Elliott J P, Overton T R, Drackley J K
Department of Animal Sciences, University of Illinois, Urbana 61801.
J Dairy Sci. 1994 Mar;77(3):789-98. doi: 10.3168/jds.S0022-0302(94)77014-4.
Four nonlactating Holstein cows fitted with ruminal cannulas were used in a 4 x 4 Latin square design with 14-d periods. Treatments were 1) control, no added fat; 2) 5.0% prilled fatty acids (iodine value = 14); 3) 5.6% prilled hydrogenated tallow (iodine value = 8); and 4) 5.0% flaked fatty acids (iodine value = 14). Diets consisted of alfalfa haylage, corn silage, and concentrate (40:20:40, DM basis). Intake of the TMR (16.4% CP and 25.4% ADF) was restricted to 1.5% of BW so that DMI was similar among diets (9.2 kg/d). Total fatty acid intakes averaged 293, 749, 747, and 686 g/d for treatments 1 to 4, respectively. Digestibilities of total C16, total C18, and total fatty acids were greater for prilled fatty acids than for prilled hydrogenated tallow. Total tract apparent digestibilities of DM, OM, CP, ADF, and NDF did not differ among treatments. Treatments did not affect concentration of total VFA or acetate:propionate ratio in ruminal fluid. Concentration of cholesterol in plasma was lowest when cows were fed the control diet and was greater when cows were fed prilled fatty acids than when they were fed prilled hydrogenated tallow or flaked fatty acids. The three forms of saturated fatty acids did not affect nutrient digestibilities or ruminal fermentation characteristics, but the digestibility of fatty acids in prilled hydrogenated tallow was lower than in prilled fatty acids. Digestibilities of fatty acids and other nutrient fractions and characteristics of ruminal fluid generally were similar between flaked and prilled fatty acids, despite the larger particle size of flaked fatty acids.
选用4头安装有瘤胃瘘管的非泌乳荷斯坦奶牛，采用4×4拉丁方设计，试验期为14天。处理组分别为：1）对照组，不添加脂肪；2）5.0%颗粒状脂肪酸（碘值=14）；3）5.6%颗粒状氢化牛脂（碘值=8）；4）5.0%片状脂肪酸（碘值=14）。日粮由苜蓿青贮、玉米青贮和精料组成（干物质基础为40:20:40）。全混合日粮（粗蛋白含量16.4%，酸性洗涤纤维含量25.4%）的采食量限制为体重的1.5%，以使各日粮间的干物质采食量相似（9.2千克/天）。处理1至4组的总脂肪酸摄入量分别平均为293、749、747和686克/天。颗粒状脂肪酸的总C16、总C18和总脂肪酸消化率高于颗粒状氢化牛脂。各处理组间干物质、有机物、粗蛋白、酸性洗涤纤维和中性洗涤纤维的全肠道表观消化率无差异。各处理对瘤胃液中总挥发性脂肪酸浓度或乙酸:丙酸比值无影响。当奶牛饲喂对照日粮时，血浆中胆固醇浓度最低；与饲喂颗粒状氢化牛脂或片状脂肪酸相比，饲喂颗粒状脂肪酸时奶牛血浆中胆固醇浓度更高。三种饱和脂肪酸形式对养分消化率或瘤胃发酵特性无影响，但颗粒状氢化牛脂中脂肪酸的消化率低于颗粒状脂肪酸。尽管片状脂肪酸的颗粒尺寸较大，但片状脂肪酸和颗粒状脂肪酸之间的脂肪酸消化率及其他养分组分和瘤胃液特性总体相似。
