Georgia Reid, AgPro Management
To demonstrate the advantages of crop grazing on farm profitability and enhance producer understanding of how to apply the tool to best advantage in different seasons and situations.
Productivity driven sheep profits are hitting a ceiling in traditional mixed farm (sheep/crop) enterprises. The autumn winter feed gap is a period of the year that limits stocking rates and per head growth rates, due to lack of available feed. Current practice is to hand feed, with lower stocking rates.
Crop grazing is something farmers tend to fear and avoid due to lack of knowledge or confidence in the method. This is due to some having played with crop grazing and not understood its place, or how to limit its impact on crop yields, which has led to bad experiences and results. There is also a lack of quantifiable evidence of the impact of crop grazing on whole-farm profitability, which contributes to this low confidence. Running demonstration sites on several properties in different situations and seasons allows the producers to see unbiased and objective results for themselves and understand how grazing crops can work for them.
Current common practice to address this feed gap is to lower stocking rates from summer until late winter, in order to reduce expensive hand feeding costs. This can involve selling off lighter store sheep early and having fewer wethers on farm or just running a lighter stocking rate all year round. This can result in sub-optimal stocking rates during the growing season. Crop grazing can rectify this by providing an alternative feed source to reduce hand feeding and potentially increase stocking rates.
Accessing the crop area of the farm as a feed source at this time of year unlocks potential to increase stocking rate, as well as allowing high value animals such as twin bearing ewes and lambs access to easily accessible high value feed as shown in the MMPIG producer research site project. To quantify this, there is potentially a 10-20% increase in stocking rate opportunity, due to unlocking the area and a 20-30% increase in growth rates opportunity, from accessing the higher value, easily accessible feed. During the period while stock crop graze, pasture can be deferred, leading to greater pasture growth and allowing lambing ewes to lamb onto higher FOO levels. This can be directly correlated with higher lambing percentages.
Crops were grazed at four sites across the Great Southern for between 20 and 44 days during June-July 2018. Stocking rates varied, two sites grazed at approx. 6.6DSE for 20-21 days, while a Kojonup producer crash grazed multiple crops at 30DSE over 29days. The final site grazed for 44 days at 1ewe/ha during lambing at Wagin.
Crops had better quality feed than pastures at the time, having on average 17% higher metabolisable energy, 76% more Feed On Offer and were 18% more dry matter digestibility compared to pastures. It was also more accessible, being erect and easier to eat compared to prostrate pastures. Murdoch University is potentially investigating the value of this ease of grazing. Grazing these crops allowed paddocks to be spelled, with deferred pasture had considerably more Feed On Offer compared to pastures grazed during the crop grazing period-for example, in Boyup Brook three weeks of deferment lead to FOO doubling.
Crop grazing sheep were measured to be in better condition compared to those grazing normal pastures, especially as pastures were tight in 2018. Crop grazing led to the sheep being in 0.2, 0.25 and 0.28 CS better than pasture grazers. On average, sheep had a comparative advantage of 0.25 CS on grazing crops compared to pastures.
These condition score advantages were modelled to result in production benefits of $6.60 to $10.74 per ewe, based on increased ewe survival (4-6%), lambing increase (4-6%) weaning percentage (8-12% and ewe and lamb fleece production. The Kojonup site was not included in these results as weaners were grazed.
There were further benefits to the sheep enterprise, such as reduced labour in time spent feeding in the 2018 late break, and reduced feed costs. This was included in the modelling to give crop grazing a benefit of $10.90 to $82.10/ha to the sheep enterprise.
OVERALL FINANCIAL IMPACT
Despite benefits to sheep, crop grazing can result in negative impacts on the cropping enterprise. In 2017, due to correct grazing management (grazing early, lightly and in low-weed paddocks) and the soft finish, crop grazing had no significant impact on crop yield. In 2018, yield impacts ranged from zero impact to being 720kg lighter per hectare than crops that had not been grazed. This equated to a yield penalty of between zero and $252 per ha as seen in the table below.
To give an overall impact on whole business gross margin, yield impact was combined with sheep benefits, to give a net benefit of each site of $10.90/ha, $41.60/ha and -$170.00/ha.
The project will continue until the end of the 2019 growing season, with local producers and industry members welcome to attend the field days in winter.
For more information, contact Georgia Reid at firstname.lastname@example.org or, 0447 523 110.