Instructions
Locate the bull's EPD numbers below the pedigree listings in the breeder's literature or web site. Headings will read: BW, YW, WW, SC, MILK, TM and YG. Next to each heading will stand a separate column under the abbreviation of Acc.
Check the statistics under BW. These initials refer to birth weight. The numbers are expressed in either negative or positive terms. The industry average is set at zero, so the numbers in the column reflect how much higher or lower, relative to the average in pounds, a calf sired by the bull is expected to weigh at birth.
Move to the WW column, which stands for weaning weight. This is the stage at which a calf will begin feeding on adult forage and reduce the percentage of mother's milk in its diet. These figures are formatted as before, as pound comparisons to the established average.
Study the numbers in the YW column. Yearling weight is taken at one year of age or during the second year of life. Like the other weight comparisons, it is listed as higher or lower in relation to the average yearling weight determined by the breeding industry.
Examine the information in the SC column. These figures are measured in centimeters, reflecting the anticipated scrotal circumference of a bull's offspring compared to the breed's average.
Continue on to the MILK column, which reflects the expected ability of the bull's female offspring to feed her calves sufficiently prior to weaning. Therefore, a positive number in the column will represent a higher number of calf pounds gained from its mother's milk than is average.
Shift to the TM column to discover relative performance in the Total Maternal category. Here is where weaning weights of the calves of a bull's female progeny are compared to the average determination. It gives an indication of the cow's milking performance and at what size her calves will be weaned.
Check the YG column for comparative numbers reflecting expected weight gain of a bull's offspring from weaning to one year of age. Though weaning periods differ, EPD summaries fix weaning at 205 days old.
Study the figures under the Acc. Headings next to each EPD column. These are levels of accuracy to which you can ascribe the corresponding EPD measurements. The highest rating is 1.0, meaning that the EPD is virtually certain not to change. Lower ratings, which will bottom at zero, reflect less certainty concerning the permanence of a given EPD comparison.
How to Read Bull Weight & Description
When evaluating a bull for breeding, a prospective buyer must keep intention and purpose in mind. Bulls are bought and sold for beef, for rodeo or further breeding. Each of those final destinations has specific requirements for bulls. A stock contractor, for example, will want to produce animals that can rack up impressive statistics in bull rides. Meanwhile, a beef cattle rancher will seek bulls that have the genetic capacity to gain impressive poundage. For each of these parties, the Expected Progeny Difference -- a calculated prediction of weight and performance -- is necessary to make the appropriate investment. Knowing how to interpret this descriptive information is essential for selecting a quality bovine.