RESTRICTED FEED DEPRIVATION IN AQUACULTURE; ROLE OF RESTRICTED FEEDING AND COMPENSATORY GROWTH

On the process of intensification which lead aquaculture to be one of the fast-growing food production sector feed manufacturing remained as its greatest obstacle for the growth. Therefore, considerable effort has been given in developing practices to reduce the amount of feed required on fish farms. One such practice is delivering temporary feeding period which is one of the most simple and widely used practices to limit the quantity of feed where the amount of food given to fish is drastically reduced for days to months before the fish are re-fed to satiation levels.

Inducing compensatory growth in aquaculture helps in increased growth rate or feed utilization, decreased feed wastage and flexible feeding regime. There have also been studies reporting better feed conversion efficiency or digestive efficiency in fishes like barramundi.

The basic explanation behind this compensatory growth is that fish undergoes a stage of hyperphagic response under satiation feeding resulting in faster growth. This has been observed in many fishes like cichlids, cyprinids, gadoids etc. The responses to these patterns majorly depend on the feeding regimes and the intensity of feed restriction. A period of feed restriction has been described to elicit the compensatory growth pattern in fishes. Feed restrictions often refer to the practice of temporarily limiting the amount of feed given to fish. These feed restrictions last from weeks to months before fish are again re-fed to satiation.

In fish, compensatory growth is the unusually-fast growth which they typically exhibit when they are re-fed after an extended period of feed restriction. In Compensatory Growth (CG) fish grow faster-than normal when recovering from a period of growth suppression. This represents a unique opportunity to boost profit margins in aquaculture. Food and feeding costs can be reduced temporarily, which suppresses fish growth, but once the fish are re-fed, CG ensures the regain of fish's lost mass. It has been observed that Channel Catfish in production ponds can partially or completely recover weight as a response to the limited feeding provided, they are subsequently fed to satiety.

In summary, moderate feed restrictions have resulted in compensatory growth and therefore feed restriction practices have the potential to benefit aquaculture economically.