But Mr Oswald said juggling his book launch with the lambing season had been challenging.
They found many fights took place during the lambing season, when food was scarce.
BBC: NEWS | UK | Scotland | Edinburgh, East and Fife | Ewes not sheepish over fighting
The bacteria responsible were thought to have been carried on the wind from lambing nearby.
Sheep farmers are on "tenterhooks" as lambing season builds because of the Schmallenberg virus, a Herefordshire farmer says.
"You expect one problem in one department every year, be it drought or wet, or poor lambing percentages or something, " he said.
The cold weather "couldn't have come at a worse time" because it coincided with the height of the lambing season, said NFU spokesman Mike Thomas.
The sheep would normally return to farms on higher land at this time of year for lambing and to allow cattle onto the lowland pastures.
CNN's crew visited the biggest sheep farm in Southern Greenland with about 800 animals during lambing season, when baby sheep are born every few minutes.
He added that he had heard anecdotal evidence of "up to 45% of lambs on some farms" being affected in the lambing season so far, which runs from December to May.
North Wales was hit by very heavy snow for several days from 21 March with large drifts that prevented farmers in many areas reaching their sheep at the height of the lambing season.
Pregnant women should also avoid contact with sheep and newborn lambs during the lambing season because there is a small risk that an infected sheep or lamb could pass the infection on at this time.
"With lambing only a few months away, that would send out a positive signal to producers and help lift some of the gloom generated by one of the more difficult seasons on record, " he said.
Although hill farmers are used to dealing with snow, this year it has come much later in the season when sheep are at their most vulnerable because they are in the late stages of pregnancy or at the start of lambing.
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