Page 81 - NZ Hereford Magazine 2023

Genetic link to differences in
hill country grazing

behaviour

Bluestone Herefords cows after the installation of GPS collars.

By Cristian Moreno García.
Department of Agricultural and Life Sciences, Lincoln University
I

came to New Zealand [from Argentina] with a simple
task: I wanted to record differences in grazing behaviours
among cows and test if such differences were explained
genetically. I conducted the research using Hereford
farmers with partial funding from NZ Herefords.
A large majority of farmers would agree they have cows
that graze and behave differently. For example, there are
cows that may quickly come close to unfamiliar people, while
others would not bother at all and may continue grazing or
ruminating after a quick and uninterested look. There are
also those cows you will only see from the distance and may Cristian talking to World Hereford Conference 2020 participants
disappear immediately from your sight. Farmers might also about his research.
agree that culling the one cow that consistently breaks the
electric fence can solve the problem in the entire herd, as if WHAT WAS DONE
such behaviour is removed with the rebellious and naughty
cow. I can even tell that farmers not only know cows behave In 2018, I started with a pilot experiment at Lees Valley Station
differently but also believe such differences are heritable, using a set of solar-powered GPS tracking collars borrowed
at least partially. So, how difficult could it be to detect from Israel. These collars were used successfully in Israel, the
scientifically the differences in grazing behaviour among United States of America, and Uruguay, but they seemed to
cows? Furthermore, if such differences exist, how difficult fail under the environmental conditions of New Zealand’s
could it be to test for genetic associations? high terrain, and after three months of measurements, lots of
My research suggests cows display consistent differences data was lost. We concluded that probably the available sun
in grazing behaviours such as the home range (referring to in winter was insufficient to recharge the collars’ batteries,
the size of the daily exploration area of an animal) and the causing failure in the data collection. After some research, I
movement tortuosity (referring to the straightness of walking found an alternative and prototyped a self-made GPS tracking
trajectories) and that such differences are smaller for the collar adapting a simple GPS device with an extra-large battery
range of elevation and the horizontal distance travelled. I was that could last up to six months.
lucky enough to find genetic associations and trends toward During 2019 and 2020, I deployed the 90 self-made collars
associations between a specific ‘grazing gene’ and the above- and recorded grazing behaviour from more than 300 cows
mentioned grazing behaviours. Overall, these findings might with the great help of Yvonne Lee at Bluestone Herefords,
be useful for implementing selection programmes aimed at Robert and Alex Peacock at Orari Gorge Station, Simon Lee at
improving the grazing distribution of beef cattle in hill and Mendip Hills Station, and Brandon Dalton and Rapha Meier
high-country grasslands of New Zealand. Let me explain to from Lees Valley Station.
you what I have done, and what I learnt about the behavioural The self-made collars performed relatively well and allowed
genetics of beef cattle! me to collect of a large amount of behavioural data, which,

Year 2023 HEREFORD MAGAZINE 79