Utilization Of Plant Protein Sources For Juvenile White Shrimp, Penaeus Vannamei

This paper presents the effect of replacing fish meal protein by mixed plant protein sources (soybean meal and peanut meal), extruded soybean meal and fermented defatted soybean meal on growth performance, feed utilization, body composition and non-specific immune response of juvenile shrimp (Penaeus vannamei), in order to determine the dietary optimum level of fish meal protein replacement with these plant protein sources. The results can be briefly summarized as follows:1. A growth trial was conducted to evaluate the effects of replacement fish meal by mixed plant protein sources on growth performance, feed utilization and body composition of juvenile white shrimp. Seven isonitrogenous and isoenergetic experimental diets were formulated. The control group M1 contained 15% soybean meal and 20% peanut meal, groups M2-M4 contained 17% soybean meal and 22.5% peanut meal, groups M5-M7 contained 19% soybean meal and 24.5% peanut meal. Triplicate groups of 30 shrimps (initial body weight was about 0.3 g) were fed to apparent satiation three times daily for 8 weeks. The results showed that the weight gain, specific growth rate, feed conversion rate were not significantly affected by the dietary mixed plant protein sources. There was no significant effect on moisture and hepatosomatic index of whole body and muscle. However, protein, lipid and ash content in whole body and muscle were significantly affected by the mixed plant protein sources supplementation. In conclusion, mixed plant protein sources as a substitute with high quality protein would not have negative effect on the growth of Litopenaeus vannamei and would provide with nutrient components which is necessary for Litopenaeus vannamei. MPPS was able to substitute 21.4% fish meal without decreasing the growth of Litopenaeus vannamei and cut the cost in cultivation.2. A growth trial was conducted to study the effect of replacement fish meal by extruded soybean meal (ES) on the growth performance, body composition, and non-specific immunity of juvenile white shrimp at graded substitution levels (0%,5%,10%,15%,20%,25%). Six semi-purified diets were formulated to contain 38.5% crude protein and 6.5% lipid. Triplicate groups of 30 shrimps (initial body weight 1.01±0.01g) were fed to apparent satiation three times daily for 8 weeks. Results showed that Litopenaeus vannamei fed the reference diet had significant lower total feed intake (250.50g) than the other treat groups (P<0.05); the 25%ES group showed the lowest final body weight (6.20g) and survival (77.78%), which was significant lower than the control and 10%ES group (P<0.05); the 20% and 25%ES group had similar weight gain, which was significant lower than the reference and 10%ES diet(P<0.05); compared with the reference, 10%ES and 15%ES group, the 25%ES group had significant lower specific growth rate(P<0.05), protein efficiency followed the same trend as specific growth rate; the feed conversion ratio of the reference die was significant lower than other treatments except the 10%ES group (P<0.05). As the dietary level of extruded soybean increased, the whole body protein content of Litopenaeus vannamei decreased whereas the lipid content increased, and the 25%ES group had significant lower body protein content than the reference and 10%ES group(P<0.05). However, there was no significant difference on the muscle protein and lipid content regardless of the diets. Litopenaeus vannamei fed different diets showed similar non-specific immunity indexes, for there was no significant difference on the total serum protein content, alkaline phosphatase and phenol oxidase activity between different treat groups( P>0.05). Based on growth performance, the optimum substitute level of fish meal replaced by extruded soybean meal was 10-15%.3. A growth trial was conducted to evaluate the effects of replacement fish meal with fermented soybean meal on the growth performance, body composition, and non-specific immunity of juvenile white shrimp (initial body weight 1.01±0.003g) at varied substitution levels(0%, 7%, 14%, 21%, 28% and 35%). Six semi-purified diets were formulated to contain 38.5% crude protein and 6.5% lipid. Triplicate groups of 30 shrimps (initial body weight 1.01±0.01g) were fed to apparent satiation three times daily for 8 weeks. The results showed that the weight gain of the control group and feed utilization was best and high fermented soybean meal substitution would decrease the weight gain of the control group and feed utilization significantly. Fermented soybean meal substitution has no significant effect on body and muscle moisture, lipid, protein and ash. Also, fermented soybean meal substitution has no significant effect on serum alkaline phosphatase (ALP) and acid phosphatase (ACP) activity. In the contrary, serum phenol oxidase activity increased significantly along with the fermented soybean meal substitution. Fermented soybean meal did enhance the nonspecific immunity. The result showed that fermented soybean meal was able to substitute 14% fish meal without making significant effect on the growth and feed utilization of Litopenaeus vannamei.