Investigations on growth performance of grass carp Ctenopharyngodon idella (Cuvier and Valenciennes,1844) under forage crops and aquatic macrophyte feeding regimes

The objective of the study was to assess the growth, survival, and production performanceof grass carp Ctenopharyngodon Idella (Cuvier and Valenciennes, 1844) under differentfeeding regimes of forage crops and aquatic macrophytes. In the present experiment, 650fingerlings (average length, 11.13±0.29 cm and average weight, 13.89±0.81 g) of grass carpwere stocked separately in two earthen ponds (40 x 25 x 2.0 m). Fishes in pond one (T1)were fed with forage crops, chopped Napier grass (Pennisetum purpureum) from June toNovember 2017 and chopped Berseem (Trifolium alexandrinum) from January to May 2018.Similarly, fishes in pond 2 (T2) were fed with Azolla (Azolla pinnata) and Lemna (Lemna minor)during the period June to November 2017 and January to May 2018, respectively. Lineartrend analysis for the length of grass carp showed a significant (p<0.05) increase in size inboth treatments (T1 and T2) and r2 was found to be 0.94 and 0.95, while increasing trend ofweight of grass carp showed significantly (p<0.05) high r2 for T1 (0.88) and T2 (0.84). It isobserved that the application of forage (T1) and aquatic macrophytes (T2) had no significant(p>0.05) effect on the water quality parameters of each pond. The overall specific growthrate, average daily weight gain and feed conversion ratio of grass carp were significantly(p<0.05) higher in T1 compared to T2, while the survival rate was significantly (p<0.05) high in T2.   Keywords:Earthen pond, Feed conversion ratio, Macrophytes,Specific growth rate, Survival