Wanapat Metha, Foiklang Suban, Rowlinson Peter, Pilajun Ruangyote
Tropical Feed Resources Research and Development Center (TROFREC), Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, 40002, Thailand.
Trop Anim Health Prod. 2012 Jan;44(1):35-42. doi: 10.1007/s11250-011-0014-z. Epub 2011 Nov 10.
Four, rumen fistulated crossbred (Brahman × native) beef cattle steers were randomly assigned to receive four dietary treatments according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. Factor A was carbohydrate source; cassava chip (CC) or CC + rice bran at a ratio 3:1 (CR3:1) and Factor B was cotton seed meal level (CM); and 109 g CP/kg (LCM) and 328 g CP/kg (HCM) at similar overall CP levels (490 g CP/kg). The animals were fed 5 g concentrate/kg BW, and urea-treated rice straw (UTS) (50 g urea/kg DM) was fed ad libitum. Carbohydrate source did not affect feed intake, nutrient digestibility, blood urea nitrogen, rumen fermentation, or microbial protein synthesis; however, animals fed with CC had a higher population of total viable bacteria than the CR3:1 treatment (P<0.05). Animals that received HCM had a lower total feed intake while ruminal pH was higher than the LCM fed treatment (P<0.05). The population of total viable and cellulolytic bacteria in animals that received HCM were lower than the LCM fed treatment (P<0.05). Moreover, use of HCM in beef cattle diets resulted in lower microbial protein synthesis when compared with the LCM fed treatment (P<0.05) although efficiency of microbial protein synthesis was nonsignificantly different among treatments. Therefore, cassava chip combined with rice bran can be used in a concentrate diet for beef cattle. It is also noted that a high level of cotton seed meal in the concentrate may impact rumen fermentation and animal performance.
四头装有瘤胃瘘管的杂交（婆罗门牛×本地牛）肉牛公牛，按照4×4拉丁方设计的2×2析因安排，随机分配接受四种日粮处理。因素A为碳水化合物来源；木薯片（CC）或木薯片与米糠按3:1比例混合（CR3:1），因素B为棉籽粕水平（CM）；在相似的总粗蛋白水平（490 g CP/kg）下，分别为109 g CP/kg（低棉籽粕，LCM）和328 g CP/kg（高棉籽粕，HCM）。给动物饲喂5 g精料/kg体重，自由采食经尿素处理的稻草（UTS）（50 g尿素/kg干物质）。碳水化合物来源不影响采食量、养分消化率、血尿素氮、瘤胃发酵或微生物蛋白合成；然而，饲喂CC的动物总活菌数高于CR3:1处理组（P<0.05）。接受HCM的动物总采食量较低，而瘤胃pH高于饲喂LCM的处理组（P<0.05）。接受HCM的动物总活菌数和纤维素分解菌数低于饲喂LCM的处理组（P<0.05）。此外，与饲喂LCM的处理组相比，肉牛日粮中使用HCM导致微生物蛋白合成较低（P<0.05），尽管各处理间微生物蛋白合成效率差异不显著。因此，木薯片与米糠混合可用于肉牛的精料日粮。还应注意的是，精料中高水平的棉籽粕可能会影响瘤胃发酵和动物生产性能。
