Monday, April 6, 2015

Let's Raise Our Bull Calves

We have a good market, price is good, costs look reasonable, let's do it!

At the beginning the bull calves gained well and brought a good price.

Then, we noticed that our treatment rate for pneumonia in the calf/heifer barn seemed high. The treatment records showed that our impression was correct. Our vet commented on the ammonia odor in the barn when he was there checking out several calves with pneumonia.

Oh, by the way, did you remember that when you double the number of calves in the same space (sometimes called overcrowding) they produce twice as much feces and urine?

This automatic-feeder operation was working well before adding the bull calves. Calves step up to 12L a day and the ten days before weaning they start decreasing one liter daily until weaned. With heifers only there was about 30 square feet of resting space per calf. Pneumonia treatment rates were elevated a little -probably some improvement in ventilation would have been desirable even before the bull raising began.

Then, the number of calves doubled. Ammonia concentration went up. Overcrowding stress increased - space per calf went from about 30 square feet per animal down to barely 15 square feet. Whole-pen treatment for pneumonia began when fall weather arrived. 

Solution to the pneumonia problem?

1. Stop raising bull calves - cut pen population in half. 
2. Install positive pressure ventilation tubes to increase rates of air exchange.

Current pneumonia treatment rate is well under ten percent and no whole-pen treatment has been needed.

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