FEATURE
"PAPs are high quality protein sources. Their re-introduction into European aquafeeds will facilitate the formulation of high proteins fish feeds, since their availability is better than fishmeal" ing essential unsaturated fatty acids (linolenic, EPA and DHA for salmonids and EPA and DHA for marine fishes) and as energy source. For fish species that can tolerate higher amounts of lipids in their diet, like salmonids, sea bream and sea bass, a combination of animal, vegetable and fish oil can satisfy both requirements, without altering the fatty acid content of the fish flesh. Diets contained 17 % Fish oil, 12 % fish oil + 5 % poultry oil or porc bone oil. In treatment Poultry oil/Fish oil, the fish receive first the diet with poultry oil and than the diet with only fish oil
Presence of some nutrients which still need to be investigated Due to the ever-increas-
Table 2: Overview of Apparent Digestibility Coefficients (ADC) and Apparent Digestibility of Proteins (ADP) observed for Rainbow trout and Gilthead seabream compared to other protein sources
Rainbow trout
LT fish meal
Gilthead sea bream
ADC
ADP
ADC
ADP
72,6
90,5
71,8
87,5
Danish fish meal Hydrolyzed feather meal Meat and bone meal Poultry meal Soybean meal Soy protein concentrate Corn gluten
95,8 65,7-84 %
71,6-87
55,9-72
83-89
48,8
51,6-57,7 35-79
59,8-77
83-91
80-89,9
29,5-75,3
95,9
86-90,9
53,2
90,4
80-95
74,5-89,5
90
16 | International AquaFeed | March-April 2013
ing prices and scarcity of fishmeal, research is continuously searching for alternatives. This is often possible up to a certain level, but total replacement often results in growth loss, even though diets were formulated to contain the same amounts of essential nutrients for which the requirements are known. Replacing fishmeal by PAPs generally results in better results than replacing fishmeal by vegetable proteins. There are probably some unknown nutrients still to be discovered, which are present in animal proteins but not in vegetable proteins. Hydroxyproline, taurine and nucleic acids are some nutrients that has attracted attention recently by researchers, but their requirements still need further investigation. There are probably more nutrients to be discovered in the near future.
Conclusion PAPs are high quality protein sources. Their re-introduction into European aquafeeds will facilitate the formulation of high proteins fish feeds, since their availability is better than fishmeal. This will also help the strive towards more sustainable aquaculture. PAPs contain a lot of interesting nutrients and are a better alternative to replace fishmeal than vegetable protein sources. â– More Information: Website: www.sonac.biz 1CreveTec, eric@crevetec.be 2Sonac BV, geertvandervelden@sonac.biz