DIETARY VALINE REQUIREMENT OF AFRICAN CATFISH (Clarias gariepinus) JUVENILES

Abstract

use of high level of plant proteins in aquafeed usually causes severe essential amino acids imbalance in feed, resulting in poor growth and feed utilization rate. Quite often, these ingredients are limited in dietary valine which is considered mandatory to formulate well balanced diets to enhance protein synthesis. This study determined the growth performance, nutrient utilization, mineral composition, blood profile, the amino acid profile and cholesterol content of Clarias gariepinus juvenile fed diets containing different levels of valine. Five experimental diets of 40% crude protein were prepared to contain 0.00, 0.40, 0.80, 1.20 and 1.60 of valine respectively. A total of 400 Clarias gariepinus juveniles with a mean weight of 5.59 ± 0.37g were fed to apparent satiation twice daily in triplicates for a period of 56 days. Fourth degree polynomial regression analysis was used to determine the optimum dietary valine requirement of the fish. The results revealed that the dietary valine increased growth performance of the fish up to the fish fed diet with 0.8g/100g and declined consistently to the fish fed diet with 1.20g/100g of valine. The mineral contents (Na, K, Ca and Mg) of the fish increased with increasing valine levels. The haematological profile distribution did not follow any definite pattern, while erythrocyte sedimentation rate differed significantly with different valine levels (P<0.05). The amino acid profile of the diets showed that the valine contents increased consistently in accordance with the supplemental levels. However, different levels of valine in the diets lead to significant increases in the valine concentration in the fish. The cholesterol levels of the C. gariepinus juveniles reduced with increasing levels of valine in the diet. In Conclusion, the addition of valine into the diets enhanced growth performance and nutrient utilization of the fish. And, the dietary valine requirement of C. gariepinus juveniles was estimated as 0.72g/100g diet.