Dairy farmers looking to cut back on feed costs and labour might want to think about outwintering their heifers.
Melanie Jenkins looks at how this can be done...
Heifer rearing is the second largest cost to dairy farms after feed, according to figures compiled by AHDB Dairy, so looking at ways to cut back on this outlay can help improve farm efficiencies.
With much less known about the performance of outwintered heifers compared to housed, taking an in-depth look at the system can help farmers decide if it would work for them.
This could be through reducing rearing costs, improving animal health, cutting labour inputs or removing strain from buildings.
Tom Mitchell, tenant farmer at Higher Mere Park Farm, Mere, Dorset, and consultant at Andersons, says the most important first step is preparation.
“Have a well thought-out plan in place including feed budgets, how much crop and what supplements you will need,” he says.
“Set up electric fences – have a second wire for breakouts – and lay out a water supply, using a mobile trough where possible.”
Mr Mitchell says outwintering does not necessarily mean November right through to March, and when it comes to crop choices for outwintering, there are a number of different options.
These include fodder beet, swede, kale, turnips, rape, swift forage rape, forage cereals, short rotation grasses and pasture for deferred grazing (removing stock to allow grass supplies to build up).
Each has a different sowing rate and time, yield, dry matter, protein, metabolic energy (ME) and growing cost – all of which can impact upon crop choice.
Fodder beet costs the most at £1,460/ha, but has the highest levels of ME at 162,500-202,500MJ/ha and dry matter yield at 15-17t/ha.
Stubble turnips are a cheap option at £305/ha and has a high crude protein content of 17-18%, but its ME is much less at 38,500-44,000MJ/ha.
“Higher protein is better for heifers, whereas high energy crops are better for cows. We should aim to grow crops which will increase overall farm dry matter production,” he says.
Crop choice will also depend on the age of the grazing animals. Younger heifers still have soft baby teeth which are not suited to grazing tougher root crops efficiently.
Some crops will also need protein supplements when grown for younger heifers.
Mr Mitchell advises introducing brassicas slowly to avoid bloat, and supplement with fibrous forage to in order to avoid issues such as nitrate toxicity.
“With mineral supplementation, farmers could have mineral licks in the field or mineral boluses. Some brassicas are quite low in iodine and high in calcium, so take care to avoid milk fever,” he adds.
Both copper and selenium are other supplements stock are likely to need.
During the first 48 days of turnout, heifers in a AHDB Dairy/Harper Adams trial lost an average of 0.30kg in weight per day.
However, post-48 days this increased to a daily liveweight gain (DLWG) of 1.37kg.
From start to finish they therefore averaged +0.88kg, compared to +0.82kg in housed animals, meaning there is no significant difference overall.
Research has also shown there is also no significant difference in milk performance between housed and outwintered cattle.
THE AHDB Dairy/ Harper Adams trial shows there is the potential to reduce rearing costs by £150/heifer – or 50 per cent - during the winter months, as feed costs are approximately 70-80 per cent of housed animal expenditure, although this will vary depending on crop and yield, explains Mr Mitchell.
“The biggest savings are in capital costs such as housing, yards, slurry, silage and storage. However, cost savings can only be realised if good animal performance is achieved.”