Sheep producers can boost their bottom line by thousands of dollars by using rams that are genetically resistant to intestinal worms.
Intestinal worms cost the national sheep flock $370 million each year in lost production, drenching and flystrike.
Research on the Department of Agriculture and Food’s Rylington Merino Flock has demonstrated that gains of $2.50 per head can be achieved by including breeding for worm resistance – equating to $5000 per average sized flock of 2000 head.
Department senior research officer Johan Greeff said immediate gains could be achieved by using rams with low Australian Sheep Breeding Values for worm egg count (WEC).
“Genetic theory indicates that by using rams with a WEC of minus 50 and crossing it with an average ewe, a 25 per cent gain in WEC resistance can be expected in its progeny,” Dr Greeff said.
“However, research by the department has shown that an increase of 33 per cent was achieved at a flock level, as the improved resistance and reduced pasture contamination protects the more susceptible animals, making it more possible for them to deal with higher worm burdens.”
The cost savings are actually greater, as drenching can be reduced by 10 per cent in adults and 15 per cent in young animals.
Importantly, the gains in WEC resistance did not compromise other traits – rather production performance improved.
“The sheep were on average 0.5 kilograms heavier, because the animal’s performance was less affected by worms due to the higher resistance and reduce pasture contamination,” Dr Greeff said.
“The wool was also 0.5 microns finer and there was no loss in clean fleece weight.”
Flystrike was also reduced, as there was less scouring from worm resistant sheep.
Dr Greeff said the financial gains were likely to be higher than $2.50 per head, when cost savings from reduced drenching, flystrike treatments and labour costs were incorporated.
The Rylington Merino Sheep Flock, based at the department’s Mount Barker Research Station, recently celebrated its 25th anniversary and is profiled in this edition of Ag in Focus available from department offices.
Media contact: Jodie Thomson/Lisa Bertram, media liaison +61 (0)8 9368 3937