Supplemental Effects Of Coated Amino Acids In The Feed Of Fish Meal Replacement With Poultry By-product Meal On The Growth Performance Of Litopenaeus Vanmamei

In the study, the effects of supplementation of crystalline amino acids and the crystalline amino acids coated by gelatin, agar, starch or hardening grease in the diets of complete fish meal replacement with poultry by-product were investigated on the growth of Litopenaeus vanmamei. Twelve diets were formulated, namely, control(fish meal-based diet, FM diet), poultry by-product-based diet(PBM diet), PBM+EAAs diet, PBM+EAAs+NEAAs diet, 4 PBM diets containing EAAs coated with 4 types of coating materials, and 4 PBM diets containing EAAs+NEAAs coated with 4 types of coating materials. The juvenile Litopenaeus vanmamei of initial body weight of 0.3±0.01 g were randomly assigned into 36 cylinder tanks(150 L), 30 animals per tank. The shrimp of groups with 3 replicates were fed one of the 12 diets to apparent satiation, three times a day across the 8-week feeding period. The results are shown as follows:There are no significant differences in percent weight gain, specific growth rate, feed conversion ratio and survival between group fed PBM diet containing EAAs coated with starch and the control group(P>0.05), and growth performance of the shrimp of other groups are significantly lower than the control group(P<0.05). Growth performance of the shrimp of the groups of adding crystalline amino acids are better than the ones of chicken meal group(P<0.05). Growth performance in groups fed the diets containing coated crystalline AAs are better than those fed the non- AAs coated diets(P<0.05). Shrimp of groups receiving EAAs-coated diets had better growth performance than those receiving NEAAs-coated diets(P<0.05). There were no significant differences in whole-body composition between the control and groups fed diets containing coated AAs with coating materials except the group fed diet containing AAs coated with hardening grease had higher fat content than the control(P>0.05). The concentrations of total plasma free AAs in shrimp fed the diets supplemented with AAs were higher than that in shrimp fed the FM diet and the values of shrimp fed the diet supplemented with AAs were the highest among all treatments. The order of the 4 kinds of coating materials was agar, starch, gelatin and hardening grease according to concentration of total plasma free AAs from high to low when the shrimp fed the diets containing AAs coated with different coating materials. The concentration of muscle free glycine of shrimp fed PBM diet was higher than that in the control(P<0.05). The concentrations for muscle free AAs in groups of shrimp fed the PBM-based diets with or without AA supplementation were not different from that of shrimp fed the FM-based diet except the values of glycine, glutamate and proline(P>0.05), as was the value of total muscle free AAs. The muscle EAA/NEAA were relatively similar among dietary treatments.The results indicate that the supplementation of coated crystalline AAs in the feed of complete FM replacement with PBM could promote the growth of Litopenaeus vanmamei, and the addition of EAAs coated by starch in the feed without addition with NEEAs could product the positive growth effect similar to the control, however, the additions of EAA coated with other three coating materials produced inferior growth performance compared with the former.