饲料不同粉碎粒度对蛋鸡饲料不同粉碎粒度对蛋鸡粗蛋白代谢率和十二指肠形态的影响

Influence of Different Feed Particle Size on Crude Protein Metabolic Rate and Duodenum Morphology of Laying Hens

试验旨在研究饲料不同粉碎粒度及粒度分布对产蛋期海兰灰蛋鸡粗蛋白代谢率和十二指肠形态的影响。选取216只46周龄健康海兰灰蛋鸡，随机分为9组，每组3个重复，每个重复8只。将玉米、豆粕分别用4．50、6．00、8．00mm孔径筛片粉碎，两两交互后按同一配方配制试验饲粮，饲喂海兰灰蛋鸡7周。结果表明：玉米粒度对饲料粗蛋白代谢率有显著影响（P〈0．05）；豆粕粒度和玉米与豆粕粒度的交互作用对饲料粗蛋白代谢率影响不显著（P〉0．05），随着玉米、豆粕粒度的增大，饲料粗蛋白代谢率会随之降低；豆粕粒度、玉米粒度及其交互作用对十二指肠肠绒毛高度和肠壁厚度的影响差异显著（P〈0．05）；十二指肠肠绒毛高度和肠壁厚度会随粒度的增大而增大，但豆粕粒度的增大会使十二指肠壁变薄。在试验条件下基于饲料粗蛋白代谢率和海兰灰蛋鸡的十二指肠形态适合蛋鸡生产的饲料粒度为：8．00mm筛片粉碎的玉米，其中大于75％粒度分布在400～5000μm，约0．1％的粒度大于5000um且最大粒径为5008μm，重量几何平均粒径为704．15μm。4．50mm筛片粉碎的豆粕，其中大于75％的粒度分布在400～2000μm，最大粒径为2875μm，重量几何平均粒径为668．00μm。

The experiment was conducted to study the effects of feed particle size and distribution on crude protein （CP） metabolic rate and duodenum morphology of laying hens. A total of 216 Hy-Line gray hens of 46 weeks of age were randomly allocated to 9 groups with 3 replicates per group and 8 hens per replicate. Corn and soybean meal were crushed by 4.50,6.00,8.00 mm aperture sieve and then pairwise interaction formulated diets. The experiment lasted for 7 weeks. The results showed that corn particle size and distribution had a significant effect on CP metabolic rate （P〈0.05）,but soybean meal particle size and distribution and the interaction of corn and soybean meal were not significant （P〉0.05）, with increasing particle size of corn and soybean, CP metabolic rate reduced; Particle size and distribution of corn and soybean, interaction of corn and soybean meal had significant effects on duodenal villus height and wall thickness （P〈0.05）;Duodenal villus height and wall thickness grew with particle size increasing,but soybean meal made the size of the duodenal wall thinning. Under the experimental conditions, considering the indicators for corn-soybean meal diet of laying hens,appropriate particle size of corn was crushed by 8.00 mm sieve,of which more than 75% particle size distribution was 400 to 5 000 μm,about 0.1% was more than 5 000 μm and the maximum particle size was 5 008 μm, Gw was 704.15 μm; appropriate particle size of soybean meal was crushed by 4.50 mm sieve,of which more than 75% particle size distribution was 400 to 5 000 μm,the maximum particle size was 2 875 μm and dgw was 668.00μm.