Northland bull beef farmers Dennis and Rachelle O’Callaghan have been involved in Beef + Lamb New Zealand’s Beef Profit from Pasture programme, which has helped them further focus on pasture management – a key driver in their business.
The couple, who were Supreme winners in the Northland Ballance Farm Environment Awards in 2018 have successfully maximised productivity and profitability while protecting and enhancing their natural resources.
One of the unexpected benefits of Dennis and Rachelle O’Callaghan’s intensive bull grazing system has been the build-up of topsoil.
Dennis says the sub-soils over much of the farm are poor, but 10 years after setting up the system, top-soils have doubled in volume which has had benefits in soil water holding capacity, drainage and in getting nutrient cycles underway.
Confined to small areas means the cattle means there is no transferring of fertility to paddock campsites and water sources and the organic matter is continually building up.
The farm’s podzols soils were once under kauri forests and the leaf litter from these ancient forests created a pan in the soil. Dennis explains that the soils are unique in that they cannot hold onto nutrients so they use slow-release Reactive Phosphate Rock.
While they don’t get a boost from this fertilizer application, they don’t get a tail-off either. They measure Resin. P levels rather than Olsen.P to measure phosphate levels in their soils.
Dennis and Rachelle won the Supreme Award in the Northland Ballance Farm Environment Awards in 2018, along with the Waterforce Integrated Management Award, Ballance Agri-Nutrients Soil Management Award and the Beef + Lamb New Zealand Livestock Award primarily because of the care they take to protect their soils, waterways and sensitive areas of the farm.
As well as the farm policy of selling the majority of their bulls as yearlings, the couple have fenced across their hill-sides to minimize run-off and protect the soils. As they have fenced-up areas of the farm, they have also invested in a reticulated water system which carries water to micro-troughs.
Phosphate has been identified as a problem in waterways in their catchment and the O’Callaghans have taken steps on their farm to minimize P losses, such as contour fencing, planting all gullies and the fencing off of all waterways on the farm.
As well as benefitting the environment, these measures have been advantageous to the business in that nutrients and soils have been retained across the farm, rather than being lost into waterways.
Dennis favours taking a catchment approach to improving water quality as it allows all stakeholders to work together to address the issues specific to their catchment.
Beef Profit from Pasture
In the past three years Dennis has been chairman of Beef + Lamb New Zealand’s Beef Profit from Pasture Group. This group, which was facilitated by AgFirst farm consultant Gareth Baynham, sought to identify strategies that lift pasture eaten from May to December by 1000kgDM/ha on Northland farms.
At 30c/kgDM this is $300/ha more revenue – or 25-35% increase for a typical Northland farm.
Pasture growth from May to December is typically more profitable and growth rates more consistent than summer and autumn months.
The group worked to identify, test and demonstrate the effectiveness of pasture management strategies and share these strategies with other farmers. They drew on many of the tools and techniques used by dairy farmers.
The focus was very much on managing pasture, rather than re-grassing or cropping, although the group did look at sowing annual (or Italian) ryegrass into Kikuyu.
Amongst the management practices the group considered were rotational grazing versus set-stocking, 30-day versus 60-day winter rotations, autumn Kikuyu management and the relationship between stocking rate and pugging.
What they learnt
Faster winter rotations resulted in less pasture growth, lower pasture covers and more pugging, but rotational grazing was still superior to set-stocking with 29% more pasture harvested, 50% less pugging, 60% more liveweight gain and $574/ha more income.
A longer 60-day rotation resulted in 77% more pasture harvested, 44% more liveweight gain and $212/ha more income than a 30-day winter rotation. Pasture quality was also better in winter and spring under the longer rotation.
Mulching or mowing Kikuyu increased liveweight gain by 35% over hard-grazing which only increased liveweight gain by 18% compared to doing nothing.
There was a net benefit of around $150/ha for hard grazing or mulching compared to no kikuyu control but mowing had the highest net financial benefit of around $240/ha or 60% more because it was a cheaper than mulching.
Stocking rate and pugging. Two of the past three winters have been very wet so pugging has been a major issue on Northland farms. A 2017 demonstration comparing R1 and R2 cattle highlighted significant differences in pugging, production and profit.
There was more pugging in the R2 cattle system (78% pugged compared to 50% for R1). While production was good under both systems, weight gain in the R1 cattle was exceptional at 941 kgLWG/ha which was 72% more than the R2 cattle. Pugging would have contributed to this difference in performance.
While running lower stocking rates reduced pugging, production and revenue were similar across low, medium and high stocking rates.
Variable stocking rates. A strategy of running lower stocking rates through winter then topping up with extra cattle in spring did benefit with high pasture covers and reduced pugging even after the extra stock was added. This resulted in 29% more liveweight gain, however this was off-set by the premium paid for extra cattle in spring – so revenue was similar.
It is also important to remember that adding extra bulls to mobs in spring can be logistically challenging.
Annual/Italian ryegrass. While sowing annual ryegrass into Kikuyu increased pasture growth and cover resulting in a 10-50% liveweight gain, most of the advantage was lost in the cost of buying and establishing seed.
