197 Evaluating the Associations Between Piglet’s Characteristics at Birth and Growth Performance During Lactation Period on Piglets from Hyperprolific Sows

Abstract

Abstract This study aimed to identify the impact of birth body weight (BBW) and average daily gain (ADG) during the first week (ADG07) on the weaning body weight (WBW) of piglets from hyperprolific sows, as well as to evaluate the role played by other perinatal factors against the ADG07 and WBW. A total of 1,398 piglets [(Landrace x Yorkshire) x Pietrain] born from 87 sows between first and tenth parity (mean ± SD: 3.7 ± 2.2) were used. Each farrowing was monitored to record birth order (BO), birth time (BT), BBW, sex (SX), rectal temperature (RT), and total number of piglets born. Vitality score (VS) was established by monitoring udder stimulation and number of completed circles around the enclosure. At day 1 of life, litters were equalized to 15 piglets (62.17 ± 19.44 % BBW > 1.15 kg piglets; 37.83 ± 19.44 % BBW ≤ 1.15 kg piglets per litter). Piglets were individually weighed after litter equalization, at day 7, and at weaning (26.1 ± 0.45 d). Linear mixed models were fitted to the two study outcomes (ADG07 and WBW) and all possible explanatory variables. The adoptive sow was used as the random effect. Stepwise backward elimination of fixed effects was done to obtain optimized models. Differences between optimized models with or without fixed effects interactions were tested by ANOVA. The individual impact of BBW and ADG07 on WBW was analyzed with individual linear mixed models including only the explanatory variable to be studied (BBW or ADG07). The interaction BBW x RT (P < 0.001) fitted the best model for ADG07 prediction (Marginal R-sq = 0.22). Concerning the BBW, despite being a significant predictor (P < 0.001), it did not explain a great fraction of the variation of ADG07 (R-sq = 0.21). Increments of 100 g in BBW were associated with ADG07 increments of 8.9 g/d. The WBW final model (Marginal R-sq = 0.64) had BBW (P < 0.001), ADG07 (P < 0.001), and VS (P = 0.03) as significant predictors. Individual linear mixed models showed that ADG07 was a better predictor than BBW on WBW (R-sq = 0.59 vs. 0.31). Interaction BBW x ADG07 was significant (P < 0.001), indicating that ADG07 had a greater impact on WBW in piglets with low BBW. Regarding VS, piglets with the best VS at birth had better WBW compared with piglets with the least VS at birth (7.06 ± 1.92 vs. 6.47 ± 1.87 kg). These results suggest that growth performance during the first week has at least an equivalent influence as BBW on WBW, giving an early-life window of opportunity to apply strategies to improve the future performance of the piglets. The VS and RT have a significant role in ADG07 and WBW models.