The economics of phosphorus supplementation of beef cattle grazing northern Australian rangelands

Abstract

Context Phosphorus (P) deficiency occurs in beef cattle grazing many rangeland regions with low-P soils, including in northern Australia, and may severely reduce cattle productivity in terms of growth, reproductive efficiency and mortality. However, adoption of effective P supplementation by cattle producers in northern Australia is low. This is likely to be due to lack of information and understanding of the profitability of P supplementation where cattle are P-deficient. Aims The profitability of P supplementation was evaluated for two dissimilar regions of northern Australia, namely (1) the Katherine region of the Northern Territory, and (2) the Fitzroy Natural Resource Management (NRM) region of central Queensland. Methods Property-level, regionally relevant herd models were used to determine whole-of-business productivity and profitability over 30 years. The estimated costs and benefits of P supplementation were obtained from collation of experimental data and expert opinion of persons with extensive experience of the industry. The economic consequences of P supplementation at the property level were assessed by comparison of base production without P supplementation with the expected production of P-supplemented herds, and included the implementation phase and changes over time in herd structure. In the Katherine region, it was assumed that the entire cattle herd (breeders and growing cattle) grazed acutely P-deficient land types and the consequences of (1) no P supplementation, or P supplementation during (2) the dry season, or (3) both the wet and dry seasons (i.e. 3 scenarios) were evaluated. In the Fitzroy NRM region, it was assumed that only the breeders grazed P-deficient land types with three categories of P deficiency (marginal, deficient and acutely deficient), each with either (1) no P supplementation, or P supplementation during (2) the wet season, (3) the dry season, or (4) both the wet and dry seasons (i.e. 12 scenarios). Key results In the Katherine region, year-round P supplementation of the entire cattle herd (7400 adult equivalents) grazing acutely P-deficient pasture resulted in a large increase in annual business profit (+AU$500000). Supplementing with P (and N) only in the dry season increased annual business profit by +AU$200000. In the Fitzroy NRM region, P supplementation during any season of the breeder herd grazing deficient or acutely P-deficient pastures increased profit by +AU$2400–AU$45000/annum (total cattle herd 1500 adult equivalents). Importantly, P supplementation during the wet season-only resulted in the greatest increases in profit within each category of P deficiency, comprising +AU$5600, AU$6300 and AU$45000 additional profit per annum for marginal, deficient and acutely P-deficient herds respectively. Conclusions The large economic benefits of P supplementation for northern beef enterprises estimated in the present study substantiate the current industry recommendation that effective P supplementation is highly profitable when cattle are grazing P-deficient land types. Implications The contradiction of large economic benefits of P supplementation and the generally low adoption rates by the cattle industry in northern Australia suggests a need for targeted research and extension to identify the specific constraints to adoption, including potential high initial capital costs.

The Relationship between Satellite-Derived Vegetation Indices and Live Weight Changes of Beef Cattle in Extensive Grazing Conditions

“…There could be several reasons for this, and one possible explanation is the lack of wet season phosphorus supplementation in year 2. Phosphorus supplementation during the wet season is critical to maintain the growth rate and fertility of cattle in northern Australia due to deficiency in soils and vegetation [45,46]; therefore, demonstrating that there may be other factors influencing cow LWC.…”

An economic framework to evaluate alternative management strategies for beef enterprises in northern Australia

“…Effective P supplementation of the acutely P-deficient base cattle herd that was being fed no P supplement resulted in the greatest potential benefit of all strategies examined for the Katherine region, namely, AU$332 200 extra profit/annum, 152% IRR (for comparable results, see Bowen et al 2020b). This strategy had a short payback period of 2 years, but resulted in a substantial peak deficit (-AU$328 300).…”

Achieving drought resilience in the grazing lands of northern Australia: preparing, responding and recovering

“…In doing this we have drawn examples from analyses primarily conducted as part of a project funded by the Queensland Government's, Drought and Climate Adaptation Program (DCAP) and published in a series of final reports (Bowen and Chudleigh 2018, in press a, in press b;Bowen et al 2019aBowen et al , 2019bBowen et al , 2020aChudleigh et al 2019b) available at: https://futurebeef.com.au/projects/improving-profitability-and-resilience-of-beef-and-sheep-businessesin-queensland-preparing-for-responding-to-and-recoveringfrom-drought/. Some aspects of this work have also been reported in Chudleigh et al (2019a), Bowen et al (2020b and .…”