Spray Dried Plasma Increases Protein and Meat Inclusion in Extruded Dog Kibbles

Abstract A common goal for pet food manufacturers extruding dry kibbles is to increase meat inclusion and protein content in both grain and grain free formulas. When extruding high meat formulas, variation of moisture and fat of the incoming raw meat ingredients adds to the complexity of producing consistent quality kibbles meeting all specifications. Spray dried plasma (SDP) is a consistent high protein ingredient commonly utilized in wet pet food for water binding and fat emulsification characteristics and in dry kibble extrusion with meat meals and other dry ingredients to produce quality kibbles. Thus, the objective of two studies was to evaluate if meat inclusion levels could be increased in extruded formulas with the use of SDP. Tests were done at the Wenger technology testing center to evaluate combinations of SDP levels ranging from 2.5 to 20% with meat level feed rates ranging from 25 to 50%. The ability to produce kibbles was conducted utilizing both grain free and grain formulations. Processing conditions were monitored on the various formulations during production along with kibble outcome measurements such as ability to extrude, solids, protein, and durability. In the first study, extrusion of grain free formulations with 0% SDP resulted in meat inclusion limit at 35% feed rate. Addition of 5, 10, and 15% SDP in grain free formulas increased protein content of the extruded kibble but meat inclusion was limited at 35% feed rate. However, use of 20% SDP in grain free formulas allowed for greater inclusion of meat from 35% and up to 45% feed rate while maintaining kibble quality and increasing protein. Extrusion of a grain formulation with 0% SDP also resulted in limits of 35% feed rate of meat inclusion. Addition of 2.5, 5, 10, or 20% SDP to grain formulations allowed for meat inclusion feed rate to be increased up to 50% depending on levels of SDP used, and protein was increased in all combinations. The second study was completed to evaluate a longer run extrusion measuring ability to extrude, cook, and durability. Grain free formulas were run at 35% feed rate of meat with 5, 10, or 20% SDP and maintained cook and durability. Grain formulas were run at 45% feed rate of meat with 2.5, 5, and 10% SDP and maintained durability with further optimization of cook needed. Overall, SDP included in the formulation allows for greater feed rate of meat inclusion and maintain or increase protein and durability in the dry kibble. Thus, depending on target meat inclusion feed rates or protein levels, SDP may be used during the extrusion process to produce dry kibbles with high meat inclusion.