Whey Utilization in Animal Feeding: A Summary and Evaluation1,2

Abstract

Whey is a highly nutritious by product of the cheese industry which can be utilized well when fed to animals in a variety of forms such as liquid whey, condensed whey, dried whey, or as dried whey products. Ruminants can consume up to 30% of their dry-matter intake as liquid whey without impaired performance while swine may experience diarrhea when more than 20% of their dry matter is liquid whey. Fermented, ammoniated condensed whey is an acceptable liquid protein supplement for ruminants. Small amounts of dried whey or partially delactosed whey in nonruminant rations often increase weight gains, feed efficiency, protein digestibility, and fat digestibility, as well as mineral absorption and retention. Including 10% or more dried whey or partially delactosed whey in high concentrate rations of lactating cows usually prevents most of the milk fat depression experienced with such rations without reducing concentrate consumption. Rumen butyrate usually is increased when rations contain whey or whey products. Adding whey to grass and legume silages improved the silage quality and digestibility, and ammonia nitrogen concentrations were reduced in silage when whey was added to urea-treated corn silage. Growth rates have been favorable when calves were fed milk replacers containing up to 89% dried whey. Human foods should command first priority for whey protein concentrates because of the high quality protein although some use in animal feeds may be anticipated. Limited research indicates that deproteinized whey is an acceptable animal feed providing an acceptable source of lactose and minerals.