蛋白质,纤维素和单宁酸对东方田鼠摄食的影响

食物选择性是动物对取食生境中现存的食物种类做出的选择,是一个复杂的生态适应过程,与动物自身生理状及环境中食物的可利用量密切相关。单宁酸、蛋白质和纤维素是影响植食性动物食物选择的重要因素。在控制其它营养因子的条件下,设置10%蛋白质+2.25%纤维素+3%单宁酸(食物1)/6%单宁酸(食物2)和20%蛋白质+4.51%纤维素+3%单宁酸(食物3)/6%单宁酸(食物4)4个处理组,通过自助餐式选择笼内的喂养实验,测定单宁酸、蛋白质和纤维素对东方田鼠食物选择的影响。结果表明,东方田鼠对3%单宁酸处理组食物摄食量显著高于对6%单宁酸处理组(P0.001);但东方田鼠对6%单宁酸食物摄食量依蛋白质浓度变化,在20%蛋白质处理组的摄食量显著高于10%蛋白质处理组(P0.05);在含3%单宁酸处理组中,纤维素成为影响东方田鼠摄食的主要因素,而当单宁酸浓度增加到6%时,纤维素和蛋白质对东方田鼠摄食影响差异不显著;总之,单宁酸、蛋白质和纤维素对东方田鼠的摄食都产生重要影响,单宁酸对东方田鼠食物选择的影响程度最大,纤维素次之,蛋白质对东方田鼠摄食的影响会随单宁酸浓度的升高而增大。

Effects of protein, fiber, and tannic acid on food intake of Microtus fortis

To maximize fitness, animals must choose food appropriate for their physiological status and dependent on the food available in the environment. Tannic acid, protein and fiber content of food affects the physiology of herbivorous mammals, so we studied the effects of these factors on food selection of Microtus fortis. We used laboratory paired-choice tests with four experimental diets: 10% protein + 2.25% fiber with 3 % and 6 % tannic acid content (foods 1 and 2, respectively), 20% protein + 2.25% fiber with 3% and 6% tannic acid content(foods 3 and 4, respectively). The four diets were presented to M. fortis in six paired combinations: food 1 with foods 2, 3, and 4, and food 2 with foods 3 and 4. and food 3 with food 4 .M. fortis ate more of the diets with 3% tannic acid than those with 6% tannic acid , regardless of protein content(4.41 vs 1.83 g; 4.00 vs 2.36 g for the low and high protein diets, respectively, P<0.001) . Further, they ate significantly more of the 6% tannic acid diet when it was coupled with 20% protein vs. 10% protein (2.36 g vs 1.83g, respectively; P<0.05). Unexpectedly, when tannic acid was low (3%): voles ate much more of the 10% protein diet than the 20% protein diet (3.21 g. vs 2.01 g, respectively; P<0.001). However, there was no significant difference between the intake of low and high protein diets when coupled with high (6%) tannic acid. Overall, Microtus fortis food intake was most strongly determined by tannic acid content, then by fiber content, and lastly by protein content (but there was no statistical difference between protein and fiber when tannic acid content was 6%).