(Adds details on exports, background)
Aug 1 (Reuters) - Fonterra FSF.NZ FCG.NZ , the world's biggest dairy exporter, on Thursday said milk production in June climbed 13.9% year-on-year in New Zealand, as mild weather conditions improved collection in the current season.
New Zealand milk collection rose 8% from a year ago in June, the first month of the 2019/20 season, the company said.
The dairy exporter, however, said Australian milk output declined 13.6% in May due to reduced herd sizes and high input costs.
In May, the firm said it would shut a plant in Australia as reduced supplemental feeding, increased cow cull rates and a high number of farmers leaving the industry has dented its output in the country. group's dairy exports from New Zealand climbed 17.1% in May compared with a year-ago period, driven by whole milk powder and fluid milk products, while exports from Australia rose 1.7%.