RIGHT ROADS TO BETTER GRAZING
RIGHT ROADS TO BETTER GRAZING
Investing in farm
infrastructure is difficult at a
time when incomes are
dropping. But to maximise
use of grazed grass it makes
sense. UK-based New
Zealand dairy consultant
Paul Bird runs through
whats required
INCREASING numbers of farmers are investing in farm tracks as a way to increase the grazing season and improve grass use.
But before any money is spent, careful thought must go into how you are going to use the tracks, where they should go, and how they can be made.
Good tracks are particularly essential when soils become wet so animals can be brought back and forth from the grass.
To decide where to position the track, walk around the farm with an aerial map which includes hedges, gullies and existing tracks. Then draw in where new tracks should go.
If possible aim to get cows to every part of the farm. Seek several different opinions and also visit other farms with good track systems in place.
Figs 1 and 2 outline alternative ways of laying down farm tracks. Both farms here have ended up with the same number of divisions, 24 in this case. The best option is Fig 1. By creating a ring road or a U-shaped track, grazing areas become square rather than rectangle. Cows dont have to walk as far and it is easier to use alternative gateways into the fields. Less grass is walked over and utilisation improved.
It is not always easy to place tracks in the ideal location due to hedges, roads, and streams. But the key principals shown in Figs 1 and 2 can be applied to most farms:
• Square rather than rectangle grazing areas.
• Ensure access to grazing on either side of the track rather than from just one side.
• 90í bends in tracks should be avoided; each adds 5-10min to the time it takes to bring stock in for milking.
Tracks must be wide for quick and efficient movement of stock and to minimise stress, and width will vary according to herd size (see box).
The grass area taken up by tracks in Fig 1 is only 2% or 1ha (0.4 acres) – assuming a 50ha (124-acre) farm with 5m (16ft) wide tracks. Extra grass used would far outweigh the loss in grass.
The second issue is how the farm is divided up. Electric fences are the cheapest and most effective way of controlling where stock graze. Some farmers have opted for permanent paddocks and others for more flexible systems where the electric fence is shifted daily. On most farms half to two-thirds of the farm will need to be cut for silage because there will be a grass surplus. If temporary electric fences are used these can be pulled down at silage making time.
Silage fields within walking distance of the milking parlour, 0.8-1.2km (0.5-0.75 mile) should also be accessible for grazing. In fact they should not be called silage fields. They should be grazing with the option to make silage.
Track Construction involves
several stages:
• Removal of grass and top soil.
• Construction of a sound base.
• Adequate surface material.
• Crowning for drainage.
Removal of grass and topsoil
Top soil has no strength and should be removed for adequate construction.
Construction of a base
Preferably a hard gravelly rock. This should be rolled several times during construction with a vibrating roller.
Surface material
A good surface material will generally be softer than the base and suitable for the cows to walk on. It will also prevent or reduce seepage of water into the base. The surface material should be fine so it fills in any gaps. Avoid using anything that will need redoing every year – such as wood chippings. Lime rock is one option which has worked well on farms.
If you are unsure of the suitability of a material lay a small portion of track and watch the cows walking on it. If they slow down significantly and lameness increases, use something else.
Cows walking in single file down a track is an indication that the surface material is not suitable or there is poor drainage.
Crowning and Drainage (Fig 3)
Water held on a track will reduce its life. Crowning of the track drainage is, therefore, essential. Crowning ensures waters flow off the track and good drainage allows the water to flow away. Lameness increases on tracks which have poor drainage.
Irish Idea
Some producers with suitable rock on their farms are using this for both the base and the surface. One excellent idea from Ireland is that those farms with suitable rock under the topsoil can, using a digger, scrape off the topsoil where the track will be positioned. If the track is going to be 5m (16ft) wide scrape off topsoil from 6-6.5m (20-21ft) wide. Next, dig out the rock from the extra meter-wide strip and place this rock where the track will be. When enough rock has been dug out and the track has been formed, place the topsoil in where the rock was dug from. The effect is you have a moving farm quarry which producers a track costing £1-3/m length.
Concrete Tracks
Concrete tracks are expensive but require very low maintenance. They may be an option for the high traffic areas around the buildings, but small stones are easily transferred from a rock track to the concrete and can cause lameness. Regular sweeping or cleaning will minimise this risk.n
TRACK WIDTHS
Track width guidelines for different herd sizes
Herd size (cows)Track width
(m)
Up to 1205
120 to 2505.5-6
250 to 3506-7
350 to 4506.5-7.5