单宁酸对棕色田鼠和小鼠食物选择、日食量和蛋白质消化率的影响

目的用不同浓度单宁酸（tannic acid,TA）处理后的花生喂养棕色田鼠（Lasiopodomys mandarinus）和小鼠（Mus musculus）,研究单宁酸对两种鼠食物选择倾向、食物摄入量、蛋白质消化率的影响。方法本研究的设计如下：1）选择一批棕色田鼠和小鼠,单笼饲养,自由饮水。用正常花生饲喂二周实验用棕色田鼠和小鼠,使其适应这种食物;2）随机选出棕色田鼠和小鼠各10只（雌雄各半）,单笼饲养。用经0%、5%、10%TA处理的花生饲喂供试鼠一周,观察和记录两种鼠对TA处理后花生的选择和取食特征;3）随机选出18只棕色田鼠和18只小鼠,单笼饲养,并各分为3组（每组均为6只）,按两种鼠分别命名为对照组、低单宁酸组、高单宁酸组,并分别用经0%、5%和10%TA处理的花生饲喂一周,测定两种鼠的食物摄入量;同时收集粪便,用凯氏定氮仪测定粗蛋白含量,计算蛋白质消化率。结果1）棕色田鼠和小鼠均优先选择无TA食物（P〈0.001）,二者间差异达显著性水平（P〈0.001）;2）食物中的TA降低棕色田鼠和小鼠的相对日食量（P〈0.001）和食物中蛋白质的消化率,随TA含量的升高,棕色田鼠和小鼠的相对日食量和蛋白质消化率均显著下降。结论TA降低棕色田鼠和小鼠的食物摄入量和食物中蛋白质的消化率。TA对鼠类的食物摄入量和蛋白质消化率的影响有种间差异性,小鼠对TA的适应性更强。

Effect of Tannic Acid on Food Selection, Food Intake and Protein Digestion Rate in Mandarin Vole and Mice

Objective To investigate the effects of Tannic acid（TA） on food selection, food intake, and protein digestion rate between Mandarin vole, Lasiopodomys madarinus, and mice, Mus musculus, and to analyze the adaptation of small rodents to those food resources with Tannic acid. Methods The procedure of this research were listed as follows ： 1 ） Mandarin voles were live trapped from farmland in Xinzheng, Henan, China; while the mice were provided by experimental animal center of Henan Province. All the animals were singly raised in PVC cages （350 mm× 300 mm × 190 mm）. Tested animals were fed with untreated peanuts to let them familiar to tested food item; 2） three sets of peanuts were soaked in TA solutions with a concentration of 0%, 5%, and 10%, respectively, for 48 hour, Then 10 Mandarin vole and 10 mice were randomly assigned and given ad libitum access to water for investigation. Tested animals were fed with treated peanuts for 7 days, and selection and consumption on treated peanuts by two rodent species were checked and recorded. 3 ） Eighteen randomly selected Mandarin voles were categoried into three groups, and 6 individuals in each group. The groups were titled as control groups, low TA group, and high TA group, respectively. The tested animals of control group were provided with 0% TA-treated-peanuts, while the low TA group with 5% TA-treated-peanuts, and the high TA group with 10% TA-treated-peanuts. On the next morning, we checked and recorded the remained peanuts to evaluate intake rate of tested animals, we also collected the oven-weight of faeces, to evaluate the digestion rate of protein within food. The check and record lasted 7 days. We randomly chose 18 mice and designed an experiment as the same as that in Mandarin vole above mentioned. Results 1 ）Mandarin vole and mice preferred the food items with low TA level （P 〈 0.001 ） and there was significant difference between two tested rodent species （P 〈 0.001 ）. 2） Daily consumed food and digestion rate of protein decreased significantly with increasing of TA in food both in Mandarin vole and mice （ P 〈 0. 001 ）. Conclusion Food items with TA will significantly decrease the of quantity of food intake and digestion rate of protein within food, whereas the extent of this effect might differed among animals experience under different evolutionary history. Mice is more adaptation for TA than Mandarin vole.