The uncontrolled expansion of intensive milkfish production in the Philippines is causing congestion in marine areas and the overstocking of many ponds and cages.
The intensification has also increased the demand for feed, which currently accounts for 50 to 60 per cent of production costs, and has led to negative impacts on the environment.
In order to try and reduce feed costs for farmers and improve the environment, Russel Borski, North Carolina State University, and his team looked at the potential of alternative day feeding.
The study examined daily feeding against alternate day feeding in marine cages and brackish water ponds.
In brackish water ponds with a stocking density of 0.5 fish/m2, body weights, daily growth and survival rates were all similar between the two feeding regimes. Survival rates were slighty higher and daily growth slightly smaller in the alternate day feeding. However, there was a huge 50 per cent saving on the feed applied.
The marine cage study, with a stocking density of 35 fish/m2, also showed the same results for body weight, daily growth and survival rates.
There was a 32.9 per cent saving on feed costs and the water/sediment quality around the cages showed great improvement, with lower soil sulfides, phosphates and ammonia.
The study also found that if a fallow period was applied then the environmental quality would return to previous levels.
In conclusion, alternate day feeding generated 15-20 per cent profit for farmers as it saved on feed costs. This method of feeding can also be easily adapted by farmers and is better for the environment.
This research was sponsored by the Oregon State University through a grant from the US Agency for International Development.
