Traditionally producers considered the use of grazing crops for in-lamb ewes as being dicey at best. The practice was associated with high incidences of costly metabolic diseases.

Yet new data from Charles Sturt University (CSU) in Wagga paints a more positive picture.

The research was conducted at the CSU farm and with producers in southern NSW and the Riverina.

School of Animal and Veterinary Sciences lecturer, Dr Shawn McGrath has focused his PhD on grazing late pregnant and lambing ewes on dual-purpose wheat. All of the ewes in the study were grazed on Wedgetail wheat.

“We took measurements of lamb growth rates to establish whether this was an option farmers could consider in their system,” he said.

“The reason we were grazing late pregnant and lambing ewes on crop is because this is the time that ewes are most susceptible to metabolic diseases such as hypoglycemia and pregnancy toxemia,” he said. 

“By grazing them during that period we could establish whether the deficiencies we expected to see … would actually cause an increase in the prevalence of these metabolic diseases.”

Dr McGrath said in the field experiments this wasn’t the case and a prevalence of metabolic diseases didn’t eventuate. 

The cautious approach to grazing meant that there was a portion of producers who chose not to graze ewes that were in lamb on crop.

Dr McGrath said the practice did in fact work for producers who combined good management techniques and fed supplements including magnesium and calcium. 

The body condition of ewes was also imperative to making the practice work. 

“Ewes have to be managed carefully and need to be in good condition (with a body score of three) to help minimise the risk of metabolic conditions,” he said.

To manage ewes carefully and make sure they are in good condition because having ewes in good condition can minimse the risk of metabolic conditions. Dr McGrath said producers now had an option and could consider lambing down on crop each year. “It also offers a solution for when the season runs out and producers are looking to put sheep on crops.”