Sixteen Holstein cows ranging from 50 to
120 d postpartum at the beginning of the
experiment were used in a 4 X 4 Latin square
design (four replicates). Two replicates were
conducted with cows fitted with permanent
ruminal fistulae. Each period of the Latin
square consisted of 16 d for cows to adapt to
the dietary treatments followed by a 5-d
collection of experimental data.
Treatments were: 1) control, 2) control plus
1.4% H-white calcium carbonate (Calcium
Carbonate Company, Quincy, IL), 3) control
plus 1.4% reagent grade calcium carbonate