Leachman Cattle of Colorado is committed to helping ranchers reduce the losses from brisket disease. We know from our own cowherds that losing calves to brisket at any time from birth through yearling stage can have significant financial cost. We are convinced that pulmonary artery pressure (PAP) scores are very strong predictors of whether or not animals will have the disease. For this reason, we have collected over 3,515 PAP scores on cattle in our program. Unfortunately, taking measurements will not solve the problem. Most ranchers know that buying PAP tested bulls reduces the problems with brisket, but most still report losing 3% - 8% of their calves to brisket depending on the year. This level of calf loss is still unacceptable! We believe that the best strategy to reduce brisket disease is to use expected progeny differences (EPDs) for PAP. Think of selecting for low birth weight. Just buying bulls under 80 pounds would help calving ease, but using low birth weight EPD bulls is a much more effective strategy. This is true, because an EPD takes into account much more information. For example, buying a 75 lb. BW bull out of a sire that generally sires very heavy calves is far less likely to be easy calving than is a similar BW bull out of a sire that generally sires light calves. The same is the case with PAP. Our PAP EPD closely relates to the actual PAP score of the bulls as shown in the graph below. The correlation between the PAP scores and the PAP EPDs are 80%. This is typical in a trait like PAP that is 30% heritable. However, as with all EPDs, you can see that some bulls score better or worse on the EPDs than on the actual score. Ranchers concerned with PAP scores should use the EPDs – not the actual PAP scores. It is clear to us that sires with PAP EPD’s over +3 have tremendous death loss on their calves. Sires with +1 or less on PAP EPD are typically considered sires that are “good at altitude.” The sixty-six sale bulls that are under -0.7 on PAP should be used to dramatically reduce brisket disease in herds that suffer from significant high altitude disease problems.
Key points to regarding PAP and PAP EPDs: • We have taken 3,515
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Leachman PAP Score vs PAP EPD 90
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PAP Score
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PAP scores (all by Dr. Tim Holt). PAP is 30% heritable. The PAP EPDs reported were calculated by Colorado State University. Selecting bulls using the PAP EPD is FAR more accurate than simply using the PAP scores. Herds that have significant brisket disease should use the lowest PAP EPD bulls.
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Score = (5.5 x EPD) + 43 R² = 0.80
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Dr. Tim Holt PAP Testing.
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PAP EPD
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ALTITUDE APPROVED
High Altitude Ranchers– Use sires marked with this logo with confidence!