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Health of Dairy Calves When Using Automated Feeders in the Midwest USA
Research is limited regarding best housing and management practices for automated calf feeding systems, particularly in terms of how these factors influence animal health and welfare. This ongoing study is characterizing health scores, morbidity and mortality of group-housed calves in US farms and relating these to housing and management practices. Thirty-eight dairy farms in the Midwest USA were visited every 60 days. During each visit, calves (n=7779) were scored for health using four categories: attitude (0-4); ears (0-4); nose (0-3); eyes (0-3); and cleanliness (an indicator of diarrhea, 0-2), with 0 representing a normal, healthy calf. In addition, blood was drawn from any calves 1-5 days old (n=711) and serum protein concentration was used to assess passive immunity transfer. During each season, milk samples were collected from the mixing container inside the feeder and the tube leading to the nipple for measurement of standard plate count (SPC) and coliform count. Pearson’s correlation coefficient was used to analyze the relationship between mean SPC and health scores. There was a large variation between farms in calf health. On the 10 farms with the best health scores, a mean of 9.7% (range of 2.9–12.9) of animals displayed abnormal scores for attitude, 3.7% (1.7-5.1) for ears, 12.2% (7.8-14.8) for nose, 7.2% (2.0-11.9) for eyes, and 26.4% (20.1-32.6) for cleanliness. On the 10 farms with the worst health scores, a mean of 22.8% (15.7-30.3) of animals displayed abnormal scores for attitude, 14.4% (10.0-22.5) for ears, 27.2% (22.8-30.6) for nose, 30.3% (22.5-36.4) for eyes, and 54.9% (50.6-60.3) for cleanliness. Mean serum protein across all samples was 5.40 ± 0.74 mg/dl. Mean serum protein by farm was 5.34 mg/dl (minimum=4.27, maximum=6.5). The highest overall bacterial counts were recorded in feeder tube samples (median, coliform=2,550 CFU/ml; SPC=330,000 CFU/ml; Q3=3,350,000). No relationship was observed between tube SPC and attitude, ears, nose, or eyes scores; however, SPC was correlated with calf cleanliness scores (r = 0.26, P = 0.002). The variation in health scores among farms shows that welfare in automated feeder systems can be improved. In addition, results indicate that the cleanliness of automated feeder equipment may influence calf health; however, further data collection and analyses of calf morbidity and mortality should provide a more complete understanding of risk factors.
This project is supported by Agriculture and Food Research Initiative competitive grant no. 2012-67021-19280 from the USDA National Institute of Food and Agriculture.
Keywords: calf health, automated calf feeders