The Study Of Protein And Fat Requirements Levels In The Quasipaa Spinosa Tadpoles

Quasipaa spinosa has the same origin as medicine and food,and is known as the"King of Frogs",but the low survival rate of tadpoles during metamorphosis limits the development of the industry.The survival rate of Q.spinosa tadpoles during metamorphosis was mainly affected by factors such as nutrition,disease,development and environmental stress.Malnutrition may lead to stunted growth,high deformity rate,frequent liver disease and even death in Q.spinosa tadpoles.At present,there is no special feed for the frog tadpoles,and it is generally replaced by other feeds,resulting in high mortality and deformity rate of metamorphosis.In this paper,the three stages of the tadpoles of Q.spinosa were measured,namely stageⅠ（stage 26-30 of hindlimb bud development）,stage Ⅱ（stage 31-40 of five-toed differentiation）,and stage Ⅲ（stage of metamorphosis 41-46）,to understand the nutritional requirements of tadpoles in different periods,and designed 11 feeds with different protein or fat levels（Plant protein V35%,V40%,V45%,V50%;Animal protein A35%,A40%,A45%,A50%;Fat F14%,F19%,F23%）,compared with 2 kinds of commercial feeds（CK₁,CK₂）of Q.spinosa tadpoles,to explore the effects of different nutritional levels on the growth and development and liver function of Q.spinosa tadpoles.It provides a theoretical reference for the development of special feed for the frog tadpoles and the realization of precise feeding and healthy breeding.The main conclusions are:（1）The fresh weight protein contents of the tadpoles of stageⅠ,Ⅱand Ⅲ were 8.23%,9.47%and 10.6%;the fat contents were 6.00%,3.30%and 6.10%;the carbohydrate contents were 0.90%,3.10%and 1.20%,respectively.%;∑EAA/∑AA is46.77%,of which∑BACC accounts for 41.85%of∑EAA;∑PUFA accounts for 0.4222%of∑FA,of which C_18:2n6caccounts for 89.48%of∑PUFA.（2）The level of plant protein in the range of 35%～50%had no significant effect on the survival rate of metamorphosis（P>0.05）,all above 97.65%;high plant protein was beneficial to the growth and development of tadpoles,V_45%,V_50%The growth index of Q.spinosa tadpoles at was better than other groups;with the increase of plant protein level,the activities of SOD and LZM reached the peak at 45%,while the activities of AST,ALT,CAT and T-AOC decreased significantly（P<0.05）.the activity of MDA was significantly increased（P<0.05）.Excessive levels of plant protein would damage the antioxidant capacity,metabolic capacity and defense system of the liver of Q.spinosa tadpoles,which is not conducive to the health of the liver.The suitable plant protein level of the frog tadpole is about 40%.（3）The level of animal protein in the range of 35%～50%had no significant effect on the growth of tadpoles of the frog chestnut（P>0.05）,but affected the survival rate of metamorphosis.The survival rate of metamorphosis in the A_50%group was only21.54%,a significant lower than other groups（P<0.05）;with the increase of animal protein levels,the activities of SOD and LZM in the liver of Q.spinosa tadpoles reached a peak at 40%,and the activity of AKP reached a peak at 45%（P<0.05）.The activity of AST was significantly decreased（P<0.05）,and the activities of MDA and ALT were significantly increased（P<0.05）.High animal protein affected the antioxidant capacity,metabolic capacity and defense system of the liver,and the health of the liver was affected.The suitable animal protein level of the frog tadpole is about 35%.（4）When the levels of animal protein and vegetable protein were both 35%,there was no significant difference in the survival rate of metamorphosis（P>0.05）;at the same protein level,the body weight,body length and liver enzyme activity of frogs in the vegetable protein group were significantly higher than those in the animal protein group.group（P<0.05）,but the deformity rate was significantly higher than that of the animal protein group（P<0.05）.Comprehensive analysis of the metamorphosis survival rate,deformity rate,and liver health status of Q.spinosa young frogs found that excessive protein levels would affect the antioxidant capacity,metabolic capacity and defense system of the liver of Q.spinosa tadpoles,and the optimal protein level was 35%～40%.It is not advisable to use a single protein source in the tadpole stage of Q.spinosa.Pure animal protein source will reduce the survival rate of metamorphosis,and pure plant protein source will increase the deformity rate of juvenile frogs.In the early stage,plant protein-based animal and plant protein sources are used,and animal protein sources are used in the later stage.Protein-based animal and plant protein sources.（5）At 45%animal protein level,different fat levels had no significant effect on metamorphosis survival rate,deformity rate,liver-to-body ratio,visceral-body ratio,carcass ratio,and MDA activity in juvenile Q.spinosa（P>0.05）.However,the activities of SOD,LZM,AKP,CAT and T-AOC in the F14%group were significantly lower than those in the other groups,while the activities of AST and ALT were significantly higher than those in the other groups,and the LZM activity in the F23%group was significantly higher than that in the other groups（P<0.05）,with the increase of fat level within the appropriate range,the antioxidant and defense capacity of the liver of Q.spinosa tadpoles enhanced,but the metabolic capacity of the liver would be affected.The appropriate fat level of the frog tadpole is about 19%.