Ahead of tomorrow’s GDT auction, dairy giant Fonterra has announced changes to its product volumes which tell us a lot about the evolving supply picture in New Zealand. With the country experiencing a wetter than normal spring, milk production on many New Zealand dairy farms has slowed sharply and milk collections in October are well back, according to Fonterra. October is the month when milk output in New Zealand hits its peak. As a result of the tightening milk supplies, Fonterra has been reducing its forecasts for the amount of product it will be able to sell at this week’s GDT auction, as well as for the rest of the year. The reduction in product volumes is likely to help dairy commodity prices continue their recent upward momentum.