Short term starvation and re-feeding in Nile tilapia (Oreochromis niloticus, Linnaeus 1758): Growth measurements, and immune responses

The effects of short term starvation and re-feeding to satiation on compensatory growth performance, haematological parameters, biochemical parameters, and immune responses were investigated in Oreochromis niloticus of average weights 96.10 +/- 0.47 g and 96.44 +/- 0.49 g for feeding group and starvation group respectively under the same rearing condition within 21 days period. The fish were divided into two groups namely control group (continuous feeding/ feeding group) and starvation group (days; 0, 3, 7, 10, 14, 21) and re-feeding was done immediately after starvation (days 7, 14, 21). The changes in growth performance, haematological indices, biochemical parameters, and immune responses of the fish were examined (days; 0, 3, 7, 10, 14, 21) and during re-feeding of the fish (days; 7, 14, 21). The results of the growth measurements decreased significantly during starvation and recover significantly after re-feeding (P < 0.05). The re-feeding group indicated a compensatory growth. Haematological indices such as WBCs, Hgb, Hct, and RBCs increased significantly (P < 0.05) after 14 days of starvation while re-feeding group decreases significantly within the successive times (P < 0.05). In the starvation group, blood glucfundose decreases significantly while the re-feeding group increases significantly within successive times (P < 0.05). The levels of Lactate dehydrogenase (LDH) and Pyruvate kinase (PK) increased significantly in the starvation group while the re-feeding group was maintained significantly within successive times. In the serum and liver, the levels of antioxidant enzymes activities in the starvation group were increased significantly while the re-feeding varied significantly within successive times. The immunological responses including lysozyme, immunoglobulin, and antiproteases increased significantly after 21 days of starvation but decrease significantly in the re-feeding group. The protease and lipase in the starvation group decrease significantly during starvation but increase after 21 days of re-feeding. These findings showed that short term starvation had significant effects on growth performance, haematological and biochemical parameters, and immunological parameters in Nile tilapia and recover positively after re-feeding. Taken together, the present findings provide new sight into the beneficial role of short term starvation and re-feeding in fish.