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Piglet body weight at weaning: a key success factor for post-weaning performance?
The aim of the study was to evaluate the importance of piglet BW at weaning (WBW) on post-weaning performance and mortality. A total of 4,320 male and female crossbreed piglets [Pietrain x (Landrace x Large White)] were used. All the animals were individually weighted at weaning (28 d-old). The selected animals (240 per batch without those corresponding to the percentile 10 and 90) were distributed into 3 BW categories: Low (L; BW < 6.5 kg, n = 92); Middle (M; 6.5 kg < BW < 8.5 kg, n = 216) and High (H; BW > 8.5 kg, n = 94) and allocated in groups of 10 piglets. The same commercial pre-starter diet formulated to contain 10.35 MJ/kg NE, 17.9% CP and 1.32% Lys was offered ad libitum. Feed intake (FI), BW and mortality rate (MR) were weekly monitored to calculate FI and ADG (0 to 14 d post-weaning). Performance data were analyzed with ANOVA by using the GLM procedure of SAS taking into account the WBW category. The initial differences between WBW categories were maintained along the pre-starter period (P < 0.01). Lower ADG (P < 0.01) but not FI (P > 0.10) was observed between WBW categories for the first week post-weaning (H = 99b g/d; M = 115a g/d and L = 122a g/d; P < 0.01). For the second week post-weaning, higher ADG and FI was observed for H compared to M and L groups (P < 0.01). Overall, higher FI was observed for H than M and L (H = 325a g/d; M = 293b g/d and L = 265c g/d; P < 0.01), however, no difference in ADG was achieved (H = 207 g/d; M = 203 g/d and L = 192 g/d; P > 0.05). Moreover, higher MR was observed for H than for M and L during the pre-starter period (1.98 vs. 0.2 and 0.3%; P < 0.05). The H animals failed to meet the energy requirements during the first week after weaning probably due to a longer anorexia period. After that, H animals start suddenly to eat high amounts of solid feed, following digestive and malabsorptive problems which may explain the higher MR, causing important losses. These results confirmed that in large suckling periods (28 d) the early contact with solid feed may optimize performance and reduce mortality after weaning in pigs with high BW.
Keywords: Performance, mortality, weaning, piglet