Cash dairy prices were mostly down Thursday at the Chicago Mercantile Exchange. Dry whey was down $0.01 to $0.69. One sale was reported at that price. Forty-pound cheese blocks were unchanged at $1.67. Five sales were recorded ranging from $1.6675 to $1.68. Cheese barrels were up $0.0025 $1.63. No sales were recorded. Butter was down $0.03 to $1.51. Sixteen sales were reported ranging from $1.50 to $1.51. Nonfat dry milk was down $0.01 to $1.40. Nine sales were reported ranging from $1.40 to $1…