title: Effects of Acomastylis rossii tannins on a mammalian herbivore, the North American pika, Ochotona princeps.
abstract: 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.
authors.affiliation: Biology Department, University of Utah, Salt Lake City, UT 84112 USA fax: (801) 581-4668; e-mail: dearing@biology.utah.edu, , , , , , US.
authors.forename: M D
authors.initials: MD
authors.lastname: Dearing
keywords: Detoxification; Digestibility; Key words Acomastylis rossii; Ochotona princeps; Tannins