Two crofters have sought compensation after a neighbours' bull broke through a fence and impregnated one of their pedigree Highland cows.
Bernard and Kathleen Allen, of Great Bernera, Isle of Lewis, allege the Belted Galloway bull was repeatedly found on land where their livestock was kept.
They claim the incidents compromised the status of their herd.
The Allens have sought more than £20,000 in compensation.
The case being heard at Stornoway Sheriff Court on Lewis is expected to last several days.
Their former neighbours David and Janine Hargreaves, who owned three pedigree Belted Galloway heifers and a bull, now live in Ardgay in Sutherland.
They deny the claims and argue that it was the responsibility of their neighbours to ensure their fence was stock-proof and that other cattle nearby could not compromise or interfere with the animals' high-health status.
The court heard that Mr and Mrs Allen became aware in 2009 that the bull was among their cows and it had damaged fences.
This happened, they claimed, about 30 times until 2010 when a two-metre high fence had to be erected.
It is further alleged that in 2010 one of the pedigree Highland cows gave birth to a Belted Galloway calf.
The case continues.