Piglets' early body weight and milk consumption partially explain post-weaning performance
It’s well known that piglets' BW at birth is an important factor determining their subsequent performance. Furthermore, equally important is trying to maximize milk intake during the suckling period. The objective was to assess the influence of the piglets’ BW at birth and BW at weaning on pig performance over time. A total of 305 crossbreed piglets [Pietrain x (Landrace x Large White)] from 30 litters were used. All the animals were individually weighed at day 2 (CF; cross fostering), 27 (weaning), 41 (14 d post-weaning), 62 (35 d post-weaning), 98 (growing) and 173 (slaughter). Piglets were fed ad libitum the same commercial pre-starter, starter, growing and finishing diets. The relationship between the BW at CF and BW at weaning with the BW at the different productive steps until slaughter was analyzed using the CORR procedure of SAS. BW at CF was related with BW at weaning (P = 0.002). Considering the Pearson Correlation Coefficient (r), showed that the BW at weaning was highly related to the BW at 14 d post-weaning [41 d-old (r = 0.80, P < 0.001)] but its influence was progressively reduced on days 62 (r=0.51, P<0.001), 98 (r = 0.19, P < 0.001) and 173 (r = 0.18, P < 0.001), respectively. The strong relationship between BW at weaning and at 14 d post-weaning resulted in a huge BW difference between the 30% heavier and 30% lighter piglets (at weaning: 8.52 kg vs 6.43 kg, P < 0.001; 14 d post-weaning: 12.17 kg vs 10.63 kg, P < 0.001); difference which were reduced from 32.5% at weaning to 14.5% two weeks later. The BW at CF also had an effect, but not as strong as BW at weaning, having the best correlation at 14 d post-weaning (r = 0.40, P < 0.001). Thus, we observed an attenuated effect on day 27 (r = 0.36, P < 0.001), 62 (r = 0.33, P < 0.001), and 173 (r = 0.27, P < 0.001) respectively. It is concluded that both BW at CF and at weaning, play a significant role on pig BW performance and variability along the productive cycle. However these effects are gradually replaced over time, indicating that new factors become more important explaining BW variability. A higher effect of the BW at weaning was observed at the beginning of the nursing period, but it was diluted later on.
Keywords: Performance, correlation, piglet