Growth performance of genetically modified tilapia (Oreochromis niloticus) cultured in concrete pond

Abstract

Reproductive data from 24 does (Chinchilla X New Zealand White) of twenty weeks, were analyzed to determine the effect of generation, housing systems and season on the reproductive performance of rabbits raised in the humid tropics. The experiment was carried out during four seasons namely: early dry season (EDS-September to November), late dry season (LDS- December to February), early rainy season (ERS-March to May) and late rainy season (LRS June to August). The study was repeated in the second generation and the data obtained were subjected to analysis of variance in a 2x2x4 factorial arrangement. Factors considered were generations, housing systems, and seasons respectively. Highest breeding efficiency of 83.33% was obtained in the first generation and maximum litter size at birth (35) and weaning (28) were observed in caged-does that kindled in EDS of first and second generations respectively, while does housed on deep litter system produced the smallest litter size at birth (24) and weaning (18) in the ERS of the second generation. Highest (12) and least (4) pre-weaning losses were recorded in caged-does that kindled in ERS of the first and second generation respectively, whereas highest average birth weight (120.58g) was observed in litters of deep litter-does that kindled in EDS of the second generation. These results indicated that the production of rabbits for breeding purposes is better achieved during early dry season (September-November) and also revealed that deep litter system allows satisfactory performance and has comparative advantage over wooden cage system considering the reduction in housing cost and can be used to improve the nutritional status of the family and also to obtain some supplementary income. Keywords: Season, Breeding efficiency, Litter size, Cage, Deep litter