高粱替代玉米不同比例及调质温度对颗粒饲料质量影响

Effects of Different Proportions of Sorghum Instead of Corn and Conditioning Temperature on Pellet Feed Quality

本实验旨在研究高粱替代玉米不同比例及调质温度对颗粒饲料成型率、硬度、颗粒耐久性、淀粉糊化度和颗粒色泽的影响。实验以肉鸡玉米-豆粕典型日粮为基础,使用高粱替代玉米,替代比例分别为0%、20%、40%、60%、80%、100%,测定分析6组物料的糊化特性及热特性的区别;调质温度分别为75、85℃,测定各组颗粒饲料的成型特性及加工质量指标。结果表明:1)在物料基本理化特性方面,随着高粱替代比例的增加,峰值黏度、最终黏度等呈现显著下降趋势,糊化温度、峰值温度、相变热焓等呈现显著上升趋势(P<0.05)。2)在颗粒饲料质量方面,随着高粱替代比例的增加,颗粒饲料成型率总体呈现上升趋势,颗粒饲料硬度呈现先下降后上升趋势,但差异不显著(P>0.05),颗粒饲料耐久性呈现显著上升趋势,淀粉糊化度呈现显著下降趋势,L、a、b值均呈现显著下降趋势(P<0.05);随调质温度的上升,颗粒饲料成型率变化不显著(P>0.05);颗粒饲料硬度呈现显著下降趋势,颗粒耐久性和淀粉糊化度呈现显著上升趋势,L、a、b值均呈现显著上升趋势(P<0.05);高粱替代比例及调质温度对颗粒饲料硬度、淀粉糊化度、L、a、b值均有显著的交互作用(P<0.05)。因此,高粱替代玉米比例对颗粒饲料的影响作用较小,各组颗粒饲料质量指标均符合要求范围;调质温度对颗粒饲料的影响作用较显著,建议对添加高粱的日粮使用85℃的调质温度。

This experiment was conducted to study the effects of different proportions of sorghum replacing corn and conditioning temperature on the forming rate,hardness,pellet durability index,starch gelatinization degree and color of the pellet feed.Based on the typical corn-soybean meal diet for broilers,sorghum was used to replace corn with substitution mass fraction of 0%,20%,40%,60%,80%and 100%,respectively.The gelatinization characteristics and thermal characteristics of the six groups of materials were determined and analyzed.The conditioning temperature was 75℃and 85℃,respectively.The pelleting characteristics and processing quality of each group of pellet feed were measured.The results indicated that:1)In terms of the basic physical and chemical properties of the mash,with the increase of sorghum substitution ratio,the peak viscosity and final viscosity showed a significant downward trend,and the pasting temperature,peak temperature and enthalpy change of gelatinization showed a significant upward trend(P<0.05).2)In terms of pellet feed quality,with the increase of sorghum substitution ratio,the forming rate of pellet feed showed an overall upward trend,and the hardness of pellet feed showed a trend of decreasing firstly and then increasing,however,the difference was not significant(P>0.05).The pellet durability index showed a significant upward trend,the starch gelatinization degree showed a significant downward trend,and the values of L,a and b showed a significant downward trend(P<0.05).With the increase of conditioning temperature,the forming rate of pellet feed did not change significantly(P>0.05).The hardness of pellet feed showed a significant downward trend,the pellet durability index and starch gelatinization degree showed a significant upward trend,and the values of L,a and b showed a significant upward trend(P<0.05);there were significant interactions between sorghum substitution ratio and conditioning temperature on the hardness,starch gelatinization degree,values of L,a and b of pellet feed(P<0.05).In summary,the proportion of sorghum replacing corn had little effect on the pellet feed,and the quality of pellet feed in each group meet the standard requirements.The effect of conditioning temperature on pellet feed was significant,and it was recommended to use the conditioning temperature of 85℃for the diet supplemented with sorghum.