In the October edition of Beef Producer you'll find an article about the value of blending African beef genetics into the U.S. beef herd.
It was a fairly short article for such a complex topic, and the longer explanation can be downloaded below.
Basically, the Zimbabwean rancher and consultant said on his tour of the U.S. in 2013 he had never as many heat-stressed cattle.
He wrote that he thinks there are several things contributing to heat stress in U.S. cattle, including:
• Extremes between winter and summer temperatures.
• High summer humidity in the Midwest and Southeast.
• Predominance of European breeds.
• The photoperiodic effect which should be a mitigating factor by encouraging sleek summer coats, seems to have the opposite effect due to long summer days. Animals have difficulty cooling down at night.
Zietsman added that the conventional composites such as the Bonsmara, Beefmaster, Brangus, Braford, Simbra and Droughtmaster may be adapted to heat, but they fall far short when it comes to adaptation to conditions of poor nutrition, parasites and disease.
Then he said the African breeds, both Sanga and Zebu types, have those added advantages and more.
He said they have strong herd instinct and "an affinity for man," and they have extremely good meat quality.
Although the numbers of available African cattle in the U.S. are limited, Zietsman said the use of artificial insemination can expedite their use for those who want to create better-adapted composite breeds.
Zietsman says the improvement in what he calls "inherent body condition," which is a trait many U.S. beef producers would describe as the "easy keepers" in their herds, is dramatically important to improve true efficiency on forage, a trait that was once prized here but now is largely lost.
Further, he said, the exceptionally high meat-to-bone ratio of the African cattle can be used to compliment that condition which is generally lacking in American breeds.