Heat-tolerant hybrid cows may be the Goldilocks of cattle
The Gyr cattle farmed in Tanzania handle the African heat and arid conditions well, but they produce much less milk than less-tolerant Holstein or Jersey cows. Scientists have set about addressing that problem, by creating hybrid cattle that combine both attributes.
First of all, it should be noted that Holstein-Gyr hybrids known as Girolandos have been farmed in Brazil for some time now. Due to the fact that they may carry diseases which are endemic to the region, however, they're typically not exported to other markets.
With that limiting factor in mind, scientists at the University of Illinois Urbana-Champaign set about creating Holstein-Gyr and Jersey-Gyr hybrids of their own.
After five generations of such crosses, they ended up with cattle which are capable of producing up to 10 liters (2.6 US gal) of milk a day under typical Tanzanian farming conditions. By contrast, Gyr cows only produce about half a liter (17 fl oz) per day.
Lead scientist Prof. Matt Wheeler and colleagues now plan on implanting 100 half-blood Holstein-Gyr or Jersey-Gyr embryos into Gyr cattle at two locations in Tanzania.
The resulting calves will in turn be artificially inseminated over successive generations, with the ultimate goal of creating "pure synthetic" cattle with five-eighths Holstein or Jersey and three-eighths Gyr genetics. When either of these hybrids mate with others of their kind, their offspring will maintain that same genetic ratio – in other words, no more crossbreeding will be necessary.
More work still needs to be done, such as educating Tanzanian veterinarians and herdsmen on the unique needs and characteristics of the hybrid cattle. It's even possible that as global warming continues, the cattle may end up on farms in the southern regions of North America.
"These cattle would work very well in Mexico, Texas, New Mexico, and California. Maybe it's time to start thinking about that now," said Wheeler. "People don't usually think that far ahead, but my prediction is that people are going to look back and realize having tropical genetics earlier would have been a good thing."
A paper on the research was recently published in the journal Animal Frontiers.