Land animal proteins are a sustainable source of nutrients for animal feed, including aquatic feeds. They have favorable amino acid profiles and digestibility is good to high, depending on the type of ingredient. Some of the land animal proteins can bring functionality on top of their nutritional value. This can be techno-functional properties - like pellet binding, and bio-functional properties that improve the immunity and health of the fed animals.
The presented study focusses on Spray-dried Plasma (Proglobulin), this is a high quality protein derived from blood. The relatively mild drying processes that are used during production preserve the functionality of the proteins present in plasma and is critical to maintain the studied additive effects of these components.
A study was performed to elaborate the positive effect of Proglobulin in relation to the high level of immunoglobulins and other immune mediators contained in the Proglobulin. The immunoglobulins bind bacteria and viruses. They subsequently cannot invest the gut wall. As a consequence intestinal villi stay longer, and less energy is needed for inflammation processes in the gut wall.
Because IgG is a heat sensitive molecule additional assessment were done to determine the effect of heat on the functionality of the immunoglobulins. Therefore feeds were tested with Proglobulin either mixed together with the other ingredients (and undergoing the heat treatment of the pelleting process) or Proglobulin added after pelleting at low temperature through coating.
The presented experiment consisted of a control without plasma included in the diet. And 4 groups with plasma included in the diet; for 3 weeks or 6 weeks and added during mixing or after pelleting.
The results show an effect of Proglobulin on the performance in shrimp and the effect on the gut wall. After 6 weeks the performance in the groups on Proglobulin were improved and intestinal villi were longer. No difference was found in the way the Progobulin was included in the diets. This shows that both ways of production preserve the functionality of the Proglobulin.
No difference in survival was between the groups.
It is concluded that Proglobulin is an excellent example of an functional land animal protein that can improve quality of shrimp feed. Results are in line with result in other aquatic species.