Short-term periodic feed deprivation in Labeo rohita fingerlings: Effect on the activities of digestive, metabolic and anti-oxidative enzymes

Abstract

This study aimed to determine the effect of periodic feed deprivation on the activities of digestive, metabolic and anti-oxidative enzymes of Labeo rohita (commonly known as rohu) fingerlings. Fish (average weight, 3.73±0.06g) were periodically starved for 0 (0day-per-week, dpw), 1 (1dpw), 2 (2dpw) or 3 (3dpw) consecutive day (s) per week for a total duration of 10weeks. On the day of feeding, fish were fed to satiation twice daily with a diet containing 30% crude protein and 6% lipid. Results showed increased protease and amylase activities in the 1dpw and 2dpw groups, suggesting that feeding fish for 6 or 5days a week markedly improved the digestive capacity of fish when compared to daily feeding (0dpw). However, the activities of lipase and alkaline phosphatase did not respond significantly (P>0.05) due to periodic feed deprivation. Periodic feed deprivation of 1dpw did not lead to any changes in the metabolic and anti-oxidative enzyme activities of the fish. In fingerlings deprived of feed for 2dpw, higher hepatic glycolytic enzyme activities, hexokinase and pyruvate kinase, were observed but with no change in the activities of gluconeogenic (glucose-6-phosphatase, aspartate amino-transferase and alanine amino-transferase) and Kreb's cycle (malate dehydrogenase) enzymes. The group deprived of feed for 3dpw exhibited lower activities of malate dehydrogenase, glucose-6-phosphatase and glucose-6-phosphate dehydrogenase. Increased activities of anti-oxidative enzymes, superoxide dismutase and catalase, in the 2 and 3dpw groups in this study implied an adaptive response of L. rohita fingerlings to cope with the oxidative stress caused due to feed deprivation. Higher activities of protease and amylase in the 1 and 2dpw groups, and higher key glycolytic enzyme activities in the 2dpw group would suggest improved digestive and metabolic functions, however, feed deprivation beyond 2dpw seemed to have adverse effect on L. rohita fingerlings.