棉籽壳作为绵羊饲料营养特性的研究

通过消化代谢试验研究绵羊对棉籽壳(含仁棉籽壳、无仁棉籽壳)和粉碎玉米秸秆的自由采食量和表观消化率,旨在对棉籽壳的营养价值和消化特点进行评价.试验选择12只成年新疆美利奴公羊,随机分为2组(n=6),在饲喂300 g/(只·d)混合精料的基础上分别喂给400(试验1组)、800(试验2组)g/(只·d)无仁棉籽壳,用差数法测定绵羊对棉籽壳的表观消化率.另外,选择18只成年新疆美利奴公羊,随机分为3组(n=6),在饲喂300 g/(只·d)混合精料的基础上,分别自由采食含仁棉籽壳(试验3组)、无仁棉籽壳(试验4组)和粉碎玉米秸秆(试验5组),研究绵羊对其的消化代谢情况.结果表明,绵羊对无仁棉籽壳干物质、有机物、粗蛋白质、纤维素、半纤维素和能量的表观消化率分别为46.71%、47.37%、-53.40%、66.60%、62.48%和42.59%.饲喂含仁棉籽壳、无仁棉籽壳和粉碎玉米秸秆时,饲喂含仁和无仁棉籽壳组的干物质、有机物、纤维素、半纤维素、能量和钙等的采食量均无明显差异(P> 0.05),但采食含仁棉籽壳组粗蛋白质和磷的采食量极显著高于无仁棉籽壳组(P< 0.01),木质素采食量极显著低于无仁棉籽壳组(P< 0.01).饲喂含仁棉籽壳日粮和无仁棉籽壳日粮绵羊间干物质、有机物和能量的表观消化率均无明显差异(P> 0.05),但无仁棉籽壳组绵羊的纤维素和半纤维素的表观消化率却分别显著和极显著高于含仁棉籽壳组(P< 0.05;P< 0.05),含仁棉籽壳组粗蛋白质的表观消化率极显著高于无仁棉籽壳组(P< 0.01);饲喂玉米秸秆时绵羊的干物质、有机物、粗蛋白质、纤维素和能量的表观消化率均极显著高于饲喂含仁或无仁棉籽壳的绵羊(P< 0.01),但钙和磷的表观消化率却低于饲喂棉籽壳的绵羊(P> 0.05).饲喂含仁棉籽壳日粮绵羊的氮摄入量和氮保留率极显著高于无仁棉籽壳日粮绵羊(P< 0.01);饲喂玉米秸秆日粮绵羊和饲喂无仁棉籽壳绵羊在氮保留上无明显差异(P> 0.05).因此,棉籽壳是一种特殊的粗饲料,绵羊对其采食量大,纤维素类物质和能量的消化率较高,但存在着严重的蛋白质消化障碍;无仁棉籽壳日粮与玉米秸秆日粮的营养价值基本相当,但绵羊对无仁棉籽壳日粮的氮消化率较低.

Study on Nutritional Characteristics of Cottonseed Hull as a Feed of Sheep

In this paper through digestive and metabolic experiments studied the voluntary intake and apparent digestibility of cottonseed hulls (kernel-contained CH,kernel-free CH) and cornstalk on sheep to evaluate the nutrition value and digestion characteristics of cottonseed hulls.12 of adult Xinjiang merino rams were selected and divided into two groups (n=6 each group),and on the basis of 300 g/(head·day) of mixed concentrate,fed with kernel-free CH by 400 (group 1) or 800 (group 2) g/(head·day) respectively,to estimate the digestibility of CH by difference method;As well,another 18 of adult Xinjiang merino rams were selected and divided into three groups (n=6 each group),and on the basis of 300 g/(head·day) of mixed concentrate,cafeteria feeding with kernel-contained CH (group 3),kernel-free CH (group 4) or ground cornstalks (group 5) respectively,to study the effects of three diets on the voluntary intake,digestion and metabolism of sheep.The results showed that the apparent digestibility of the DM,OM,CP,cellulose,hemicellulose and energy of kernel-free CH by sheep were 46.71%,47.37%,-53.40%,66.60%,62.48% and 42.59%,respectively.There were no significant differences in the intake of DM,OM,cellulose,hemicellulose,energy and Ca between kernel-contained CH and kernel-free CH groups (P> 0.05);Intake of CP and P in kernel-contained CH group were extremely significantly higher than that in kernel-free CH group (P< 0.01);Intake of lignin in kernel-contained CH group was extremely significantly lower than that in kernel-free CH group (P< 0.01).There were no significant differences in the apparent digestibility of DM,OM and energy between kernel-contained CH and kernel-free CH groups (P> 0.05).The apparent digestibility of cellulose and hemicellulose in kernel-free CH group were significantly and extremely significantly higher than that in kernel-contained CH group (P< 0.05;P< 0.01),respectively.The apparent digestibility of CP in kernel-contained CH group was extremely significantly higher than that in kernel-free CH group (P< 0.01).The apparent digestibility of DM,OM,CP,cellulose and energy in ground cornstalks group were extremely significantly higher than that in kernel-contained CH and kernel-free CH groups (P< 0.01),however,the apparent digestibility of Ca and P were lower than that in kernel-contained CH and kernel-free CH groups (P> 0.05).Intake and retention of nitrogen in kernel-contained CH group were extremely significantly higher than that in kernel-free CH group (P< 0.01);The was no significant difference in the retention of nitrogen between kernel-free diet group and cornstalk diet group (P> 0.05).It was concluded that CH was a kind of special forage with larger intake,higher digestibility on the fiber substances and energy,but with a serious obstruction on protein digestion;The nutritional value between kernel-free diet and cornstalk diet was almost equal,and with lower nitrogen digestibility on kernel-free diet.