Livestock grazing behaviour in large Mallee paddocks

Michael Moodie¹,Zac Economou² , Mark Trotter² , Ali Frischke³ and James Murray³
¹Mallee Sustainable Farming, VIC, ²University of New England, NSW, ³Birchip Cropping Group, VIC

Why was the project was done?
The integration of cropping and grazing remains a major management challenge in the Mallee. Technology such as portable fencing systems and virtual fencing potentially offer a solution to improve grazing management in large Mallee paddocks with high soil variability. However, to effectively design and deploy these innovative grazing techniques, the grazing behaviour of livestock in these paddocks needs to be understood and quantified.

About the project?
A flock of two-year-old merino ewes (approximately 200) grazed a 107 ha paddock near Nandaly during summer (barley stubble) and then again in winter grazing (vetch) in 2015. Prior to the commencement of grazing, 25 animals within the flock were fitted with UNE Tracker II GPS collars (Figure 1). Livestock monitoring was supported with on-ground assessment of vegetative soil cover and feed quantity over both grazing periods. At the conclusion of each grazing period, the collars were removed and the data downloaded from the GPS devices. Data was then analysed for the purpose of quantifying variable grazing pressure.

Key Messages
• For the first time sheep grazing behaviour in a Mallee paddock was monitored and mapped using GPS tracking collars
• Sheep grazed the entire stubble paddock as they sought out spilt grain during the summer fallow, but they preferred to graze on sandy soil types first
• While grazing a vetch pasture in the same paddock, livestock spent 50% of the time grazing only 25% of the paddock and 25% of the paddock was not utilised
• At least $4000 profit was foregone from the paddock through the under-utilisation of the vetch pasture
• Within-paddock fencing technology in large Mallee paddocks has the potential to capture this potential profit by improving feed utilisation