Bioclip vs shearing to reduce grass seeds
From the November 2008 edition of Agriculture Today.
It’s the dreaded grass seed season, which costs the sheep industry greatly each year.
Recent research is backing up previous logic that shows reducing wool length leaves both wool, and the carcases of sheep destined for slaughter far less contaminated than if sheep remain unshorn.
Grass seeds from species such as Barley grass, Spear grass, Silver grass, Wire grass and Erodium wool, cause the problem.
"Processors suffer inefficiency along the slaughter chain, associated with the heavy trimming required on heavily infested lambs," one of the trial operators, Jane Mason, said.
Ms Mason, NSW Department of Primary Industries (DPI) sheep and wool livestock officer for the Central Tablelands, says producers pay the price in downgraded carcases and skins and must also suffer the animal health and production consequences of seed infestation.
These consequences include abscesses, reduced weight gains, increased lamb mortality, reduced market advantage and quality assurance, and food safety.
Ms Mason said a recent trial set up at multiple sites near Yeoval in the Central West aims to explore the most efficient and economic methods for reducing grass seed contamination in weaner sheep in their first summer.
The trial, funded by Meat and Livestock Australia, was initiated by a group of local sheep producers under the direction of Karl Behrendt of Agrorum Consulting in Bathurst.
The trial examines the animal and pasture management systems suggested to reduce the amount of grass seed pick up.
Conventional shearing is one strategy known from previous research to reduce grass seed.
However, no research had ever been done on whether reducing wool length by the Bioclip method of de-fleecing consequently reduced seed contamination.
The Bioclip side of the trial has been performed by Shepherd Operations, Molong, with a major contribution by Anthony Shepherd.
The first part of the current trial, initiated last summer at Roseville Park Merino Stud near Yeoval, explored the biological benefit of using Bioclip to reduce grass seed pickup, compared to conventionally shearing or not shearing at all.
Results have been consistent with previous research, suggesting that reducing wool length, regardless of the harvest method used, reduces seed contamination in weaners in both skin and carcase.
Similar results were recorded for bioclipped or conventionally shorn sheep but leaving sheep unshorn was significantly unfavourable.
Economic comparison between conventional shearing and the Bioclip method is yet to be completed.
Other NSW DPI staff, livestock officer Ashley White and researcher, Edwina Toohey, have also provided expertise into the meat science side of the trial.
The next stage of development will look at pasture management systems that can be used to reduce grass seed contamination in young sheep.
Contact Karl Behrendt, Bathurst, (02) 6336 3001, or Jane Mason, Orange, (02) 6391 3967.
