He urged those farmers who had yet to make a decision or cast their vote to take part and make sure they had their say.
"This is really one of the most important decisions that farmers will make.
"Our strategy and capital structure - they really go hand in hand – one helps the other."
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Protecting a strong New Zealand farmer-owned co-operative of scale was in all of New Zealand's interests, Rivers said.
"Scale efficiencies is what we need to deliver value to all of our New Zealand communities."
Fonterra's milk price also set the benchmark for the prices Kiwi dairy farmers were paid for their milk, Rivers said.
"So even farmers who don't supply the co-op actually benefit from it."
Scale efficiencies kept Fonterra's manufacturing sites utilised effectively and increased the co-op's ability to invest in on-farm support services, innovation, new markets and product development, Rivers said.
"All of that creates value for New Zealand in terms of milk price and profits, export performance, employment, environmental performance, and community development.
"So, I just really encourage farmers to vote."
If farmers had any questions, they should contact their director or area manager, Rivers said.
The special meeting on the capital structure is at 1pm on Thursday December 9. During that time voting opens for those who attend the meeting.
Once the meeting is closed the votes will be counted and Fonterra will let farmers know the results as soon as possible after they have come in.