A father and son-in-law partnership farming in Co Antrim have adopted a new grazing system after witnessing the success it has brought to other farmers in their local CAFRE Business Development Group (BDG).
Kevin McAuley and his son-in-law Derek O’Melvena operate their farm at Broughshane. They developed their beef finishing system based upon the backbone of sustainable grassland management.
The pair had been operating a set-stocked grazing system but have now learned that they can get much more from grazed grass. So, they have opted to use rotational grazing to increase the amount of beef produced from the farm in the most economical way possible.
This has been achieved by growing and utilising more grass, increasing stocking rate, making high-quality silage from the excess grown on paddocks and decreasing fertiliser usage.
Having been convinced of the system’s success by members of their CAFRE BDG, both men thought, ‘we’ll not give it a go?’
Stephen Flanagan, a Beef and Sheep Adviser at CAFRE said: “The majority of the 320 purchased heifers have been turned out to grass and Derek is planning to fine-tune the rotational grazing system using sub divisions to obtain compensatory growth rates of between 0.8-1.0 kg of daily liveweight gain from the heifers.”
“So, is rotational grazing worth the hassle? The straightforward answer to that is yes. This is because stocking rates can be increased by 15 to 20 per cent on average and, in some situations, the amount of grass grown increased by 50 to 70 per cent.”
“However, growing all this grass is fine, but if it cannot be consistently grazed at the correct growth stage or correct stage of maturity, all the efforts are wasted because you won’t get the required performance from the stock.”
Grazing and resting
The primary principle behind rotational grazing is the idea of ‘grazing and resting’. Ideally, the sward should be grazed for three to four days then rested for around 18 to 20 days before being grazed again.
This should ensure that the grass is at the correct stage of growth and maturity. But, dependent on growing conditions, this will vary throughout the year.
Stephen Flanagan added: “Let’s look at the science behind the humble grass plant. It uses energy from the sun to combine carbon dioxide and water to produce simple sugars which form leaves and stems using nutrients like phosphate and potash from the soil.”
“It takes around 21 days at this time of year for three new leaves to be produced. The oldest leaves will start to die off after 21 days, so ideally a grass plant should be grazed every 21 days.”
“So, if the sward is not grazed at the three-leaf stage and dead material builds up at the base of the sward, it results in ‘stemmy’ herbage of lower digestibility. These grass plants will have a higher fibre and lignin content plus lower crude protein and energy level’s reducing cattle performance.”
At present, grass growth is increasing and it is not too late to start a rotational system like Kevin and Derek’s. Flexibility is key and if you are considering setting up a rotational grazing system on your farm, below are some points that you should consider:
Start small for the first year and try it out on one field or with one batch of stock until you are confident enough to change the whole grazing area over to paddocks. 7-8 paddocks are enough to manage in the first year or two.
Paddocks should be square if possible. Long narrow paddocks unsettle stock particularly in wet weather when they are unsettled and will paddle and trample a lot.
Ideally, paddocks should be 1-2 acres in size providing 3-4 days grazing for the batch of stock. Paddock size, however, is often dictated by hedges and ditches and batch size.
The paddocks can be subdivided when grass growth outstrips demand and the excess can be baled for silage.
Water and fencing
Lightweight plastic drinking troughs supplied by water pipe placed on top of the ground is used successfully and can be moved from paddock to paddock with the stock. An alternative is to use an IBC on wheels that can be filled and moved from paddock to paddock.
Use plastic electric fencing posts and wire with a battery or solar-powered fencer unit initially until you have decided on the long-term use of the system, but a mains powered system is a good investment.
Days 1 and 2 are ‘luxury’ grazing days with days 3 and 4 ‘tight’ days. Cattle may struggle to graze down to the ideal 4-5 cm height if the sward has become stemmy but don’t jeopardise performance by holding them in the paddock. Use the topper or allow dry cows or ewes to graze off the remainder.
Demand is 2.5% of body weight. For example 400kg cattle, 10 kg DM/day. In at 3000kg DM/ha, out at 1600 kg DM/ha = 1400 kg DM/ha supply or 565kg DM/acre.
So, 565/3 days grazing/10kg DM demand per 400 kg animal = 18 store cattle at 400 kg per acre. Go with 15 cattle to start with to allow flexibility
Remember the three 3’s, graze at the 3-leaf stage, graze for 3 days, rest for 3 weeks!
Image source: CAFRE