Grummer R R, Slark K, Bertics S J, Luck M L, Barmore J A
Department of Dairy Science, University of Wisconsin, Madison 53706, USA.
J Dairy Sci. 1996 Oct;79(10):1809-16. doi: 10.3168/jds.s0022-0302(96)76549-9.
Fifteen multiparous Holstein cows averaging 39 DIM were used in a replicated 5 x 5 Latin square design to compare roasted soybeans and animal by-products as supplements for increasing the RUP content of lactation diets based on alfalfa. The control diet contained roasted soybeans and was formulated to meet requirements for RUP. Rumen-undegradable protein in the diet was increased by including additional roasted soybeans or animal by-product proteins. To achieve diets with similar amounts of fat, we added tallow, hydrolyzed tallow fatty acids, or partially hydrogenated tallow to the control diet and to diets containing animal by-product proteins. Control diets and diets with high RUP were estimated to be 5.8 and 7.6% RUP (DM basis). The RDP of all diets was estimated to be approximately 11.3% of DM. Milk yield was increased by additional dietary RUP. Yield of FCM was greater for cows receiving animal byproducts than for those fed additional roasted soybeans. Cows fed additional RUP yielded more milk protein, but milk protein percentage was decreased. Milk fat percentage was reduced by additional dietary RUP, but fat yield was not affected. Nutrient digestibility was greatest for diets containing animal byproducts. Cows fed tallow yielded more milk, FCM, and protein that did those fed hydrolyzed tallow fatty acids or partially hydrogenated tallow. Lactation performance can be enhanced by supplementing animal by-products or roasted soybeans to diets based on alfalfa and formulated to meet NRC recommendations for RUP.
选用15头平均处于泌乳39天的经产荷斯坦奶牛，采用重复5×5拉丁方设计，比较烤大豆和动物副产品作为补充料，用于提高以苜蓿为基础的泌乳日粮中RUP含量的效果。对照日粮含有烤大豆，其配方设计能满足RUP需求。通过添加额外的烤大豆或动物副产品蛋白来提高日粮中瘤胃不可降解蛋白的含量。为使各日粮的脂肪含量相近，我们在对照日粮以及含有动物副产品蛋白的日粮中添加了牛脂、水解牛脂脂肪酸或部分氢化牛脂。对照日粮和高RUP日粮的RUP含量（以干物质计）估计分别为5.8%和7.6%。所有日粮的RDP估计约为干物质的11.3%。额外的日粮RUP可提高产奶量。采食动物副产品的奶牛的FCM产量高于采食额外烤大豆的奶牛。采食额外RUP的奶牛产奶蛋白更多，但乳蛋白率降低。日粮中额外的RUP降低了乳脂率，但脂肪产量不受影响。含有动物副产品的日粮营养物质消化率最高。采食牛脂的奶牛比采食水解牛脂脂肪酸或部分氢化牛脂的奶牛产奶量、FCM和蛋白更多。在以苜蓿为基础且按NRC对RUP的建议配制的日粮中补充动物副产品或烤大豆，可提高泌乳性能。
