Burrows, W.H. and Orr, D.M. and Hendricksen, R.E. and Rutherford, M.T. and Myles, D.J. and Back, P.V. and Gowen, R. (2010) Impacts of grazing management options on pasture and animal productivity in a Heteropogon contortus (black speargrass) pasture in central Queensland. 4. Animal production. Animal Production Science, 50 (4). pp. 284-292.
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Article Link(s): http://dx.doi.org/10.1071/an09145
Publisher URL: http://www.publish.csiro.au
Steer liveweight gains were measured in an extensive grazing study conducted in a Heteropogon contortus (black speargrass) pasture in central Queensland between 1988 and 2001. Treatments included a range of stocking rates in native pastures, legume-oversown native pasture and animal diet supplement/spring-burning pastures. Seasonal rainfall throughout this study was below the long-term mean. Mean annual pasture utilisation ranged from 13 to 61%. Annual liveweight gains per head in native pasture were highly variable among years and ranged from a low of 43 kg/steer at 2 ha/steer to a high of 182 kg/steer at 8 ha/steer. Annual liveweight gains were consistently highest at light stocking and decreased with increasing stocking rate. Annual liveweight gain per hectare increased linearly with stocking rate. These stocking rate trends were also evident in legume-oversown pastures although both the intercept and slope of the regressions for legume-oversown pastures were higher than that for native pasture. The highest annual liveweight gain for legume-oversown pasture was 221 kg/steer at 4 ha/steer. After 13 years, annual liveweight gain per unit area occurred at the heaviest stocking rate despite deleterious changes in the pasture. Across all years, the annual liveweight advantage for legume-oversown pastures was 37 kg/steer. Compared with native pasture, changes in annual liveweight gain with burning were variable. It was concluded that cattle productivity is sustainable when stocking rates are maintained at 4 ha/steer or lighter (equivalent to a utilisation rate around 30%). Although steer liveweight gain occurred at all stocking rates and economic returns were highest at heaviest stocking rates, stocking rates heavier than 4 ha/steer are unsustainable because of their long-term impact on pasture productivity.
|Additional Information:||© The State of Queensland (through the Department of Primary Industries and Fisheries). © CSIRO Publishing|
|Keywords:||Burning; economic evaluation; legume oversowing; steer age effects; steer liveweight gain; stocking rate; native pasture; stocking rates; Australia; steers; legumes; tropics; gains; yield.|
|Subjects:||Agriculture > Animal culture > Cattle > Meat production|
Animal culture > Cattle > Meat production
Agriculture > Animal culture > Feeds and feeding. Animal nutrition
Animal culture > Feeds and feeding. Animal nutrition
|Deposited On:||18 Jun 2010 07:15|
|Last Modified:||21 Jun 2010 01:16|
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