Zinn R A, Adam C F, Tamayo M S
Department of Animal Science, Imperial Valley Agricultural Center, University of California, El Centro 92243, USA.
J Anim Sci. 1995 May;73(5):1239-45. doi: 10.2527/1995.7351239x.
Four Holstein steers (208 kg) with "T" cannulas in the rumen and proximal duodenum were used in a 4 x 4 Latin square design experiment to evaluate the interaction of feed intake level on comparative ruminal and total tract digestion of dry-rolled and steam-flaked corn. The basal diet contained (DM basis) 6% alfalfa hay, 6% sudangrass hay, 75% corn, 2% yellow grease, 5% cottonseed meal, 3% cane molasses, and 3% supplement. The corn portion of the diet was provided as either dry-rolled (density = .54 kg/L) or steam-flaked (density = .36 kg/L). Dry matter intake was restricted to allow for .64 vs 1.28 kg/d of weight gain (1.6 vs 2.4% of BW). Ruminal digestibility of OM, starch, and feed N were not affected (P > .10) by DMI. Postruminal digestion of OM and N and total tract digestibility of OM and DE decreased (P < .05) as DMI was increased. Total tract starch digestibility was not influenced (P > .10) by DMI. Steam flaking corn increased (P < .05) ruminal digestibility of OM and starch and postruminal and total tract digestibility of OM, starch, N, DE, and ME. Increasing DMI and steam flaking decreased (P < .05) ruminal pH and molar proportion of acetate. It is concluded that corn processing is the primary factor influencing site and extent of starch digestion. Decreasing DMI increases DE value of the diet; however, ME value is not affected because of increased energy loss as methane.
选用4头安装有瘤胃和十二指肠近端“T”形套管的荷斯坦公牛（体重208千克），采用4×4拉丁方设计试验，以评估采食量水平对干碾压玉米和蒸汽压片玉米瘤胃消化率及全消化道消化率的交互作用。基础日粮（以干物质计）包含6%苜蓿干草、6%苏丹草干草、75%玉米、2%黄油脂、5%棉籽粕、3%甘蔗 molasses和3%预混料。日粮中的玉米部分分别以干碾压（密度 = 0.54千克/升）或蒸汽压片（密度 = 0.36千克/升）形式提供。限制干物质采食量，以使体重日增重分别为0.64千克和1.28千克（占体重的1.6%和2.4%）。采食量对瘤胃中有机物、淀粉和饲料氮的消化率无影响（P > 0.10）。随着采食量增加，瘤胃后段有机物和氮的消化率以及全消化道有机物和消化能的消化率降低（P < 0.05）。采食量对全消化道淀粉消化率无影响（P > 0.10）。蒸汽压片玉米提高了瘤胃中有机物和淀粉的消化率以及瘤胃后段和全消化道中有机物、淀粉、氮、消化能和代谢能的消化率（P < 0.05）。采食量增加和蒸汽压片降低了瘤胃pH值和乙酸的摩尔比例（P < 0.05）。得出的结论是，玉米加工是影响淀粉消化部位和程度的主要因素。采食量降低会提高日粮的消化能值；然而，代谢能值不受影响，因为甲烷导致的能量损失增加。
