ODUHO. G.W., BAKER D.H., TUITOEK J.K.
Abstract
In recent years the small pelagic fish Rastriobola argentea found in Lake Victoria has become of interest as a protein source for both humans, non-ruminant animals and poultry and pigs in Kenya, Uganda and Tanzania. A study was conducted to evaluate the nutritional value and the potential of R. argentea fishmeal (RFM) as a protein and a lysine source for broiler chicks. When samples from different landing beaches were subjected to proximate analysis the mean composition was: dry matter 90.06%; crude protein 57.10%, ash 10.56 %; ether extract 12.39 % and crude fibre 1.11 %. The amino acid composition showed no differences except in proline and leucine. The lysine content was 6.08 %. A feeding trial was conducted where RFM replaced soybean at 0 %, 4 %, 8 % and 12 % in broiler diets. The diets with RFM elicited significantly better weight gains, feed intake and feed conversion, which increased with increases in the RFM levels. Broiler chicks fed on a diet of 89.3 % RFM grew normally after taking 3 days to adapt to the diet and had normal intestinal organs of the digestive system when they were killed and their organs compared to those of other chicks fed on diets with low levels of, or without RFM. This indicated that RFM had no gizzerozines that produce adverse effects in the digestive organs of broiler chickens. The bioavailability of lysine from RFM was estimated using a chick bioassay and found to be 97.3 %, an indication of little or no damage to lysine during processing. The high protein content (58.50 %), the essential amino acid profile, the performance of broiler chicks on RFM and the high bioavailability of lysine in RFM, all indicate the high potential this fishmeal has as a source of protein and essential amino acids in poultry diets.
Key words:
R. argentea fish, protein, chicken.