Mukhopadhyay N., 2000. Improvement of quality of copra (dried kernel of Cocos nucifera) seed meal protein with supplemental amino acids in feeds for rohu, Labeo rohita (Hamilton) fingerlings. Acta Ichthyol. Piscat. 30 (2): 21-34.
An eight-week feeding trial was conducted in a static indoor rearing system to examine the effects of partial substitution of fish meal (FM) protein with copra meal protein with and without supplemental amino acids in diets for rohu, Labeo rohita fingerlings (average weight 5.50 ±0.19 g). Prior to incorporation into diets, the meal was fermented with lactic acid bacteria (Lactobacillus acidophilus) in order to reduce / eliminate the anti-nutritional factors, tanin and phytic acid present in it. Twelve experimental diets (D1 to D12) were formulated replacing the FM protein from a reference diet with copra meal protein at different levels (four sets of diets, of which each set of three diets contained 30, 40, and 50% replacement of FM protein by copra meal protein respectively). Diets D1 to D3 were not supplemented with any amino acid. Lysine was added to diets D4 to D6. Diets D7 to D9 were supplemented with methionine-cystine (together) and diets D10 to D12 contained lysine and methionine-cystine (together). Lysine and methionine-cystine (together) were added to the diets at 5.7% and 3.1% of dietary protein respectively. The groups of fish fed diets without any supplemental amino-acids had significantly lower percentage weight gain, SGR and high FCR than the groups of fish fed other experimental diets. The addition of lysine and methionine-cystine to the diet in which 50% of FM protein was replaced by copra protein (diet D12) significantly improved fish weight gain and FCR. The percentage live weight gain and SGR values differed significantly (P < 0.01) from each other in the fish fed diets D10 to D12 which were supplemented with all three amino acids. The results of the present study suggest that rohu fingerlings can effectively utilise the supplemented amino acids and that copra meal protein can replace up to 50% of FM protein in the diets for rohu if the meal is properly fermented and supplemented with deficient amino acids.