Effects Of Dietary Xylan Levels And Xylanase Supplementation On Growth Performance And Intestinal Flora Of Weaned Piglets

A 2×3 factorial design trial was conducted to study the effects of xylanase supplementation on growth performance, nutrient digestibility, microbial metabolites and intestinal flora of weaned piglets. The 2 main effects were xylanase supplementation (0 and 1000 U/kg) and dietary xylan levels (4.58%,6.23%, and 7.54%) respectively. Thirty 31-old-day weaned DLY barrows with similar genetic background were randomly allotted to 1 of 6 treatments (5 pigs per group). The experiment lasted for 14 days. The results showed that:①The supplementation of xylanase improved average daily gain of piglets during 0-7 days to some extent (P> 0.05), and significantly improved average daily gain of piglets during 8-14 days (P< 0.01) and the whole trial period (P< 0.01), and when dietary xylan content was 7.54%, the effects of xylanase supplementation were most obvious (P< 0.05). The supplementation of xylanase significantly reduced feed/gain ratio during 0-7 days, 8-14 days and the whole trial period (P<0.01). There were tend to have some interaction effects between dietary xylan levels and xylanase supplementation on feed/gain ratio during 8-14 days and the whole trial period (P<0.1). The supplementation of xylanase significantly reduced diarrhea index of piglets. However, dietary xylan levels did not significantly affect growth performance and diarrhea index of piglets.②The supplementation of xylanase significantly improved the digestibilities of energy and crude protein (P<0.05), and when dietary xylan content was 7.54%, the effects of xylanase supplementation were most obvious (P<0.05). However, dietary xylan levels did not significantly affect nutrient digestibility (P>0.05).③Both dietary xylan levels and xylanase supplementation did not significantly affect the digesta viscosity of ileum (P>0.05).④The supplementation of xylanase tended to improve the acetate content of ileum digesta (P<0.1), and improved the total VFA content of ileum digesta (P<0.05), and there were tend to have some interaction effects between dietary xylan levels and xylanase supplementation on the content of acetate and the total VFA in ileum digesta (P<0.1). The supplementation of xylanase significantly reduced the ammonia content of caecum digeta (P<0.05), and increased the amount of bifidobacterium in caecum digeta (P<0.05), and when dietary xylan content was 7.54%, the effects of xylanase supplementation were most obvious (P< 0.05). However, dietary xylan levels did not significantly affect the content of microbial metabolic products and the amount of coliform bacterium, Lactobacillus, bifidobacterium and all bacteria (P> 0.05).In conclusion, under the condition of this trial, the supplementation of xylanase improved growth performance, nutrient digestibility, and intestinal micro environment of weaned piglets, and there was a dose-dependent relationship between effects of xylanase and dietary xylan levels, when dietary xylan content was 7.54%, the effects of xylanase supplementation were most obvious. However, dietary xylan levels (<7.54%) did not significantly affect growth performance, nutrient digestibility, and intestinal microenvitronment of weaned piglets.