Effect of Diet Complexity and Multicarbohydrase on Growth Performance and Intestinal Morphology in Wenaed Pigs

An experiment was conducted to investigate the effects of diet complexity and multicarbohydrase (MC) on growth performance and intestinal morphology in newly-weaned pigs. One hundred and forty-two piglets (Yorkshire–Landrace × Duroc, initial BW 6.70± 0.81 kg) weaned at 21 d of age (1:1 male to female ratio) were assigned to 1 of 6 diets in a 3 × 2 factorial arrangement of treatments based on diet complexity (complex1, complex2, and simple) and MC addition (0 vs. 0.1g/kg), giving 8 replicates per treatment with 3 pigs per pen. Diets were provided in a 2-phase feeding program with phase I (d 0 to 14) and phase II diets (d 15 to 28). Complex1 contained conventional levels of animal protein sources and dairy products (i.e., whey, skim milk powder, fishmeal, and spray-dried animal plasma), whereas complex2 contained a variety of plant-based ingredients such as distillers dried grains with solubles, millrun, canola meal, peas and flaxseed meal. The simple diet comprised primarily of corn, wheat, and soybean meal. No interactions were found between diet complexity and MC supplementation (P > 0.10). Pigs fed complex1 had higher (P < 0.01) ADG, ADFI and G:F than those fed the other diets during the first wk post-weaning. However, no difference in BW was observed for pigs fed complex1 and the simple diet at the end of the experiment (P > 0.10), whereas pigs fed complex1 were heavier than those fed complex2 (P < 0.05). Also, no differences in ADG or ADFI of pigs fed the complex1 and simple diets were observed during the overall experimental period (P > 0.10), but complex2 led to poorer ADG and ADFI than complex1 (P < 0.05). Overall, G:F was higher for pigs fed the simple diet compared to those fed the complex1 (P < 0.01). Pigs fed complex1 had higher ileal villus height:crypt depth (VH:CD) ratio compared to those fed the complex2 or simple diets. Dietary supplementation with MC had no effect on ADG or ADFI (P > 0.10), but it did improve G:F during the overall experimental period, ileal VH, and ileal VH:CD ratio (P < 0.05). In conclusion, weaned pigs fed a simple diet had greater G:F than those fed a conventional complex diet (complex1) without compromising BW, although complex1 improved intestinal morphology in weaned pigs. Also, the addition of MC could be a beneficial feeding strategy for weaned pigs, improving G:F and intestinal morphology.