Replacement of fishmeal by fermented spent coffee ground: Effects on growth performance, feed stability, blood biochemistry, liver, and intestinal morphology of African catfish (Clarias gariepinus)

Abstract

There has been a consistent interest in the aquaculture industry in the use of plant elements as a substitute for fish meal (FM). The present study aimed to examine the impact of substituting FM with varying proportions of fermented spent coffee grounds (FCG) on the growth performance, feed stability, blood biochemistry, liver, and intestinal histology of African catfish, Clarias gariepinus. Five isonitrogenous diets were formulated with a crude protein content of 32 %. These diets were created with different percentages of FM replacement, specifically 0 % (T1), 10 % (T2), 20 % (T3), 40 % (T4), and 80 % (T5). The fish were then fed these diets for a duration of 70 days. The results showed that fish provided with 10 % FCG (T2) gave the highest improvement (p < 0.05) in growth conditions compared with other treatments. The feed’s physical properties were varying, but floatability and water stability were highest in T2 diets. Total bacteria (TB) in feed and intestine were more elevated in fish fed with 10 % FCG compared to other treatments. The histopathological damage in the intestine and liver morphology was observed when the level of inclusion of FCG was increased in all treatments. In addition, T2 gave the highest value (p < 0.05) in villus length, width, and crypt depth. Some parameters were improved in both blood haematology and blood biochemical parameters, and T2 gave the highest value (p < 0.05) in white blood cells, lymphocytosis, monocytes, red blood cells, haemoglobin, albumin, globulin, total protein, and creatine. In summary, the substitution of 10 % FCG with FM holds potential for application within the aquafeed sector, as it has been observed to contribute to enhanced growth and improved health conditions in African catfish and other freshwater species.