Dry matter and protein apparent digestibility of different ingredients at two dietary levels, in diet for Litopenaeus vannamei juveniles.

Student: 
Yann Guezenec

A nutritional trial was conducted to determine the apparent digestibility coefficients (ADC) of dry matter and protein in fish meal (FM), soybean protein (SP) and wheat meal (WM), at two inclusion levels (15% and 30%) in diets for Pacific whiteleg shrimp (Litopenaeus vannamei). A reference diet containing 1% chromic oxide as inert marker and 6 experimental diets were tested. Juvenile shrimp (7.0-8.6 g) were cultured in 60-L rectangular fiberglass tanks at a density of 8 organisms per tank with three replicates per diet. The meal’s highest dry matter ADC values were found for FM15 (98.4%) and WM30 (91.8%) while the lowest values were found for SP15 (67.1%) and SP30 (69.6%). The meal’s highest protein ADC values were found for WM15 (97.6%) and WM30 (96.32%) while the lowest values were found for FM30 (86.9%) and FM15 (93.1%). It is concluded that dry matter and protein ADC of the meals are significantly affected by the type of meal but not by the inclusion level, while significant interaction between the two factors was detected for dry matter digestibility. The digestibility values of the ingredients obtained here would provide useful information to create more accurate and economical formulation of shrimp feeds, and to optimize digestibility determination methods.