Hao X Y, Gao H, Wang X Y, Zhang G N, Zhang Y G
College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, China.
College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, China.
J Dairy Sci. 2017 Apr;100(4):2672-2681. doi: 10.3168/jds.2016-11645. Epub 2017 Feb 16.
This experiment was conducted to investigate nutrient digestibility, rumen microbial protein synthesis, and lactation performance when a portion of alfalfa was replaced with combinations of dry corn gluten feed (DCGF) and Chinese wild rye grass in the diet of lactating cows. Six multiparous and 3 primiparous Chinese Holsteins were arranged in a replicated 3 × 3 Latin square experiment for 21-d periods. The animals were fed 1 of 3 treatment diets during each period: (1) 0% DCGF (0DCGF); (2) 6.5% DCGF (7DCGF); and (3) 11% DCGF (11DCGF). Diets were isonitrogenous, and a portion of alfalfa hay was replaced with DCGF and Chinese wild rye grass, with similar concentrate mixtures and corn silage contents. The dry matter intake was greater for 11DCGF (21.9 kg/d) than for 0DCGF (20.7 kg/d) or 7DCGF (21.2 kg/d). The treatment diets did not result in difference in milk production, fat and lactose concentration, or yield. Compared with 0DCGF, the ration containing 11% DCGF improved the milk protein concentration. Dry matter and neutral detergent fiber digestibility was greater for 7DCGF (62.7% and 45.6%) and 11DCGF (63.1% and 47.2%) than for 0DCGF (59.4% and 42.3%), and the nitrogen digestibility was similar for the 3 treatments. The concentration of rumen volatile fatty acids was higher in cows fed the 11DCGF diet than in those fed the 0DCGF diet, with no difference between the 7DCGF and 11DCGF diets. The estimated microbial crude protein yield was greater for the 11DCGF diet (1985.1 g/d) than for the 0DCGF diet (1745.0 g/d), with no difference between the 0DCGF and 7DCGF diets. Thus, it appears that feeding DCGF and Chinese wild rye grass in combination can effectively replace a portion of alfalfa hay in the rations of lactating dairy cows.
本试验旨在研究在泌乳奶牛日粮中用干玉米蛋白粉（DCGF）和中华野黑麦草组合替代部分苜蓿时的养分消化率、瘤胃微生物蛋白合成及泌乳性能。选用6头经产和3头初产中国荷斯坦奶牛，按重复3×3拉丁方试验设计，每期21天。每期给动物饲喂3种处理日粮中的1种：（1）0% DCGF（0DCGF）；（2）6.5% DCGF（7DCGF）；（3）11% DCGF（11DCGF）。日粮等氮，部分苜蓿干草用DCGF和中华野黑麦草替代，精料混合料和玉米青贮含量相似。11DCGF组（21.9千克/天）的干物质采食量高于0DCGF组（20.7千克/天）或7DCGF组（21.2千克/天）。处理日粮对产奶量、乳脂肪和乳糖浓度或产量无影响。与0DCGF相比，含11% DCGF的日粮提高了乳蛋白浓度。7DCGF组（62.7%和45.6%）和11DCGF组（63.1%和47.2%）的干物质和中性洗涤纤维消化率高于0DCGF组（59.4%和42.3%），3种处理的氮消化率相似。饲喂11DCGF日粮的奶牛瘤胃挥发性脂肪酸浓度高于饲喂0DCGF日粮的奶牛，7DCGF和11DCGF日粮之间无差异。11DCGF日粮的估计微生物粗蛋白产量（1985.1克/天）高于0DCGF日粮（1745.0克/天），0DCGF和7DCGF日粮之间无差异。因此，在泌乳奶牛日粮中同时饲喂DCGF和中华野黑麦草似乎可以有效替代部分苜蓿干草。
