Within each dairy, cows were allocated
alternately to breeding pens upon leaving the fresh pen
(approximately 10 ± 5 d postpartum). Pens (n = 4 to
5 pens/dairy) were randomized to treatment (n = 2 to
3 pens/treatment per dairy). Pen (CON, n = 6; FLX,
n = 7) was considered the experimental unit and data
were analyzed as a split plot with pen as the whole-plot
error term