New research by Dairy UP aims to unlock the nutritive potential of kikuyu pastures used by NSW dairy farmers.
Kikuyu is fast-growing and well-adapted to subtropical areas, but generally perceived as being of poor nutritive value for dairy cattle.
However, Dairy UP project leader Professor Yani Garcia said the research team was working to change that.
“We are exploring new management options to grow and utilise more kikuyu over summer and increase the productivity of kikuyu-based pastures,” he said.
Prof Garcia said the timing of grazing had a big impact on kikuyu’s nutritive value, affecting pasture utilisation and profitability.
“Kikuyu leaves lose quality very rapidly if not consumed at the right time, and the window of opportunity is generally smaller than for temperate grasses,” he said.
Grazing intervals also affect stem content.
The research aims to better understand and predict the rapid, short-term daily changes in the nutritive quality of kikuyu, enabling the development of strategies to better manage the quality of pasture regrowth and prevent milk production losses due to the decline in nutritive value.
The Dairy UP team is modelling changes in the nutritive value of kikuyu plants at different stages of regrowth using a model originally developed for tall fescue and ryegrass by Dr Juan Insua.
Controlled field studies with small, replicated plots of kikuyu under different growing conditions have enabled detailed assessment of plant structure and nutritive value traits.
The data is being used to quantify, model and predict the main factors affecting the fast decline in kikuyu nutritive value during regrowth.
Prof Garcia said the main factors affecting nutritive value had been identified as leaf length, leaf age and leaf decay.
He said future work would explore the relationships between nutritive value data and yield to link changes in nutritive value with satellite imagery.
“Hopefully this will improve the efficacy of remote monitoring tools for farmers,” he said.
The project is a collaboration between the University of Sydney and the UIB, National University of Mar del Plata, Argentina.