Effects of L-Lysine on growth and histological changes in liver and intestine of GIFT Strain Oreochromis niloticus

EFECTS OF L-LYSINE ON O. NILOTICUS

Abstract

Four experimental diets were used for four treatments viz.T1 (SD+1.95% lysine of diet), T2 (SD+2.05% lysine of diet), T3 (SD+2.15% lysine of diet) and T4 (Control, SD+0.00% lysine of diet) with each having three replications to understand the effects of lysine on growth, histological changes in liver and intestine of GIFT strain of tilapia (Oreochromis niloticus). Forty-eight days old tilapia fry were stocked in experimental cemented tanks and fed twice a day with experimental diets containing different doses of L-lysine for 40 days from May to June 2016 and then the growth and health status of experimental fish were checked at every 10 days interval. The mean body weight treatment T2fish (13.04±0.3 g) was significantly higher (p<0.0001) followed by T3(10.58±0.14g), T1(9.86±0.07 g) and T4, (7.79±0.05 g), respectively. In addition, the body length was also increased 8.63±0.81 cm with T2 treatment followed by 8.59±0.08 cm, 8.42±0.12 cm and 8.1±0.06 cm with T3, T1and T4, respectively. SGR of fish were 2.41±0.004, 2.52±0.04, 245±0.07 and 2.07±0.04% in T1, T2, T3 and T4, respectively. Histology of liver and intestine was carried out with T1, T2, T3 and T4 treatment where the microvillus fold and height in the intestine were comparatively higher in T2, but there were no vacuoles and infiltrations in T2 compared to T1, T3 and T4. The present findings revealed that 2.05% supplementary lysine for tilapia might be a good promoter for their growth and culture.