291 Effect of Early vs. Late Maturing Sire Lines and Creep Feeding on the Stress Response, Intestinal Permeability, and Growth Performance of Nursery and Finishing Pigs

Abstract

Abstract A total of 21 litters (early or late maturing Duroc × DNA 241) resulting in 247 pigs were used in a 170-day trial to determine the effect of sire lines selected for either early or late maturing growth rates and creep feeding on the stress response, intestinal permeability, and growth performance of nursery and finishing pigs. Treatments were arranged in a 2 x 2 factorial with main effect of Duroc sire line (early or late maturing) and creep feeding (with or without starting 14 d before weaning). In the nursery, there were 4 or 5 pigs per pen and 12 or 13 replications per treatment. Thirty minutes after weaning (initially 6.4 kg BW), 7 gilts per treatment were used to determine cortisol concentrations in response to weaning. Blood cortisol concentrations were increased (P < 0.01; 104.0 v. 83.5 ng/mL) in late maturing pigs compared with early maturing pigs. After almost no feed consumption by either group on d 1, late maturing pigs had decreased daily feed intake (P < 0.001) than early maturing pigs from days 2 to 14 post-weaning. Likewise, a greater percentage (P < 0.001) of late maturing pigs had BW less than their weaning weights on d 3 post-weaning compared with early maturing pigs (Table). Thus, late maturing pigs had decreased (P < 0.001) ADG and ADFI during the first 3 days in the nursery. Creep feeding had no effect on initial performance. No differences were observed in intestinal permeability between treatments. For overall nursery performance, a significant interaction was observed for ADG (P = 0.007) and ADFI (P < 0.001), with creep feeding providing a benefit in late maturing pigs, but not in early maturing pigs. Early maturing pigs had poorer G:F (P < 0.001) than late maturing pigs. At the end of the nursery, 241 pigs were transported to the finisher and randomly placed in pens based on treatment. There were 7 or 8 pigs per pen and 7 or 8 replications per treatment. For overall finishing performance, an interaction was observed for ADG (P = 0.037), with late maturing pigs that received creep feed having increased ADG compared with the other treatments. An interaction was also observed for ADFI (P = 0.007), with late maturing pigs that did not receive creep feed having decreased ADFI compared with late maturing pigs that received creep feed or early maturing pigs whether they received creep feed or not. In summary, early maturing pigs had lower stress response at weaning and improved ADG and ADFI until approximately 100 kg, at which point late maturing pigs began to exhibit greater ADG. Late maturing pigs had improved feed efficiency throughout the experiment. Creep feeding late maturing pigs resulted in improved growth performance compared with providing no creep feed, whereas creep feed did not impact early maturing pigs.