Robert F Kennedy Jr and Mehmet Oz have failed in their efforts to spare the lives of 400 ostriches at a farm infected with avian flu.

A panel of three judges in Canada dismissed the appeal of Karen Espersen and Dave Bilinski, the owners of Universal Ostrich Farms, 55 miles north of the US border.

Mr Kennedy, the US health secretary and Dr Oz, director of the Centres for Medicare and Medicaid Services (CMS), joined a raft of activists fighting for the cull to be stopped.

The mass slaughter had been ordered by the Canadian authorities after the highly contagious disease was detected in two bird carcases at the 65-acre farm in Edgewood, British Columbia.

A federal court upheld the ruling despite hundreds of protesters descending on the farm to plead for the birds to be spared.

The farm’s owners resisted the demands for a cull, saying the remainder of the flock was healthy.