| Due to rampant poaching and habitat fragmentation,the Chinese pangolin is on the verge of extinction in the wild.At present,artificial rescue and breeding of Chinese pangolins are an important means to help their wild population rejuvenate.Pangolins have special dietary habits,staple food termites,ants,etc.It is difficult to formulate artificial diets to meet their nutritional needs,and there is little or even lack of data on their digestive physiology and energy metabolism,which may lead to unscientific diets nutrition ratio and artificial dieting amounts,leading to the emergence of digestive tract,nutritional diseases and obesity problems of Chinese pangolins,the rescue dieting of Chinese pangolins and the rejuvenation of wild populations.In this study,digestion test,dieting test and breath calorimetry test were carried out to determine the amount of termite addition,food retention time and artificial dieting amount.Optimize the existing diets formula for Chinese pangolins and formulate a scientific dieting system.1.Six adult Chinese pangolins（3♀3♂）were divided into three stages for pre-dieting and experimental period 7d digestion test.The nutrient composition of Coptotermes formosanus,Polyrhachis vicina Roger and diets were analyzed.Based on the dry matter,the energy value of Coptotermes formosanus was 24.04 k J/g,the crude protein and crude fat content were 62.22%and 27.54%.The energy value of Polyrhachis vicina Roger is 22.42k J/g,the crude protein and crude fat content are 47.98%and 13.73%,respectively.The energy values of diets I,II and III were 20.6k J/g,20.79k J/g and 20.04k J/g,respectively.The crude protein contents were 34.58%,37.83%and 29.82%,and the crude fat contents were 18.76%,19.33%and 19.84%,respectively.The average dry matter digestibility of diet I（0 termites）was 77.3±9.6%,the digestibility energy value was 81.5±7.9%,the crude protein was 77.5±13%,and the crude fat was93.8±3.4%;the dry matter digestibility of diet II（10%termites）was 81.4±8.1%.digestibility energy value 86.1±6.3%,crude protein 83.6±7.8%,crude fat 96.3±1.8%;diets III（25%termites）dry matter digestibility was 72.3±12.1%,digestibility energy value was 81.6±8.2%,crude protein was 74.3±11.6%and crude fat was 94.3±2.9%.Except that the crude protein content of diets III was much lower than that of diets I and II,the content of nutrients in the three diets was similar,and the addition of termites had no significant effect on the content of nutrients in the diets.Comparing the three diets with termites and ants,the crude protein content in the diets is much lower than that of termites and ants;the calcium content is higher than that of termites and ants;and the content of lysine and cysteine in the diets is lower.Adding 10%termites can improve the digestibility of various nutrients in the diets,but adding termites has no significant effect on the digestibility of the diets（P>0.05）.2.The particle size of diets and feces was analyzed by wet sieving,and liquid phase and particle phase markers were added to the diets to measure the mean retention time（MRT）of six Chinese pangolins（3♀3♂）for 14 days.Wet sieve the Chinese pangolin diets,captive feces and field feces,and measure the average retention time of liquid phase and particle markers.The mean particle size（d MEAN）of Chinese pangolins feces in the wild was 0.452 mm.The d MEAN of Chinese pangolins feces in the captive was 0.434 mm.The d MEAN of diets was 0.362mm.The straws causing feces d MEAN larger than diets.The fecal particle size of wild pangolins was larger than that in captivity,and the size distribution of fecal particles of Chinese pangolins in captivity was similar to that of diets.The passage time of granular food was 60.8-104.3 h,and the passage time of liquid food was 41-65 h.The MRT of particle food was significantly longer than that of liquid food.3.The Resting Metabolic Rate（RMR）of four adult Chinese pangolins（2♀2♂）and the all-day energy of 8 Chinese pangolins（4 adults,4 sub-adults）were determined using open breath calorimetry consumption（Daily Energy Expenditure,DEE）and analysis of its behavioral,morphological and physiological characteristics.Under the ambient temperature of 25-28℃,the average RMR of Chinese pangolins with an average weight of 5.43±1.08kg was 198.5±39.7m L O2·kg-1·h-1,and the relationship between ambient temperature and resting metabolic rate was not significant.Adult Chinese pangolins with an average weight of 4.63±0.58 kg had an average DEE of 744.9±27.8 k J/day.Sub-adult animals with an average body weight of 2.56±0.21 kg had a mean DEE of 597.3±30.8 k J/day,and body weight had a significant effect on DEE.The energy consumption per unit weight of adult Chinese pangolins was lower than that of sub-adults.Captive Chinese pangolins spent 10%of their time in activities every day,while wild Chinese pangolins spent 20%of their time in activities.There was a significant difference between captive and wild Chinese pangolins（P<0.0001）.After removing the dry weight of the nail plate,the expected value of RMR and DEE increased by 5.5%and 3.2%,respectively.Chinese pangolin liver and kidney weights were 86.9%and 78.5%of the expected value,and tree pangolin brain weight was 53.9%of the expected value.The above results show that（1）the content of various nutrients in the diets in this study is similar to that of natural food（Coptotermes formosanus,Polyrhachis vicina Roger）,and can be better absorbed and utilized by animals,which can basically meet the nutritional needs of animals,but the crude protein,lysine and cysteine contents were low.The addition of termites to the diets the digestibility of the main nutrients in the diets no effects.（2）The distribution and average particle size of the feces of Chinese pangolins in captivity were close to those of the diets,and were smaller than those of the wild Chinese pangolins.The average retention time of liquid chyme in the digestive tract of Chinese pangolins was shorter than that of granular chyme.（3）Chinese pangolins have lower metabolic rate and energy consumption,which is consistent with the weight reduction of pangolins’thermogenic organs（brain,liver,kidney）to varying degrees,and a large reduction in activity time. |
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