The objective of the study was to investigate the effects of dietary forage and distillers dried grains with solubles (DDGS) concentration on the performance of lactating dairy cows. Twelve Holstein cows were blocked by parity and milk production and assigned to replicated 4 × 4 Latin squares with a 2 × 2 factorial arrangement of treatments. Diets were formulated to contain low forage [LF; 17% forage neutral detergent fiber (NDF)] or high forage (HF; 24.5% forage NDF) and DDGS at 0 or 18% of diet dry matter. The forage portion of the diet consisted of 80% corn silage and 20% alfalfa hay (dry matter basis). A portion of the ground corn and all of the expeller soybean meal and extruded soybeans from 0% DDGS diets were replaced with DDGS to formulate 18% DDGS diets. Overall, we found no interactions of forage × DDGS concentrations for any of the production measures. We observed no effect of diet on dry matter intake. Milk yield was greater when cows were fed LF diets compared with HF diets (43.3 vs. 41.5 kg/d). Milk fat concentration (3.03 vs. 3.38%) was lower for cows fed LF diets compared with HF diets, whereas protein concentration (3.11 vs. 2.98%) and yield (1.34 vs. 1.24 kg/d) were greater for cows fed LF diets compared with HF diets. Yields of fat, total solids, energy-corrected milk, and feed efficiency were not affected by diets. Cows partitioned equally for milk, maintenance, and body reserves. Replacing starch from ground corn and protein from soybean feeds with DDGS at either 17 or 24.5% of forage NDF concentration in the diet was cost-effective and did not affect the production performance of lactating dairy cows.

该研究的目的是调查日粮饲料和可溶物干酒糟 (DDGS) 浓度对泌乳奶牛生产性能的影响。将 12 头荷斯坦奶牛按胎次和产奶量进行分组，并分配到重复的 4 × 4 拉丁方格中，并进行 2 × 2 因子排列处理。日粮配制为含有低草料[LF； 17% 饲料中性洗涤纤维 (NDF)] 或高饲料（HF；24.5% 饲料 NDF）和 DDGS，占日粮干物质的 0 或 18%。日粮的草料部分由 80% 玉米青贮饲料和 20% 苜蓿干草（干物质基础）组成。将 0% DDGS 日粮中的一部分磨碎的玉米、所有压榨豆粕和挤压大豆用 DDGS 替代，以配制 18% DDGS 日粮。总体而言，我们发现任何生产措施中草料 × DDGS 浓度都没有相互作用。我们观察到饮食对干物质摄入量没有影响。与饲喂HF日粮的奶牛相比，饲喂LF日粮的产奶量更高（43.3公斤/天对41.5公斤/天）。与HF日粮相​​比，饲喂LF日粮的奶牛的乳脂浓度（3.03 vs. 3.38%）较低，而饲喂LF日粮的奶牛的蛋白质浓度（3.11 vs. 2.98%）和产量（1.34 vs. 1.24 kg/d）更高与高频饮食相比。脂肪、总固体量、能量校正奶的产量和饲料效率不受日粮的影响。奶牛平均分配牛奶、维持饲料和身体储备。在日粮中饲草 NDF 浓度为 17% 或 24.5% 的 DDGS 中替代玉米粉饲料和大豆饲料中的蛋白质具有成本效益，并且不会影响泌乳奶牛的生产性能。