Moving the focus back to grass

Date: 2010-04-12 | Category: Dairy News

Inglewood dairy farmer David Powell understands the benefits of new grass. After a period of intensification, using high inputs and pushing production to 1350kg MS/ha, he is now moving back to a less intensive regime of mainly grass, with maize silage to fill feed pinches.

Production should settle back to 1000kg MS/ha, about where it was before he built a feed pad six years ago and ramped up the production with palm kernel extract (PKE) and lots of maize silage.

“Grass is still the cheapest feed – it always has been,” he says. After four years of having his son Ian at home working with him on the farm, Ian has moved on to Canterbury to get some large-herd experience and David and his wife, Jan, have contracted a sharemilker on the 230-cow farm.

Arron Riddick and his partner, Fiona Hogan, are first-year sharemilkers, after Arron won the Taranaki Farm Manager of the Year title in 2008.

David says they have scaled back the supplements as it gets tricky splitting the costs with a sharemilker.

A proponent of pasture renewal for the past 20 years, David says he regrasses on average 6-8ha each year on his 87ha Norfolk Road farm. “I reckon I have had a shot at every perennial ryegrass over the years,” he says.

The milking platform is 75ha effective and David owns a 25ha support block and leases 36ha next door from a local contractor who has been developing the land with his digger and bulldozer.

The support blocks are used for cropping maize silage and grazing the young stock as well as running dairy grazers. Each winter 33 of the skinnier cows are wintered off on the support block for six weeks.

This season 12ha of maize silage (240t DM) will be grown on the support bock, half the amount grown last season.

The silage is used in feed pinches – usually during August and September , then again in March. Calving starts on August 10 and David likes to “hit calving with unrestricted intake for the cows – it is the cheapest way to produce milk”.

By removing the lighter cows from the milking platform in the autumn he says he can milk for longer but still reach the target 2500kg DM/ha cover for August 1. The cows are calved at a condition score of five, or close to it, but David says in his climate they soon start to lose weight.

On the eastern slopes of Mt Taranaki at 350m above sea level, the farm is just 2.5km from the bushline of the National Park, recording an annual rainfall of 3300mm.

The Facts	Grass is the cheapest feed and it always has been, says David Powell.
David and Jean Powell, Taranaki Milking platform 87ha, 75ha effective Support blocks 36ha leased, 25ha owned 230 cows for 2009/2010 season, estimated production 80,000kg MS (1000kg MS/ha, 347kg MS/ cow) Last season: 275 cows, production, 96,000kg MS (1200kg MS/ha, 349kg MS/cow) Pasture renewal: 6-8ha/year, sown

The winters are not as cold as expected. The cold air tends to slide down off the mountain preventing the frost from settling. However the spring tends to be late so there is usually an energy shortage by the end of August – the cows cannot eat enough to get adequate nutrients and there is not enough sun, so the maize silage is a great strategic supplement.

“Nothing puts weight on cows like maize silage and evidently it is good for the environment as the cows belch less methane after eating it.”

The rainfall level of 3.3m is challenging and requires careful pasture management as pugging of soils can cause damage.

The feedpad has made the feeding of silage feasible because they can’t feed out on the wet pastures. However the rainfall is reliable in the summer and the Egmont ash soils are fertile. David farms LIC-bred cows, Jersey and X-bred which are smaller and lighter on the soil.

“They don’t sink into the mud as much at about 420kg each.” He is impressed with the growth attained by the new ryegrasses he grows and their energy content.

Revolution, Bronsyn and Bealey are favourite varieties of his, particularly the Bealey which he says is very palatable – “we have to stop the cows grazing it too hard” – as it has a high sugar content and a higher energy content.

The ME level is around 11 MJ ME/kg DM for most of the year, except for spring when it gets down to 9.5 or 10 when the sward hasn’t seen much sun.

Production for the Bealey is topping 14t DM/ha/year compared with 7-8 t/ha/yr for the older pastures and David estimates he grows around 10.5t/ha over the whole farm.

Pastures have been renewed after a turnip crop in the past but David says he usually just grazes the pasture down to 1600kg DM/ha in the autumn and gets in with the disc drill or a roll/seed/ roll combination.

The disc drill tends to do the job well whereas a direct drill tends to bounce over hollows and farming on the slopes of a volcano means the ground has a high stone content.

If the paddock is grazed hard in the autumn they don’t usually have to spray the existing pasture out, he says.

The ryegrass is sown down with white and sometimes red clover. He is using Kotare white clover on the dairy farm as it has long stems which get up into the sunlight and are not so prone to being shaded out.

Remarking that a healthy vigorous clover sward will produce 400kg N/ ha/year, David says it is important not to suppress the clover with artificial N application. “We dribble the N on – in small doses and often – to protect the clover.”

Total N application is limited to 160-180kg/ha/year, which David says “seems to be enough”. The first N application each season is in the first week of August when the soil temperature gets to over 7deg C.

Fertiliser dressings (phosphate and potash) are also split into three to try to reduce the chance of it getting washed off in heavy rainfall. “It’s Murphy’s Law that if we put a lot on then we get a big rain and half of it washes off,” David says. So the fertiliser is split between dressings in October, at the end of December (with N), and in March (also with N).

This works out to be after every second grazing and David says it helps grow heaps of grass, the cows milk well and by following the cows around the risk of surface run-off and leaching is reduced.

Published courtesy of Country-Wide Dec 2009

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