Thirty-two multiparous mid-lactation Holstein cows (between
110 and 160 days postpartum) were blocked into eight groups
according to milk production and assigned to one of four
treatments being: (C) Control group, eight cows cooled before
milking, which was twice a day (0500 and 1700 h); (AM) eight
cows cooled at 1100 h and before milking; (PM) eight cows
cooled at 2300 h and beforemilking; and (AM+PM) eight cows
cooled at 1100 and 2300 h, as well as before milking. Cooling
periods were 60 min long, except before milking which was
30 min, so that the total cooling time dailywas 1 h for the control
group, 2 h for groupsAMandPM, and 3 h for theAM+PMgroup.