Klusmeyer T H, Lynch G L, Clark J H, Nelson D R
Department of Animal Sciences, University of Illinois, Urbana 61801.
J Dairy Sci. 1991 Jul;74(7):2220-32. doi: 10.3168/jds.S0022-0302(91)78395-1.
Four Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square to investigate the effects of calcium salts of long-chain fatty acids (fat) and proportion of forage in diet on ruminal fermentation, flow of nutrients to the small intestine, and animal performance. Treatments, arranged in a 2 x 2 (fat x forage) factorial, were 1) low (50%) forage, no fat; 2) low forage, fat; 3) high (67%) forage, no fat; and 4) high forage, fat. Feeding fat decreased OM intake and OM truly digested in the rumen. Feeding high forage diets decreased intakes of OM and starch and increased intakes of ADF and NDF. Ruminal pH and ratio of acetate to propionate were increased with high forage diets compared with low forage diets. Feeding fat and different amounts of forage to cows did not alter the flows of NAN and microbial N to the duodenum or efficiency of microbial growth. Production of milk and 4% FCM and percentage of fat in milk were increased by feeding fat. Feeding high forage diets decreased milk production, increased percentage of fat in milk, increased the yield of fat, and caused no change in 4% FCM production. The percentage of protein in milk was decreased by feeding high forage diets and fat, but yield of milk protein was decreased only by feeding high forage diets to cows.
选用4头安装了瘤胃和十二指肠瘘管的荷斯坦奶牛，采用4×4拉丁方设计，研究长链脂肪酸钙盐（脂肪）和日粮中粗饲料比例对瘤胃发酵、养分向小肠的流动以及动物生产性能的影响。处理因素按2×2（脂肪×粗饲料）析因排列，分别为：1）低（50%）粗饲料，无脂肪；2）低粗饲料，脂肪；3）高（67%）粗饲料，无脂肪；4）高粗饲料，脂肪。饲喂脂肪降低了瘤胃中有机物摄入量和真正消化的有机物量。饲喂高粗饲料日粮降低了有机物和淀粉的摄入量，增加了酸性洗涤纤维和中性洗涤纤维的摄入量。与低粗饲料日粮相比，高粗饲料日粮提高了瘤胃pH值和乙酸与丙酸的比例。给奶牛饲喂脂肪和不同量的粗饲料并未改变非氨氮和微生物氮向十二指肠的流量或微生物生长效率。饲喂脂肪提高了牛奶产量、4%乳脂校正乳产量和牛奶中的脂肪百分比。饲喂高粗饲料日粮降低了牛奶产量，提高了牛奶中的脂肪百分比，增加了脂肪产量，且4%乳脂校正乳产量没有变化。饲喂高粗饲料日粮和脂肪降低了牛奶中的蛋白质百分比，但仅给奶牛饲喂高粗饲料日粮降低了牛奶蛋白产量。
