绵羊对4种蛋白饲料日粮营养物质消化动态变化的比较

试验采用3头35 kg左右的美利奴绵羊研究不同蛋白饲料日粮对绵羊营养物质消化的影响。为自身对照试验设计,整个试验分4期进行,每期3头羊饲喂同一种蛋白饲料日粮。4种蛋白来源分别为棉籽粕、大豆粕、葵粕和菜籽粕。试验结果表明:绵羊采食蛋白来源为棉籽粕的日粮时,干物质、有机物和氮采食量最高,而菜籽粕采食量最低。饲喂棉籽粕日粮,干物质、有机物和纤维素十二指肠流量显著高于大豆粕日粮和菜籽粕日粮(P<0.05)。大豆粕日粮粗蛋白在前胃的消失率最高为33%,其余3组日粮粗蛋白前胃的降解率为16%~20%。到达小肠的菌体蛋白(MCP)量各组间无差异,而到达小肠过瘤胃饲料蛋白的量(率)棉籽粕组显著高于葵粕组、菜籽粕组、大豆粕组。大豆粕组粗蛋白在小肠的表观消化率最低为48%,其余3组日粮粗蛋白小肠表观降解率均为66%。

Effects of Different Dietary Crude Protein Sources on Nutrition Digestibility of Growing Sheep

An experiment was conducted to determine the effects of supplementing different protein sources on site and extent of nutrient digestibility.Three 35 kg growing Merino sheep was used in this experiment with four periods.Sheep was fed with four diets supplemented crude protein by cottonseed meal,sun flower meal,rape seed meal and soybean meal,respectively.The results indicated that:the DM,OM,N intake of cottonseed meal was highest and the DM,OM,N intake of rape seed was lowest among four diets.When sheep was fed four diets respectively,the DM,OM and crude protein flowing to the duodenum were higher for cottonseed meal group than other three diets groups.The ratio of CP disappearance in forestomach for soybean meal was 33%.The ratios of CP disappearance in forestomach for the other three protein sources were about 16%-20%.Microbial protein(MCP) flowing to duodenum was not different among four treatments.Ruminal undegraded protein (RUP) flowing to duodenum was higher for cottonseeds meal than sun flower meal,rape seed meal and soybean meal.The CP apparent digestibility of soybean meal in small intestine was only 48%,and the CP apparent digestibilities of the other three protein sources were 66%.