A team of researchers is exploring the use of surrogate sires to step up production in goats in a bid to tackle the rising global food and nutrition demand.
Jon Oatley a reproductive biologist at the Center for Reproductive Biology, in Pullman, Washington State University, and team have generated a gene-edited goat, known as surrogate sire, basically a goat that can ‘host’ sperm from a different buck.
He is pairing up with scientists at the International Livestock Research Institute (ILRI) to put the new breeding approach to the test.
In the study, researchers from ILRI and the University of Nairobi are isolating, culturing and storing germ cells from Galla goats for transplanting into the surrogate sires.
Galla goats, which can weigh 70kgs at maturity, are known for milk and meat. The breed is also resistant to parasites and adapts well to the arid and semi-arid climate.
For centuries, farmers selectively breed livestock with an eye for superior traits such as disease resistance and heat tolerance, but modern techniques such as artificial insemination (AI) remain costly and widely unavailable.
“By integrating innovative technologies with conventional farming practices, we can improve the efficiency and resiliency of livestock to generate protein for human consumption,” said Jon Oatley.
This way, we can realistically aim at feeding more with less, that is, less use of land and natural resources; less use of antibiotics and hormones, while also having less impact on the environment, he noted.
A key area of focus for scientific research is the use of genetics to step up livestock breeds, which, in turn, improves their productivity.
At the moment, improved livestock breeding relies on AI, a technique where semen is harvested from a ‘superior’ male, split into lots, frozen in liquid nitrogen and later inseminated into females by specialists.
While AI is a powerful tool for breeding, scarcity of trained personnel and specialist storage equipment limits its use.
Most critically, AI relies on the farmers’ ability to detect the narrow window of time when the females are fertile to fertilize.
Steve Kemp, leader of ILRI’s genetics research programme says “improving the performance of livestock requires the right genetics, in the right place at the right time, which is hard to get done at scale. Surrogate sires can be distributed and left to do what comes naturally and are more efficient at detecting heat than a farmer would be!”
“Small ruminants especially, but also cattle, rely on natural mating because the alternatives are cumbersome and unreliable, but that means that you have little choice about the genetics you use for the next generation, surrogate sire systems change that,” adds Steve Kemp.
Oatley’s team is using a gene editing techniques to eliminate a gene that is specific to male fertility, NONOS2, in the animal embryos so that they do not produce their own sperms, enabling the scientists to effectively turn them into surrogate sires.
The study shows that such males are born sterile but after transplanting stem cells from donor animals into their testes, they start producing sperm containing only genetic material from the donor.
This effectively multiplies each donor’s genetic material, spreading desirable characteristics in livestock herds while eliminating the need for AI.
Prof James Mwangi of the University of Nairobi says, “with time, the African governments will embrace this technology as a way of improving breeds and overcoming challenges of livestock disease that hinder animal productivity and so improve the livelihoods of livestock-dependent communities.”
Globally, the livestock farming plays a key role in providing nutrition for the world’s population, which will be nearly 10 billion people by 2050.