Here’s a Fairy Godmother story to go with the irate genie story I used in my August column.

A beautiful fairy transforms the male cat of an aging spinster into a handsome prince. The prince’s first words are, "Now, aren’t you sorry you had me castrated?"

There could be an analogy here involving you and your new high-EPD herd bull. Your bull’s first calf crop weans with good weights but bombs out on the rail-light carcasses, small ribeyes. You "cut" the bull. Will you live to regret your action?

Most of you have learned to trust EPDs in making herd bull selections. The principle is simple. You compare the EPDs of two or more bulls and select the one with the highest values. You may also consider phenotypic values-frame size, muscularity, length, etc. But do these EPDs really mean success down the road?

I am looking at a situation like this in a commercial herd on the Southern Plains with which I work. A yearling bull was acquired in mid-season 1996 to replace an injured bull cleaning up in a breeding group in which all eligible cows had been artificially inseminated. The adjusted weaning weights of the bull’s 1997 calves were phenomenal, but they were the late-end and barely within the time window for calculating adjusted weights. One steer of the group was sent to the feedyard as part of a 10-head group on which carcass data was collected. This steer finished above the group average for hot carcass weight and ribeye area in spite of his age handicap. Was the new bull this good?

The new bull worked the 1997 season under regular conditions-cleaning up in a breeding group in which all eligible cows had been artificially inseminated. The adjusted weaning weights of the bull’s 1998 calves were not phenomenal but equaled those of a heavily used AI sire, which was a high-ranking bull in the breed. Eleven steers from this crop were sent to the feedyard for performance and carcass evaluation. Despite a promising start, these steers had a very discouraging closeout-carcass weights and ribeye areas both went "south." Was the new bull this bad?

It could have been an easy decision to "cut" this bull and go on with another good prospect. But, for several reasons, the bull was retained and used again. For example, the carcass data was not received until a late date, leaving little time to go into the market for another selection. The weight and ribeye data were sufficiently different from historical herd data as to provide cause for doubt. The ribeye data was collected by ultrasound, which by itself doesn’t make the data bad. But again, the difference from prior measurements made one or the other data set doubtful.

The fact that the bull in question was sired by a bull with exceptional growth and ribeye EPDs was also a consideration. The bull’s dam’s EPDs for growth are also strong. And the fact that the adjusted weaning weights of the bull equaled those of the AI sire also was considered.

It goes without saying that you as a producer are pretty much on your own as a decision-maker when the progeny of a good bull produces bad data. If you were running a bull stud you’d probably cross any bull with bad progeny data off your list after the first year. But it is different in the field, particularly if you’re operating a one-bull, two-bull or three-bull herd. It is not an easy call when the problem may be anything from poor performance records to genetic variation. After all, it would be hard to take if the current progeny of your deposed bull turned out well. Like the spinster and her cat, it would be tough to face your ex-bull and be asked, "Now aren’t you sorry you had me castrated?"

To contact Fred Knop, write Drovers or send e-mail to: