Liao Kuoyao, Cai Jingyi, Shi Zhujun, Tian Gang, Yan Dong, Chen Delin
Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu 611130, China.
Anim Nutr. 2017 Jun;3(2):151-155. doi: 10.1016/j.aninu.2017.03.006. Epub 2017 Apr 29.
This study was conducted to investigate the effects of raw material extrusion and steam conditioning on feed pellet quality and nutrient digestibility of growing meat rabbits, in order to determine appropriate rabbit feed processing methods and processing parameters. In Exp. 1, an orthogonal design was adopted. Barrel temperature, material moisture content and feed rate were selected as test factors, and acid detergent fiber (ADF) content was selected as an evaluation index to research the optimum extrusion parameters. In Exp. 2, a two-factor design was adopted. Four kinds of rabbit feeds were processed and raw material extrusion adopted optimum extrusion parameters of Exp. 1. A total of 40 healthy and 42-day-old rabbits with similar weight were used in a randomized design, which consisted of 4 groups and 10 replicates in each group (1 rabbits in each replicate). The adaptation period lasted for 7 d, and the digestion trial lasted for 4 d. The results showed as follows: 1) ADF was significantly affected by barrel temperature ( < 0.05); the optimum extrusion parameters were barrel temperature 125 °C, moisture content 16% and feed rate 9 Hz. 2) Raw material extrusion and steam conditioning both significantly decreased powder percentage, pulverization ratio and protein solubility ( < 0.05), significantly improved hardness and starch gelatinization degree of rabbit feed ( < 0.05). They both had significant interaction effects on the processing quality of rabbit feed ( < 0.05). 3) Extrusion significantly improved the apparent digestibility of dry matter and total energy ( < 0.05). Extrusion and steam conditioning both significantly improved the apparent digestibility of crude fiber (CF), ADF and NDF ( < 0.05), but they had no interaction effects on the apparent digestibility of rabbit feed. Thus, using extrusion and steam conditioning technology at the same time in the weaning rabbits feed processing can improve the pellet quality and nutrient apparent digestibility of rabbit feed.
本研究旨在探讨原料挤压和蒸汽调质对生长肉兔饲料颗粒质量和养分消化率的影响，以确定合适的家兔饲料加工方法和加工参数。在试验1中，采用正交设计。选择机筒温度、物料水分含量和进料速度作为试验因素，选择酸性洗涤纤维（ADF）含量作为评价指标来研究最佳挤压参数。在试验2中，采用两因素设计。加工4种家兔饲料，原料挤压采用试验1的最佳挤压参数。选用40只体重相近、健康的42日龄家兔，采用随机设计，分为4组，每组10个重复（每个重复1只兔）。适应期持续7天，消化试验持续4天。结果如下：1）ADF受机筒温度影响显著（P<0.05）；最佳挤压参数为机筒温度125℃、水分含量16%、进料速度9Hz。2）原料挤压和蒸汽调质均显著降低了粉化率、粉碎率和蛋白质溶解度（P<0.05），显著提高了家兔饲料的硬度和淀粉糊化度（P<0.05）。它们在家兔饲料加工质量上均有显著的交互作用（P<0.05）。3）挤压显著提高了干物质和总能的表观消化率（P<0.05）。挤压和蒸汽调质均显著提高了粗纤维（CF）、ADF和中性洗涤纤维（NDF）的表观消化率（P<0.05），但它们在家兔饲料表观消化率上无交互作用。因此，在断奶家兔饲料加工中同时使用挤压和蒸汽调质技术可提高家兔饲料的颗粒质量和养分表观消化率。
