GRAZING PADDOCKS according to how many leaves grass plants have has resulted in more grass for silage, boosted production from grazing and helped cut fertiliser inputs, says milk producer Andrew Farrant.
He began using the three-leaf system (see panel) in 2003, one week after hosting an MDC meeting at which Australian extension officer Frank Tyndall explained the theory that a ryegrass tiller only ever grew three green leaves. At this stage, the plant is top quality in terms of sugar, nitrate, minerals, starch and fibre. So counting leaves indicates when paddocks are ready to graze.
“I liked it because it was simple yet gives criteria for deciding when to graze,” says Mr Farrant, who runs 398 cows at Manor Farm, Abingdon.
“Historically, this has been a cost-conscious business, and when I added a spring-calving block to the autumn calving herd this doubled the complexity, as we have two grazing groups. So, I wanted a simple grazing system without the effort or conversion charts needed for a plate meter.”
Mr Farrant changed from set stocking to a rotational system in 1994 and installed cow tracks, which brought turnout forward a month to mid-March. As a result the 5984-litre herd produced 549 litres a cow more from grass.
By implementing the three-leaf system he was able to improve efficiency even more, he says. “I took on board the idea that the third leaf grows more than either the first or second leaf in the same time span. We”ve certainly seen that.
“We cut 15 acres more as silage in 2003 and had an embarrassment of grass last year, having to cut another 30 acres for silage because it grew ahead of us. Cows also produced another 327 litres a cow from grazed grass, bringing the total to 2356 litres a cow.”
Mr Farrant counts leaves when gathering cows for milking or moving fences for the next grazing. He multiplies the leaf appearance rate (LAR) – the number of days it takes for a new leaf to appear – by three to set the rotation length. This ensures each paddock is grazed when it has three leaves.
“In the past two years, the range in LAR has been from eight days in May/June giving a rotation length of 24 days to just over 30 days in winter, a 90-day rotation.”
Dividing grazing area by rotation length gives the number of hectares needed to feed cows. Each paddock is 4-6ha (10-15 acres) split into 3-4 grazings allocated after each milking.
Mr Farrant says his only difficulty is getting cows to graze down to 5cm, particularly when grass growth is fast in May and June. “At three leaves, grass is taller than most producers like to see and to get it down to 5cm is hard. On a wet day, some gets trampled.”
But the three-leaf system uses mowing to rectify grazing mistakes. Last year he topped some paddocks down to 5cm and mowed others ahead of cows. Grass was left for a 24-hour wilt and cows cleared it up.
Feeding supplements also takes pressure off grass. Spring calvers are fed up to 10kg a head of maize silage and 4kg a head of a cereal blend to maintain cow fertility, but Mr Farrant says manipulating this helps grass growth.
“The three-leaf theory is that you can grow more grass using sunlight, so should be able to reduce fertiliser. We made savings because we had the confidence in grass growth to use less nitrogen on grazing in May and June. We cut out one 60 unit/acre application.”
This year he plans to reduce fertiliser again to cut costs and because he has fewer spring calvers. “We will apply 60 units/acre every six weeks instead of every four weeks.”
The simplicity of the system has kept him going and Mr Farrant has received encouragement from producers who contribute to a three-leaf discussion group via email.
“I”ve tried things because of the positive attitude of other producers. Three-leaf isn”t perfect, the aim is to graze at three leaves, but in practice sometimes it has to be 2-2.5. However, it is maximising herbage grown. I think we can grow more grass and expand cow numbers as a result.