Study pits grass against PKE

Farmers learn the financial results of the dairying feed research during the NARF field day earlier this month.

Results of the two years the BNZ Northland Dairy Development Trust (NDDT) has been comparing the profitability of dairying with cows fed grass-only, or plus home-grown crops and imported palm kernel, are of national significance, according to Chris Boom, science manager for the research project.

NDDT investigations into how farmers might reduce their use of imported feed were carried out on the Northland Agricultural Research Farm (NARF) at Dargaville where Mr Boom said: "We are starting to build confidence in our results, and they are really interesting."

Dairy farmers were starting to learn about the fat evaluation index (FEI) of their milk. In some cases, the FEI would show the need to reduce the use of palm kernel expeller (PKE) to avoid going over Fonterra limits.

"This is going to result in them having to change their systems. We hope they can learn from what we have been studying at NARF," Mr Boom said.

NARF is split up into three small farms. One farm uses only pasture (grass-only farm), the second farm also doesn't import feed but grows crops (cropping farm). The third farm uses PKE to fill in feed gaps (PKE farm).

"Sometimes simple systems are best, though grass-only farming definitely has its risks."

This season the PKE farm had the highest production at 1118 kgMS/ha, the cropping farm was next at 1053 kgMS/ha, and the grass-only farm produced 965 kgMS/ha. Last season the cropping farm produced the most and then the PKE farm, followed by the grass-only farm.

"The cropping farm struggled during spring," Mr Boom said. "This was somewhat due to very soft soils that had been cropped the previous season."

Despite this, all farms exceeded their 2015/16 production this season.

In the 2015/16 season the grass-only farm was slightly more profitable than the other farms at the $3.90/kgMS milk price, despite having the lowest production of the three farms.

The draft 2016/17 financial results have been calculated and were presented at the NARF field day on June 8. Farm working expenses were $3.81/kgMS for the grass-only farm, $4.21/kgMS for the cropping farm and $3.95/kgMS for the PKE farm.

At a $6/kgMS milk price, the PKE farm had marginally more operating profit than the grass-only farm at $2713/ha compared to $2670/ha respectively. The cropping farm was lower with an operating profit of $2207/ha. The figures are sensitive to milk price however.

At a $4/kgMS milk price the grass-only farm would have been significantly more profitable than the others. At $8/kgMS the PKE farm would have been significantly more profitable.

"At a $6/kgMS milk price, there was 150kgMS difference in production per ha but similar profit levels between the grass-only and PKE farms. We all need to be careful we farm for profit not just production," Mr Boom said.

"At NARF we measure the extra labour and machinery costs that cropping or supplementary feeding incur. Sometimes the simple systems are the best, though grass-only farming definitely has its risks."

Mr Boom said use of PKE was going to be challenged going forward. Since January, milk from the PKE farm at NARF exceeded the FEI limit around 30 per cent of the time, while cows were receiving 3kg PKE through much of this time.

"Farmers are going to quickly learn about the interaction of PKE and FEI on their farms.

This is something we don't need to worry about on the grass-only farm," Mr Boom said.

"The trial demonstrates what we see as best practice in how each of these systems operate, not that we get it right all the time. Getting the grass-only farm through a drought could be challenging; that farm was fortunate it rained in February this year."

The trial will continue for a third and, possibly, a fourth season. We want to ensure we have tested the systems in a variety of different climatic conditions," Mr Boom said.

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