Successful extended grazing
EXTENDED grazing on the notoriously wet Culm Measures in north Devon has been successfully practised by Tim Wall for the last six years.
He has defied this convention by getting maximum milk production from grazed grass with cows calved in a tight 11-week block, starting in February, he told the Tiverton meeting. Block calving ensures grass supply coincides with maximum demand.
To achieve a tight block, on Apr 16, 24 days before artificial insemination is due to start, he tail-paints every cow blue.
When cows are seen bulling, he changes their tail-paint colour to green. Then on Apr 30, 10 days before inseminations start on May 10, he starts using red paint for cows seen bulling.
Those still tail-painted blue at this time are easily identified and sorted for vet examination, he said. After first service, he uses pink tail-paint and then selects other colours for repeats.
Those seen bulling just before serving starts – cows marked red – at day six of the service period are given prostaglandin to bring them bulling again. This really helps to concentrate the calving period, he added. *