“We wanted to develop a high health-status herd in the U.S. so we could export their genetics anywhere in the world.”
‘Climate-smart cows’ could yield plenty more milk in Africa
Milk is an important source of protein for millions of people in Africa and it will be especially so in the face of a changing climate, which is threatening food security. Yet having far more cows is unsustainable and also bad for the climate.
A solution lies in boosting the milk-producing capacity of climate-resilient native breeds.
A team of animal scientists from the University of Illinois Urbana-Champaign is doing just that for subsistence farmers in Tanzania by creating a new breed of cows that produce up to 20 times the milk produced by indigenous breeds.
By combining the milk-producing prowess of Holsteins and Jerseys with the heat-, drought-, and disease-resistance of indigenous cattle breed known as Gyrs, the scientists are seeking to create cattle capable of producing 10 liters of milk a day, well beyond the half-liter yield of indigenous cattle.
“High-yielding Girolandos (Holstein-Gyr crosses) are common in Brazil, but because of endemic diseases there, those cattle can’t be exported to most other countries,” says Matt Wheeler, a professor at the Department of Animal Sciences in the College of Agricultural, Consumer and Environmental Sciences at Illinois who was an author of a new study.
“We wanted to develop a high health-status herd in the U.S. so we could export their genetics anywhere in the world,” he adds.
Wheeler’s team plans to implant 100 half-blood Holstein-Gyr or Jersey-Gyr embryos into indigenous cattle in two Tanzanian locations. The resulting calves will be inseminated through successive generations to create “pure synthetic” cattle with five-eighths Holstein or Jersey and three-eighths Gyr genetics. Unlike Girolandos, Jersey-Gyr pure synthetics do not yet have an official name, the scientist explain.
“Pure synthetics are worth the time and effort; once the five-eighths/three-eighths genetics are established, they’re locked in. In other words, calves from successive matings will maintain the same genetic ratio,” they write.
“The whole idea is to keep the disease and pest resistance linked together with the milk production so that as you breed, those traits don’t separate,” Wheeler notes. “That’s going to be the challenge in developing countries. Until you get to the pure synthetic generation, there will always be the temptation to breed to the bull down the road, losing the effect.”
To prevent that, the scientists are training local cattle breeders, veterinarians and graduate students to adopt the technology and adhere to it. They are also taking local cultural traditions into account.
“We’ve learned some Maasai clans strongly prefer smaller, red cattle, so the Holstein crosses we made initially, which were large and black, weren’t going to work,” Wheeler says. “I had to start over with Jerseys, which set us back a bit. It will be worth it if they’re better accepted.”
However, some aspects of current local cattle management will still have to change to realize the full potential of the improved genetics of the new breeds. This includes the practice whereby nomadic Maasai herders often graze cattle 25 miles from their enclosures every day, which limits the energy available for milk production.
If it takes hold, the new cattle will bolster food security in Africa and elsewhere in the Global South where climate change is hitting hardest, Wheeler says. But the technogy could work both ways by having heat- and drought-resistant genes from tropical breeds inserted into high-yielding cattle in Central and North America to fortify them against a changing climate.
“These cattle would work very well in Mexico, Texas, New Mexico, and California. Maybe it’s time to start thinking about that now,” Wheeler observes. “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.”
