高粱的加工、粒度和水分对饲料制粒和肉鸡生长性能的影响

Effects of processing,grain size and moisture of sorghum on feed pellet quality and broiler growth performance

本研究旨在评价不同水分和颗粒粒度的高粱制粒或膨化对不同原料粒度、肉鸡代谢能、氨基酸回肠消化率和肉鸡生长性能的影响。试验以720只雄性雏鸡为研究对象,随机分为6组,每组6个重复,每个重复20只。试验处理以2×2×2因子设计,即2种加工方式(制粒和膨化),2个调质水分(1.6%和0.8%),2个颗粒粉碎粒度(650和850μm)。结果显示:在添加1.6%水分的膨化日粮中,制粒制粒和颗粒耐久指数较高。850μm的粒径增加了饲料颗粒耐久指数。各处理组对肉鸡日增重和屠体性状均无显著影响(P>0.05)。在10~13 d饲喂颗粒饲料和添加1.6%水分的饲料的肉鸡表观代谢能和氮校正代谢能均较高(P<0.05),与添加膨化性饲料相比,高粱制粒饲料回肠赖氨酸和甘氨酸消化系数显著提高(P<0.05)。在评价饲料加湿效果时,饲料添加1.6%水分后赖氨酸、蛋氨酸、胱氨酸、甘氨酸、组氨酸、异亮氨酸和精氨酸回肠表观消化系数显著升高(P<0.05)。1.6%水分的膨化饲料较0.8%水分显著提高了21 d肉鸡采食量(P<0.05),在42 d时,0.8%水分的颗粒饲料显著提高了采食量(P<0.05)。结论:以650μm的粉碎粒度和1.6%的水分制备颗粒饲料在肉鸡生长后期可以提高回肠氨基酸消化率和表观代谢能,而膨化工艺提高了42 d肉鸡饲料颗粒制粒和饲料转化率。

The purpose of this study was to evaluate the effects of processing,grain size and moisture of sorghum on feed pellet quality and growth performance of broilers.We selected 720 male chicks which were randomly divided into 6 groups with 6 replicates and 20 each.The experimental treatment was designed with 2×2×2 factors,i.e.,2 processing methods(pelleted and extruded),2 condition moisture(1.6%and 0.8%),and 2 particle size(650 and 850 mum).The results showed that higher pellet quality and pellet durability index were obtained in expanded diets and inclusion of 1.6%moisture.Particle size of 850μm increases the grain durability index of feed.All treatment groups had no significant effect on daily weight gain and carcass traits of broilers(P>0.05).At 10~13 d,the values of apparent metabolic energy and nitrogen corrected metabolic energy of broilers fed pelleted feed with 1.6%moisture were both higher(P<0.05),and the ileal digestibility coefficients of lysine and glycine of sorghum pelleted feed were significantly increased compared with that of bulking feed(P<0.05).When evaluating the humidification effect of feed,the apparent digestibility coefficient of ileum increased significantly after the addition of 1.6%water in feed(P<0.05).Compared with 0.8%water,the extruded feed with 1.6%water significantly increased feed intake of broiler chickens on 21 d(P<0.05),and at 42 d,the pelleted feed with 0.8%water significantly increased feed intake(P<0.05).In conclusion:the pelleted feed prepared with particle size of 650μm and moisture content of 1.6%can improve ileum amino acid digestibility and apparent metabolic energy in later growth period of broilers,while the extruded process can improve pellet quality and feed conversion rate of broilers at 42 d.