Chang'a Edwin Peter, Abdallh Medani Eldow, Ahiwe Emmanuel Uchenna, Mbaga Said, Zhu Ze Yuan, Fru-Nji Fidelis, Iji Paul Ade
Department of Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia.
Tanzania Livestock Research Institute, P.O. Box 6191, TALIRI-Uyole, Mbeya, Tanzania.
Asian-Australas J Anim Sci. 2020 Jul;33(7):1126-1137. doi: 10.5713/ajas.19.0263. Epub 2019 Aug 3.
Pellet durability, particle size distribution, growth response, tibia bone characteristics and energy retention were measured to evaluate cassava as an alternative energy source to replace maize in broiler diets with or without Ronozyme (A+VP) enzyme composites.
A total of 480 one-day broiler chicks were randomly assigned to 8 treatments in a 4×2 factorial arrangement. Four levels of cassava: (0%, 25%, 50%, 75%) and 2 levels of enzymes (0 and 500 g/tonne) were used. Each treatment was replicated six times, with ten birds per replicate.
The particle size distribution in the diets showed an increasing trend of small particles with increase in cassava level. Pellet durability decreased (p<0.05) with cassava inclusion. Feed intake was highest in birds fed diets with medium cassava level at 1 to 24 d and 1 to 35 d of age. The body weight gain of birds reduced (p<0.037) as cassava level increased, but it increased (p<0.017 when enzymes were added. The feed conversion ratio was high (p<0.05) when cassava level was increased, but it reduced (p<0.05) when enzymes were added. The dressing percentage (DP), and weight of drumsticks reduced (p<0.05) with increasing cassava level. Enzyme supplementation increased (p<0.05) DP, and weight of breast, thighs and drumsticks. Ash content, weight, length, width, and bone strength decreased (p<0.05) when cassava level was increased, however, they were increased with enzyme addition. The contents of Ca, K, and Zn were raised (p<0.001) with increasing cassava level. Enzyme inclusion increased (p<0.001) all mineral contents in tibia bones. Body fat and energy retained as fat decreased (p<0.001) as cassava level increased. Enzyme inclusion increased (p<0.05) body protein content and energy retained as protein.
Although broiler performance was depressed by high levels of cassava inclusion, it was not affected by low levels, which further improved by enzyme supplementation.
测定颗粒耐久性、粒度分布、生长反应、胫骨骨骼特性和能量保留情况，以评估木薯作为替代能源在添加或不添加罗酶宝（A+VP）酶复合物的肉鸡日粮中替代玉米的效果。
将480只1日龄肉鸡雏鸡随机分为8组，采用4×2析因设计。使用四个木薯水平（0%、25%、50%、75%）和两个酶水平（0和500克/吨）。每个处理重复6次，每个重复10只鸡。
日粮中的粒度分布显示，随着木薯水平的增加，小颗粒有增加趋势。随着木薯添加量的增加，颗粒耐久性降低（p<0.05）。在1至24日龄和1至35日龄时，饲喂中等木薯水平日粮的鸡采食量最高。随着木薯水平的增加，鸡的体重增加量降低（p<0.037），但添加酶后体重增加量增加（p<0.017）。随着木薯水平的增加，饲料转化率较高（p<0.05），但添加酶后饲料转化率降低（p<0.05）。随着木薯水平的增加，屠宰率（DP）和鸡腿重量降低（p<0.05）。添加酶可提高（p<0.05）DP以及胸肉、大腿和鸡腿的重量。随着木薯水平的增加，灰分含量、重量、长度、宽度和骨强度降低（p<0.05），但添加酶后则增加。随着木薯水平的增加，钙、钾和锌的含量升高（p<0.001）。添加酶可增加（p<0.001）胫骨中所有矿物质含量。随着木薯水平的增加，体脂和以脂肪形式保留的能量降低（p<0.001）。添加酶可增加（p<0.05）体蛋白含量和以蛋白质形式保留的能量。
虽然高木薯添加量会降低肉鸡生产性能，但低木薯水平不会产生影响，添加酶可进一步改善生产性能。
