Chairman Pete Morrison said 93.7 per cent of votes cast were in favour of the sale, and 89.8 per cent of votes able to be cast supported the move.
Around 6 per cent of votes were against the sale and 10 votes abstained.
Westland has only one interest class of shareholders and 2775 votes available for voting.
Yili is offering farmers $3.41 a share. Independent advisor Grant Samuel valued the shares at between 88c and $1.38.
In an offer valued at $588 million in total, it has committed under the conditional sale agreement to take on $342m of Westland’s debt and liabilities. Yili has also undertaken to match Fonterra’s milk price for 10 years and to pick up all milk for a decade after the sale.

Westland farmers have not received a market price for their milk for several years.
The deal now needs Government approval through the Overseas Investment Office and a tick from the High Court.