 Average lactation yield for 534 Reyna cows with 1,750 lactation was 1,319 kg with large variations between herds and time periods.Test-day records on milk yield and fat and protein contents were collected monthly during one year for three Reyna herds and two herds with crossbred cows.Commercial dairy breed crosses had the highest production, and Reyna the lowest, but large differences were noted in management between the herds.