Partial replacement of dietary animal protein with vegetable protein blend with different proportions of glucosamine on growth, feed efficiency, body composition and survival of fingerlings of Asian catfish (Clarias batrachus)

Abstract

A 12-week feeding trials was conducted to evaluate the use of animal and plant protein, in combination with glucosamine source for Asian catfish, Clarias batrachus (average weight 2.1–2.6 g). This study was performed to evaluate the effect on fish growth performance by replacing animal protein with a blend of vegetable protein sources. In experiment, six (40.45–43.51 % crude protein, 16.45–16.76 kJ/g energy, and crude lipid 5.01–6.69 %) practical diets were formulated. The animal and plant protein component of the diets was progressively added with glucosamine 0.0 %, 0.5 %, 5.0 % and 10.0 % with fish meal, silkworm pupae, soybean meal (SBM) and casein (F1, PAG 0:100:0.5; F2, PAG 0:100:5.0; F3, PAG 0:100:10.0; F4, PAG 25:75:0.5; F5, PAG 25:75:5.0; F6, PAG 25:75:10.0). The experimental diets were fed to triplicate groups of fingerlings ad libitum and results were compared with control feed (natural feed). Growth performance and feed utilization efficiency of catfish, fed diets with animal protein are better than those of plant protein supplemented feeds. After 12-week study the final weight gain recorded as 18.6, 19.7, 19.9, 16.3, 15.2, 15.6 and 13.1 g in control fed fishes. The best growth among the animal protein group (F1–F3) were recorded as 745.5 %, 838.1 % and 765.2 % respectively. The growth percentage in 25 % replaced feeds (F4, PAG 25:75:0.5; F5, PAG 25:75:5.0; F6, PAG 25:75:10.0), recorded as 579.2 %, 484.6 % and 609.1 % respectively whereas in control it was 469.6 %. The results suggests that the growth is better in total animal protein feeds and the best growth (p < 0.05) recorded in the feed incorporated with 10 % glucosamine. The data on growth and feed conversion ratio (FCR) were considered animal protein content of the diet along with glucosamine has better growth performances. The survival was recorded in F1–F6 as 88 %, 83 %, 76 %, 78 %, 80 % and 75 % respectively and in control it is recorded as 68 %. The hepatosomatic and viscerosomatic indices ranged between 0.78–1.51 and 1.9–3.03 respectively in F1 to F6. The feed efficiency in terms of FCR recorded as 2.34–2.95 among all the feeding trials. Results indicate that animal protein rich diets with glucosamine were much acceptable than natural diets for Asian catfish, C. batrachus and the potential for replacing animal protein with SBM in the diets of fish need more evaluation along with synergistic approach of incorporating glucosamine. Inclusion of plant protein blend affected growth performance and reduced digestibility, but was not compensated by increased feed intake.