28/03/2017 (NZFarmer.co.nz) - High-input dairy farmers in Taranaki are overhauling the way they farm to reduce their reliance on the popular supplementary feed palm kernel.

It comes after dairy giant Fonterra issued a voluntary guideline in September 2015, recommending a cow's intake of palm kernel be capped at 3kg per day. A higher usage of palm kernel can alter the fatty acids in milk, making it difficult to process into products like butter.

Last week the co-operative told its 10,500 suppliers it will start testing milk for "fatty acid changes caused by PKE" from next month. It said "initially, the results will be for advisory purposes only" and farmers won't incur penalties if they exceed them.

Johanna and Dion Bishell, speak during a field day at the Manaia farm where they sharemilk.

ESTHER TAUNTON

Johanna and Dion Bishell, speak during a field day at the Manaia farm where they sharemilk.

Our cows eat palm kernel. They love it. The bulk of their diet is lush, green, high-quality grass. But when grass growth isn't enough to meet the demands of 360 cows, grass silage, maize, hay, turnips and palm kernel are added to the menu.

Earlier this month, I attended a field day hosted by Taranaki Dairy Industry Awards winners Johanna and Dion Bishell. They 50/50 sharemilk 470 cows at Manaia.

Their coastal farm is prone to dry weather, which halts grass growth. Last summer was the opposite of the one we have just paddled through. Dry weather hit early and dragged into the autumn. The Bishell's milk production plummeted 13.6 per cent and the cows were dried off in early April.

Dion told attendees that during the summer last season they were "feeding 8kg of palm kernel per cow a day". They use 300t-400t annually. But like many farmers, the Bishell's are devising ways to curb their reliance on the cheap and easily accessible food source.

The couple has been talking with their farm owners about growing crops such as turnips and fodder beet next season to help fill future feed gaps. But that will mean more paddocks out of their grazing rotation. They already grow "8ha-9ha of maize" on the property.

It was a theme which dominated the field day. Dairy Manager of the Year, Shaun Neal, currently manages a 325-cow farm at Auroa. That farm also uses palm kernel to ensure cows are fully feed during "a couple of pinch points" in the season. He said during those times "we are feeding more than 3kg/cow/day".

Shaun's already made changes and is growing fodder beet for the first time, with 3.5ha planted. He hopes "having the fodder beet will cut our palm kernel usage by 50-80 tonnes". A 4ha crop of turnips was used to supplement the cows' diet over summer.

Changing how a farm is run is a bit like trying to turn around the Titanic; it's a slow process which takes careful planning.

It's our first season in Taranaki on a high-input, high-altitude dairy farm with a high stocking rate. We have a feed pad and fed a lot of palm kernel last spring. But like Shaun, Dion and Jo, we're making changes to cut the amount of palm kernel our cows devour.

Last spring, we planted 9.5ha of turnips, which we started feeding in late January. That enabled us to cut more grass silage, which will be saved for next spring. A fodder beet crop of 6.5ha will be fed over the winter, allowing us to build pasture covers ahead of calving. Both moves are designed to reduce our palm kernel usage.

New Zealand's soaring demand for palm kernel has been mainly driven by dairy farmers trying to produce more milk from the same area of land. It's also been a versatile source of feed during droughts or wet springs.

New Zealand is the largest user of palm kernel, importing about a quarter of the world's supply. Statistics NZ figures show imports fell slightly to 1.86 million tonnes in the year to June 2016. The feed is a by-product of the palm oil industry.

Hawke's Bay 50/50 sharemilker Rachel Baker examined Fonterra's palm kernel guideline as part of a Kellogg Rural Leadership Programme research project. The annual amount of palm kernel being fed by high input farmers she interviewed ranged from 256 kg/cow to 1.4 t/cow. They all rated it "as either 'important' or 'very important' to their business".

Baker's research found that once Fonterra rolls out its milk testing, the 3kg/cow/day guideline will become obsolete as farmers "individually work out what factors keep them above or below the penalty threshold".

Like the aforementioned farmers, her research indicated farmers would look to increase their amount of homegrown feed in response using less palm kernel.