Fed: Global warming effects milk supply, CSIRO finds

AAP General News (Australia)
08-18-2000
Fed: Global warming effects milk supply, CSIRO finds

By Rosemary Desmond

BRISBANE, Aug 18 AAP - Happy cows are productive cows - something dairy farmers have
known for many years.

But scientists now believe the need to keep dairy cows comfortable will take on new
significance for agriculture and infrastructure projects as temperatures rise due to global
warming.

Dr Roger Jones, from the CSIRO's Atmospheric Research Centre in Victoria, said today
a study of dairy cattle in the NSW Hunter Valley had shown those cows left out in open
paddocks produced about three per cent less milk than those kept under shelter.

The loss represented about 230 litres of milk per cow each year for a high-yield herd.

Dr Jones said that by using shade sheds and sprinklers in hot weather, milk losses
could be reduced to about 50 litres per cow per year at present.

But the losses were likely to rise in the future to between 250 and 310 litres per
cow per year by 2030 due to climate change - depending on the rate of warming.

The milk losses also would translate into big income losses for farmers.

Dr Jones said that at 25 cents a litre, that was a loss of nearly $6,000 a year for
a 100 head herd.

The CSIRO study found that if farmers used shade sheds and sprinklers, each of their
cows would produce between 190 and 220 litres more milk each year than cows left exposed
in paddocks, limiting milk losses to about 60 to 90 litres per cow per year.

"Our study shows that where measures limiting the effect of high temperatures on livestock
are economic now, they will save even more money in future," Dr Jones said.

The study also had wider implications for long-term planning of land use and infrastructure
projects, such as water resources, he said.

"What we are interested in developing is trying to overcome the uncertainty, so instead
of predicting future climate change, we want to look at the risk to various activities,"

Dr Jones said.

AAP rad/sc/hu/bwl

KEYWORD: COWS

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