Bremmer D R, Ruppert L D, Clark J H, Drackley J K
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
J Dairy Sci. 1998 Jan;81(1):176-88. doi: 10.3168/jds.S0022-0302(98)75565-1.
Six cows were utilized in a 6 x 6 Latin square design with 21-d periods to determine effects of the postruminal profile of fatty acids on dry matter (DM) intake, milk yield and composition, nutrient digestibilities, and plasma metabolites. Treatments were abomasal infusions of 1) control [168 g/d of meat solubles (carrier for fatty acids) plus 10.6 g/d of Tween 80 (emulsifier)], 2) control plus 450 g/d of mostly saturated fatty acids, 3) control plus 450 g/d of palm oil fatty acids low in linoleic acid, 4) control plus 450 g/d of palm oil fatty acids, 5) control plus 450 g/d of soybean oil fatty acids, and 6) control plus 450 g/d of soybean oil fatty acids high in palmitic acid. Treatments 2, 3, 4, and 6 contained similar ratios of C16 to C18 fatty acids. Infusion of soybean oil fatty acids or soybean oil fatty acids high in palmitic acid decreased intakes of DM, organic matter, crude protein, acid detergent fiber, neutral detergent fiber, gross energy, and total fatty acids and tended to decrease yields of milk and fat-corrected milk compared with the infusion of mostly saturated fatty acids. Infusion of palm oil fatty acids low in linoleic acid or palm oil fatty acids decreased milk fat percentage compared with other treatments. Ruminal characteristics and apparent digestibilities of DM, organic matter, crude protein, acid detergent fiber, neutral detergent fiber, energy, total fatty acids, and total C18 fatty acids were not different. Infusion of fatty acids increased concentrations of cholesterol in plasma. The amount of unsaturated fatty acids passing into the small intestine may influence responses of dairy cows to supplemental fat.
采用6×6拉丁方设计，选用6头奶牛，试验期为21天，以确定瘤胃后脂肪酸分布对干物质（DM）采食量、产奶量及成分、养分消化率和血浆代谢物的影响。处理方式为真胃灌注：1）对照 [168克/天肉渣（脂肪酸载体）加10.6克/天吐温80（乳化剂）]，2）对照加450克/天主要为饱和脂肪酸，3）对照加450克/天亚油酸含量低的棕榈油脂肪酸，4）对照加450克/天棕榈油脂肪酸，5）对照加450克/天大豆油脂肪酸，6）对照加450克/天棕榈酸含量高的大豆油脂肪酸。处理2、3、4和6的C16与C18脂肪酸比例相似。与灌注主要为饱和脂肪酸相比，灌注大豆油脂肪酸或棕榈酸含量高的大豆油脂肪酸会降低干物质、有机物、粗蛋白、酸性洗涤纤维、中性洗涤纤维、总能和总脂肪酸的采食量，并倾向于降低产奶量和乳脂校正乳产量。与其他处理相比，灌注亚油酸含量低的棕榈油脂肪酸或棕榈油脂肪酸会降低乳脂率。瘤胃特性以及干物质、有机物、粗蛋白、酸性洗涤纤维、中性洗涤纤维、能量、总脂肪酸和总C18脂肪酸的表观消化率没有差异。灌注脂肪酸会增加血浆中胆固醇的浓度。进入小肠的不饱和脂肪酸量可能会影响奶牛对补充脂肪的反应。
