Ground Cover Supplement : GC Supplement - Integration of livestock cropping
6 Issue 129 | July -- August 2017 | GRDC GROUNDCOVERTM SUPPLEMENT GROUNDCOVER GRAZING CHAFF KEY POINT n Grazing chaff piles has the potential to cut feed costs by up to $29,000 on an average-sized mixed farm, with the added benefit of higher weight gains for sheep and better lambing survival rates CHAFF CARTS PAY THEIR WAY WITH LIVESTOCK GAINS By Ed Riggall, Georgia Reid and Kate Jefferies n Traditionally, chaff carts have been introduced to cut weed numbers, but they can also be used to provide a cheap and available feed source to reduce the summer--autumn feeding gap on mixed farms. Despite supplementary feeding being one of the main expenses for mixed farms, there is little information available on the actual benefits of chaff piles to both livestock and the business's bottom line. Trials in south-western Western Australia aimed to quantify the impact of chaff-pile grazing on sheep live- weight gain, condition and lambing rates, as well as undertaking economic analysis of its profitability. Using paired-paddock set-ups across five farms, sheep gains were compared between two paddocks -- one that utilised chaff carts and another where chaff was spread in the usual way by the harvester. Sheep were weighed and condition-scored every two weeks during the six-week summer grazing period. In the trial, grazing chaff piles led to: n higher weight gains and better- conditioned ewes, with an average 2.4-kilogram additional weight increase compared to stubble- grazing sheep (Figure 1); n lamb survival increases of 18 per cent; n an increase in scanning potential of up to 25 per cent; n higher weight gains on canola chaff piles compared to other crops; n a reduction in feeding costs of $29,000 per annum, based on a model 2000-hectare mixed enterprise; and n an internal rate of return (IRR) on investment in a chaff cart of 36 per cent. This research shows that chaff carts can increase productivity and profitability on mixed enterprises in the south-west of WA by cutting feed costs and increasing ewe productivity. The economic analysis was modelled only on the feed costs and based on a wet summer with green pick, so economic benefits may vary, especially when the value of higher lambing percentages is included. Further benefits such as increased lambing percentages and weed control were not included in the economic analysis. The trial also compared a seed destructor to chaff carts. While the sheep showed similar weight gain, there was a 0.3kg advantage in chaff- pile grazing as the seed destructor produced a lower-value feed. Further research is required to support the results, as well as to investigate the impact of different crop stubbles and the impact of grazing on the success of chaff carts as a weed management tool. o More information: Ed Riggall, AgPro Management, 0428 299 007, firstname.lastname@example.org Producer Ben Webb of Kojonup, WA, has been using chaff carts for the past two years with promising results. PHOTO: AGPRO MANAGEMENT SOURCE: AGPRO MANAGEMENT FIGURE 1 The comparative advantage of cha -pile grazing on sheep weight gains after six weeks compared with non-pile treatments. Average weight gain over non-pile treatments (kg) 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Kojonup 2017 (canola) Tenterden 2016 (barley) Kojonup 2016 (canola) Darkan 2016 (oats) Location and stubble type Cranbrook 2016 (wheat) FAST FACT Feeding livestock with chaff cart dumps improves both productivity and profitability.
GC Supplement - Weeds