Pastures From Space and Cow Microphones

GLOBAL - Intensive dairying may lend itself to precision technologies but grass-based systems can also benefit from gadgets.

6 May 2014

2 minute read

This allows grazing management to become an act of science rather than an ‘act of faith’, attendees at the British Society of Animal Science (BSAS) Annual Meeting heard on Wednesday.

High above Western Australia, three satellites are measuring pasture availability on a livestock farm near Perth.

Instruments on board the satellites measure the reflectance of visible and invisible light from the earth’s surface, producing images and colours, to which numbers can be assigned.

These numbers are then used to calculate kilograms of pasture per hectare which can be used to assist feed budgeting, grazing, fertiliser application and rotation decisions, according to the CSIRO, the organisation partnering the Australian government in the project.

As well as producing a biomass figure for ‘feed on offer’ (FOO), daily grass growth rates can be reached by using climate information to estimate kilograms of herbage per hectare.

For Dr Mark Rutter of Harper Adams University, this has great potential in increasing agricultural productivity as it optimises the use of farmland making up two thirds of the world’s agricultural space – rangeland and pasture.

However, satellite pasture management falls down where there is greater cloud cover, explained Dr Rutter, although other alternatives are at hand, he told the BSAS audience.

Rising plate meters and vehicle-based pasture meters do the same job as the Australian satellites but on a field level.

Drawn by a quad bike or tractor, pasture meters can give estimations of pasture availability across greater areas and in less time than a rising plate can, although neither can rival the coverage of satellites.

And while greater accuracy can be expected by measurements taken from instruments within fields, the Australians are able to measure feed in areas as small as 20 square metres.

But Dr Rutter suggested that attaching microphones to cows’ skulls to detect chewing and biting could offer the greatest benefits, particularly if combined with a accelerometer to monitor head movements.

Describing the merits of bioacoustics, Dr Rutter said: “By giving a ‘bite to chew ratio’ and clocking grazing time, an estimate of herbage intake and quantity can be given.”

"It is through combining chew sounds and measuring head movement that farming could have the greatest opportunity for on-farm grazing monitoring."