Study On The Retention Time Of Food In Digestive Tract And Intake Protein Of Captivity Francois' Langurs(Trachypithecus Francoisi)

Animal nutrition is a science that describes the relationship between nutritional intake and biological activity.Digestion and absorption are the core of animal nutrition.The direct measurement of digestive mean retention time(MRT)is impossible,since food digestion,absorption and digesta passage are occur at the same time.Thus proper markers(nontoxic colored plastic balls)are developed to indirectly measure MRT of animals.In this study,we chosed captive Francois' langurs(Trachypithecus francoisi)to study their digestive MRT.The targeted animals included adult male and females,subadults.The results were as follows:1.Except for a few months,the MRT of all adult Francois' langurs were higher than that of subadult ones in most of the months;There is significant difference in MRT of adult male,all adults and minor female franco is' langurs in summer and winter.There was no significant variation in MRT among female individuals in a year as a total.There was a significant variation in MRT among adult male,adult mixed and minor female was significantly much longer in summer,but it was much shorter in winter.(summer>winter).2.The markers were firstly detected 20 h after the marked food was fed.The last marker was found 44 after the marked food was fed.The number of markers in the feces peaked 44h after the marked food was fed.3.There was significant difference between crude protein content of captive francois'langurs dungs in seasonal variation.During summer and winter,it is significant difference between adult male and adult female.3.There was seasonal variation of digestion rate of crude protein of captive Francois'langurs.4.The digestive retention time affects the digestion and absorption of crude protein.The crude protein content in the feces of langus was the highest in winter and the least in summer.The results showed that there was a negative correlation relationship between the MRT and the crude protein content of captive langurs dungs.The crude protein content in the feces varied with digestive time.The MRT of captive Francois' langurs was the longest in summer(average=41.26h)and least in winter(average=34.08h).It's may be related to the temperature conditions.Langurs moved less in higher temperature environment,while more in low temperature environment.Animals need to generate more heat by move more in lower temperature conditions.