| Giant panda chose bamboo diets as their main food by the long course of evolution.However,their digestive system did not evolve with diet shift,and was still equipped with digestive characteristics similar with the carnivorous animal.The gut microbiota might play a critical role in the diets shift.Giant panda has their own consume preference for different bamboo plant parts(culm,leaf and shoot)which has significant different nuritents.Because of the low digestibility of the bamboo diets on giant panda,body metabolism was affected by gut microbiota change caused by undigested nutrients in digestive tract.The aim of this study was to determine the effects of different bamboo diets on digestibility,gut microbiota and metabolic response in giant pandas(Ailuropoda melanoleuca).Giant pandas were provisioned with three species of bamboo:Phyllostachys bissetii culm consumption only(culm group);Bashania fargesii leaves consumption only(leaf group);and Qiongzhuea opienensis shoots consumption only(shoot group).Three experiments were carried out:Exp.1 Effect of different diets on the apparent digestibility and the health on giant pandaA total of 28 giant pandas were weighted and divided into 3 groups(Culm,Leaf and Shoot)randomly by body weight.The groups were fed by different single bamboo plant parts ad libitum.Giant pandas were weighed at 20 d for consuming one specific bamboo diets,and blood was collected at 20 d.Meanwhile,one male and one female giant pandas from each group were selected randomly for the apparent digestibility trial.The apparent digestibility trial was conducted at 11 d to 14 d.The result showed that:(1)The average daily DM intake of culm group(7.14 kg)is higher than leaf group(3.94 g,P<0.05)and shoot group(2.07 g,P<0.05)significantly.However,the pandas of culm group exhibited negative growth,the body weight gain of shoot group(232.04 g)was higher than culm goup(-124.87 g,P<0.05)and leaf group(62.03 g,P<0.05).(2)Blood TP and GLP levels of giant panda were not affected by different diets(P>0.05),but the level of ALB in leaf group(35.49 g/L)was greater than culm group significantly(31.36 g/L,P<0.05).Meanwhile,blood BUN concentration was affected by different bamboo diets.The level of BUN in shoot group(11.81 mmol/L)is higher than leaf group(7.60 mmol/L,P<0.05)and culm group(1.99 mmol/L,P<0.05)significantly,and the level of BUN/CRE in shoot group(0.11)is also higher than leaf group(0.06,P<0.05)and culm group(0.02,P<0.05)significantly.(3)Lipid’s metabolism was affected by different bamboo diets.TCHO,VLDL and TG levels in leaf group were greater than culm group significantly(P<0.05),and the level of VLDL and TG in leaf group were greater than shoot group significantly(P<0.05).But the levels of TCHO,VLDL and TG were not different between the culm group and shoot group(P>0.05).(4)Blood immunity cells amounts were affected by different bamboo diets.The content of WBC of shoot group(9.57×109/L)was higher than leaf group(6.52×109/L)and culm group(6.26×109/L)significantly(P<0.05).The percentage of blood neutrophil in shoot-fed pandas(68.56%)was higher than leaf-fed pandas(56.99%)significantly(P<0.05).The levels of lymph and monocytes were not different among three groups.(5)The result of the digestibility trial shows that the shoot group CP digestibility is higher than leaf group(P<0.05),and leaf group is higher than culm group(P<0.05).Thus,despite of similar amount of daily CP intake in shoot group and leaf group,the amount of daily digestible CP intake in shoot group(509.39 g/d)is higher than leaf group(374.96 g/d)significantly(P<0.05).The amount of EE daily intake in the leaf group(130.82 g/d)was significantly higher than that in the culm group(33.81 g/d),while the EE digestibility of the culm group(77.08%)was significantly higher than the leaf group(41.43%)(P<0.05).The digestibility of CF in culm group(50.54%)is higher than shoot group(18.11%)significantly(P<0.05).The digestibility of GE was not different among three groups,but the amount GE intake in culm group(134.14 MJ/d)is higher than leaf group(75.43 MJ/d)and shoot group(37.00 MJ/d)significantly.Exp.2 Study on the different bamboo diets on gut microbiotaA total of 18 giant pandas were weighted and divided into three groups(culm,leaf and shoot)randomly by doby weight.The groups were fed by different single bamboo plant parts ad libitum.Fresh feaces were collected at 10 d.Extract DNA from feaces,and sequencing the V3 region of 16S rRNA to analysis the effect of different bamboo diets on gut microbiota of giant panda.The result of Chao 1 index showed that the diversity of gut microbiota in shoot group was higher than culm group(P = 0.07).Beta diversity index in Shoot group was higher than culm group significantly(P<0.01),this might be the dominant population which was different between two groups.Dominant population of culm group was relevant to digesting fiber,contain Paenibacillus,Leuconostoc,Acinetobacter,Enterococcus,Weissella and Pseudomonas.Exp.3 Study on the different bamboo diets on metabolisimThis experiment was conducted to investige the effects of different bamboo diets on serum metabolism of giant panda by NMR and GC-MS.A total of 28 giant pandas were weighted and divided into three groups(culm,leaf and shoot)randomly by body weight.The different treatments were fed by single bamboo plants parts ad libitum.Serum samples were collected at 20 d to determine the effects of dfferent bamboo diets on metabolism of giant panda.The results showed that:(1)The energy reserve in the culm and leaf groups were lower than the shoot group pandas.Moreover,the leaf group had lower tricarboxylic acid cycle activity than shoot group.(2)The culm group had a more compromised energy source and tricarboxylic acid cycle activity compared to the shoot group.However,this was mobilized amino acids,glycogen and lipids to compensatively trigger the tricarboxylic acid cycle to meet their energy requirements.These showed that culm group pandas were in short supply of energy with depressed tricarboxylic acid cycle activity and culm pandas were in trend of negative energy balance.(3)The level of ketone bodies,lactate and urea were higher in shoot group than in leaf group and culm groups,which indicates that long-term bamboo shoot intake lead to abnormal nitrogen metabolism.Overall conclusions:(1)The digestibility of culm,leaf and shoot are different on giant panda.The microflora abundance relevant to digeste fiber is higher in culm group,and the diversity of gut microbiota in shoot group is the highest.(2)Different bamboo diets intak change the metabolism of energy and nitrogen.Shoot intake is beneficial for the anabolism.Culm pandas are in condition of negative energy balance,the amount of CP intake in culm group cannot meet the maintain and grwth requirements. |
PDF Full Text Request