EVALUATION OF 5 CARBOHYDRATE SOURCES FOR PENAEUS-VANNAMEI

Utilizing chromic oxide as an inert marker, apparent digestibility coe fficients of five carbohydrate sources were evaluated in 8.8 g Penaeus vannamei. Test diets for each ingredient, wheat starch, whole wheat, Nutribinder(R), sorghum and steam cracked corn, were prepared containi ng 70% semi-purified reference diet and 30% of the test ingredient. Ap parent dry matter digestibility (ADMD) of steam cracked com was 23.27% and was significantly lower than all other ingredients tested. The AD MD of Nutribinder(R), whole wheat, wheat starch and sorghum were 56.87 , 52.46, 50.62 and 38.39%, respectively. ADMD of Nutribinder(R) was si gnificantly higher than that of sorghum but not significantly differen t from whole wheat and wheat starch. Apparent digestible energy (ADE) values for the test diets ranged from 90.82% for the reference diet to 78.09% for the test diet containing corn. ADE values for wheat starch (71.30%), whole wheat (67.73%), Nutribinder(R) (69.54%) and sorghum ( 57.93%) were significantly higher than the ADE of steam cracked com (4 0.17%). ADE values for wheat starch, whole wheat, Nutribinder(R), sorg hum and steam cracked corn were estimated to be 2966, 2915, 3209, 2604 and 1610 kcal/kg. Consumption of the test diets appeared to be invers ely related to the digestibility coefficients, indicating that consump tion may be energy regulated. Based on the observed results, digestibi lity of the tested carbohydrate sources appears to vary with source an d gelatinization. Additionally, a significant depression in the protei n digestibility of the reference diet as compared to the test diet con taining the same carbohydrate source (wheat starch) may indicate assoc iative effects.