Zinn R A, Barajas R
Department of Animal Science, Imperial Valley Agricultural Center, University of California, El Centro 92243, USA.
J Anim Sci. 1997 Apr;75(4):904-9. doi: 10.2527/1997.754904x.
Ninety-six medium-frame crossbred steers (209 kg) were used in an 86-d feeding trial. Dietary treatments consisted of a 92% concentrate diet containing 76.15% (DM basis) grain as 1) steam-flaked barley (SFB), flake density (FD) = .26 kg/L; 2) blend of 2/3 barley and 1/3 corn steam-flaked (SFBLEND), FD = .36 kg/L; 3) SFBLEND, FD = .31 kg/L; 4) SFBLEND, FD = .26 kg/L. There were no treatment effects (P > .10) on growth performance of feedlot steers or NE value of the diet. Weight gain averaged 1.46 kg/d. Feed efficiency was in close agreement (101%) with expected values based on observed DMI and tabular dietary NE values. Treatment effects on characteristics of ruminal and total tract digestion were evaluated using four Holstein steers (280 kg) with cannulas in the rumen and proximal duodenum in a 4 x 4 Latin square design. Ruminal digestibility of OM (P < .01), starch (P < .01), and feed N (P < .10) increased, and ruminal N efficiency (duodenal nonammonia N/N intake, P < .01) decreased (linear component) with decreasing FD. Net microbial N flow to the small intestine was greater (P < .05) for SFB than for the SFBLEND. Total tract digestion of OM (P < .01), starch (P < .05), and DE (P < .05) was greater for the SFBLEND than for SFB. There were no treatment effects (P < .10) on postruminal and total tract digestibility of N. We conclude that blending barley and corn before flaking will have very little impact on the feeding value of the grains compared with flaking the grains separately.
96头中等体格的杂交阉牛（体重209千克）被用于一项为期86天的饲养试验。日粮处理包括一种92%精料日粮，其中含76.15%（干物质基础）谷物，具体如下：1）蒸汽压片大麦（SFB），片密度（FD）=0.26千克/升；2）2/3大麦与1/3玉米的混合蒸汽压片料（SFBLEND），FD =0.36千克/升；3）SFBLEND，FD =0.31千克/升；4）SFBLEND，FD =0.26千克/升。对于育肥牛的生长性能或日粮的净能值，各处理间均无显著影响（P＞0.10）。平均日增重为1.46千克。饲料效率与基于观察到的干物质采食量和表格日粮净能值的预期值非常接近（101%）。采用4×4拉丁方设计，使用4头装有瘤胃和十二指肠近端套管的荷斯坦阉牛（体重280千克），评估各处理对瘤胃及全消化道消化特性的影响。随着片密度降低，瘤胃有机物（OM）（P＜0.01）、淀粉（P＜0.01）和饲料氮（P＜0.10）的消化率升高，瘤胃氮效率（十二指肠非氨氮/氮摄入量，P＜0.01）降低（线性成分）。SFB的小肠净微生物氮流量高于SFBLEND（P＜0.05）。SFBLEND的全消化道OM（P＜0.01）、淀粉（P＜0.05）和消化能（DE）（P＜0.05）消化率高于SFB。各处理对瘤胃后段及全消化道氮消化率均无显著影响（P＜0.10）。我们得出结论，与分别对谷物进行压片相比，在压片前将大麦和玉米混合对谷物的饲喂价值影响很小。
