Gilbery T C, Lardy G P, Soto-Navarro S A, Bauer M L, Caton J S
Department of Animal and Range Sciences, North Dakota State University, Fargo, 58105, USA.
J Anim Sci. 2006 Jun;84(6):1468-80. doi: 10.2527/2006.8461468x.
Two metabolism (4 x 4 Latin square design) experiments were conducted to evaluate the effects of corn condensed distillers solubles (CCDS) supplementation on intake, ruminal fermentation, site of digestion, and the in situ disappearance rate of forage in beef steers fed low-quality switchgrass hay (Panicum virgatum L.). Experimental periods for both trials consisted of a 9-d diet adaptation and 5 d of collection. In Exp. 1, 4 ruminally and duodenally cannulated steers (561 +/- 53 kg of initial BW) were fed low-quality switchgrass hay (5.1% CP, 40.3% ADF, 7.5% ash; DM basis) and supplemented with CCDS (15.4% CP, 4.2% fat; DM basis). Treatments included 1) no CCDS; 2) 5% CCDS; 3) 10% CCDS; and 4) 15% CCDS (DM basis), which was offered separately from the hay. In Exp. 2, 4 ruminally and duodenally cannulated steers (266.7 +/- 9.5 kg of initial BW) were assigned to treatments similar to Exp. 1, except forage (Panicum virgatum L.; 3.3% CP, 42.5% ADF, 5.9% ash; DM basis) and CCDS (21.6% CP, 17.4% fat; DM basis) were fed as a mixed ration, using a forage mixer to blend the CCDS with the hay. In Exp. 1, ruminal, postruminal, and total tract OM digestibilities were not affected (P = 0.21 to 0.59) by treatment. Crude protein intake and total tract CP digestibility increased linearly with increasing CCDS (P = 0.001 and 0.009, respectively). Microbial CP synthesis tended (P = 0.11) to increase linearly with increasing CCDS, whereas microbial efficiency was not different (P = 0.38). Supplementation of CCDS to low-quality hay-based diets tended to increase total DM and OM intakes (P = 0.11 and 0.13, respectively) without affecting hay DMI (P = 0.70). In Exp. 2, ruminal OM digestion increased linearly (P = 0.003) with increasing CCDS, whereas postruminal and total tract OM digestibilities were not affected (P > or = 0.37) by treatment. Crude protein intake, total tract CP digestibility, and microbial CP synthesis increased (P < or = 0.06) with increasing level of CCDS supplementation, whereas microbial efficiency did not change (P = 0.43). Ruminal digestion of ADF and NDF increased (P = 0.02 and 0.008, respectively) with CCDS supplementation. Based on this data, CCDS used in Exp. 2 was 86.7% rumen degradable protein. The results indicate that CCDS supplementation improves nutrient availability and use of low-quality forages.
进行了两项代谢试验（4×4拉丁方设计），以评估在以低质量柳枝稷干草（Panicum virgatum L.）为食的肉牛中添加玉米浓缩酒糟可溶物（CCDS）对采食量、瘤胃发酵、消化部位以及饲草原位消失率的影响。两项试验的试验期均包括9天的日粮适应期和5天的采集期。在试验1中，选用4头安装了瘤胃和十二指肠瘘管的肉牛（初始体重561±53千克），给它们饲喂低质量柳枝稷干草（粗蛋白含量5.1%、酸性洗涤纤维含量40.3%、灰分含量7.5%；干物质基础），并补充CCDS（粗蛋白含量15.4%、脂肪含量4.2%；干物质基础）。处理组包括：1）不添加CCDS；2）添加5% CCDS；3）添加10% CCDS；4）添加15% CCDS（干物质基础），CCDS与干草分开投喂。在试验2中，选用4头安装了瘤胃和十二指肠瘘管的肉牛（初始体重266.7±9.5千克），除了将饲草（Panicum virgatum L.；粗蛋白含量3.3%、酸性洗涤纤维含量42.5%、灰分含量5.9%；干物质基础）和CCDS（粗蛋白含量21.6%、脂肪含量17.4%；干物质基础）用饲料搅拌机混合后作为混合日粮投喂外，其他处理与试验1相似。在试验1中，处理对瘤胃、瘤胃后和全消化道有机物消化率没有影响（P=0.21至0.59）。随着CCDS添加量的增加，粗蛋白摄入量和全消化道粗蛋白消化率呈线性增加（分别为P=0.001和0.009）。微生物蛋白合成有随CCDS添加量增加呈线性增加的趋势（P=0.11），而微生物效率没有差异（P=0.38）。在以低质量干草为基础的日粮中添加CCDS有增加总干物质和有机物摄入量的趋势（分别为P=0.11和0.13），但对干草干物质采食量没有影响（P=0.70）。在试验2中，随着CCDS添加量的增加，瘤胃有机物消化呈线性增加（P=0.003），而瘤胃后和全消化道有机物消化率不受处理影响（P≥0.37）。随着CCDS添加水平的增加，粗蛋白摄入量、全消化道粗蛋白消化率和微生物蛋白合成增加（P≤0.06），而微生物效率没有变化（P=0.43）。添加CCDS后，酸性洗涤纤维和中性洗涤纤维的瘤胃消化增加（分别为P=0.02和0.008）。根据这些数据，试验2中使用的CCDS瘤胃可降解蛋白含量为86.7%。结果表明，添加CCDS可提高低质量饲草的养分利用率。
