Preservation of grass juice and wet leaf protein concentrate for animal feeds

Authors

• Matti Näsi Department of Animal Husbandry, University of Helsinki, SF-00710 Helsinki 71

DOI: https://doi.org/10.23986/afsci.72142

Abstract

Formic acid, mixtures of acids (AIV 1, AIV 2) and formalin-acid mixtures (Viher solution, Viher acid) were tested as preservatives of juice and wet leaf protein concentrate (LPC) obtained from grass, clover and pea. The main criteria used in judging the success of preservation were changes in the protein fraction, fermentation of sugars, and losses of dry matter and true protein during storage. Fermentation of sugars and moulding could be inhibited in plant juices by adding 0.5 % v/w preservative, but proteolysis continued and true protein was degraded in unheated juices. Ensiling losses of pea juice were considerable, 4.0-15.6 % of DM, in all treatments. For wet leaf protein concentrate precipitated by steaming (85°C), good preservation could be obtained with the additives used in silage making applied at a level of 1 % v/w. In these treatments protein breakdown was minimal, because heating eliminated proteolytic enzymes and partly sterilized the LPC product.