BACKGROUND
This is a post about genetic modification, and genetically modified organisms, or GMO's for short. Using farming as an example I will discuss how genetics can be used to improve traits such as milk production in cows, and disease resistance in potato crops. The aim of this post is to show how genetics has some real-world applications that affect all of us.
THE ORIGINS OF GENETICS
This is a post about genetic modification, and genetically modified organisms, or GMO's for short. Using farming as an example I will discuss how genetics can be used to improve traits such as milk production in cows, and disease resistance in potato crops. The aim of this post is to show how genetics has some real-world applications that affect all of us.
THE ORIGINS OF GENETICS
Although farmers across Europe have been breeding their cattle and crops selectively for centuries, it was a nineteenth century Augustinian monk who first realised the power of genetics. Friar Gregor Mendel used his monastery's pea garden to study the size, shape and colour of pea plants and their seeds. This unassuming research allowed him to identify the root of how individual traits are passed from parents to offspring, a term now named in his honour as Mendelian inheritance. The term “Mendelian Inheritance” refers to the transfer of genetic material, DNA, from parent to offspring. Centuries of research since Mendel’s humble beginnings in his pea garden has shown that many characteristics of plants and animals are determined by small packages of DNA called genes. I have discussed, genes, and DNA in detail in a previous post so I won't go into detail here.
THE IMPORTANCE OF GENETICS
In the 150 years since Mendel our understanding of genetics has developed enormously, and modern scientists have now gained more precise control over the characteristics that can be added or removed from a variety of plants and animals. With the help of Teagasc, an independent state-funded agricultural research body, we are moving away from older and more costly methods of crossbreeding. Modern genetic manipulation now means that desirable traits can be selected for while undesirable ones can be left behind. This means that today’s farmers can save both time and money crossbreeding cattle and crops and increase crop yields for an ever expanding food market.
Genetically modified organisms, or GMOs are organisms which have been altered through the addition or removal of individual genes. Human beings have been living in harmony with genetically modified food since the beginning of agriculture in the form of disease-resistant crops or bulkier cattle for better meat production. Although sensationalised media reports sometimes paint GM food as unnatural “Frankenstein food” that may pose a risk to our health or the environment, the reality is much less sinister. In fact, modern genetic modification techniques allow farmers to better control desirable gene inheritance in a fraction of the time traditional methods would have required.
CASE STUDY 1: THE HOLSTEIN-FRIESIAN/NEW ZEALAND JERSEY MIX
In 2013, for the first time in our history, Irish food and drink exports approached €10 billion and the dairy industry accounted for almost a third of this. Dairy exports in 2013 amounted to €3 billion, up 15% from 2012, and are expected to rise again this year. This is a testament to the high standards Ireland sets and maintains in this sector. The majority of Irelands milk production and calving is seasonal, with over 75% of milk production occurring from April to September, whilst 79% of calves are born between January and April.
The Irish dairy herd is dominated by the Holstein-Friesian breed, which makes up 63% of the national herd. Our farmers favour this breed because of its exceptional milk yields, a characteristic arising from breeding programmes in the US. When we consider that Ireland has a limited calving season of only four months, we can see that improving our herds reproductive success would have a knock-on gain in the milking season and allow farmers to boost their profit margins. Until recently, any potential gains to be had from cross-breeding the Holstein-Friesian with a more fertile breed were disregarded by farmers wary of tampering with the Holstein-Friesian’s milk yield. But all that changed when the Holstein-Friesian was crossbred with the New Zealand Jersey.
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| The Holstein-Friesian (left) and New Zealand Jersey (Right) |
Although the New Zealand Jersey has slightly inferior milk production properties compared to the Holstein-Friesian, it does have superior reproductive qualities and tends to live longer. A recent Teagasc study showed that the offspring of the Holstein-Friesian and New Zealand Jersey, called F1, had the characteristics required to improve the overall profitability of the Irish herd.
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| The results of the Teagasc study, with all values displayed relative to the Holstein-Friesian breed. |
The Teagasc study revealed that the quantity of milk produced by the F1 crossbreed was marginally lower than the Holstein-Friesian, but this issue was compensated for with higher fat and protein content. The results also showed a modest improvement in turnaround time from calving to conception compared to the Holstein-Friesian. On top of this, the significantly hardier body condition of the F1 means lower maintenance costs for the farmer. When we add up the findings of this study, it clear that the benefits far outweigh the negligible disadvantages of crossbreeding these two strains. It’s no wonder then that New Zealand has already begun adopting this breed, with the F1 making up 33% of their national herd.
Potatoes are a staple ingredient on dinner tables all over Ireland, but it’s hard to mention this delicious starch without thinking about the Great Famine of 1845. This tragic episode in Irish history was caused by a fungus called Phytophthora infestans, commonly known as potato blight. Incredibly, over 150 years on, blight continues to be a serious concern for present day potato farmers.
In the battle against blight, fungicide remains our main weapon of choice. Fungicide is effective, but it requires as many as 15 to 20 sprays a year to secure a good potato crop. European regulations on fungicides are becoming more restrictive and, although many welcome this decision from an environmental perspective, potato farmers will need new weapons to protect their crop. As yet there are no blight-resistant strains of potato in Ireland but genetic modification may hold the key.
In the battle against blight, fungicide remains our main weapon of choice. Fungicide is effective, but it requires as many as 15 to 20 sprays a year to secure a good potato crop. European regulations on fungicides are becoming more restrictive and, although many welcome this decision from an environmental perspective, potato farmers will need new weapons to protect their crop. As yet there are no blight-resistant strains of potato in Ireland but genetic modification may hold the key.
Some Central America potato strains possess genes known to provide protection against blight. Traditional methods of cross-breeding potatoes are both time consuming and inefficient, but new genetic modification methods have had great success in introducing these genes to European strains of potato. Teagasc collaborations on an international level have led to possibility of blight-resistant potatoes being developed in Ireland. The picture below highlight the significance of their efforts.
The effects of blight on both strains can be seen, with the GM potato crop remaining healthy despite the presence of blight, while the unmodified crop succumbs to the disease. This development provides farmers with new options going forward. However Ireland proceeds, the decisions made by this generation is likely to have very real and long-lasting consequences to future generations.
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| The image on the left shows a GM potato line (A15-031) containing genes for blight-resistance, while that on the right shows a unmodified potato crop |
CURRENT OPINION GMOs
As with any new technology, a decision needs to be made on how and when it should be implemented. Those in favour of GMOs will urge for an early adoption to get ahead of European fungicide restrictions as well as to take advantage of any financial gains that can be made. Those who favour caution will prefer to wait and see how GMOs pan out for other nations. Teagasc is very clear about its stance on the issue of GMOs, making sure to distance itself from the commercial profit-oriented organisations and instead favouring unbiased publically-funded research. Dr. Ewen Mullins, Senior Research Officer of the Crop Science Department at Teagasc says, “We can’t rely on research done outside of the country by groups that are either for or against the technology”. Ireland has a lot to gain from probative research like this, but we need to be sure we are acting on the best available evidence. Teagasc is cautiously optimistic about introducing this GM potato crop in the field, stating, “Arising from the preliminary study completed in 2012, we now know that the GM potato variety we are researching has the potential to resist Irish blight strains but much more work is required and this will commence in 2013.”
THE FUTURE OF GMO IN IRELAND
Genetic modification will play an ever-increasing role in the growth and development of Irish agriculture. Ireland is fortunate to have a unique blend of traditional farming experience and a highly-developed scientific sector, allowing us to integrate old and new expertise to our benefit. The ability to skillfully handle GMOs will mean we can find tailor-made solutions to the various challenges facing the Irish agricultural sector. We can only speculate what Mendel would make of these modern advance, but I’d think he’d agree it’s not exactly “easy peasy” work.
REFERENCES
- Radio interview with Dr. Ewen Mullins: http://www.teagasc.ie/news/GMspud1.mp3
- Blight research article, http://www.teagasc.ie/crops/potatoes/gm.asp
