Comparative growth performance of two Nile tilapia (Chitralada and Red-Stirling), their crosses and the Israeli tetra hybrid ND-56

Growth performance of two Oreochromis niloticus strains, Chitralada and Red‐Stirling, their reciprocal crossbred and the Israeli tetra‐hybrid ND‐56 were assessed in net cages under on‐farming conditions. Throughout 268 days of grow‐out, the strains were weighed monthly and mortality, feed consumption and water quality were recorded. Ten rigid net cages (1.5 × 1.5 × 1.7 m) immersed in a 10 ha reservoir were linearly arranged near the reservoir outlet following a completely randomized design with two replicates for each treatment (strain). Each cage was stocked with 459 fish (120 fish m^?3) and fed twice daily to apparent satiation with a commercial tilapia diet following the recommended feeding program. The final mean weights were higher for Chitralada (557.20 g) and the reciprocal crossbreds (522.95, 496.40 g) than those of Red‐Stirling (421.90 g). All treatments outperformed the ND‐56 tetra hybrid. Daily growth showed statistical differences between Chitralada (2.04 g) and Red‐Stirling (1.52 g) but they were statistically the same when compared with the reciprocal crossbreds (1.90, 1.80 g). The relative growth ratios showed the same trend observed in the results for daily growth. The mean survival rate was 98%. The overall growth rate showed that crossbred performed as well as the parental lines. All crossbred progeny presented red colouration with variable pattern of black marks corroborating the dominant inheritance of the red trait in Red‐Stirling strain.