Whey Disposal: Recovery of Nutrients for Animal Feeding

Abstract

It has been estimated that over 50% of whey production world wide constitutes a pollution problem to the environment. A proportion of the work carried out to make use of whey nutrients has not been commercially viable. A simple process has been developed, at the laboratory and pilot plant scales, resulting in a complete recovery of nutrients from whole whey or whey fractions for animal feeding and no further waste or effluent is generated. The economics of the proposed process rely on efficient use of inexpensive ingredients (or waste materials, from other agricultural sources) to overcome the high cost of dewatering and drying. Using this approach a number of products are possible. In the first product bentonite is used to precipitate whey protein which can be processed into a dry protein concentrate for use in intensive animal, poultry or fish production. This product compares favourably with conventional protein supplements such as meat and bone, soybean, or fish meal. The deproteinised whey, (mainly lactose and minerals) arising from this process, is concentrated and mixed with a carrier to produce a second product for ruminants that can compete with hay or grains. Further, whole whey may be used in a similar process. Animal feeding trials with sheep and dairy cattle have demonstrated advantages of the developed whey products over conventional feed supplements for wool growth, live sheep export or milk production.