Pond W G, Pond K R, Ellis W C, Matis J H
J Anim Sci. 1986 Oct;63(4):1140-9. doi: 10.2527/jas1986.6341140x.
Effects of diluting the energy content of a corn-soybean meal diet with either alfalfa meal or corn cobs on nutrient digestibility and rate of passage of feed residues and particle markers were measured in crossbred (Yorkshire X Landrace X Chester White X Large White) barrows with a mean body weight of about 80 kg. The excretion pattern in the feces of Cr-mordanted diet and of rare earths initially bound individually to the mixed diet or to the corn or soybean meal suggested a model having a single age-dependent compartment with time delay. The compartmental turnover rate parameter (lambda 1) estimated by this model did not differ for the rare earths individually used to mark the corn-soybean meal diet (Yb), the corn (La) or the soybean meal (Sm). In contrast, lambda 1 for Cr was smaller (P less than .001) than that of the mean for the three rare earths. The residence time due to displacement flow (tau) did not differ among markers. These results were interpreted to indicate that the high specific gravity of Cr-mordanted feed slowed flow due to mixing but not due to displacement. Correlations between lambda 1 and tau were less than .71. These results suggested that the flow of rare earths initially bound to feed ingredients provides a reasonable estimate of the flow of their undigested residues through the gastrointestinal tracts of nonruminant animals. Inclusion of the fibrous feeds reduced digestibility of dry matter, cell contents, crude protein and acid detergent lignin and increased digestibility of cell walls, cellulose and acid detergent fiber. Digestibilities of cellulose and acid detergent fiber were greater with alfalfa than with corn cobs as the fiber source. Differences in digestibility of crude protein and acid detergent fiber existed due to litter in one replicate of the experiment. Variation in digestibility was not significantly related to variation in lambda 1 or tau within or among treatments and litters. This suggests that variations in lambda 1 and tau were not important causes of the observed variation in digestibility.
在平均体重约80千克的杂交（约克夏×长白×切斯特白×大白）公猪中，测定了用苜蓿粉或玉米芯稀释玉米 - 豆粕型日粮能量含量对养分消化率、饲料残渣及颗粒标记物通过速率的影响。铬媒染日粮以及最初分别与混合日粮、玉米或豆粕结合的稀土元素在粪便中的排泄模式表明，存在一个具有时间延迟的单一年龄依赖性隔室模型。该模型估计的隔室周转率参数（λ1），对于分别用于标记玉米 - 豆粕型日粮（镱）、玉米（镧）或豆粕（钐）的稀土元素而言并无差异。相比之下，铬的λ1小于（P < 0.001）三种稀土元素均值的λ1。因置换流导致的停留时间（τ）在各标记物之间并无差异。这些结果被解释为表明铬媒染饲料的高比重减缓了混合导致的流动，但并非置换导致的流动。λ1与τ之间的相关性小于0.71。这些结果表明，最初与饲料成分结合的稀土元素的流动为其未消化残渣在非反刍动物胃肠道中的流动提供了合理估计。添加纤维性饲料降低了干物质、细胞内容物、粗蛋白和酸性洗涤木质素的消化率，并提高了细胞壁、纤维素和酸性洗涤纤维的消化率。以苜蓿作为纤维来源时，纤维素和酸性洗涤纤维的消化率高于以玉米芯作为纤维来源时。在实验的一个重复中，由于窝别不同，粗蛋白和酸性洗涤纤维的消化率存在差异。消化率的变化与各处理组和窝别内或之间的λ1或τ的变化并无显著关联。这表明λ1和τ的变化并非观察到的消化率变化的重要原因。
