Effects Of Plant Secondary Metabolites On Feeding And Physiology Of Plateau Pika

Plant secondary metabolites(PSMs)have a great influence on the nutritional ecology of grassland rodents.Grassland rodents have a wide range of behavioral and physiological mechanisms to mitigate the negative effects of plant secondary metabolites.Grassland rodents can regulate the intake of PSMs by the feedback of physiological sensation of taste and smell or the learned behavior of life experience before their feeding.Some grassland rodent species can counteract tannins by secreting tannin-binding salivary proteins(TBSPs).They can also use permeability glycoprotein and biotransformation enzymes to control toxin absorption.This study was designed to investigate the mechanism that plateau pika use to response to the plant secondary metabolites.The diet for pika that caught in wild was supplemented with 4 different natural grassland plants(Kobresia kansuensis Kukenth,Leontopodium nanum,Pedicularis kansuensis,Potentilla anserina)in indoor rearing experiment.This study evaluated the effect of dietary high-tannin and low-tannin plant on the food intake,the body weight and organ of plateau pika.The results are as follows:1.Feeding at different ratio of four kinds of plants,plateau pika performance significantly different in their food intake.In addition to the feeding ratio of 20%,the relationship between food intake and feeding time were significantly negatively correlated with the increase of feed ratio.The negative effects on food intake were increase in turn(Kobresia kansuensis Kukenth<Leontopodium nanum< Pedicularis kansuensis< Potentilla anserina).The results show that the higher the tannin content and the feeding ratio of the plant,the smaller the food intake.2.Four plants that contain different levels of tannins have different effects on the body weight of plateau pika.Feeding by the proportion of 20% and 40% of Kobresia kansuensis Kukenth,the weight of plateau pika increased with the feeding time,showed a significant positive correlation.There was significant negative correlation between the body weight of plateau pika and feeding time in the proportion of20%,60% and 100% of Leontopodium nanum.There was significant negative correlation between the two in the proportion of 20%,40%,60% and 100% of Pedicularis kansuensis and Potentilla anserina.The results showed that the tannin content is higher and the feeding time is longer,the adverse effects on plateau pika is bigger.3.The plants that contain different level of tannins have significant effects on the organ of plateau pika.In the feeding proportion of 60%,compared with CK,tannin had no significant effect on the heart and lung weight of plateau pika(P > 0.05),but significant effect on the liver,spleen,kidney(P < 0.05).The results suggest that the tannin content is high,it can cause physiological toxicity to rodents.