Using PAP Scores
Using PAP Scores to help choose your seed stock replacements
What cattle are at risk?
Any cattle above 6,000 feet but it has even been known to cause problems in feed yards as low as 3,000 ft. Cattle grazing around 9,000 and above are at high risk.
What is a valid PAP test? This is a test that is performed according to specific parameters created through the study of the disease and its relationship to the pressure in the pulmonary artery. When the tests are done and these parameters are not meant the results may not be valid. In other words the score and results are not reliable.
What are the parameters for a valid test?
The test must be done on cattle at 6500 feet or above in elevation. The cattle must be acclimated to this elevation for at least 3-6 weeks. 6 weeks is best especially if the cattle are coming from lower elevations. Some literature has cited the use of 5000 feet and only 3 weeks of acclimation. The higher the elevation and the longer the acclimation the more accurate the test. So if the cattle are brought from low elevation to 5000 feet are only there for 3 weeks before testing and are only about 12 months old the test will not be as accurate as older cattle at higher elevations for a longer time. Freezing temperatures also adversely affect the results.
What test score should we be looking for?
Test score of 35 and less are considered excellent for cattle of any age. Test scores less than 41 are acceptable but yearling should measure less than that. Scores of 41-45 is acceptable only for animals more than 16 months old and well acclimated. A score from 45-48 should only be accepted in older animals that have been at higher altitudes for a long time and show not problem with high altitude disease. Any score 49 and above is not acceptable and would be considered high risk.
What recommendations would you use for purchasing yearling heifers and bulls?
- Never buy a bull or heifer with a PAP score over 41
- Use caution when purchasing bulls with PAP scores from 36 to 40.
- Risks increases the younger the bull, the lower the altitude when tested, the less time for acclimation, and the higher the number.
- The higher the altitude your cattle will be grazing the higher the risk.
- Retest before breeding in any questionable or higher risk cattle.
- Remember that cattle should be at least 16 months old to be a very reliable test. There is already one strike against young cattle with a questionable score.
- Higher numbers can be used for older cattle, better acclimated cattle, cattle tested at higher elevations, cattle grazing at lower elevations.
As I have looked through several papers on this subject it was quickly apparent that on the surface it appeared like different parameters could be used for a cut off on what we could accept. At times it seemed a bit confusing. When I started to organize the information and we understand that we are looking at risks it becomes quite apparent that we have to take several parameters into consideration. Understand that at 4,999 feet all cattle have no risks and then when they take a couple more steps up a hill they all of the sudden start falling over dead. Evaluation must be made on altitude of cattle, age and acclimation time, and then the score its self.
See chart below:
- The higher the altitude the higher the risk
- The higher the PAP score the higher the risk
- The younger the animal the higher the risk of an accurate test
- The less time used for acclimation the higher the risk for an accurate test.