不同工艺参数组合对肉鸡颗粒饲料加工质量、生长性能和养分表观消化率的影响

Effects of Different Process Parameters Combination on Pellet Feed Quality,Growth Performance and Nutrient Apparent Digestibility of Broilers

本试验旨在研究筛片孔径、调质温度、模孔直径的不同工艺参数组合对肉鸡颗粒饲料加工质量、生长性能和养分表观消化率的影响。以玉米-豆粕型全价配合饲料为肉鸡试验饲粮,在相同配方及模孔长径比一致的条件下,设计3因素2水平(筛片孔径:2.0和2.5 mm;调质温度:70和80℃;模孔直径:3和4 mm)的肉鸡颗粒饲料加工试验,选用864只1日龄爱拔益加(AA)肉仔鸡,随机分为8个处理,每个处理6个重复,每个重复18只鸡。饲养试验共42 d,分1~21日龄和22~42日龄2个阶段。结果表明:1)筛片孔径和模孔直径的交互作用以及调质温度和模孔直径的交互作用对颗粒硬度有极显著影响(P<0.01),调质温度和模孔直径的交互作用、筛片孔径和调质温度的交互作用以及筛片孔径、调质温度和模孔直径的交互作用对颗粒耐久性有极显著影响(P<0.01),筛片孔径和模孔直径的交互作用对颗粒耐久性有显著影响(P<0.05)。2)调质温度对1~21日龄肉鸡末重、平均日增重和平均日采食量有极显著影响(P<0.01),对22~42日龄肉鸡末重有极显著影响(P<0.01)。3)肉鸡1~21日龄,筛片孔径、调质温度以及2因素的交互作用对肉鸡养分表观消化率的影响不显著(P>0.05);肉鸡22~42日龄,筛片孔径、调质温度和模孔直径的交互作用对肉鸡干物质、能量和粗蛋白质表观消化率有极显著影响(P<0.01)。综合得出:相同筛片孔径和模孔直径下,颗粒硬度和耐久性随调质温度升高有增大趋势;相同筛片孔径和调质温度下,颗粒硬度和耐久性随模孔直径的增大有降低趋势;肉鸡1~21日龄,筛片孔径选择2.0和2.5 mm均可,调质温度为70℃时肉鸡的生长性能极显著高于80℃时,且料重比显著低于80℃时;肉鸡22~42日龄,当筛片孔径为2.0或2.5 mm、调质温度为70℃、模孔直径为4.0 mm时肉鸡生长性能较高、料重比较低;肉鸡1~42日龄,当筛片孔径为2.0或2.5 mm、调质温度为70℃、模孔直径为4.0 mm时肉鸡的生长性能较高、料重比较低;当筛片孔径为2.5 mm、调质温度为80℃时,1~21日龄肉鸡干物质、能量和粗蛋白质表观消化率较高;当筛片孔径为2.5 mm、调质温度为70℃、模孔直径为4.0 mm时,22~42日龄肉鸡干物质、能量和粗蛋白质表观消化率最高。

This research aimed to study the effects of different combination of mesh size of screen,conditioning temperature and diameter of die hole on processing quality of pellet feed,growth performance and nutrient apparent digestibility of broilers.A common corn-soybean meal type diet for broilers was used in this experiment,and under the same recipe and slenderness ratio of die hole,a pellet feed processing test with 3 factors of 2 levels（mesh size of screen was 2.0 and 2.5 mm,conditioning temperature was 70 and 80℃,and diameter of die hole was 3 and 4 mm）was designed.A total of 864 one-day-old Arbor Acres broilers were randomly divided to 8 treatments with 6 replicates each and 18 broilers per replicate.The feeding experiment lasted for 42 days consisting of 2 stages with 1 to 21 days and 22 to 42 days of age.The results showas follows：1）the pellet hardness was significantly affected by the interaction of screen mesh size and diameter of die hole and the interaction of diameter of die hole and conditioning temperature（P〈0.01）.The pellet durability index（PDI）was significantly affected by interaction of diameter of die hole and conditioning temperature,the interaction of screen mesh size and conditioning temperature and the interaction of screen mesh size,conditioning temperature and diameter of die hole（P〈0.01）.The PDI was significantly affected by the interaction of screen mesh size and diameter of die hole（P〈0.05）.2）The final body weight,average daily gain and average daily feed intake of broilers of 1 to 21 days of age were significantly affected by conditioning temperature（P〈0.01）.The final body weight of broilers of 22 to 42 days of age was significantly affected by conditioning temperature（P〈0.01）,too.3）Nutrient apparent digestibility of broilers of 1 to 21 days of age was not significantly affected by screen mesh size,conditioning temperature and the interaction of both（P〈0.05）.While apparent digestibility of dry matter,energy and crude protein of broilers of 22 to 42 days of age were significantly affected by the interaction of screen mesh size,conditioning temperature and diameter of die hole（P〈0.01）.In conclusion,under the same screen mesh size and diameter of die hole,pellet hardness and PDI were increased with the conditioning temperature increasing.Under the same screen mesh size and conditioning temperature,pellet hardness and PDI were decreased with the diameter of die hole increasing.Growth performance of broilers of 1 to 21 days of age was increased with conditioning temperature increasing which showed significantly higher under 70℃than 80℃whatever screen mesh size was 2.0 or 2.5 mm,and the ratio of feed to gain was decreased with conditioning temperature increasing with the same tendency.Growth performance and the ratio of feed to gain of broilers of 22 to 42 days of age showed a better value when screen mesh size was 2.0 or 2.5 mm,conditioning temperature was 70℃and diameter of die hole was 4.0 mm.Growth performance and the ratio of feed to gain of broilers of 1 to 42 days of age showed a better value when screen mesh size was 2.0 or 2.5 mm,conditioning temperature was 70℃and diameter of die hole was 4.0 mm.Apparent digestibility of dry matter,energy and crude protein of broilers of 1 to 21 days of age showed a better value when screen mesh size was 2.5 mm and conditioning temperature was 80℃.Apparent digestibility of dry matter,energy and crude protein of broilers of 22 to 42 days of age showed a better value when screen mesh size was 2.5 mm,conditioning temperature was 70℃and diameter of die hole was 4.0 mm.