AUSTRALIA - Cows last into pasture from the milking parlour could be regularly eating “markedly” lower quality grass, says Australian research.
Furthermore, these cows have less to eat, with 70 per cent of grass consumed before they arrive.
The University of Sydney dairy team found that cows back to the Kikuyu pasture first (Pennisetum clandestinum) accessed grass with a fifth more crude protein and 15 per cent lower acid detergent fibre levels.
This was on 'paddock' style Australian grazing, a feature common to the rapidly growing automated milking segment, according to Dairy Australia.
Daily rumination time increased by 23 minutes for those cows returning to pasture last, “presumably due to the greater proportion of fibre on offer in the pasture and associated increased requirement for rumination to break down particle size”.
The study, conducted at the 350 cow Camden farm, was designed to test systems seeing cows returning straight back to graze following milking.
Grass canopies are known to contain higher crude protein and lower neutral detergent fibre than lower fractions, although the report said this was the first look at the “substantial variation” in pasture quantity and quality in association with pasture access after milking.
Kikuyu pastures were depleted by 36 per cent to ground level and 70 per cent to post-grazing pasture mass during the time between first and last cow.
Further work looking at pasture of different species had the effect on milk solids and individual yield was called for.
Senior researcher, Dr Cameron Clark, said: “As the milking order of dairy cows is relatively consistent, the objective of this study was to determine the effects of milking order on the quality and quantity of pasture accessed by dairy cows.
“Two experiments were conducted. The association between milking order and time of paddock access was evaluated in the first experiment whilst the second experiment determined the association between the order in which cows entered the paddock and the quality and quantity of kikuyu pasture ingested by cows after milking.”
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