The effects of weaning weight and rate of growth immediately after weaningon subsequent pig growth performance and carcass characteristics

Effect of accelerated weight gain immediately after weaning on subsequent p erformance was evaluated in pigs with heavy and light weaning weights. The study was carried out as a randomized complete block design with a 2 x 2 x 2 factorial arrangement with the treatments being weaning weight (Heavy vs. Light), post-weaning growth rate (Accelerated vs. Conventional) and sex (B arrow vs. Gilt). Pigs were weaned at 18 to 22 d of age, weighed and classif ied as either Heavy or Light (5.4 vs. 3.9 kg, SE +/- 0.04). During the firs t 14 d after weaning, pigs on the Accelerated growth treatment were housed in a specialized nursery and provided with liquid milk replacer and a dry d iet; pigs on the Conventional treatment were housed in a standard nursery a nd provided with a dry diet only. Subsequent to the 14 d post-weaning treat ment period, pigs from all treatments were housed in standard accommodation and provided the same dietary regimen to slaughter weight (110 kg). Pigs o n the Accelerated treatment were heavier (P < 0.01) than pigs on the Conven tional treatment at the end of the treatment period (9.2 vs. 8.1 kg, SE +/- 0.13) and at 56 d of age (19.6 vs. 18.3 kg, SE +/- 0.28). Early growth rat e did not affect growth from 35 d of age to slaughter weight, or days to re ach slaughter weight. Pigs on the Conventional treatment had greater (15.6 vs. 14.1 mm, SE +/- 0.47, P < 0.01) backfat depths at slaughter than those on the Accelerated treatment. Heavy pigs at weaning were heavier (P < 0.001 ) at birth and 56 d of age than light pigs, and reached slaughter weight 8. 6 d earlier (P < 0.001). In summary, weaning weight, but not growth rate in the first 2 wk after weaning, influenced age at slaughter.