Effect of birth weight of piglets on growth rate and rearing performance up to 8 weeks of age

Effect of birth weight of piglets on growth rate and rearing performance up to 8 weeks of age. The aim of the experiment was to determine the effect of the birth weight of piglets on their rearing results up to 56th day of age, as expressed by growth rate and survival. Observations were made on 277 crossbred piglets from 22 litters of F1 sows (Polish Landrace × Polish Large White) derived from crossbred boars (Duroc × Pietrain), which were kept and fed the same way. Piglets were reared with mothers for 5 weeks and observed for 8 weeks. At 1st, 7th, 21st and 56th day of age, piglets were individually weighed. The body weight on day 1 of age served as a basis for dividing the piglets into groups I, II, III and IV (≤1.2; 1.21–1.39; 1.40–1.59; and ≥1.60 kg body weight, respectively). Coefficients of correlation were estimated between body weight on day 1 of age and at day 7, 21 and 56 of life, and daily gains. In the subsequent rearing periods, daily gains in groups I–IV increased and the differences between the groups showed similar relationships. Differences between groups II and III were small (P >0.05), and those between groups I and IV considerable and highly significant. The coefficients of correlation for piglets from groups I (the lightest at birth) and IV (the heaviest at birth) confirm the relationship between birth weight and body weight at 7th (P ≤0.01), 21st (P ≤0.01) and 56th day of age (P ≤0.05), with a downward tendency for the calculated relationships. Furthermore, in group I piglet birth weight was correlated with daily gains from 1st to 7th day (r = +0.365, P ≤0.01) and from 1st to 56th day of age (r = +0.291, P ≤0.05). With the increasing mean body weight at birth, piglet survival increased and was higher in group IV vs I by 13.64 percentage points. The birth weight ≥1.60 kg ensured the best growth rate and survival of the piglets.