Department of Animal Sciences, North Dakota State University, Fargo 58108, USA.
J Anim Sci. 2009 Dec;87(12):4064-72. doi: 10.2527/jas.2008-1711. Epub 2009 Aug 14.
Supplementation of forage-fed livestock has been studied for decades; however, as by-products become available research is needed to determine optimal feeding rates for increased efficiency. Five ruminally and duodenally cannulated beef steers (446 +/- 42 kg of initial BW) were used in a 5 x 5 Latin square to evaluate effects of increasing level of supplemental corn distillers dried grains with solubles (DDGS; 25.4% CP, 9.8% fat, DM basis) on DMI, rate and site of digestion, ruminal fermentation, and microbial efficiency. Diets consisted of ad libitum quantities of moderate-quality smooth brome hay (10.6% CP; DM basis), free access to water and trace mineral salt block, and 1 of 5 levels of DDGS (0, 0.3, 0.6, 0.9, and 1.2% of BW daily of DDGS; DM basis). Diets were formulated to meet or exceed the estimated rumen degradable protein requirements (assumed microbial yield = 10.5%). All supplements were fed at 0600 h before forage was fed. Steers were adapted to diets for 14 d followed by a 7-d collection period. Hay OM intake decreased (linear; P < 0.001), whereas total OM intake increased (linear; P < 0.001) with increasing DDGS level. Total CP intake, duodenal OM and CP flows, and total tract OM and NDF digestibilities increased (linear; P <or= 0.01) with increasing level of DDGS. Apparent ruminal and true ruminal CP digestibilities increased linearly (P <or= 0.007), and total-tract CP digestibility increased quadratically (P = 0.02) with increasing DDGS level. Average ruminal pH was not different (P = 0.89) among treatments. Ammonia concentration increased (quadratic; P = 0.02) with increasing DDGS. Acetate proportions (molar %) decreased linearly (P < 0.001), whereas butyrate (molar %) increased linearly (P = 0.007), and propionate (molar %) increased quadratically (P = 0.04) with increasing DDGS. Ruminal DM fill decreased quadratically (P = 0.03), whereas fluid dilution rate tended to increase cubically (P = 0.08) with increasing DDGS. In situ rate of hay and DDGS DM disappearance responded cubically (P <or= 0.03) with greatest disappearance occurring with the 0.9% treatment. In situ rate of ruminal CP degradation of hay and DDGS increased (linear; P <or= 0.003) with increasing DDGS. Feeding 0.3% up to 1.2% of BW daily of DDGS as a supplement to forage-based diets resulted in no adverse effects on forage digestion or fermentation and resulted in increased nutrient supply in steers fed moderate-quality smooth brome hay.
对饲料喂养的牲畜进行补充已经研究了几十年；然而，随着副产品的出现，需要研究确定增加效率的最佳喂养率。5 头瘤胃和十二指肠插管的肉牛（初始体重 446 ± 42 公斤）被用于 5 x 5 拉丁方设计，以评估补充玉米干酒糟及其可溶物（DDGS；25.4% CP、9.8%脂肪、DM 基础）水平对 DMI、消化率和部位、瘤胃发酵和微生物效率的影响。日粮由适量中等质量的光滑百慕大干草（10.6% CP；DM 基础）、自由采食水和痕量矿物质盐块以及 5 种 DDGS 水平（0、0.3、0.6、0.9 和 1.2% BW 每日 DDGS；DM 基础）组成。日粮的配制符合或超过估计的瘤胃可降解蛋白需求（假设微生物产量=10.5%）。所有补充剂均在 0600 时在喂饲前喂饲。牛适应日粮 14 天，然后进行 7 天的收集期。干草 OM 摄入量减少（线性；P < 0.001），而总 OM 摄入量增加（线性；P < 0.001）随着 DDGS 水平的增加而增加。总 CP 摄入量、十二指肠 OM 和 CP 流量以及总消化道 OM 和 NDF 消化率随着 DDGS 水平的增加而增加（线性；P < 0.01）。表观瘤胃和真瘤胃 CP 消化率线性增加（P < 0.007），总消化道 CP 消化率二次增加（P = 0.02）随着 DDGS 水平的增加而增加。平均瘤胃 pH 在处理之间没有差异（P = 0.89）。氨浓度随 DDGS 的增加而增加（二次；P = 0.02）。乙酸比例（摩尔%）线性减少（P < 0.001），而丁酸（摩尔%）线性增加（P = 0.007），丙酸（摩尔%）二次增加（P = 0.04）随着 DDGS 的增加。瘤胃 DM 填充量二次减少（P = 0.03），而流体稀释率倾向于随 DDGS 呈立方增加（P = 0.08）。干草和 DDGS DM 原位消失率呈立方（P < 0.03），0.9%处理的消失率最大。随着 DDGS 的增加，原位瘤胃 CP 降解的干草和 DDGS 速率呈线性增加（P < 0.003）。在以中等质量光滑百慕大干草为基础的日粮中，每天补充 0.3%至 1.2% BW 的 DDGS 作为补充剂不会对饲料消化或发酵产生不利影响，反而会增加牛的养分供应。
