Ahmed Imtiaz, Khan Mukhtar A
Fish Nutrition Research Laboratory, Department of Zoology, Aligarh Muslim University, Aligarh 202,002, India.
Br J Nutr. 2006 Sep;96(3):450-60.
Three 8-week growth experiments were conducted to quantify the requirements of the fingerling Cirrhinus mrigala for the dietary branched-chain amino acids valine (experiment 1), isoleucine (experiment 2) and leucine (experiment 3). Six isonitrogenous (400 g/kg) and isoenergetic (17.90 kJ/g) test diets were formulated with a gradation of 2.5 g/kg for each test amino acid, valine (7.5-20 g/kg), isoleucine (5.0-17.5 g/kg) and leucine (7.5-20 g/kg), and fed to randomly stocked fish in circular troughs. In experiment 1, the maximum weight gain (312 %), best feed conversion ratio (FCR; 1.45) and best protein efficiency ratio (PER; 1.72) were obtained in fish fed 15.0 g dietary valine/kg. In experiment 2, the highest weight gain (317 %), best FCR (1.47) and best PER (1.70) were recorded at 12.5 g dietary isoleucine/kg, and in experiment 3, the highest weight gain (308 %), best FCR (1.46) and best PER (1.71) were noted at 15.0 g dietary leucine/kg. A quadratic regression analysis of weight gain, FCR and PER data showed an optimum requirement at 15.9, 15.0 and 14.8 g/kg for valine, 13.2, 12.3 and 12.1 g/kg for isoleucine and 15.6, 15.4 and 15.1 g/kg for leucine in dry diets. Low body moisture and higher protein were noted in fish fed diets containing 15.5, 12.5 and 15.0 g valine, isoleucine and leucine per kg, respectively. Body fat increased with increasing levels of the branched-chain amino acids. On the basis of a regression analysis of growth data, it is recommended that a diet for C. mrigala should contain valine at 15.2, isoleucine at 12.6 and leucine at 15.4 g/kg dry diet, corresponding to 38.0, 31.5 and 38.5 g/kg dietary protein, respectively.
进行了三项为期8周的生长实验，以量化鲮鱼幼鱼对日粮中支链氨基酸缬氨酸（实验1）、异亮氨酸（实验2）和亮氨酸（实验3）的需求量。配制了六种等氮（400 g/kg）和等能（17.90 kJ/g）的试验日粮，每种试验氨基酸（缬氨酸7.5 - 20 g/kg、异亮氨酸5.0 - 17.5 g/kg和亮氨酸7.5 - 20 g/kg）以2.5 g/kg的梯度变化，投喂于圆形水槽中随机放养的鱼。在实验1中，投喂含15.0 g日粮缬氨酸/kg的鱼获得了最大体重增加（312%）、最佳饲料转化率（FCR；1.45）和最佳蛋白质效率比（PER；1.72）。在实验2中，投喂含12.5 g日粮异亮氨酸/kg的鱼记录到最高体重增加（317%）、最佳FCR（1.47）和最佳PER（1.70），而在实验3中，投喂含15.0 g日粮亮氨酸/kg的鱼体重增加最高（308%）、最佳FCR（1.46）和最佳PER（1.71）。对体重增加、FCR和PER数据进行二次回归分析表明，干日粮中缬氨酸、异亮氨酸和亮氨酸的最佳需求量分别为15.9、15.0和14.8 g/kg，13.2、12.3和12.1 g/kg，以及15.6、15.4和15.1 g/kg。分别投喂含15.5、12.5和15.0 g缬氨酸、异亮氨酸和亮氨酸/kg日粮的鱼体水分含量较低且蛋白质含量较高。鱼体脂肪随着支链氨基酸水平的增加而增加。基于生长数据的回归分析，建议鲮鱼日粮中干日粮的缬氨酸含量应为15.2 g、异亮氨酸含量应为12.6 g、亮氨酸含量应为15.4 g/kg，分别相当于日粮蛋白质含量为38.0、31.5和38.5 g/kg。
