Unconventional protein sources for poultry feeding – opportunities and threats

In search for sustainable alternatives for fish meal and overseas vegetable protein sources some selected protein sources were evaluated. These included oil seed co-products, grain legumes and their concentrates, insects, leaf and aquatic proteins, etc. These sources differ substantially in terms of protein yield, environmental sustainability, nutritional value and availability. Products with a low dry matter content, i.e. lucerne, leaves, aquatic proteins are considered to be less sustainable due to the high energy costs for drying. Some values, however, are lacking for some of the protein sources. Within the category of oil seeds, European produced soybean meal seems to be the most promising alternative for soybean meal from beans imported from South America. Nutritional value and especially protein digestibility of soybean meal is very good. Protein yield of soybean meal produced in Europe should be further increased to make this crop feasible for the farmer. To realize this, varieties have to be selected with an ultra-short growth season. Within the category of grain legumes, peas seem the most promising alternative for soybean meal, at least for the short-term. The protein yield is reasonably high, but should be further improved. In long-term, leaf proteins and aquatic proteins probably might contribute to reduce soybean imports. Therefore, more knowledge regarding protein separating techniques and nutritional value of these products is necessary. Leafs, aquatic and insect protein sources are not in direct competition with the land use of other crops. Enhancing the protein content of these plant protein sources by processing needs further development; especially products such as duckweed and algae seems promising, but sustainability aspects should be studied. We also realize, that the nutritional value of products such as leaf proteins, some aquatic proteins and insects is not known sufficiently. For these sources, aspects of cell wall degradation, feed safety and legislation should definitely be covered. At this moment it is not possible to draw sound conclusions with respect to the environmental sustainability of the selected protein sources