蒸汽压片玉米水分含量和密度对育肥牛消化部位、消化程度及饲用价值的影响。

Influence of steam-flaked corn moisture level and density on the site and extent of digestibility and feeding value for finishing cattle.

作者信息

Sindt J J, Drouillard J S, Titgemeyer E C, Montgomery S P, Loe E R, Depenbusch B E, Walz P H

机构信息

Department of Animal Sciences and Industry, Kansas State University, Manhattan, 66506-1600, USA.

出版信息

J Anim Sci. 2006 Feb;84(2):424-32. doi: 10.2527/2006.842424x.

DOI:10.2527/2006.842424x

PMID:16424271

Abstract

Performance and digestibility experiments were conducted to determine the influence of moisture and flake density (FD) on the feeding value of steam-flaked corn (SFC). Dietary treatments consisted of finishing diets that contained 78% (DM basis) SFC that was tempered using 0, 6, or 12% moisture and processed to either 360 (SF28) or 310 (SF24) g/L. A 3 x 2 factorial arrangement of treatments was used. In Exp. 1, 78 steers were individually fed the respective treatments for 106 d. Moisture added during tempering tended (linear; P < 0.10) to increase starch availability but linearly decreased (P < 0.01) particle size. Decreasing flake density increased (P < 0.001) starch availability and also decreased (P < 0.001) particle size. Starch availability (P < 0.001), moisture (P < 0.001), and particle size (P = 0.05) were all greater for SFC that was collected the day of processing compared with SFC that had been processed the previous day. Steers fed diets containing SF24 consumed less DM as the moisture level increased, whereas steers fed diets containing SF28 had increased DMI as moisture level increased (moisture x FD interaction; P < 0.01). Nonetheless, ADG, G:F, and most carcass characteristics did not differ among treatments. In Exp. 2, 6 multicannulated Jersey steers were used in a 6 x 6 Latin square using the same treatments as in Exp. 1. Increasing moisture intake linearly decreased (P < 0.05) starch intakes. Organic matter and N intakes followed similar trends but were not different. Decreasing FD tended to increase (P < 0.10) microbial N flow to the duodenum and increased microbial efficiency (P < 0.05). Ruminal starch digestibility was 90.5%, and total tract starch digestibility was 99.5% without adding moisture or processing beyond SF28. Moisture additions to corn before steam flaking resulted in few differences in performance or digestibility, despite increases in starch availability that occurred as moisture increased. Processing corn more extensively than SF28 may be unnecessary and cost-prohibitive.

摘要

进行了性能和消化率试验，以确定水分和片状密度（FD）对蒸汽压片玉米（SFC）饲用价值的影响。日粮处理包括育肥日粮，其中含有78%（干物质基础）的SFC，分别用0%、6%或12%的水分进行调质，并加工至360（SF28）或310（SF24）g/L。采用3×2析因处理设计。在试验1中，78头阉牛分别饲喂相应处理的日粮106天。调质过程中添加的水分有增加淀粉可利用性的趋势（线性；P<0.10），但粒径呈线性下降（P<0.01）。降低片状密度可提高（P<0.001）淀粉可利用性，同时也降低（P<0.001）粒径。与前一天加工的SFC相比，加工当天采集的SFC的淀粉可利用性（P<0.001）、水分（P<0.001）和粒径（P=0.05）均更高。随着水分水平的增加，饲喂含SF24日粮的阉牛干物质采食量减少，而饲喂含SF28日粮的阉牛干物质采食量随着水分水平的增加而增加（水分×FD互作；P<0.01）。尽管如此，各处理间的平均日增重、料重比和大多数胴体性状并无差异。在试验2中，6头多瘘管泽西阉牛采用6×6拉丁方设计，使用与试验1相同的处理。水分摄入量增加使淀粉摄入量呈线性下降（P<0.05）。有机物和氮摄入量呈现相似趋势，但无差异。降低FD有增加微生物氮向十二指肠流动的趋势（P<0.10），并提高了微生物效率（P<0.05）。在不添加水分或加工超过SF28的情况下，瘤胃淀粉消化率为90.5%，全肠道淀粉消化率为99.5%。尽管随着水分增加淀粉可利用性提高，但在蒸汽压片前向玉米中添加水分对性能或消化率影响不大。比SF28更广泛地加工玉米可能没有必要且成本过高。