Novel coproducts from corn milling and their use in ruminants' nutrition

Abstract

The article reviews published data on two novel coproducts originating from corn milling: high-protein distillers grain(HPDG) and reduced-fat distillers grain (RFDG). Based on a literature survey over the last decade, this article focuses on their chemicalcomposition and, consequently, nutritive value and on the efects of their inclusion in ruminants diets on rumen activity and animalperformance. Compared to the classic distillers grains, the two new coproducts expressed lower variability of their chemical composition,nutritive value, and specifc feeding characteristics, allowing more targeted feeding strategies (protein balancing, avoidance of milk fatdepression, etc.). Tus, HPDG has signifcantly higher crude protein content (~44%), lower fat content (~4.3%), and lower fbre content(~26.8% neutral detergent fbre (NDF) and ~12.3% acid detergent fbre (ADF)) compared to the classical distillers grains. In the case ofRFDG, only the fat content is signifcantly lower (~4.8%), whereas the crude protein content (~32.1%) and the fbre content (~36.1%NDF and ~14.7% ADF) are only slightly lower compared to the classical distillers grains. On this basis, HPDG can successfully replaceclassic high-protein meals, such as soybean meal, thus providing high levels of rumen undegradable protein, although it has the sameamino acid limitations as the originating raw material, corn grains. Te use of RFDG instead of the classical distillers grains allowsmuch higher dietary inclusion, without adverse efects on rumen metabolism and animal performances. A further development of thetwo coproducts and further diversifcation of corn coproducts, allowing better solutions to various feeding situations, is expected.