大菱鲆利用水解鱼蛋白和牛蛙蛋白的差异

为探究大菱鲆对不同来源水解蛋白的利用效率，实验选取太平洋狭鳕和牛蛙下脚料为蛋白来源，分别制备水解鱼蛋白和水解牛蛙蛋白，以初始体重为(8.00±0.01) g的大菱鲆为研究对象，进行为期56 d的养殖实验。实验设2个对照组，正对照组(PC)鱼粉含量为35.0%，负对照组(NC)鱼粉含量为26.5%；设2个实验组，水解鱼组(FPH)为26.5%的鱼粉和8.0%的水解鱼蛋白，水解牛蛙组(BPH)为26.5%的鱼粉和9.5%的水解牛蛙蛋白。结果显示，FPH组的终末体重、增重率和特定生长率显著高于BPH组和NC组，与PC组无显著差异。摄食6 h后，食糜必需氨基酸中赖氨酸、精氨酸、苏氨酸和缬氨酸在BPH组的含量显著高于PC组；多数非必需氨基酸在BPH组含量最高，但无显著差异。质子偶联氨基酸转运载体PAT1和小肽转运载体PepT1的mRNA表达量分别在FPH组和BPH组都显著高于PC组和NC组；碱性氨基酸转运载体CAT1和y⁺L型氨基酸转运载体y⁺LAT2的mRNA表达量在各处理组中无显著差异。研究表明，在饲料中添加鳕和牛蛙蛋白水解物均能提高大菱鲆的生长性...

Comparative study on the utilization of protein hydrolysates of fish and Rana catesbeiana by turbot (Scophthalmus maximus)

Cod and bullfrog scraps were selected as protein sources to prepare fish protein hydrolysate and bullfrog protein hydrolysate, and four isonitrogenous and isolipidic diets were formulated. Turbot with an initial body weight of (8.00±0.01) g was fed for a period of.56d in order to explore the utilization efficiency of turbot on protein hydrolysates from different sources. The experimental diets contained two control groups with no protein hydrolysate, the positive control group including 35% fish meal and the negative control group including 26.5% fish meal. Two experimental groups with different sources of protein hydrolysates, the FPH group contained 26.5% fish meal and 8.0% fish protein hydrolysate, and the BPH group contained 26.5% fish meal and 9.5% bullfrog protein hydrolysate. The results showed as follows: the final body weight, weight gain rate and special growth rate of the FPH group were significantly higher than those of the BPH and NC groups (P<0.05), but there was no significant difference between the FPH and PC groups (P>0.05). The concentrations of essential amino acids in chyme including lysine, arginine, threonine and valine in the BPH group were significantly higher than those in the PC group (P<0.05). There was no significant difference in the contents of other non-essential amino acids except for taurine and tyrosine, and the concentrations of most amino acids were the highest in the BPH group. The mRNA levels of proton-coupled amino acid transporter PAT1 and small peptide transporter PepT1 in the FPH and BPH groups were significantly higher than those in the PC and NC groups (P<0.05). There was no significant difference in the mRNA levels between cationic amino acid transporter CAT1 and Y+L-type amino acid transporter Y+LAT2 among all treatment groups (P>0.05). In conclusion, the addition of protein hydrolysates in the feed could promote growth performance of turbot, and fish protein hydrolysate showed more beneficial effects on the growth than that of bullfrog protein hydrolysate. The responses of amino acid concentrations in chyme and the expressions of amino acid and small peptide transporters also indicated that the feed utilization efficiency of turbot supplemented with fish protein hydrolysate was higher than that of bullfrog protein hydrolysate.