Studies On The Requirements Of Vitamin E, Choline And Myo-inositol In The Diet To Chinese Sucker(Myxocyprinus Asiatius)

A study was conducted to evaluate the effects of dietary vitamin E, choline and myo-inositol on the growth performance, body composition and liver and serum biochemical indices of Chinese sucker to detect the suitable requirement of vitamin E, choline and myo-inositol. Results of the studies were presented as follows:Part 1 A growth trial was conducted to investigate the vitamin E(dl-a-tocopheryl acetate) requirement of juvenile Chinese sucker. Semi-purified diets containing seven levels of dl-a-tocopheryl acetate(0.51, 15.23, 31.86, 62.30, 120.32, 240.42 and 483.71 mg/kg diet, respectively) were fed to triplicate groups of Chinese sucker(mean weight: 5.52±0.09g) for 8 weeks. The experiment was to determine the dietary vitamin E requirement of juvenile Chinese sucker on the basis of growth performance, liver antioxidant index and vitamin E concentration in liver. The results showed that, weight gain rate(WGR) and special growth rate(SGR) increased at first and then decreased with the increasing dietary vitamin E content(P<0.05), and both reached the maximum values at 62.30 mg/kg diet. The lipid content in muscle decreased at first and then increased with the increasing dietary vitamin E content(P<0.05), and reached the minimum values at 62.30 mg/kg diet. The total antioxidant capacity(T-AOC) and superoxide dismutase(SOD) activity in liver, with the increasing dietary vitamin E content, increased at first and then decreased(P<0.05)and both reached the maximum values at 31.86 mg/kg diet. Malondialdehyde(MDA) content in liver decreased significantly with the increasing dietary vitamin E content(P<0.05). Liver vitamin E concentration increased linearly with the increasing dietary vitamin E content(P<0.05). Regarding SGR as the evaluation index, it can be concluded that the dietary vitamin E requirement for juvenile Chinese sucker was considered to be 50.6 mg/kg based on broken-line regression analysis.Part 2 A growth trial was conducted to investigate the choline requirement of juvenile Chinese sucker. Purified diets containing seven levels of choline(44.79, 163.95, 278.7, 574.29, 1076.52, 2124.29 and 4477.72mg/kg diet, respectively) were fed to triplicate groups of Chinese sucker(mean weight: 5.24±0.07g) for 8 weeks. The experiment was to determine the dietary choline requirement of juvenile Chinese sucker on the basis of growth performance, liver biochemical index and choline concentration in whole body and muscle. The results showed that, weight gain rate(WGR) and special growth rate(SGR) increased at first and then decreased with the increasing dietary choline chloride content(P<0.05), and both reached the maximum values at 574.29 mg/kg diet, while moisture, crude lipid, crude protein and ash content in whole body had no significant differences among various treatments(P<0.05). The crude lipid in muscle increased at first and then decreased with the increasing dietary choline content(P<0.05). The aspartate aminotransferase(AST)and alanine aminotransferase(ALT) in liver, with the increasing dietary choline chloride content, increased at first and then decreased(P < 0.05)and both reached the peak values at 574.29 mg/kg diet, while triglyceride(TG) in liver showed the opposite tendency. The Chinese sucker whole body and muscle choline chloride concentration increased linearly at first and then remained unchanged when dietary choline chloride content is 574.29 mg/kg(P<0.05). Regarding SGR as the evaluation index, it can be concluded that the dietary choline requirement for juvenile Chinese sucker was considered to be 491.1mg/kg based on broken-line regression analysis.Part 3 A growth trial was conducted to investigate the myo-inositol requirement of juvenile Chinese sucker. Semi-purified diets containing six levels of myo-inositol(0, 75, 150, 300, 600, and 1200 mg/kg diet, respectively) were fed to triplicate groups of Chinese sucker(mean weight: 10.01±0.24g) for 8 weeks. The experiment was to determine the dietary myo-inositol requirement of juvenile Chinese sucker on the basis of growth performance, serum biochemical indexes and body composition. The results showed that, weight gain rate(WGR), survival rate(SR) and special growth rate(SGR) increased at first and then remained stable with the increasing dietary myo-inositol content(P<0.05), and all of them reached the maximum values at 300 mg/kg diet.There were no significant differences in whole body composition(P>0.05), the crude lipid in muscle was lower than the control at 300 mg/kg diet. With the increasing dietary myo-inositol content, serum total cholesterol(T-CHO) and low density lipoprotein cholesterol content(LDL-C) were much higher than that of the control(P<0.05), but the triacylglycerol(TG) in serum increased at fisrt and then decreased. The aspartate aminotransferase(AST) and alanine aminotransferase(ALT) in serum, with the increasing dietary myo-inositol content, were lower than that of control(P<0.05). Regarding SGR as the evaluation index, it can be concluded that the dietary myo-inositol requirement for juvenile Chinese sucker was considered to be 310.3mg/kg based on broken-line regression analysis.