Abstract
The application of agricultural by-products as alternative feed has received tremendous interest from the aquaculture industry. The current study explored the potential of hydrolyzed chicken feather meal (CFM) at different percentages as fish meal (FM) replacement and the impacts on growth, feed stability, apparent protein digestibility, digestive enzyme, body amino acid profiling, body proximate analysis, hematology, and morphology of African catfish (Clarias gariepinus) fingerlings. Five isonitrogenous (32% crude protein) CFM diets were prepared [0% CFM (T1), 5% CFM (T2), 15% CFM (T3), and 30% CFM (T4)] and applied in a 70-day feeding trial. At the end of the experiment, fingerlings fed with the T2 diet exhibited the best final length, final weight, net weight gain, weight gain, specific growth rate, intraperitoneal fat, and condition factor than other treatment groups. Furthermore, the highest digestive enzyme activity and apparent protein digestibility (APD) were highest in the T2 diet. There were significant differences between the groups in the liver, muscle, and intestine amino acid profiles and proximate analysis. Moreover, the T2 group recorded the best villus length, width, and crypt depth in the anterior and posterior regions. The highest white blood cells, lymphocytosis, monocytes, red blood cells, hemoglobin, and hematocrit were also found in the T2 diet group. Meanwhile, albumin, globulin, and creatine levels were the lowest in the T4 diet group. Notably, fingerlings supplemented with the highest CFM percentage demonstrated the highest morphological deterioration in the liver and intestine. In conclusion, 5% CFM is a promising FM replacement to improve the growth, apparent protein digestibility, digestive enzyme, liver and intestine histology, and blood indices of African catfish fingerlings.
