The impact of the availability and rate of growth of pasture on livestock productivity at a regional scale

Abstract

Pasture management is the most essential component of a grazing enterprise. Within grazing systems a complex interaction exists between the type, quality and amount of pasture, the livestock and the overall productivity of the system. These interactions occur not only at a farm scale but also at a regional and national scale. Graziers need to continually assess the changing availability of pasture growth rates and biomass to maintain and optimise livestock productivity. Within a changing climatic environment farmers must be aware of regional effects of livestock production and the requirement to have flexible production enterprises within farms. Having the capacity to source suitable input cattle within a cost effective distance and being aware of regional pasture conditions are very much part of the farm business management routine. In this study we examine the relationship between weekly pasture growth and gross annual pasture production (GAPP) as derived from satellite remote sensing and the annual farm cattle numbers sold as derived from the National Livestock Identification Scheme (NLIS). The study was undertaken for the year 2007 and was isolated to the Northern Slopes of New South Wales. The area was selected due to its similar climate conditions within southern area of the ABARE cattle beef region 6. Weekly pasture growth rates (PGR) were extracted from CSIRO Pastures from Space for the area at ~250m² and compared to cattle turn-off as reported by the NLIS. Current data suggests the higher producing pastures within this area are turning off no more than 0.4 head of cattle per hectare when averaged out over all cleared agricultural land in areas with greater than 5 ton/ha.year of GAPP. This assumption includes those lands used for crop and other livestock enterprises. The study also reveals that there is a high correlation between pasture growth, elevation, rainfall and soil. The higher elevation areas in this study have areas under improved perennial pastures with GAPP's exceeding 8 ton/ha.year. The correlation of NLIS cattle numbers sold and remote sensing data holds significant potential in helping producers understand the movement of livestock at a national scale to better source input stock.