Dearing M D
Biology Department, University of Utah, Salt Lake City, UT 84112 USA fax: (801) 581-4668; e-mail:
Oecologia. 1996 Dec;109(1):122-131. doi: 10.1007/s004420050066.
I investigated the effects of tannin consumption, using plant tannins naturally occurring in the diet, on a herbivorous mammal, the North American pika, Ochotona princeps. The objectives were to determine if a high-tannin diet influenced protein and dry matter apparent digestibility, fiber digestibility and production of detoxification by-products. Additionally, I examined the possibility that pikas produce salivary tannin-binding proteins, a potential mechanism for avoiding detrimental effects of tannins. My results demonstrate that although pikas constitutively produce salivary tannin-binding proteins, animals consuming a high-tannin diet of Acomastylis rossii exhibited lower dry matter, protein and fiber digestion and excreted higher concentrations of detoxification by-products. Thus, A. rossii tannins are potential toxins as well as digestibility reducers. I propose a hypothesis coupling detoxification to reduced fiber digestion that is applicable to pikas as well as other mammalian herbivores consuming phenolic-rich diets.
我研究了食用膳食中天然存在的植物单宁对草食性哺乳动物北美鼠兔（Ochotona princeps）的影响。目的是确定高单宁饮食是否会影响蛋白质和干物质的表观消化率、纤维消化率以及解毒副产品的产生。此外，我还研究了鼠兔产生唾液单宁结合蛋白的可能性，这是一种避免单宁有害影响的潜在机制。我的研究结果表明，尽管鼠兔会持续产生唾液单宁结合蛋白，但食用高单宁的紫萼委陵菜（Acomastylis rossii）饮食的动物，其干物质、蛋白质和纤维消化率较低，且解毒副产品的排泄浓度较高。因此，紫萼委陵菜单宁既是潜在的毒素，也是消化率降低剂。我提出了一个将解毒与纤维消化减少联系起来的假设，该假设适用于鼠兔以及其他食用富含酚类食物的哺乳动物食草动物。
