Kiwi cow a scientific breakthrough
Allergy-free milk for children is a step closer after New Zealand scientists made a world-first breakthrough using a geneticallymodified cloned cow.
The country’s largest crown research institute AgResearch said it had bred the first cow in the world to produce high-protein milk with greatly reduced amounts of a protein believed to be the leading cause of milk allergies in children.
‘‘It’s a very significant result,’’ the institute’s research director Dr Warren McNabb said.
He was unable to say how much the breakthrough could mean financially for New Zealand, or how much the project had cost to date.
It had been under way since 2006, and was funded by the Business, Innovation and Employment Ministry and AgResearch.
The question of whether the milk was hypoallergenic (low allergy), and could eventually be produced and marketed as such, was the subject of further experiments, he said.
The cow was called Daisy and was about 11-months-old.
She had a mysterious missing tail that AgResearch said it was investigating.
It expected to have an answer in a couple of weeks, but did not believe that the lack of a tail was linked to genetic modification.
Before the milk could be tasted by humans, tested in clinical trials on humans or produced commercially, New Zealand’s genetic modification policies would need to change, McNabb said.
Currently New Zealand had restrictive policies, with strict rules on genetic modification including containment provisions for research.
‘‘It’s going to come down to what this country decides. It’s more of a social issue than a scientific one.’’
The scientists, led by Dr Goetz Laible, worked in containment at Ruakura in Hamilton and used scientific processes to reduce the amount of a milk protein known as beta-lactoglobulin (BLG) in Daisy’s milk.
BLG is a milk whey component believed to be the main cause of allergic reactions to cows’ milk, particularly in infants and children, McNabb said. It is not in breast milk.
The research results had been published in a prestigious American scientific journal, Proceedings of the National Academy of Sciences.
McNabb said AgResearch achieved the results by working successfully with mice first.
It then produced Daisy, a female calf genetically engineered to express two micro RNAs (short ribonucleic acid molecules).
Using a technique called ‘‘RNA interference’’, the micro RNAs ‘‘knocked-down’’ the expression of the BLG protein.
AgResearch’s Dr Stefan Wagner said Daisy was created using similar technology that was used to create the world-famous cloned sheep Dolly.
He confirmed the cow Daisy was ‘‘all cow’’ without any components of other animals. McNabb said the milk research was still in its early days.
The initial results came from inducing Daisy to milk, as she was too young to produce milk naturally.
She had produced about a cup of milk over five consecutive days, which was ‘‘more than enough’’ to do the analysis and allergenicity tests.
Next steps in the project include breeding from Daisy, possibly next year, to produce a calf and for Daisy to start milking naturally so further tests could be done.
‘‘If we can see similar results in another lactation, we suddenly have cows’ milk without what everyone believes is the main allergen in cow’s milk,’’ McNabb said.
There were also plans to produce a few more cows the same as Daisy by the start of next year.
McNabb said possible commercial production of hypoallergenic milk was a long way off.
‘‘If this milk is to be hypoallergenic, as we suspect it will be, then we’ve got to get over the hurdle of social acceptance of this type of technology before you can then apply it in the national herd.
‘‘It’s going to come down to what this country decides. It’s more of a social issue than a scientific one.’’
The successful research team comprised co-authors Anower Jabed, Stefan Wagner, Judi McCracken, David Wells and Goetz Laible.