【摘要】 80只断奶新西兰兔分成5组,饲喂5种中性洗涤纤维(NDF)水平的日粮(分别为24%、27%、30%33%和36%),研究了日粮NDF水平对断奶至2月龄的肉兔生产性能、营养物质消化利用、免疫指标、盲肠纤维酶活性和盲肠内环境的影响。结果表明:日粮NDF水平对试兔日增重、饲料转化率影响显著(P<0.05),随NDF水平增加,日增重先增加后降低,料重比先降低后增加,30%NDF水平对日增重最高为31.52g/d,饲料转化率最低为3.23:1。随日粮NDF水平的增加,粗纤维、能量、粗蛋白和粗脂肪消化率显著或极显著降低(P<0.05,P<0.01),NDF消化率显著提高(P<0.05),氮沉积先升高后下降,以30%NDF组最高为1.24g/d。不同NDF间胸腺指数和脾脏指数差异不显著(P>0.05)。日粮NDF能极显著提高盲肠纤维素酶的活性(P<0.01),纤维素酶活性由13.79IU/g提高到58.68IU/g。NDF水平对断奶至2月龄试兔盲肠发育影响显著(P<0.05),盲肠占活重的比例随NDF水平的增加呈上升趋势。盲肠氨氮浓度呈下降趋势,24%、27%NDF组与36%NDF组差异显著(P<0.05),总VFA含量呈上升趋势,24%NDF和36%NDF组差异显著(P<0.05),VFA中乙酸比例上升,丙酸、丁酸比例下降。综合以上结果,断奶至2月龄肉兔NDF水平以30%～33%为宜。更多还原

【Abstract】 An experiment was conducted to determine the effect of varying levels of dietary neutral detergent fiber(NDF) on growing development,nutrient utilization,caecal cellulase activity,immunity index and caecum fermentation of weaning to 2 month old New Zealand rabbits.Eighty weaner rabbits were allocated in individual cages for five treatments in which they were fed each diet with NDF at 24%,27%,30%,33% and 36%,respectively.The results showed as follows:NDF level had significantly influences on average daily gain(ADG) and feed/gain(F/G)(P<0.05),ADG was the largest(31.52g/d) and FCR was the lowest(3.23:1)when NDF was 30%.The digestibilities of crude fiber,energy,crude protein(CP) and ether extract dropped when dietary NDF increased(P<0.05,P<0.01),the digestibility of NDF raised when NDF increased(P<0.05).Nitrogen retention(RN) raised then dropped when dietary NDF increased and got the maximum,1.24g/d,when NDF was 30%.NDF level had not significantly influence on thymus index and spleen index(P<0.05).The cellulase activity of cecum raised when NDF level increased(P<0.01) and was 58.68 IU/g when NDF was 36%.NDF level had significantly influence on cecum development(P<0.05),the cecum weight/body weight raised when NDF increased.The caecum NH3-N concentration dropped when NDF enhanced,there were significant difference among 24%,27% and 30% NDF groups.The difference of total VFA concentration between 24% and 36% NDF was significant(P<0.05).The acetic acid ratio increased,propionic acid ratio and butyric acid ratio descended when dietary NDF increased.According to ADG,F/G and RN,the optimum NDF level of weaning to 2 month old rabbits was 30%～33%.更多还原