PKE, pasture picked to come out tops

The new study, planned for the Northland Dairy Development Trust’s (NDDT) agricultural research farm (NARF) 10km northwest of Dargaville, follows a trial of ryegrass vs kikuyu in Northland farming systems. In that trial’s final season (2012-13) the region was hit with its second severe drought in two years, conditions becoming so dry even kikuyu stopped growing.

Profits on the ryegrass farm were $1249/ha for the season, compared to $918/ha for the kikuyu farm largely because stock on the ryegrass farmlet had access to a summer turnip crop while the kikuyu farmlet had to rely on high-priced PKE.

Farmers at a 2013 NARF field day had questioned the implications of this given the large role PKE played in their own operations.

Launching the new trial at a DairyNZ field day at NARF in early June, the research leader Chris Boom explained that for the latest trial the farm was to be split into three farmlets: one supplementing intake with PKE, one supplementing with additional crops – maize, turnips, chicory, plantain and possibly fodder beet, and a third where the cows’ feed is to be supplemented with grass silage grown on the property.

About 80 cows will go onto each farmlet, the researchers ensuring each herd has exactly the same ratio of high performers and low performers.

Each of the systems will have an equal balance of herd size and quality, N application of 127kgN/ha/annum, land quality and pasture type to ensure a fair and balanced outcome. Young stock for each farmlet will be raised off-farm until they reach the R2 level, returning to the farm in time for calving.

The only minor difference in cow numbers will be on the grass-only farm with a stocking rate of 2.5 vs the cropping and supplement systems’ rates of 2.7.

Boom says this is to show the land buffer required when operating a low-input system in a region known for its frequent wet winters and dry summers.

The cropping farmlet, stocked at 2.7 cows/ha will get maize, turnips, chicory, plantain and possibly fodder beet grown on a 2ha plot (7% of the farmlet’s area), to help maintain pasture quality and available ME through winter and summer. These will mostly be fed as standing crops.

PKE will be fed on an ad-hoc basis, costed on average at $300/tonne delivered. 

With PKE price fluctuations being one of the main reasons for the research, Boom says a lot of thought went into potential PKE price ranges when setting up the study.

Modeling a hypothesis, the researchers set a low price of $280/t delivered, an average of $300/t delivered and a high of $380/tonne delivered.

Boom says the experience of the NDDT farmer board was drawn on while setting these figures. They are affirmed by Rabobank’s New Zealand and Asia director of dairy research, Hayley Moynihan, who says PKE prices, like most global feed grain prices, are now relatively low. 

“Those prices seem to be a reasonable spread to me and indicate the volatility in market prices for PKE.”

“The market is driven by a number of factors so the wide sensitivity is required.”

While there is a wide range in PKE prices, farm models produced only two scenarios where the farmlet using PKE as a supplement wasn’t the most profitable, says Boom. 

The first is where milk prices were below $4.70/kgMS and the next is where the price of PKE averaged $380/t delivered onfarm.

In circumstances where farmers would get $4.70/kgMS the supplement farmlet would make $581/ha while the grass only system was predicted to produce $625/ha and the cropping farmlet was predicted to earn $707/ha.

When PKE prices reached $380/t delivered Farmax predicted that the supplement farmlet would earn $1888/ha – $82/ha less than the cropping farmlet but $310/ha more than the grass-only farmlet.

Boom attributes this to the accessibility and reliability of supplement when compared to cropping and grass systems which can be markedly affected by the weather.