Friday, March 30, 2018

When to Introduce Calves into Automatic Feeder Pens?

If one wishes to reduce the treatment rate for bovine respirator disease (BRD) among neonatal calves that will be group housed for automatic feeders when should the calves be introduced to the autofeeder/group pens? 5 days, 7, 9, 11, 13 days old?

The evidence seems to be inconsistent and somewhat confusing. One study will show earlier will result in lower BRD rates while another will show later has the same outcome.

A recent study seems to point at another factor tied to BRD rates. That is, when calves receive the same amount of milk (between 6 and 8 liters per day) in  the first two weeks of life the rate of BRD does not seems to differ regardless of when the calves are moved from individual to auto feeder group pens.

This evidence points at reduced milk intake at the key factor in higher BRD rates among neonatal calves. Often calves being held in individual pens before moving into the auto feeder group pens are only fed limited (usually 4 liters per day) milk. The longer calves live on a restricted ration the higher the chances of being diagnosed and treated for BRD. 

Thus, the authors conclude,
"Therefore, we suggest that if introduction to the group (that means to the automatic feeder) is going to be delayed, calves should have access to high milk allowances immediately after colostrum feeding." (p2306)

I might add from my experience trying to bring neonatal calves up on milk that the passive immunity of the calves seemed to make a big difference in my success. Calves that had plenty of clean good quality colostrum soon after birth drank like there was no tomorrow. The calves that missed out on colostrum (I bled calves at 48 hours for blood serum total protein testing - ones that tested 3.5 - 4.5 on a clinical refractometer I called "missed out") took what seemed for ever to come up on milk. And, these calves with poor colostrum management were much more likely to have scours, too.

Reference: Medrano-Galarza, Catalina and Others, " Associations between management practices and within-pen prevalence of calf diarrhea and respiratory disease on dairy farms using automatic milk feeders." Journal of Dairy Science, 101:2293-2308. April, 2018.

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