Short term ration restriction and re-alimentation: Effect on compensatory growth, body composition and insulin like growth factor gene expression in cyprinus carpio

Abstract

Advanced fry of Cyprinus carpio (mean weight 1.73±0.02g) were fed at 10%, 25%, 50% and 75% of satiation as different treatment groups and one control group (6 weeks) for first phase (restriction feeding) and a second phase (8 weeks) of satiation feeding for all the treatments. At the end of first phase, there was significant difference in mean weight among the treatment groups (P<0.05) but, after second phase (8 weeks), treatment group fed at 75% of satiation obtained significantly higher body weight than control, while 50% satiation fed group obtained similar weight as of control. FCR was found to be better at moderately restricted fed group (50% and 75% satiation). Crude protein and crude lipid content decreased in severely restricted groups (10% and 25% of satiation fed), compared to others after 14 weeks. IGF-I and IGF-2a gene expression in the liver was observed as down regulated during ration restriction and up regulated after re alimentation. However, after re-alimentation for 8 weeks, IGF-2a gene expression was recorded to be increasing and was higher than control. The study concludes that moderate levels of ration restriction (50% to 75% of satiation levels) is sufficient for effective growth and feed utilization.