Speculation is mounting that the freezing weather could result in fewer lambs on the ground next spring.
Sheep farmers struggling to manage snowbound flocks during the recent cold spell could be facing a double whammy of higher winter costs and lower litter size, experts have warned.
Flocks due to lamb down after St Patrick's Day could be worst affected because the mating coincided with the worst weather, claimed Teagasc sheep expert Michael Gottstein.
Both nutrition and fertility levels have been affected by the cold weather, he warned.
Hill ewes brought down to the lowlands for mating normally benefit from a higher plane of nutrition and gain body condition score before and during the mating season.
During a normal year, the ewe could improve from a body condition score of 2 to 2.5 or 3 during their six to seven weeks on lower ground.
However, in many cases, the nutritious lowland pastures have been covered by frost and snow for at least three weeks and, as a result, there is concern that ewe body condition scores will not improve enough.
In fact, there is a risk that the ewes will lose more body condition by searching for grass, despite being fed hay or silage.
"If the ewes do not receive adequate flushing, this could have a negative effect on both the litter size and their chances of survival on the hill this winter," Mr Gottstein said.
In some cases, thinner ewes will have to be taken back down off the hills for supplementary feeding, driving up production costs on the farm.
However, the negative effects of frost and snow are not limited to the females.
"There is potentially an issue with rams walking in snow," he said. "Some breeds, particularly the continental breeds, have less wool covering on the testicles and the low temperatures could have a negative impact on semen quality."
Meanwhile, the Department of Agriculture has insisted that the requirement to electronically tag sheep will not be extended to include lambs destined for slaughter. Last week, the ICSA sheep committee chairman, Mervyn Sunderland, predicted that electronic tagging would be extended to lambs going directly from their farms of birth to slaughter.
However, this suggestion was rejected by a Department spokesperson, who said there were no plans to change the existing derogation which allows lambs going directly for slaughter to be tagged with conventional tags.