Fatter really is better

In a divergence from normal thinking, research has shown that being fatter really is better, at least when it comes to being a sheep!

Recent research is assisting farmers to plan better sheep feeding strategies in the lead up to WA's long dry summer periods, by evidencing the benefits of putting fat on the back of sheep during spring when feed is readily available and cheap.

Sheep that are in good condition at the start of summer will be more energy efficient when processing lower quality feed over the summer period than sheep with lower body fat, according to the study's data.

Sheep that are in a better condition at the start of summer will also be in a better condition at mating time, Murdoch University researcher Sarah Blumer says.

This will require less supplementary feed and produce more lambs, she says.

"After weaning, farmers may put the lambs into the best pasture paddocks with the idea that the ewes don't need this quality feed," she says.

"But if the ewes are given this quality feed in the lead up to summer, especially those that have reared twins, they will have a better chance of maintaining their condition for the reproductive period."

Ms Blumer says this data, while yet to be tested in the field, challenges the notion that a ewe can return easily to top condition after a tough summer with poor quality feed.

"At that point it's very difficult to get condition back on a ewe and there are reproductive costs associated with that," she says.

They conducted the study to discover why some ewes survive and thrive during the long dry WA summers, while others struggled.

"It all comes down to the condition they are in as they enter this dry period which typically involves lower quality feed, such as crop stubble and dry pastures," she says.

Whole farm modelling has indicated ewes in the top 25 per cent for efficiency in this study could be $6.90/head more profitable than ewes in the bottom 25 per cent over a 100 day period during summer.

"Ewes in poorer condition not only have less fat reserves to start that summer period but they also have lower levels of the leptin hormone which drives their behaviour in terms of finding a food source," she says.

"This is turn means the ewe will use more energy to find and process the food and be less energy efficient during these summer months."