season.

Industry & Investment NSW livestock officer from the Glen Innes Agricultural Research Station, Chris Shands said the abundance of quality feed will present challenges producers had not encountered in recent, leaner years.

"The main risks to lamb survival are starvation and mismothering, mainly caused by poor nutrition in late pregnancy," said Mr Shands.

"Abundant feed supply this year should help reduce losses from this problem, but it is likely that single bearing ewes on high quality feed will be over nourishing their lamb.

"This will lead to a single lamb growing too quickly in the last two to three weeks before lambing and there is potential for this fatter than normal ewe to have difficulty lambing.

"Lambs with birth weights at six kilograms or heavier have a greater chance of getting stuck during the lambing process,” he said.

Sheep and livestock officer Orange, Jane Kelly said farmers can prevent their ewes from having difficulty this lambing season by restricting pasture access.

“Farmers should be scanning their ewes at 90 days to confirm single and twin bearing ewes so they can allocate the best feed options.

“Overweight stock should have their intake of feed minimized and score levels should be maintained with an ideal score of 3.

“Producers should be trying to bring back any overweight ewes to the ideal score level before the last four weeks of pregnancy,” she said.

Ms Kelly said that pasture targets for single bearing ewes should be no more than 800 kilograms of green pasture or fodder crop, equivalent to no more than two centimeters of pasture height.

“Twin bearing ewes should be on a pasture height of three to four centimeters,” Ms Kelly said.

“Maintaining the weight and pasture intake is vital for all ewes as they are highly susceptible to pregnancy toxeamia if they are not receiving the right energy intake through diet,” she said.