Effects of Weaning Age and Creep Feed Type on Growth Performance and Gut Maturation in Weaned Piglets

SIMPLE SUMMARY: The transition from suckling to weaning imposes challenges for piglets and often results in unwanted post-weaning growth check. This is a result of poor feed intake, which is likely a consequence of piglets’ lack of adaption to a dry vegetable-based diet. To accommodate a smoother transition, the objective of this study was to investigate the effects of four- vs. five-week weaning ages and dry vs. liquid feeds, to resemble the texture of sow’s milk, on growth performance, the activity of certain disaccharidases and the gene expression of nutrient transporters in the small intestines of weaned pigs. Later weaning and liquid feed resulted in heavier pigs during the later weaning phase. In conclusion, a clear increase in the growth performance of liquid-fed pigs was not associated with changes in the investigated disaccharidase activity or gene expression of the analyzed nutrient transporters. ABSTRACT: The objective was to study the effects of weaning in week 5 (W5) vs. week 4 (W4), as well as liquid (LF) vs. dry feed (DF), on growth performance, disaccharidase activity and nutrient transporter expression after weaning. The experiment included 12,923 pigs fed LF or DF in the pre-weaning period and a subpopulation of 15 pigs from each group, W4DF, W4LF, W5DF and W5LF, which were weighed and euthanized five days after weaning. The proximal part of the small intestine was analyzed for maltase, lactase and sucrase activity and the expression of SGLT-1, GLUT-2 and PepT-1. Pigs fed LF displayed less maltase activity (2100 vs. 2729 U/mg protein, p < 0.05) but an increased expression of SGLT-1 (∆Ct: 5.22 vs. 6.21, p = 0.01). Pigs weaned in W5 were heavier than those weaned in W4 (9.35 vs. 7.11 kg BW, p ≤ 0.05), and pigs fed LF were heavier than those fed DF (8.55 vs. 7.91 kg BW, p ≤ 0.05) five days after weaning in the subpopulation. LF pigs (21.8 kg) were heavier than DF pigs (20.6 kg) (SE 0.108, p < 0.0001), and W4 pigs (21.0 kg) were lighter than W5 pigs (21.5 kg) (SE 0.108, p = 0.01) at nine weeks. LF increased weight gain in the early post-weaning period and at nine weeks, although this was apparently not explained by accelerated gut maturation.