Wales' chief veterinary officer says it is possible that some cattle were infected with the Schmallenberg virus (SBV) and therefore anticipates "calving problems later in the year as a consequence."
Dr Christianne Glossop says since the first clinical case of the disease in Wales in November last year there have been a further 11 positive cases of SBV in sheep.
Dr Glossop is encouraging farmers to be vigilant for signs of the disease and to seek swift veterinary assistance if they have any concerns.
More top news
A milder feel than last night but there's wind and rain on the way, and ice will form in places too!
Public Health Wales has spoken to ITV Cymru Wales about how to safe and well during the winter months.
Paramedics are poised to deal with any emergency – but 35,000 feet in the air is the last place you'd expect to have to spring into action.