A feeding trial was conducted to evaluate the maximum level of substitution of dietary fish meal by various proportions of corn protein meal, cottonseed meal and soybean meal supplemented with crystalline lysine, methinoine and arginine according to amino acid profile for fish meal for Hemibarbus maculatu juveniles weighing 14.84 g. The fish were stocked into 15 net cages of each 60 cm×60 cm×120 cm placed in a flowing tank and fed with 5 diets containing 37.0% crude protein with the same amino acid profile but with 28.0%(F0,control),21.0%(F1), 14.0%(F2), 7.0%(F3)and 0%(F4)levels of fish meal at water temperature of 25.0±3.0℃ for breeding 100 days. The results showed that there were no significant differences (P0.05) in survival rate in the fish fed with different levels of fish meal. The fish fed with the diet containing 21.0% fish meal supplemented with the amino acids had significantly higher growth, immunity and digestive enzymatic activities than the fish fed with the diets containing 28.0% fish meal(control group) (P0.05). However, the fish fed with the diet containing 14.0% and 7.0% fish meal supplemented with the amino acids had the same growth, immunity and digestive enzymatic activities as the fish fed with the diets containing 28.0% fish meal (control group) (P 0.05). There was significantly lower growth, immunity and digestive enzymatic activities in the fish fed the diets containing 0% fish meal than in the fish fed the diets containing 14.0% and 7.0% fish meal (P0.05). Our experiment results suggested that plant feedstuffs supplemented with crystalline amino acids could replace dietary fish meal in Hemibarbus maculatu juveniles by 18.69%. The muscular moisture and ash levels were not significantly affected by the substitution of dietary fish meal by various plant proteins (P 0.05), but the muscular protein, total amino acid, essential amino acid and fat levels were higher in the fish fed with the diets containing various plant proteins supplemented with crystalline amino acids than in the fish fed with the control diets.

A feeding trial was conducted to evaluate effects of dietary ascorbic acid(vitamin C) on growth and some immune indexes in the juvenile Hemibarbus maculates.The juveniles with 14.84 g in initial body weight were stocked into 12 net cages of each 60 cm ×60 cm×120 cm placed in two flowing water concrete tanks of each 6.0 m×2.0 m×1.2 m at a rate of 25 individuals per cage and fed semi-purified formulated feed containing 37.0% of crude protein and 11.0% of crude lipid,and supplemented with four levels(0,1 000,2 000,3 000 mg/kg diet) of 95% coated-ascorbic acid with triplication for each diet at a water temperature of(25.0±3.0)℃ for 125 days.The survival of the juveniles ranged from 93.33% to 98.67% during the experiment,without significant differences among the groups(P>0.05).The specific growth rate(SGR) of the fish increased with increase in dietary vitamin C levels first,and then decreased.The fish fed the diets containing the vitamin C levels of 1 415.78 mg/kg and 1 451.74 mg/kg had the maximal SGR and the minimal feed conversion ratio(FCR).The maximal serurm γ-globulin level,and activities of lysozyme and superoxide dismutase(SOD),very significantly different from the control group(P<0.01),were found in the fish fed the diets containing the vitamin C levels of 973.00,2 857.00 and 1 882.00 mg/kg,respectively.There were very significantly higher activities of protease,amylase and lipase in the hepatopancreas of Hemibarbus maculates fed the diets supplemented with vitamin C than those in the fish fed the diets without vitamin C supplementation(P<0.01).

在以鱼粉和豆饼为蛋白源的含粗蛋白量为42.0%的基础饲料中,分别加入益母草、川芎(F1)、山药、党参(F2)、熟地、何首乌(F3)、枸杞、女贞子(F4)、淫羊霍、杜仲等(F5)中草药,在流水网箱中饲养平均体重12.0g的黄颡鱼(Pelteobagrus fulvidraco Richardson),以不添加中草药组为对照组(F0),研究了中草药对2冬龄黄颡鱼性腺发育的影响.

The experiment was conducted to evaluate the effects of dietary lipid levels on growth performance in Hemibarbus maculates. The juveniles (14.38 g body weight) were stocked into 18 net cages, 60 cm × 60 cm × 120 cm per cage, which were placed in two concrete ponds of each 6.0 m×2.0 m×1.2 m with flowing water. The water temperature was at 23±5 ℃. The juveniles were fed isonitrogenous semi-purified diets for 100 days containing with fish meal, corn protein, soybean meal, cottonseed meal and soybean oil. The dietary lipid levels were as follows: 5.20%, 7.21%, 9.23%, 11.18%, 13.21% and 15.20%. The results showed that the specific growth rate, feed conversion ratio and protein efficiency ratio were directly proportional to the dietary fat levels in the juveniles fed the diets containing fat less than 11.18%, whereas, there were an inverse correlation at the dietary fat levels over 11.18%. The treatments were no significant difference in crude fat content in the hepatopancreas and muscles (P>0.05) within fat levels from 5.20% to 11.18%. The maximum specific growth rate, protein efficiency ratio and minimum feed conversion ratio were observed in the juveniles fed the diets containing 11.18% of fat, significantly different from those fed the diets containing 5.20% and 15.20% of fat (P<0.05). With the increase in dietary fat, the fish had high hepatopancreas somatic indices (HSI) and muscular exudative losses. The optimal dietary fat level was suggested to be 9.23%-11.18% for the juveniles.

Juvenile Hemibarbus maculatus weighting 5.90 g were stocked into 15 net cages of each 60 cm × 60 cm × 120 cm and fed diets containing 25.0%,31.0%,37.0%,43.0% and 49.0% crude protein at(22±3)℃ for 100 days.The results showed that the fish fed the diets containing 33.42%-38.79% protein had the maximal special growth rate(SGR),and protein efficiency ratio(PER) and the minimal food conversion ratio(FCR)(P0.05).There were the maximal protein levels(from 53.18% to 57.97%) in the muscles in the fish fed the diets containing the protein levels varying from 25.0% to 37.0%.There were the maximal lipid levels(from 14.36% to 17.10%) in the muscles in the fish fed the diets containing the protein rangingfrom 25.0% to 31.0%.However,the fish fed the diet containing 49.0% protein had decrease in protein(54.14%) and lipid(15.37%) levels in the muscles.The first increase and then decrease in activities of protease and lipase were observed in the fish fed the diets containing protein varying from 25.0% to 37.0% and 43.0%,respectively.There were no significant differences in the activities of amylase in the digestive tracts in the fish fed the diets containing different protein levels.It is recommended that 38.79%-33.42% dietary protein be of optimum for juvenile and marketable Hemibarbus maculates.

A feeding trial was designed to evaluate the effects of some Chinese herb medicines on growth and digestibility in yellow catfish(Pelteobagrus fulvidraco)jveniles averaging 15.5 g at 20.0-30.0℃.The fish were stocked into 12 net cages of each 60 cm×60 cm×120 cm placed in a flowing tank and fed 4 formulated diets containing 42.0% crude protein(fishmeal and soybean meal as protein sources) supplemented with Radix Astragali and Rhizoma Chuanxiong(F1);Radix Polygoni Multiflori and Radix Angelicase Sinensis(F2);Fructus Crataegi and Fructus Hordei Germinatus(F3) and without Chinese herb medicine as control(F0) for 12 weeks.The results showed that there were 58.33%,8.33%和79.17% higher special growth rate in the fish in Group F1,Group F2,and Group F3 than that in the control group(P<0.01).The fish in Group F1,and Group F2 had 77.61%,47.52% higher intestinal protease activity and 94.51%,67.07% higher lipase activity than the animals in Group F0 had,respectively,thus,higher apparent digestibility for the dietary dry matter,protein and fat.Meanwhile,the fish in Group F1,and Group F2 had lower amylase activity than the fish in Group F0 had.There were 7.67%,6.60% and 6.23% higher amino acid levels,especially essential amino acids including methionine,in muscles in the fish Group F1,Group F2,and Group F3 than that in the fish in the control group,respectively.

The experiment was conducted to evaluate the effects of dietary lipid levels on growth performance in Hemibarbus maculates. The juveniles (14.38 g body weight) were stocked into 18 net cages, 60 cm × 60 cm × 120 cm per cage, which were placed in two concrete ponds of each 6.0 m×2.0 m×1.2 m with flowing water. The water temperature was at 23±5 ℃. The juveniles were fed isonitrogenous semi-purified diets for 100 days containing with fish meal, corn protein, soybean meal, cottonseed meal and soybean oil. The dietary lipid levels were as follows: 5.20%, 7.21%, 9.23%, 11.18%, 13.21% and 15.20%. The results showed that the specific growth rate, feed conversion ratio and protein efficiency ratio were directly proportional to the dietary fat levels in the juveniles fed the diets containing fat less than 11.18%, whereas, there were an inverse correlation at the dietary fat levels over 11.18%. The treatments were no significant difference in crude fat content in the hepatopancreas and muscles (P0.05) within fat levels from 5.20% to 11.18%. The maximum specific growth rate, protein efficiency ratio and minimum feed conversion ratio were observed in the juveniles fed the diets containing 11.18% of fat, significantly different from those fed the diets containing 5.20% and 15.20% of fat (P0.05). With the increase in dietary fat, the fish had high hepatopancreas somatic indices (HSI) and muscular exudative losses. The optimal dietary fat level was suggested to be 9.23%-11.18% for the juveniles.