Interactions between piglet weaning age and dietary creep feed composition on lifetime growth performance

The influences of creep feed composition and piglet weaning age on apparent creep feed disappearance and post-weaning performance were examined. A total of 24 gilts and 72 multiparous sows were selected at farrowing, and their litters allocated to a 2 by 2 factorial arrangement of treatments with the factors being weaning age (22 or 29 days of age) and the composition of the creep feed [simple (diet based predominately on cereals and animal and vegetable protein sources) or complex (diet based predominately on cereals, animal protein sources and 300 g/kg whey powder)]. Creep feed was offered to all litters from 9 days of age to weaning. While creep feed disappearance did not affect pre-weaning growth performance, there was a greater disappearance of the simple creep feed than the complex creep feed from 9 days of age to weaning (776 versus 461 g/litter, respectively, P = 0.004). Apparent creep feed intake from individual piglets in a subset of litters was assessed at three time points (16 and 19 days of age and at weaning), allowing the characterisation of individual pigs as good, moderate, small or non-eaters. There was no difference between treatment groups (chi(2) = 6.27, P = 0.71) in the characterisation of apparent creep feed disappearance by individual piglets, however piglets offered the simple creep diet before weaning consumed more feed (P = 0.004) and gained weight faster (P = 0.007) during the first 5 days after weaning than those animals offered the complex creep diet. Feed intake from weaning to 49 days of age also tended to be greater in pigs offered the simple creep diet before weaning (P = 0.053), with this difference reflected in daily gain from weaning to 49 days of age (P = 0.051). Despite these differences, creep feed composition did not influence lifetime growth performance or carcass composition. Pigs weaned at 22 days of age were heavier midway through the weaner period (49 days of age) than pigs weaned at 29 days of age (15.2 versus 14.3 kg, respectively, P = 0.009), and tended to grow faster from birth to slaughter (616 versus 610 g/day, respectively, P = 0.079). These data suggest that the provision of a complex creep diet during lactation may not improve lifetime growth performance above that of a less expensive creep diet. Weaning age may however influence lifetime performance, with weaning at 29 days of age tending to reduce rate of gain from birth to slaughter.