AgResearch scientists have generated transgenic cows with biomedical and agricultural applications. Here, we list potential applications of transgenic cows and describe how a transgenic farm might look in the future.
Transgenic cows at AgResearch
Transgenic cows are genetically modified (GM) cows that have an extra gene or genes inserted in their DNA. For the last 10 years, scientists at AgResearch have been developing techniques to make transgenic cows, and they’ve successfully generated cows that produce transgenic proteins in their milk.
Uses of transgenic cows
There are many potential uses of transgenic cows in biomedicine and agriculture.
Biomedicine
Making therapeutic proteins
Transgenic cows can be used as ‘biofactories’ to produce human therapeutic proteins (proteins that are used to treat diseases).
In June 2006, the first therapeutic protein made in a transgenic animal was approved for use in Europe and the USA. ATryn®, a human antithrombin protein, is made in transgenic goats. The protein prevents blood clots in patients who don’t make their own version of this protein.
At AgResearch, they’ve generated cows that produce human myelin basic protein. Treatment with human myelin basic protein may help reduce the symptoms of multiple sclerosis. See this article for further information: Transgenic cows making therapeutic proteins.
Modelling disease
Transgenic animals can provide animal models of human disease to help researchers find new treatments. Usually, small transgenic animals, such as mice or rats, are used for this type of research.
Making functional foods
Milk composition can be altered to make a functional food. For example, researchers have shown that minor proteins in milk (such as lactoferrin) could protect humans against infection and improve gut health.
Hypo-allergenic milk
In 2012, the AgResearch team published the news that they had bred the first cow in the world to produce milk with reduced amounts of beta-lactoglobulin (BLG). BLG is a milk protein largely responsible for infants’ allergic reactions to cow’s milk.
While the breakthrough was widely celebrated, there was concern that the milk came from a single genetically-engineered dairy calf named Daisy. In 2015, 12 female calves – produced from Daisy’s eggs and placed in surrogate cows – were born. Milk from Daisy’s daughters also showed no detectable levels of BLG. Senior scientist Dr Goetz Laible said that it was important to demonstrate that the changes they had seen in Daisy were stable and that they could be transmitted to the next generation. As of 2017, the milk’s functionality and benefits were still being explored.
Agriculture
Improving food quality or making novel food products
Improving the quantity or quality of the milk or meat from cows may be of value. For example, milk with extra casein requires less processing to make into cheese and will have increased calcium levels. Find out more about casein in this article Transgenic cows making modified milk.
Improving animal health
Transgenic technologies could be used to improve animal health by increasing resistance to diseases. For example, transgenic dairy cows expressing lysostaphin (an antimicrobial) in their milk show greater resistance to the mastitis-causing bacteria S. aureus. Mastitis is a common bacterial infection that can lead to severe health problems in cows.
Environmental sustainability
Farming has a big impact on our environment. Transgenic animals may offer one way of reducing the environmental impact by improving farming efficiencies and reducing pollution. An example is the Enviropig™. These transgenic pigs have an additional gene that helps them digest plant material. This lessens their need for dietary supplements and reduces environmental pollution.
The future of transgenic cows in New Zealand
Transgenic cows are unlikely to replace New Zealand’s dairy herd. They could, however, be used for specific purposes such as generating therapeutic proteins to treat human disease. A small, contained herd of transgenic cows would generate a higher profit due to the value of proteins they can produce, although there would be increased compliance costs for keeping animals in a containment facility.
A herd of transgenic cows
A herd of transgenic cows at the AgResearch animal containment facility at Ruakura in Hamilton.
Transgenic cows are unlikely to replace New Zealand’s dairy herd, but small herds could be used for specific purposes such as generating therapeutic proteins to treat human disease.
Acceptability of transgenic technology
In general, the biomedical applications of transgenic technology are more widely accepted than agricultural applications. However, groups that do not approve of using animals for commercial food production are unlikely to accept any transgenic technologies. The future direction of transgenic research will be influenced by ongoing discussion and evaluation of ethical and societal issues that are raised.
Activity ideas
Explore the ethics of generating transgenic animals with this activities:
- Ethical frameworks and transgenics – use ethical frameworks to explore some of the ethical issues raised by using transgenic cows to produce medicines to treat human diseases.
- Role-play ethics and transgenics – in this activity, students use role playing to explore different stakeholders’ perspectives on the issue of using transgenic cows to make medicines to treat human diseases.
- Ethics of modifying cows with human genes – in this activity, students explore different stakeholders’ perspectives on using transgenic cows to make medicines and weigh up the consequences, both benefits (pluses) and harms (minuses).
In the unit plan, Ethics of transgenic cows students develop their knowledge of transgenics so they can formulate an argument and make ethical decisions about using transgenic cows to make medicines to treat human diseases.
Useful link
The Enviropig™ was initially developed by the University of Guelph, Canada, but in 2012 the researchers halted the development of these genetically engineered pigs, read more about this here. In 2018 it was reported that Chinese researchers were moving forward with developing a transgenic pig.
