Impact of in-feed Multispecies Probiotic Mixtures on Growth Patterns and Length-weight Relationships of Pangasianodon hypophthalmus

This study was conducted to evaluate the effect of two commercial multispecies probiotic mixtures in dietry feed on length-weight relationships (LWRs) of the commercially important catfish Pangasianodon hypophthalmus. For this, eighty healthy fishes (13.02g ± 1.22) were assigned to four experimental groups, i.e. control group (T0), treatment 1 (T1), treatment 2 (T2) and treatment 3 (T3), with two replicates for each group and raised into experimental cemented ponds (3 ft x 1.5 ft) with 20 fishes in each experimental group. Fishes in T0 (control group) were fed a commercial diet without probiotics, T1 consumed a diet supplemented with Probiotic-A (mixture of Bacillus megaterium and B. licheniformis), T2 was fed a diet enriched with amino peptide juice prepared by using Probiotic-B (mixture of B. amyloliquefaciens, B. subtilis and B. valismortis). In contrast, fishes reared in T3 fed upon a diet same as T2 but on alternative day for 60 days. The experimental diets were manually given to the fish at a rate of 3% by body weight. The total length and weight of each fish specimen were calculated at the end of the feeding trial. The data were examined using the linear regression equation of Log W = Log a + b Log L. All treatments showed a strong correlation between fish length and weight (p < 0.001, range of r2 = 0.601-0.988). The slope (b-values) for P. hypophthalmus were 2.806 (negative allometric growth), 3.138 (positive allometric growth), 2.959 (isometric growth) and 2.690 (negative allometric growth) for T0, T1, T2, and T3 respectively. The results of LWRs in the current study indicate that the application of different probiotics mixtures mainly Bacillus megaterium and B. licheniformis, significantly influenced the growth pattern of P. hypophthalmus.