Introduction
Avocado pear (Persea americana , Mill) is a widely consumed fruit because of its delicious tast e, rich nutrient composition and several-health promoting bioactive ingredients. It is rich in minerals, vitamins and protein. However, the seed which is discarded as a waste makes up between 15 and 17% of the whole fruit. Preliminary analysis of the seed used in the study showed high protein level of 42.5% which is closely related to the protein level of 45% in soybean meal. Hence the study investigated the effect of total replacement of soybean meal with the Avocado sees meal (AM) in the diets of African catfish. DL-methionine was added due to its limitations in plant protein feed ingredients.
Materials and methods
Five isonitrogenous diets were prepared to contain 0, 25, 50, 75, 100% of Avocado seed meal (AM) in replacement for soybean meal in making diets 1 -5. Then diets 1-5 were fortified with 0, 0.20, 0.40, 0.80, 1.0 % DL-Met respectively. The diets were fed to African catfish (10.2 g) for 56 days in indoor glass tanks. Standard procedures were used in data collection and analyses.
Results
Analysis of the Avocado seed meal used in the study revealed a high protein content of 42.5% and high fibre and lipid contents (Table 1). Assessment of the mean weight gain, specific growth rate, feed conversion ratio and protein efficiency ratio indicated that AM can replace up to 50% of soybean meal in the diet of the fish (Table 2). Similarly, dietary AM significantly improved Mg , Ca, P, Mn and Zn deposition in the fish in comparison with the control diet containing 100% soybean meal (Table 3). Moreover, dietary AM significantly reduced the glucose levels in the experimental fish (Fig. 1).
Conclusion
Replacement of soybean meal with A vocado seed meal at (50% +0.4% Met) is recommended for the production of African catfish. Replacement of soybean meal with AM also significantly improved the minerals and reduced the carcass glucose levels.
References
Nwanna, L. C and E. K. Ajani (2022). Future of Aquaculture in Nigeria: the role of alternative fish feed ingredients. Selected Titles in Sustainable Fisheries and Aquaculture (Edts. Balogun A. M, B. O. Omitoyin, E. K. Ajani). Pages 403-416.
Nwanna, L.C, Lemme, A, Abdallayb-Metwallyb, D. I and Schwarz, F. J (2012). Response of common carp (Cyprinus carpio L) to supplemental DL-Methionine and different feeding strategies. Aquaculture, 6: 356-357: 365-370