Small effects of deferment of annual pastures through grazing spring wheat crops in Western Australia can benefit livestock productivity
Dean T. Thomas A D E , Andrew D. Moore B , Hayley C. Norman A D and Clinton K. Revell C DA CSIRO Agriculture Flagship, Private Bag 5, Wembley, WA 6913, Australia.
B CSIRO Agriculture Flagship, GPO Box 1600, Canberra, ACT 2601, Australia.
C Department of Agriculture and Food Western Australia, 3 Baron-Hay Court, South Perth, WA 6151, Australia.
D Future Farm Industries Cooperative Research Centre, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
E Corresponding author. Email: dean.thomas@csiro.au
Crop and Pasture Science 66(4) 410-417 https://doi.org/10.1071/CP14090
Submitted: 21 March 2014 Accepted: 30 June 2014 Published: 31 March 2015
Abstract
Grazing sheep on cereal crops in winter has become widely adopted in medium–high-rainfall zones of Australia. Interest in this practice has spread to the lower rainfall parts of the cereal–livestock zone where it is being applied to shorter season crop varieties. A farm-system modelling study was conducted to investigate the value of deferment of annual pastures by grazing spring wheat in their place. The biophysical simulation model, based on a representative wheat and sheep farming system in the wheatbelt of Western Australia, involved two grazing-management scenarios and used climate data for the period 1962–2011 for three locations in Western Australia representing low-, medium- and high-rainfall cropping regions: Merredin, Wickepin and Kojonup. The grazing-management policy of the main scenario, ‘crop grazing’, placed livestock on the crops only until the crop reached Zadoks growth stage 30, provided the green biomass of the farm’s annual pastures was <800 kg/ha. A second ‘shadow-grazing’ scenario was run in which a group of ewes identical to the main ewe flock was used to graze annual pastures simultaneously with the main ewe flock whenever the main flock grazed wheat crops. The difference between the two scenarios represented the pasture deferment value associated with grazing wheat crops.
Pasture deferment had little effect on total pasture production during the period when crops were grazed. However, there was a small benefit to feed supply through the accumulation of pasture during the period of crop grazing. This feed was available at a time of year when feed is scarce. This was reflected in improved animal production, with the weight of lambs at weaning being higher in the crop-grazing scenario than the shadow-grazing scenario. These results suggest that although increases in pasture productivity and feed supply associated with spring crop grazing are only marginal, grazing of spring wheat crops can still lead to changes in lamb production because this enterprise is sensitive to the feed supply in winter.
Additional keywords: spelling, crop grazing, sheep, dual-purpose crop, simulation model, winter feed-gap.
References
Arnold GW, Dudzinski ML (1967) Studies on diet of grazing animal. 3. Effect of pasture species and pasture structure on herbage intake of sheep. Australian Journal of Agricultural Research 18, 657–666.| Studies on diet of grazing animal. 3. Effect of pasture species and pasture structure on herbage intake of sheep.Crossref | GoogleScholarGoogle Scholar |
Barrett-Lennard P, Quinlan R, Taylor S, Warren G, Handley M, Pearce R (2013) Grazing crops in a dry year. In ‘2013 Crop Updates’. 25–26 February, Perth, W. Aust. (Grains Industry Association of Western Australia: South Perth, W. Aust.)
Bell LW, Dove H, McDonald SE, Kirkegaard JA (2015) Integrating dual-purpose wheat and canola into high-rainfall livestock systems in south-eastern Australia. 3. An extrapolation to whole-farm grazing potential, productivity and profitability. Crop & Pasture Science 66, 390–398.
Brown TH (1976) Effect of deferred autumn grazing and stocking rate of sheep on pasture production in a Mediterranean-type climate. Australian Journal of Experimental Agriculture 16, 181–188.
| Effect of deferred autumn grazing and stocking rate of sheep on pasture production in a Mediterranean-type climate.Crossref | GoogleScholarGoogle Scholar |
Davis IF, Sharkey MJ (1972) Effect of fertilizer nitrogen and feeding practices on productivity of Corriedale wethers grazing annual pasture in southern Victoria. Australian Journal of Experimental Agriculture and Animal Husbandry 12, 589–595.
| Effect of fertilizer nitrogen and feeding practices on productivity of Corriedale wethers grazing annual pasture in southern Victoria.Crossref | GoogleScholarGoogle Scholar |
Dove H, Kirkegaard JA, Kelman WM, Sprague SJ, McDonald SE, Graham JM (2015) Integrating dual-purpose wheat and canola into high-rainfall livestock systems in south-eastern Australia. 2. Pasture and livestock production. Crop & Pasture Science 66, 377–389.
Freer M, Moore AD, Donnelly JR (1997) GRAZPLAN: decision support systems for Australian grazing enterprises – II. The animal biology model for feed intake, production and reproduction and the GrazFeed DSS. Agricultural Systems 54, 77–126.
| GRAZPLAN: decision support systems for Australian grazing enterprises – II. The animal biology model for feed intake, production and reproduction and the GrazFeed DSS.Crossref | GoogleScholarGoogle Scholar |
Gutman M, Holzer Z, Baram H, Noy-Meir I, Seligman NG (1999) Heavy stocking and early-season deferment of grazing on Mediterranean-type grassland. Journal of Range Management 52, 590–599.
| Heavy stocking and early-season deferment of grazing on Mediterranean-type grassland.Crossref | GoogleScholarGoogle Scholar |
Harrison MT, Evans JR, Dove H, Moore AD (2011) Dual-purpose cereals: can the relative influences of management and environment on crop recovery and grain yield be dissected? Crop & Pasture Science 62, 930–946.
| Dual-purpose cereals: can the relative influences of management and environment on crop recovery and grain yield be dissected?Crossref | GoogleScholarGoogle Scholar |
Keating BA, Carberry PS, Hammer GL, Probert ME, Robertson MJ, Holzworth D, Huth NI, Hargreaves JNG, Meinke H, Hochman Z, McLean G, Verburg K, Snow V, Dimes JP, Silburn M, Wang E, Brown S, Bristow KL, Asseng S, Chapman S, McCown RL, Freebairn DM, Smith CJ (2003) An overview of APSIM, a model designed for farming systems simulation. European Journal of Agronomy 18, 267–288.
| An overview of APSIM, a model designed for farming systems simulation.Crossref | GoogleScholarGoogle Scholar |
Kirkegaard JA, Sprague SJ, Dove H, Kelman WM, Marcroft SJ, Lieschke A, Howe GN, Graham JM (2008) Dual-purpose canola—a new opportunity in mixed farming systems. Australian Journal of Agricultural Research 59, 291–302.
| Dual-purpose canola—a new opportunity in mixed farming systems.Crossref | GoogleScholarGoogle Scholar |
Masters DG, Thompson AN (2015) Grazing crop—implications for reproducing sheep. Animal Production Science in press.
McMullen KG, Virgona JM (2009) Dry matter production and grain yield from grazed wheat in southern New South Wales. Animal Production Science 49, 769–776.
| Dry matter production and grain yield from grazed wheat in southern New South Wales.Crossref | GoogleScholarGoogle Scholar |
Moore AD, Holzworth DP, Herrmann NI, Huth NI, Robertson MJ (2007) The Common Modelling Protocol: A hierarchical framework for simulation of agricultural and environmental systems. Agricultural Systems 95, 37–48.
| The Common Modelling Protocol: A hierarchical framework for simulation of agricultural and environmental systems.Crossref | GoogleScholarGoogle Scholar |
Moore AD, Bell LW, Revell DK (2009) Feed gaps in mixed-farming systems: insights from the Grain & Graze program. Animal Production Science 49, 736–748.
| Feed gaps in mixed-farming systems: insights from the Grain & Graze program.Crossref | GoogleScholarGoogle Scholar |
Salmon L, Palmer M, Moore AD, Donnelly JR, Simpson RJ, Stefanski AM, Freer M (2002) Testing grazing management recommendations: when is ‘Best practice’ best? Wool Technology and Sheep Breeding 50, 485–491.
Smith RCG, Biddiscombe EF, Stern WR (1972) Evaluation of five Mediterranean annual pasture species during early growth. Australian Journal of Agricultural Research 23, 703–716.
| Evaluation of five Mediterranean annual pasture species during early growth.Crossref | GoogleScholarGoogle Scholar |
Smith RCG, Biddiscombe EF, Stern WR (1973) Effect of spelling newly sown pastures. Australian Journal of Experimental Agriculture and Animal Husbandry 13, 549–555.
| Effect of spelling newly sown pastures.Crossref | GoogleScholarGoogle Scholar |
Thomas DT, Descheemaeker K, Moore AD (2012) Grazing spring variety cereal crops reduces supplementary feeding in mixed cropping and sheep farms. In ‘Proceedings 16th Australian Agronomy Conference’. 14–18 October 2012, Armidale, NSW. (Australian Society of Agronomy/The Regional Institute Ltd: Gosford, NSW) Available at: www.regional.org.au/au/asa/2012/crop-production/8117_thomasdt.htm
Virgona JM, Gummer FAJ, Angus JF (2006) Effects of grazing on wheat growth, yield, development, water use, and nitrogen use. Australian Journal of Agricultural Research 57, 1307–1319.
| Effects of grazing on wheat growth, yield, development, water use, and nitrogen use.Crossref | GoogleScholarGoogle Scholar |
Williams CMJ (1978) Studies of herbage availability and plant density in relation to animal performance. PhD Thesis, University of Adelaide, S. Aust, Australia.
Zadoks JC, Chang TT, Konzak CF (1974) Decimal code for growth stages of cereals. Weed Research 14, 415–421.
| Decimal code for growth stages of cereals.Crossref | GoogleScholarGoogle Scholar |
