Study On Dietary Arginine Requirement And Effects Of Different Arg/Lys Ratio In Juveniles Of Macrobrachium Rosenbergii

This study was carried out to investigate the growth performance 、 tissue composition 、 digestive enzyme activity 、 amino acid composition of whole shrimp and muscle as well as nutrient deposition rate in Macrobrachium Rosenbergii, appropriate arginine requirement was determined and the effects of different arginine/lysine proportions on growth and digestive properties were also discussed in order to furtherly consummate the nutritional requirement parameters in Macrobrachium Rosenbergii and providing a theoretical basis for scientific guidance production about mixed feed. The main findings were as follows:Experiment 11. This experiment was intended to discuss the effect of dietary arginine levels on growth body composition in Macrobrachium rosenbergii.840 shrimps with initial body length (3.70±0.02) cm and body weight (1.55±0.01) g were randomly divided into six groups with four repeats in each group (35 shrimps per replicates). Dietary arginine levels fed respectively were 1.62% (control treatment)、 1.90%、 2.20%、 2.51%、2.80% and 3.11%(accounts for the mass fraction of fodder). This feeding trial lasted for 9 weeks. The results indicated as follows:1) the final body weight, body weight gain, weight gain rate (WGR) and specific growth rate (SGR) increased in accordance with rising of dietary arginine levels, and the peak value was observed at 2.80% which was significantly higher than that in control (1.62%)(P<0.05).2) the contents of crude protein and EE in whole shrimps reached the highest level in treatment 3.11%, which was significantly higher than control group (P<0.05), no significant difference was observed with respect to moisture and ash in whole shrimp as well as content of moisture 、 protein and ash in muscle (P> 0.05).3) feed of different arginine levels had impact on content of amino acids in whole shrimp and muscle, the total amount of TEAA、 TNEAA and DAA in whole shrimp and muscle came to the highest level when arginine level was 2.80%, significantly higher than control group (P< 0.05).4) No apparent effects were recorded on survival rate, meat weight ratio, FCR, as well as PER among all treatments (P>0.05).5) The quadratic regression analysis of WGR and dietary arginine levels indicated that the optimal dietary arginine requirement in Macrobrachium rosenbergii was 2.94% (8.28% in dietary protein). This study implies that dietary arginine levels may affect growth performance, body composition in Macrobrachium rosenbergii. The optimal requirement of arginine would be 2.94% (8.28% of dietary protein) in diets of Macrobrachium rosenbergii.2. The test was aimed to discuss about effects of different arginine levels on digestive enzyme of hepatopancreas and nutrient utilization in the basis of above study in Macrobrachium rosenbergii, providing theoretical support for determining furtherly the suitable arginine requirement of Macrobrachium rosenbergii. The results showed:1) effects of different arginine levels had significant difference on pancreatic digestive enzyme activities (P<0.05). Maximum of protein concentration, lipase activity, the vitality of trypsin and amylase were found in the group of 2.80%, both significantly higher than control treatment (P<0.05).2) protein deposition rate of whole shrimp came to highest value when arginine level reached at 2.80%, which was significantly higher than control treatment (P<0.05), however, no significant difference about deposition rate of protein in muscle and fat in whole shrimp was found when levels of arginine changed (P>0.05).3) when the level of arginine reached to 2.80%, maximum deposition rate of TAA and EAA in whole shrimp reached the maximum value, significantly higher than control group (P<0.05), deposition rate of TAA and EAA in muscle also peaked at arginine level of 2.80%. In conclusion:different arginine levels have impact on hepatopancreas digestive enzyme activity and nutrient utilization in Macrobrachium rosenbergii. Combined digestive enzyme activity with nutrient deposition rate can be furtherly verified the above results:the optimal requirement of arginine would be 2.94% (8.28% of dietary protein) in diets of Macrobrachium rosenbergii.Experiment 21. This experiment aimed to discuss the effects of different arginine/lysine proportions to growth performance, body tissue components in Macrobrachium rosenbergii,1600 shrimps with initial body length (2.10±0.01) cm and body weight (0.38±0.02) g were randomly divided into eight groups with four repeats in each group (50 shrimps per replicates), which were fed the feed of measured dietary arginine/lysine levels were 2.92/1.74、3.54/2.14、2.34/2.11、3.52/1.48、 2.36/1.43、2.94/2.10、2.94/2.48 and 2.96/3.17 (feed accounts for the mass fraction), the feeding trial lasted for 9 weeks. The results indicated as follows:1) feed of different arginine/lysine ratio had great impact on terminal body weight (TBW), weight gain (WG), weight gain rate (WGR) and specific growth rate (SGR) (P<0.05). TBW, WG, WGR and SGR were significantly higher than control treatment when arginine/lysine was 2.94/2.10 (P<0.05).2) Different arginine/lysine ratio influenced content of whole shrimp and muscle conventional nutrient. Moisture content of whole shrimp came to the highest when arginine/lysine was 2.94/2.10, significantly higher than control group (P<0.05), the highest value of crude protein content was in group of 2.94/2.10, significantly higher than 2.96/3.17 (P<0.05), but no significant difference was found compared with other groups(P>0.05).3) Aspect of essential amino acid content in shrimp:content of essential amino acids reached the highest when level of arginine/lysine was in group of 2.94/2.10 (P<0.05).4) content of amino acid in muscle:TAA、EAA and TNEAA came to the highest value when arginine/lysine was 2.94/2.10, which was signifincantly higher than control treatment. Content of arginine and lysine also reached the highest in group of 2.94/2.10, significantly higher than control group.5) Different arginine/lysine ratio had significant difference to total essential serum free amino acid content (P<0.05). The peak concentration was in group of 2.94/2.10, significantly higher than other groups (P<0.05). In conclusion:different arginine/lysine ratios have effects on growth and body tissue components.Under the experimental conditions, the suitable arginine/lysine ratio of feed in Macrobrachium rosenbergii is 2.94/2.10.2. The experiment aimed to explore furtherly effects of different arginine/lysine ratios to digestive enzyme and nutrient utilization in Macrobrachium rosenbergii. The result showed: different arginine/lysine ratios had significant difference on digestive enzyme activity of digestive trac in Macrobrachium rosenbergii (P<0.05). Livers pepsin (P>0.05), trypsin (P<0.05) and amylase (P<0.05) were higher than control group when arginine/lysine ratio was 2.94/2.10. The highest value of stomach and intestinal protease activity, lipase activity and amylase appeared in the group of 2.94/2.10, significantly higher than control treatment (P<0.05). Amylase activity (P <0.05), trypsin vitality (P>0.05) and pepsin vitality (P<0.05) were also higher than control group when arginine/lysine ratio was 2.94/2.10 (P<0.05).2) Deposition rate of crude ash in shrimp, crude fat and crude ash in muscle peaked at group of 2.94/2.10, which was significantly higher than control treatment (P<0.05).3) Different arginine/lysine ratio had effect on essential amino acids deposit rate in shrimp and muscle, essential amino acids deposit rate in group of 2.94/2.10 was significantly higher than control group (P<0.05). Aspect of total amino acid and EAA deposition rate in muscle, the highest value was also found in group of 2.94/2.10, which was significantly higher than control group (P<0.05). In conclusion:Feeding different ratios of arginine/lysine have great impact on digestive enzyme activity of gastrointestinal and nutrient utilization, combined digestive physiology with nutrient utilize can furtherly infer that:the suitable arginine/lysine ratio in feed of Macrobrachium rosenbergii is 2.94/2.10 under the experimental conditions.Conclusion of full text1. Arginine levels and different arginine/lysine ratio in diet have impact on growths body composition digestive enzyme and nutrient utilization in Macrobrachium rosenbergii.2. The optimal requirement of arginine would be 2.94% (8.28% of dietary protein) and appropriate arginine/lysine ratio is 2.94/2.10 under the experimental conditions.