Effect of dietary supplementation with methionine on cheese-making properties.

The present research is part of a larger project aimed to investigate the effects of diets low in protein, devoid of soybean and supplemented with industrially-produced amino acids on milk production and cheese-making properties. These objectives aim, through an increased utilization of alfalfa, to reduce environmental pollution and to eliminate soybean, often GM, from the diets of animals used in the dairy production. Providing that an intake of raw protein equal to 16 % (dry weight) is fair to meet the protein requirements of milking cows of large size (650-700 kg of weight) producing 30-35 kg/day of high quality milk (NRC, 2001), a reduction of the protein content to 13 % (dry weight) can be viewed as an interesting objective, but may cause problems as to the critical aminoacids in a ruminant species, especially for methionine.