Afzalzadeh, A.; Rafiee, H.; Khadem, A.; Asadi, A. Effects of Ratios of Non-Fibre Carbohydrates to Rumen Degradable Protein in Diets of Holstein Cows: 1. Feed Intake, Digestibility and Milk Production. SA J. An. Sci. 2010, 40, 204-212.