Automated Milk Feeders for Preweaned Dairy Calves in the Upper Midwest United States

Most dairy farms in the United States house preweaned calves individually. However, the use of automated milk feeders for raising preweaned calves in groups is growing in popularity as dairy producers want more flexible labor management and consumers want animals to have a more natural life. We conducted an 18-mo cross-sectional longitudinal study on 38 farms with automated feeders in Minnesota, Wisconsin and NW Iowa to learn about best management practices for achieving good calf health when using these systems. Calf health was assessed by using a modified health scoring system (S. McGuirk, University of Wisconsin) along with analysis of health treatment and mortality rates based on farm records (from a subset of 26 farms). A total of 10,185 calves were scored for health by a single observer on all 38 farms. Our statistical analysis indicated that the following factors were associated (P < 0.05) with the successful use of automated feeder systems indicated by better calf health scores or lower mortality/or treatment rate on those farms: reduced time to reach peak milk allowance (minimum peak allowance suggested is 8 L/day); feeding milk/milk replacer with low bacterial count (SPC less than 100,000 CFU/ml); use of positive pressure ventilation tubes in the calf barn; sufficient amount of space per calf in the resting area (minimum suggested is 3.7 m²); small number of calves per group (suggested less than 15 calves); adequate farm average serum total protein concentration (an indicator of passive immune transfer); use of drinking speed as a warning signal to identify potentially sick calves; practicing navel and pen disinfection between calf groups consistently; and having narrow age range within calf groups. We also observed that winter was the season with worst health scores and highest treatment rates. Cleaning of the automated feeder and its various components seems to be one of the most important keys to making these systems work successfully. Feeding calves in groups allows calves to express natural behaviors that cannot be expressed when housed individually, but can present a challenge in relation to maintaining good health, another important aspect of good animal welfare. Our research indicated that good calf health is achievable when using automated milk feeders to raise preweaned calves in groups as long as appropriate management practices and maintenance of the feeding equipment are emphasized and implemented. This project was funded by USDA-AFRI-NIFA competitive grant no. 2012-67021-19280.