In his opening speech, Agriculture Minister Tihomir Jakovina said the fair was better every year because it had become not only a local brand, but a regional one too.
He was especially pleased by the European Commission's stall and the presentation of the common agricultural policy and partnership programmes.
Croatia has more than EUR 300 million from the Rural Development Fund available every year, so that everything we plan can help our producers and farmers, he said.
Bjelovar Fair director Zlatko Salaj said this was currently the biggest fair in Croatia by the number of exhibitors and visitors.
He said the exhibition area exceeded 25,000 hectares and that Croatia's European Union accession on July 1 enabled exhibitors from the Union to display their goods in Croatia.
Croatian Agriculture Agency head Zdenko Barac said 204 cattle breeders from Croatia were exhibiting at the fair with 552 heads of cattle.
The event closes on September 8 and organisers expect more than 50,000 visitors.