The effect of diet on the chemical characteristics and rennet coagulation properties of milk from Brown and Friesian cows was examined with three feeding levels (normal, +7 or +14% of INRA requirements) and three forage:concentrate ratios (65:35, 57:43 and 44:56). The experimental period was between the 9th and 20th week of lactation for all the animals. The increase in feeding level led to an increase in milk protein (+0.13 and +0.17%) and casein (+0.09 and +0.15%) and improved the cheesemaking properties of the milk, especially the rate of gel firming. The forage:concentrate ratio did not have any significant effect on milk composition or its cheesemaking properties. An analysis of all the experimental data revealed that the Brown cows produced a milk with a significantly higher content of protein, casein, calcium and phosphorus, with positive effects on the cheesemaking quality and particularly on the gel firmness.
