Hagen K B, Tschudin A, Liesegang A, Hatt J-M, Clauss M
Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Institute of Animal Nutrition, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
J Anim Physiol Anim Nutr (Berl). 2015 Dec;99(6):1197-209. doi: 10.1111/jpn.12323. Epub 2015 Apr 9.
It is generally assumed that animal species differ in physiological characteristics of their digestive tract. Because investigating digestive processes is often labour-intensive, requiring lengthy adaptation and collection periods, comparisons are often made on the basis of data collated from different studies. We added a new data set on dietary crude fibre (CF) and macromineral (Na, K, Ca, P, Mg) composition and apparent digestibility (aD) of organic matter (OM) and macrominerals in rabbits (Oryctolagus cuniculus; a total of 180 measurements with 12 individuals and 10 different diets) to a literature data collection for rodents and domestic horses (Equus caballus). Significant negative relationships between dietary CF and aD OM were obtained, but the significant difference in digestive efficiency between rabbits and guinea pigs (Cavia porcellus) reported from studies where both species had been investigated under identical conditions were not detectable in the larger data collection. However, the 95% confidence interval of the negative slope of the CF-aD OM relationship did not overlap between domestic horses on the one hand, and rabbits and guinea pigs on the other hand, indicating a less depressing effect of CF in horses. Akaike's information criterion indicated that aD of a macromineral did not only depend on its concentration in the diet, but also on the individual and various other diet characteristics and the presence of other macrominerals, indicating complex interactions. The data indicate similar mechanisms in the absorption of macrominerals amongst rabbits, rodents and horses, with the exception of Na and K in guinea pigs and Ca in chinchillas (Chinchilla laniger) that should be further corroborated. In particular, the occurrence of high aD Ca in hindgut fermenters, regardless of whether they employ a digestive strategy of coprophagy or whether they have fossorial habits, suggests that this peculiarity might represent an adaptation to hindgut fermentation in general.
一般认为，动物物种的消化道生理特征存在差异。由于研究消化过程通常需要大量人力，且需要较长的适应期和收集期，因此比较往往基于从不同研究中整理的数据。我们将一组关于家兔（穴兔属；对12只个体和10种不同日粮进行了共180次测量）日粮中粗纤维（CF）、常量矿物质（钠、钾、钙, 磷、镁）组成以及有机物（OM）和常量矿物质表观消化率（aD）的新数据集，添加到了针对啮齿动物和家马（马属）的文献数据收集中。我们得出了日粮CF与aD OM之间显著的负相关关系，但在更大的数据收集中，未发现对家兔和豚鼠（豚鼠属）在相同条件下进行研究时所报道的两者消化效率的显著差异。然而，CF - aD OM关系的负斜率的95%置信区间，在家马与家兔和豚鼠之间并不重叠，这表明CF对马的抑制作用较小。赤池信息准则表明，常量矿物质的aD不仅取决于其在日粮中的浓度, 还取决于个体、各种其他日粮特征以及其他常量矿物质的存在，这表明存在复杂的相互作用。数据表明，家兔、啮齿动物和马在常量矿物质吸收方面存在相似机制，但豚鼠的钠和钾以及毛丝鼠（毛丝鼠属）的钙除外，这一点应进一步得到证实。特别是，后肠发酵动物中高aD钙的出现，无论它们采用食粪性消化策略还是具有穴居习性，都表明这种特性可能代表了对一般后肠发酵的一种适应。
