Breed Improvement
Performance Data is still King Jeff Hyatt – CSA Breed Development Coordinator
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he bull sales for 2014 are wrapping up, the dust has settled and you have a new herd sire or two. Much work was put into finding which young bull was going to compliment and benefit your herd; it’s not a decision to be made lightly. A part of this decision was made using numbers, whether those were birth weight, scrotal circumference, adjusted weaning weight/yearling weight or EPDs. This information was collected and submitted to the CSA so breeders and commercial producers alike could make informed decisions. As the CSA implements genetically enhanced EPDs in the Fall 2014 Genetic Evaluation, I’ve heard the question regularly, “If I genetically test an animal, do I still have to measure and submit performance data?” The answer is YES. Performance data is more important than ever. When making predictions with genetic tests, there has to be high accuracy animals used to make the predictions with and to validate against. Basically, if we have performance data on a lot of progeny from a sire or dam, we can use that data to find out what their genetic potential is, such as a high weaning weight or a low birthweight. Once we know the genetic potential with the data, we can use this information to predict what DNA markers effect what traits and by how much. The more animals with performance data, the better the prediction is. Since genetic testing is a new technology, especially in beef cattle, we don’t know all of the markers that affect the genetic potential so the more performance data the more we can discover markers that effect traits. Aside from genetic testing, it is very important to submit performance data on all of your calves. The reason being that when EPDs are calculated,other herds using the same or related sires to yours submit data and this data is used to nullify the environmental effects of your ranch/ farm. If you were to take the genetic potential from every
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progeny a sire ever had, and there were enough, the average of that genetic potential would be the same as the genetic potential of the sire (a sire’s genetic potential for BW is +3.9, the progeny average would be +3.9 given enough progeny). For example, herd (MNO Cattle Co.) consistently has weaning weights that are 30 lbs. higher than XYZ Livestock with a similar breeding program but lives in the next province. MNO Cattle Co. submits performance data on all their calves, but XYZ Livestock submits data only on the calves they are going to register (50% in this situation). To take the environmental effect (±30 lbs. weaning weight) out of the performance data, the range of performance of the sire group would be compared between the two herds. The highest weaning weight animals from each herd would be provided similar EPDs for the sire portion and the same thing would happen for the lowest weaning weight animals. Since MNO Cattle Co. submitted performance data for all calves, the lowest weaning weight animal is truly the smallest animal at weaning. However since XYZ Livestock only submitted data on their registered animals the lowest weaning weight animal likely isn’t the smallest of all their calves at weaning; since this is all the data that the genetic evaluation has to go on, their smallest calf with data is provided a similar ww EPD as MNO Cattle Co.’s smallest calf. In figure 1 there is a comparison of what would happen if XYZ were to only submit data on their registered animals and what would happen if they were to submit data on all of their calves. For this example the sire that both breeders are using is wELL HOUSE KESTREL who has a weaning weight that is at the current breed average (+66.5). For this example, all of his calves’ genetic potential fall between 25% and 75% and that calves are selected solely on their weaning weight.