| Summary: | The dietary protein requirement of penaeid shrimp is an important nutritional considerationbecause it is a major limiting nutrient for growth. In most cases, research has focused on dietary protein levelsrather than on the actual requirements for protein. In this study, four 28 day feeding trials were conducted todetermine the maintenance requirement for protein (protein required to maintain body functions with all othernutrients provided in adequate amounts) by juvenile and sub-adult shrimp. Shrimp were offered practicaldiets containing 16 or 32% crude protein. In order to estimate the maintenance requirement, weight gain wasregressed against daily protein ration. Juvenile shrimp were found to have maintenance protein requirementsin the range of 1.8-3.8 g dietary protein/kg body weight/day (g DP/ (kg BW * d)), and sub-adult shrimp werefound to have maintenance protein requirements in the range of 1.5-2.1 g DP/ (kg BW * d). Four additional28-day trials were conducted to determine the protein requirement for maximum growth by juvenile and subadultshrimp. On an isoproteic basis, the 16% protein diet produced significantly lower weight gain, feedefficiency, and protein conversion efficiency values than the 32% protein diet for both the juvenile and subadultshrimp. The 48% protein diet produced significantly lower weight gain in the juvenile shrimp, but therewas no significant effect in the sub-adult shrimp. Feed efficiency values were higher for shrimp fed the 48%protein diet as compared to those offered the 32% protein diet. Broken line analysis was conducted on thegrowth responses for each diet and each size of shrimp in order to determine the protein requirement formaximum growth. Protein requirement for maximum growth of juvenile shrimp was found to be 46.4 g DP/(kg BW * d) when fed a 32% protein diet and 43.4 g DP/ (kg BW * d) when fed a 48% protein diet. Subadultshrimp exhibited a maximum protein requirement of 23.5 g DP/ (kg BW * d) when fed a 32% proteindiet and 20.5 g DP/ (kg BW * d) when fed a 48% protein diet. In summary, FE increased with the proteincontent of the diet and decreased with increasing feeding rates. Weight gain corresponded to daily proteinintake. Based on these results a wide range of dietary protein levels could be used to produce maximumweight gain. However, due to restriction on feed intake and consequently protein intake, low protein dietsmay not support maximum growth.
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