LIC scientists have discovered genetic variations which impact milk composition in dairy cows.
All cows have the ‘fat gene’, named AGPAT6, but LIC senior scientist Dr Matt Littlejohn says the variations they’ve discovered provide a genetic explanation as to why some cows produce higher fat content in their milk than others.
“If you think of milk production in the cow’s udder as a factory assembly line, this variation is one of a few workers in the ‘fat chain’, with that worker being very efficient in some cows, and a bit lazy in others.
“The finding of AGPAT6 helps us to better understand what goes on in a cow’s mammary gland and how milk
composition is regulated by genes,” Dr Littlejohn said.
The discovery, which was recently published by the international scientific journal PLOS ONE, will now be used to help improve the accuracy of the farmer-owned co-operative’s genomic selection programme for AB sires and drive further genetic gain improvements of the NZ dairy herd.
The finding represents one of only a few cases worldwide where the underlying gene affecting differences in milk composition has been identified.
The variation was discovered as part of LIC’s DNA sequencing programme, which aims to map variations in genes in a cow’s DNA that can impact production and health. These variations will be used to improve the accuracy of genomic selection.
The sequencing programme has led to previous discoveries including the Small Calf Syndrome gene and one which causes loss of pregnancy in cows; it utilises a large sequencing dataset developed by LIC scientists and co-funded by the Ministry for Primary Industries through the Transforming the Dairy Value Chain Primary Growth Partnership programme, led by Fonterra and DairyNZ.
Dr Littlejohn says the sequencing work is a bit like putting together the pieces of a cow puzzle – the more you put together, the clearer the overall picture becomes for genomic selection and identification of which sires are likely to perform best.
“The real benefits will be realised as we pinpoint more genes and variations that we know exist. Stack them up together and you can have quite big effects, particularly when applied to genomic selection.”
Contact: Ashleigh Sattler, LIC Communications Advisor. Phone: 078560912 or 0276171942. Email: firstname.lastname@example.org
WHAT’S IN A NAME?
AGPAT6 might not be the snappiest of names, but as an acronym for the protein it encodes, it certainly rolls off the tongue a bit
easier than 1-Acylglycerol-3-Phosphate O-Acyltransferase 6.
Genes are most commonly named for the functions or context in which they are first discovered, and then a universal symbol
representing this (e.g. AGPAT6) is decided upon by the international gene-naming organisation HUGO.
ABOUT: Transforming the Dairy Value Chain Primary Growth Partnership (PGP) programme DairyNZ and Fonterra are leading a seven-year, $170 million innovation programme called Transforming the Dairy Chain that is jointly funded by the New Zealand Government through the Ministry for Primary Industries’ Primary Growth Partnership.
DairyNZ is investing in pre farm-gate innovation, and Fonterra is leading work post farm-gate to diversify dairy products and manufacturing processes. Co-investors in the pre-farm-gate aspects of the programme are Synlait, Landcorp Farming, Livestock Improvement Corporation, New Zealand Young Farmers and Agricultural Services Ltd. For more information visit www.dairynz.co.nz/pgp