Historically New Zealand’s competitive advantage has been our ability to grow and harvest high-quality pasture at a low cost. Nothing has changed. Owl farm is into its second season as a demonstration dairy farm and optimising home-grown feed remains the key focus.
For various reasons our performance during the 2015/2016 season was poor. We had issues with staff, underweight heifers, non-cycling cows, eczema. I could go on. However one of our biggest issues was the quantity and quality of harvested home-grown feed grown. With only 11.5 tonnes drymatter (DM) of home-grown feed harvested per hectare our operating costs ($4.67kg milksolids) and per-cow performance (395kgMS/cow) were understandably disappointing.
Although this didn’t read well it did create the platform for change. PGG Wrightson Seeds as a farm partner has been instrumental in developing and supporting the farm through our pasture renovation policy. Through our farm management committee we collectively identified three closely related priorities: increase home grown feed, reduce reliance on brought in feed and decrease our cost of production. In order to improve profitability we identified a reduction in purchased feed as key. To do that while maintaining stocking rate and production it was simple, we needed to harvest more home-grown feed.
Before looking forward it’s worth looking backwards. Historically there has been very little pasture renovation undertaken on this farm. Additionally, pastures and soils have been particularly vulnerable to dry summers and wet winters. This has resulted in a heavy burden of weeds and some pest damage.
Pasture renovation policy revolves around the incorporation of a summer cropping regime as it allows us to renew pastures annually. Although we essentially started this at the beginning of the 2015/2016 season with the introduction of a summer chicory crop, it wasn’t until this season that we had the data to ensure a more-measured approach could be taken in prioritising paddocks for renewed.
As a demonstration dairy farm we rely heavily on collecting and analysing data to validate decisions and inform future management.
As a demonstration dairy farm we rely heavily on collecting and analysing data to validate decisions and inform future management. We measure pasture covers weekly as well undertake a pasture condition scoring exercise bi-annually in winter and summer with the support of PGGW Seeds and Ballance. Using this information we can earmark the paddocks which require improvement. This season we have increased from 8% of the milking platform to 10% of the milking platform with 15ha allocated for chicory.
Last season with a smaller area and therefore faster rotation we found we didn’t optimise the re-growth opportunity. We also identified a diminishing performance of the crops through the back half of the rotation as weeds began out-competing the chicory. As a result average yields from last year’s chicory crops were less than desirable (8-10.5t DM/ha). This led to the incorporation of an annual ryegrass into the rotation in March before cropping the same paddocks for chicory in October. This gave us two opportunities to spray out the paddocks and break down weeds while also allowing us to grow a modelled 3t DM/ha more feed over winter using an annual.
We follow a very structured process in measuring our pastures weekly. This allows us to build the feed wedge and grazing rotation as well as identify individual and average pasture covers and growth rates.
In February using MINDA’s Land and Feed we rank each paddock top to bottom in terms of measured pasture growth and subsequent grazing days. Last season we identified a 3.5t DM/ha gap between our best and poorest performing paddocks from June-January. Our top paddock during this period had grown 10t DM/ha compared to our worst paddock having only grown 6.5t DM/ha, and interestingly the best performing paddock was first year pasture out of chicory.
Looking at pasture growth in isolation is however problematic in the sense our high presence of weeds isn’t factored in. Our pasture meter reads height only and has no bearing of species, in several situations paddocks which had good growth didn’t necessarily have good quality.
To ensure we can accurately prioritise paddocks for improvement we also undertake pasture condition scoring using the criteria developed through the Pasture Renewal Charitable Trust. We then combine this information with the pasture growth data to identify relevant paddocks for renovation.
We undertake two pasture condition-scoring exercises a season, one in winter which works as a good benchmark for the success of the pasture renovation programme and one in summer which helps identify the worst paddocks in terms of pasture species present, weed burden and insect pressure, and ultimately in need of a facelift. Our initial winter test last season identified 55% of our paddocks as being a condition score three or less. Fast forward 12 months and this figure is now 41% with the graph showing a positive trend-line.
The table below outlines the importance of the pasture condition score. Many of our top growing paddocks had a low pasture condition score which still put them in the frame for renewal despite growth.
Along with pasture renewal through summer cropping we have also had to undertake significant undersowing given it’s not feasible to take more than 10% of the milking platform out without having to supplement with brought-in feed. This season we identified around 60ha which were particularly weedy but otherwise not too bad. These were sprayed with a valdo/baton mix and 32ha were then undersown in addition to the 15ha put into crop.
So far the results are speaking for themselves. Using Farmax we modelled the additional feed which we anticipated growing thanks to the investment. This in turn reduced our modelled imported supplements by 35% and our cost of production by more than 20%. Throughout this season we have updated our modelled Farmax file with our actuals and tracking home-grown feed compared to what we had budgeted. The second graph shows we are 7.5% ahead of what we had budgeted this season, which was 8% more than the 11.5t DM/ha harvested during the 2014/2015 season.
We are also currently tracking 22% down season to date on imported supplements with 40% less having been spent in this space. To date we are also on par on a per-cow production basis. Collectively this demonstrates we are on track to meet our objectives set at the beginning of this season.
We are due to complete our next pasture condition score which along with pasture growth data we will use to determine which paddocks need addressing next. We also have budget for undersowing if required. Ultimately we want to be harvesting >15t DM/ha but as we know that won’t happen overnight. We will keep true to this structure for the next few seasons at least with the expectation that year on year both the quantity and quality of home-grown feed will continue to improve.