Effect of early vs. late maturing sire lines and creep feeding on the cortisol response, intestinal permeability, and growth performance of nursery and finishing pigs.

Finishing pig growth potential varies across different genotypes; however, limited research is available on performance of nursery pigs sired from boars selected for different finishing growth patterns. With selection of terminal sires focused on improved lean gain in late finishing, anecdotal or field observations suggest that starting weanling pigs on feed has become more challenging. Hence, our hypothesis that improving post-weaning feed intake by creep feeding may be of greater importance today than in the past due to sire line selection criteria. Therefore, our objective was to determine the possible interaction of Duroc sires selected for early vs. late maturing growth rates and creep feeding on the growth performance of pigs from birth to market. Early maturing pigs had increased feed intake from days 2 to 14 post-weaning compared to late maturing pigs. Likewise, a lower percentage of early maturing pigs lost weight from weaning to 3 d post-weaning. Early maturing pigs had improved average daily gain (ADG) and average daily feed intake until approximately 100 kg, at which point late maturing pigs began to exhibit greater ADG. Overall, offering creep feed to late maturing pigs resulted in improved growth performance compared to no creep feed, whereas creep feed did not impact early maturing pigs.