Three Times Daily Milking of Cows in California Dairy Herds

Twenty-eight California Holstein dairy herds were on twice daily milking for 3 to 17 mo and for 36 mo on three times daily milking. Effect of three times daily milking on yields of milk, fat-corrected milk, fat, and solids-not-fat, udder health, and reproductive performance was evaluated using Dairy Herd Improvement monthly herd summaries. Data for all cows in the herd and for first lactation cows were analyzed separately. Milk yield for the entire herd increased 12% above previous production on twice daily milking. Fat and solids-not-fat percentages were not affected by three times daily milking. First lactation cows milked three times daily yielded 14% more milk over previous twice daily levels. Fat percent was lower for first lactation cows on three time milking, but solids-not-fat percent did not change. Response to three time milking was not related to herd size or production while on twice daily milking. Udder health, evaluated by California Mastitis Test scores, and reproductive indexes were not affected by milking frequency.