‘Supercow’ genes sought by scientists: October 20
October 26, 2016
Lincoln University Professor Jon Hickford is leading a team of scientists analysing the genes in dairy cows that affect how much milk a cow produces and the protein content of that milk.
“Knowing this may provide the potential for both economic and environmental benefits to New Zealand as it could allow farmers to reduce their current cow numbers, yet sustain output,” Professor Hickford says.
“We aim to identify what particular form of a gene (named FABP4) a dairy cow has as this may provide potential for farmers to identify these animals and add them to their herds. This may increase both the quantity and quality of the milk their cows produce.”
Specifically, the scientists identified that FABP4 is present in three forms or alleles that have been named A, B and C. Depending on the pairing of these alleles in the cows, an effect was seen on different milk traits.
For example, cows with the A allele produced milk with a higher protein content.
This trial involved a herd of 719 lactating Holstein-Friesian x Jersey cross dairy cows grazed in an outdoors grass-fed New Zealand dairy system on the Lincoln University Dairy Farm.
The volume of milk the individual cows produced was measured daily and once a month milk samples were collected and analysed for the percentage of protein and percentage of fat.
DNA from all the cows was also analysed using sophisticated molecular techniques to determine the variation in the FABP4 gene. This gene had previously been linked to variation in milk traits, but not with the precision used in the Lincoln University work.
Financial support was provided from the Ministry of Science and Innovation, Dairy Systems for Environmental Protection NZ Programme and the Lincoln University Gene-Marker Laboratory.