Australian researchers may have found a flaw in robotic milking of grazing cows.
The milking order of dairy cows in robotic milking is relatively consistent — and the same applies to their access to pasture after they visit the milking machine.
Some cows tend to be last into the milking parlour — which can leave them regularly eating lower quality grass, because they are last to rotate into new pasture after milking.
Furthermore, these cows have less to eat, with 70% of the grass consumed before they arrive.
This happens because the automatic milking systems (about 50% of all new milking parlours installed in many EU countries) in grazing systems depend on voluntary movement of cows from a paddock to the machine.
A three-way grazing management system is the usual system, which promotes voluntary cow movement to the milking unit at appropriate intervals. The farm is divided into three grazing sections, and cows graze defined areas of each of the three grazing sections during each 24-hour period.
Cows move between the grazing sections in the trained knowledge that they will be rewarded with fresh grass in a new paddock. As they move between sections, they are diverted through the milking yard.
But some cows tend to move early through the system, others to move late. University of Sydney dairy researchers found that early first into the pasture get grass with 20% more crude protein, and 15% fibre.
As for those cows getting to the pasture last, researchers found they spent 23 minutes longer chewing the cud, presumably due to the greater proportion of fibre in what’s left of the pasture when they get to it.
It was found pastures were depleted by 70% between the first and last cow arriving from the milking shed.
Further research looking at the effect on milk solids and individual yield was planned.
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