Intestinal digestive enzyme activity under the influence of different dietary supplements methionine and lysine in the diet of Sparidentex hasta

This study was conducted to determine the effects of dietary methionine and lysine supplementation on digestive enzymes activity in juvenile Sobaity, Sparidentex hasta. For this purpose, 180 juvenile fish with an initial average weight of 31.38 ± 1.4 g were distributed randomly in eighteen (300 L) polyethylene tanks. 6 experimental diets were prepared with different levels of methionine and lysine including control diet (without dietary methionine and lysine), Diet 1: 100% methionine; Diet 2: 75% methionine and 25% lysine; Diet 3: 50% methionine and 50% lysine; Diet 4: 25% methionine and 75% lysine; Diet 5: 100% lysine. During the experimental period, fish were fed to satiation thrice daily (8:00, 13:00 and 18:00 hours) for 8 weeks. At the end of the experiment, digestive enzymes (trypsin, chymotrypsin, alkaline phosphatase, amylase, lipase and total protease were effected by different dietary levels of methionine and lysine supplementations (P