Growth performance of Thai Pangus (Pangasianodon hypophthalmus) using different synthetic amino acids in plant protein based formulated diets

An experiment was carried out for a period of 120 days to evaluate three formulated diets among of which T1 was formulated based on animal protein, T2 was partially replaced animal protein with plant protein and adding amino acid whereas the T3 was formulated with fully plant protein with adding amino acid to assess the growth performance of Thai Pangus, Pangasionodon hypophthalmus. Each treatment had three replicates using 9 (nine) mini experimental ponds. The stocking density was 120 fish/decimal. Initially, the fish were fed twice daily at a rate of 5% of their body weight, which was progressively reduced to 2% by the end of the experiment. During the experimental period, the water quality parameters observed (temperature 26.0°C-31.5°C, pH 7.50-8.44, DO 4.30-5.94 mgL-1, ammonia-nitrogen 0.01 to 0.03 mgL-1, and total alkalinity 155-185 mgL-1) were found to be optimal and stable. The mean weight gains (WG) of Thai Pangus were 421.6±4.71 g, 407.34±1.97 g and 345.89±4.44 g for T1, T2 and T3, respectively and significantly (p<0.05) highest WG was obtained in T1 and T2 followed by T3. The specific growth rate (SGR) was found highest in T2 (2.70±0.03) followed by T1 (2.53±0.06) and T3 (2.16±0.04), respectively. The highest feed conversion ratio (FCR) was found in T1 (1.62) whereas lowest FCR obtained from T2 (1.52±0.01) followed by T3 (1.55). The protein efficiency ratio (PER) values were ranged between 2.03 and 2.13 and highest was found in T2 (2.13±0.05). The highest production was attained from T1 (13557.50±51.60 kg ha-1) followed by T2 (13227.71±50.72 kg ha-1) and T3 (11450.60±49.87 kg ha-1), respectively. The findings of this study revealed that, the partial replacement of animal protein with plant protein adding limited amino acid (lysine and methionine) exhibited the best performance on the basis of nutritive value and growth performance.