Changes in the nitrogenous components of gamma‐irradiated and inoculated ensiled ryegrass

A study was made of the role of plant and microbial enzymes in the major nitrogenous changes during ensilage. Perennial ryegrass was ensiled directly, after gamma‐irradiation, and after inoculation of the sterile grass with homofermentative lactobacilli. Plant enzymes mainly were responsible for proteolysis, whereas amino acid metabolism was the result of microbial activity. Inoculation reduced proteolysis: this was considered to be a result of rapid acidification. Lactobacillus plantarum and Streptococcus faecalis were shown to be non‐proteolytic species with a limited ability to catabolise amino acids. Substantial quantities of water‐soluble carbohydrates were made available during ensilage.