木聚糖酶对肉鸡不同类型饲粮净能值的影响

Effects of Xylanase on Net Energy Value of Different Type of Diets for Broilers

本试验使用禽用开放回流式呼吸测热装置进行能量代谢试验,探究木聚糖酶对肉鸡玉米-豆粕型饲粮和玉米干酒精糟及其可溶物(DDGS)型饲粮净能值的影响。采用2×2双因子试验设计,饲粮类型(普通饲粮、玉米DDGS饲粮)和饲粮中添加木聚糖酶(0、0.2 g/kg)为2个主效应,共4个组。选用1日龄罗斯(ROSS) 308雄性雏鸡120只,随机分为4个组,每组6个重复,每个重复5只鸡。试验分4期完成,每期31 d。每期测试1种饲粮,选用1日龄雄性雏鸡30只,1～20日龄在鸡舍内分栏饲养,1～14日龄饲喂商品基础饲粮,15日龄时换为试验饲粮一直到试验结束。21日龄称重后随机选择12只鸡放入呼吸测热装置的6个代谢室中,每个代谢室2只鸡,在代谢室中测定气体交换和排泄物共9 d,其中适应期3 d,呼吸测热3 d,绝食测热3 d,呼吸测热的同时进行消化代谢试验。结果表明:1)木聚糖酶可显著提高肉鸡的呼吸熵(P<0.05),可提高平均日增重和降低料重比(0.05≤P<0.10),对能量利用无显著影响(P>0.05)。2)与普通饲粮相比,玉米DDGS饲粮可显著提高肉鸡的平均日采食量、料重比、耗氧量、呼吸熵、总产热量和代谢能摄入量(P<0.05),显著降低表观代谢能、净能及净能/表观代谢能(P<0.05)。3)木聚糖酶和饲粮类型的交互作用对肉鸡的代谢能摄入量和沉积能有显著影响(P<0.05)。本研究在肉鸡玉米-豆粕型饲粮和30%玉米DDGS饲粮中添加0.2 g/kg木聚糖酶对饲粮净能值无显著影响。

This study was conducted to investigate the effects of xylanase on net energy value of corn-soybean meal diet and corn distillers dried grains with solubles (DDGS) diet for broilers by energy metabolism test using open-circuit respiratory calorimetry apparatus for poultry. According to 2 × 2 double factorial test design,diet type (common diet or corn DDGS diet) and diet xylanases (0 or 0.2 g/kg) as the two main factors,and4 groups were formed. A total of 120 ROSS 308 male broilers were randomly allocated to 4 groups with 6 replicates per group and 5 broilers per replicate. The test was divided into 4 periods and 31 days per period. One type of diet was used and thirty 1-day-old male broilers were selected per period. The broilers were raised in chicken houses with different pens from 1 to 20 days of age,and the broilers were fed a commercial basal diet from 1 to 14 days of age,then changed to test diets at 15 days of age until the end of test. Twelve broilers were randomly selected and placed in individual 6 respiratory chambers of respiratory calorimetry apparatus after weighed at 21 days of age,and 2 broilers per chamber. Gaseous exchange and excretion were measured in respiratory chambers for 9 days,including 3 days of adaptation period,3 days of respiratory calorimetry and 3 days of fasting heat measurement,and digestion metabolism test were carried out simultaneously. The results showed as follows: 1) xylanase significantly increased respiratory quotient (RQ) of broiler (P < 0. 05),increased average daily gain and decreased the ratio of feed to gain (F/G) (0.05≤P<0.10),and had no significant effect on energy utilization (P>0.05). 2) Compared with common diet,corn DDGS diet significantly increased average daily feed intake,F/G,O2 consumption,RQ,total heat production (THP) and metabolizable energy intake (MEI) of broilers (P< 0.05),and significantly decreased apparent metabolic energy (AME),net energy (NE) and the ratio of AM E to NE (P<0.05). 3) The interaction of xylanase and diet type had significant effects on M EI and deposition energy of broilers (P<0.05). In this study,corn-soybean meal diet and30% corn DDGS diet for broilers supplemented with 0.2 g/kg xylanase had no significant effect on NE value of diets.