木聚糖酶对肉仔鸡消化道食糜停留时间和营养消化率的影响

通过在小麦基础日粮中添加国产酶（EⅠ）和进口酶（EⅡ）两种木聚糖酶制剂，研究木聚糖酶对肉仔鸡各段消化道食糜停留时间和营养物质消化率的影响。试验将7日龄肉仔鸡随机分成5组：小麦基础日粮中分别添加0.05% EⅠ(A1组)、0.02% EⅠ（A2组）、0.02% EⅡ（B1组）、0.05% EⅡ(B2组)、0%（C组），饲喂至21日龄。结果表明：在所有组中，食糜在空肠和回肠的停留时间最长。加酶组使腺胃、结肠、盲肠的停留时间延长，使其它消化道停留时间缩短(P>0.05)，A1组、A2组、B1组、B2组使总停留时间分别比对照组减少15.2%、6.4%、13.6%、13.8%。与对照组相比，加酶组可显著提高干物质和粗蛋白的粪消化率。所有组中嗉囊、腺胃、十二指肠和盲肠消化率表现为负值，肌胃、空肠、回肠和结肠各段消化率为正值，且从空肠到结肠消化率有升高的趋势。

Effect of Wheat based Diet Supplemented with Xylanase on the Mean Retention Time of Digesta and Nutrient Digestibility in Segment of Gastrointestinal Tract of Broiler Chickens

The study was conducted to examine the effects of wheat based diet supplemented with two xylanase preparations(native xylanase EⅠ, foreign commercial xylanase EⅡ) on the mean retention time(MRT) of digesta and nutrient digestibility in segments of gastrointestinal tract of broiler chickens．Seven-day-old broiler chickens were divided into five groups，wheat based diets was supplemented with EⅠ(A1 Group), 0.02% EⅠ(A2 Group), 0.02% EⅡ(B1 Group), 0.05% EⅡ(B2 Group), 0%(C Group) for 14 days respectively．The results showed that the MRT in jejunum and ileum were the longest in all groups．The MRT in proventriculus, colon and ceca were prolonged by xylanase supplementation，and in other segments of intestinal tract the MRT were shortened，but no significant effects were observed. A1, A2, B1 and B2 groups reduced total MRT by 15.2%, 6.4%, 13.6% and13.8%, respectively. Groups with xylanase increased dry matter and crude protein digestibility in feces. In all groups，digestibility of dry matter and crude protein was negative in crop, proventriculus, duodenum and ceca， while that in gizzard, jejunum, ileum and colon was positive．There was a tendency of increase from jejunum to colon.