When I read John Maday’s excellent article on crossbreeding (“Breeding basics”) in last month’s Drovers, I was reminded of the 10-column series I wrote on this subject in 2001. I went back to those columns, re-read each and looked for changes that have occurred since they were written — changes in thinking and changes in practices.
Mr. Maday’s article contained an excellent reference to heterosis, a much-underrated factor in breeding. Heterosis involves the release of suppressed production in the straightbred — a nature-provided benefit of great importance. There has always been faith in the old axiom that the scale and weight of a crossbred calf will fall midway between the scale and weight of its sire and dam. But there is a new axiom that heterosis will push these values into the upper part of this range if its parents are of different breeds. Double heterosis is achieved if the dam is a crossbred.
I have always believed that most crossbreeding has been done primarily to increase pounds on the hoof — more to increase carcass size than carcass quality. It was reassuring that Mr. Maday’s sources emphasized both factors, but I suspect that, generally, there probably has not been much change in this goal.
There is still much value in the use of complementarity in breed selection. In the beginning, complementarity was a somewhat crude way of matching a highly muscular breed with a high marbling breed. This led genetic experts to recommend that calves be a 50-50 blend of continental and British breeds. But things have changed.
EPDs, which have helped sort through the breeds and the genetic strains within breeds, are now better than ever. You can now directly compare breeds on stature and carcass characteristics. EPDs can lead you to breeds that excel in muscling and trimness but are also strong in marbling and tenderness. And, EPDs can lead you to marbling breeds that are also strong in muscularity, carcass size and trimness.
The biggest change in crossbreeding since my 2001 series is probably the development of hybrids and composite seedstock. I devoted the last two columns in my 2001 series to this concept, endorsing these cattle as a way of simplifying crossbreeding, especially for small operations (fewer breeding pastures, mainly).
Now, in addition to several excellent breeder programs, three breed associations have registries and performance programs for hybrid cattle. The American Simmental Association promotes SimAngus, a cross of Simmental, Black Angus and Red Angus. The American Gelbvieh Association promotes Balancers, a Gelbvieh and Angus cross. The American Shorthorn Association has launched a program for a new hybrid called Durham Reds, a cross of Shorthorn and Red Angus.
But problems continue on the female side of crossbreeding. The lack of systematic schemes in the early years of this practice fostered many herds with undisciplined breed makeup. You must change this situation if it exists in your herd, and change won’t come easily. You can cull deeply and import females with your choice of breeding. One large operator quoted in Mr. Maday’s article maintains two herds, one to produce hefty terminal cattle and one to produce moderate replacement females. You can also convert your herd by just culling your cows deeply and replacing culls with home-raised heifers. This takes considerable time, as shown in the accompanying chart.
I have had to omit some important information to stay within the word limits of this column. I’ll expand this subject in future columns.
To contact Fred Knop, write Drovers or send e-mail to firstname.lastname@example.org.