P 0.05), and required seven fewer days (P 0.05) on growth performance from weaning to slaughter. However, pigs fed milk replacer required three fewer days (P 0.05) by either birth weight or milk replacer treatment. In conclusion, birth weight has a substantially greater impact on pig growth performance after weaning than increasing nutrient intake during lactation.