Heifers should be weighed for to hit conception targets.
Weigh scales can quickly pay for themselves in terms of fertility, first lactation returns and better use of wormers.
This was the message from Andrew Dodd, technical extension officer for breeding and fertility at AHDB Dairy, at a recent Calf to Calving event at Park House Farm, Wetley Rocks, Stoke on Trent.
Mr Dodd said: “The aim should be to get heifers to 50 per cent of their mature body weight at 12 months when inseminated, as this is when they hit puberty. But if they get too heavy too quick, they will become fat. At first calving, heifers should be 90 per cent of their mature weight.”
Mr Dodd said there are 386,000 dairy heifers in the UK at 24 months which have not calved.
He then added the age at calving, which is about 28 months on average, can drastically affect the length of a cow’s productive life within the dairy herd.
In some systems these heifers might not be pulled out of the main herd until they are 30 months of age. By this time they have incurred a substantial cost, considering it costs an average of £1,800 to rear a heifer to 26 months. Taking a heifer to 28 months before first service is said to increase rearing cost by 9.5 per cent.
Mr Dodd said: “Every day over 24 months of age, a heifer costs the farmer an additional £2.87. Youngstock are the future of the dairy herd and deserve the best management but, equally, if a heifer is not performing, when do you decide to drop it out of the milking herd?
“If you monitor weights you will also know when to begin monitoring heats,” he said.
Another major cost to UK dairy farms is calf mortality. On average, dairy herds have a calf mortality of 8 per cent, but 60 per cent of these calves were alive at the start of the calving process. Mr Dodd believes there has been little training on dairy farms about how to properly calve a cow to stop this problem.
Mr Dodd said: “About 2.5 per cent of heifers which are born alive and get as far as being tagged die within their first month of life, and 14 per cent of tagged heifer calves fail to reach their first calving, which is another huge cost.”
Block calvers are more likely to pull older heifers which have not conceived out of their systems, due to their management approach, and many then use them for beef production instead.
Benchmark figures from the College of Agriculture, Food and Rural Enterprise, Northern Ireland, suggest the average cost of rearing a heifer to the point of calving is 5-6ppl on all milk produced.
He said: “It can be difficult to balance the cost of rearing while not jeopardising the animal’s ability to get in-calf by 15 months, calve down at 24 months and reach its optimum body weight.”