Dr Thomas Wilson, Aquaculture Nutrition Consultant, Thailand
Aquaculture is expected to make a significant contribution to meeting increasing future demand for dietary protein by an increasing world population. To reduce the likelihood of land and water use conflicts, the aquaculture industry has to become a “good neighbor” in populated areas where it operates; if aquaculture becomes both “sustainable” and “responsible” it can largely overcome the negativity that exists.
Adopting completely closed farming methods is a good way of reducing conflicts with those sharing water resources, and increasing production by intensification reduces the need for new land. This means keeping increasing amounts of dissolved phosphorus (P) and nitrogen (N) and other wastes inside the farm, which, if not managed properly, may cause reduced growth, increased stress and disease, reduced survival and poor profitability.
Wastes from uneaten and poorly digested feed are the largest source of excess P and N in farms, so this is where attention needs to be placed to improve water quality and on farm feed performance. Sustainable feeds today contain little or no fishmeal, but this shifts ingredients towards animal and plant proteins, which come with their own problems. Improving P and N digestibility through the use of feed enzymes like phytase and carbohydrases is a sensible way to reduce the effects of anti-nutrients such as phytic acid and non-starch polysaccharides. Protease enzyme has the potential to improve protein and amino acid digestibility of all ingredients. Increasing feed digestibility and nutrient availability with enzymes provides a means to improved profitability and sustainability.