Monday, November 30, 2015

Finding Sick Calves in Group Housing

How does one find a sick preweaned calf in group housing?

If the pen of calves is fed twice or three times a day, then is seems logical to look for any calf that does not get up at feeding time.

However, what if the calves are being fed with a computer-controlled automatic feeder? There is no special feeding time even though there are hours of the day when feeding is more frequent. Thus, looking for any calf that is lying down when we are in the barn could be a pretty unreliable method of spotting sick calves. 

Recent research observed the behavior of preweaned dairy calves (N=75) in group housing (8 pens). To test for approaching a human the researcher walked calmly to the center of the pen and remained motionless for 60 seconds. To test for approaching an object the researcher walked in the center of the pen and left behind a blue plastic cone (8.5" tall, 5.5" at base). The calf behaviors were video taped for later analysis. An "approach" was defined as taking a step toward the object/human. 

The calves were observed daily by farm staff and weekly by the research team. They recorded all the cases of diarrhea (65% had at least one case of scours) and bovine respiratory disease (59% had at least one episode of treatable pneumonia).

Using both measures of exploratory behavior (that is, approaching either or both the cone or human) they found a positive association between sickness and failing to approach. The same failure to approach was found when calves had a fever (anything equal to or greater than 103F [39.4C]).

Implications for me: In addition to watching for the familiar symptoms of scours and pneumonia (that is, coughing, runny noses, dirty rumps) these finding suggest that lack of exploratory activity (approaching a stationary person or object) might tip us off to a calf running a fever or feeling sick. These are the "need to check" calves. Just one more tool in our health toolbox. 

Reference: Cramer, M.C. and A. L Stanton, "Associations between health status and the probability of approaching a novel object or stationary human in preweaned group-housed dairy calves." Journal of Dairy Science 98:7298-7308. 2015

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