Pass on the salt: I've had my nutrients today.
Image courtesy of FFI CRC 

Scientists overseeing a saline land grazing project in Western Australia have discovered that saltbush not only has the potential to slow the rate of land salinisation - it also helps grow healthier sheep.

Dr Hayley Norman, a research scientist with CSIRO Livestock Industries, said that sheep grazing on combined plantings of river saltbush (Atriplex amnicola) and old man saltbush (Atriplex nummularia) had five times higher plasma vitamin E levels than their flockmates in the paddock next door.

"Vitamin E is an antioxidant that is essential to sheep and cattle," Dr Norman said.

"Severe vitamin E deficiency results in sudden death from heart and skeletal muscle damage. This is known as white muscle disease or nutritional myopathy. It occurs most commonly during autumn when green feed is scarce.

"The 'weaner' sheep - young animals that have been weaned and are now independent of their mothers - are especially vulnerable if they have not had an opportunity to eat green feed before summer and autumn."

The Sustainable Grazing on Saline Lands (SGSL) research at Yealering, 230 kilometres south-east of Perth, is a collaborative venture by Future Farm Industries CRC, CSIRO, Land Water & Wool, and the WA Department of Agriculture and Food.

Saltbush, unlike other plants, retains salt in its leaves. Due to its extreme salt tolerance, it is a valuable plant for the management of dryland salinity.

The researchers at Yealering are studying the environmental impact of saline grazing systems on water balance and biodiversity. The discovery that saltbush grazing helps guard against muscle disease in autumn is an unexpected bonus that merits further investigation.

"There is another benefit from vitamin E further down the food chain," Dr Norman said.

"A colleague has shown that meat from sheep grazed on saltbush is retaining its red colour for longer, and therefore has a longer shelf life in supermarkets.

"This can mean less wastage and spoiling and a better outcome for the environment and the economy."

And the win-win outcome gets even better. Meat from sheep grazed over saltbush has a lower fat content, further improving its economic and nutritional value.

There are up to 200 species of saltbush found in arid regions in many parts of the world. The saltbush species used at the SGSL project are endemic to Australia, but not to the Wheatbelt region.

River saltbush is endemic to the Murchison region while old river saltbush is native to arid areas from Kalgoorlie to Victoria.

"When offered both species of saltbush, the sheep tend to prefer the river saltbush, but they perform a little better on old man saltbush," Dr Norman said.

"The river saltbush is more waterlogging tolerant so we are using both species on the project."

The SGSL project offers the potential to place healthier, more sustainable lamb roasts on our tables while improving the productivity and biodiversity of degraded saline land.