"We will probably have to go to 24 hours [production] to keep up."
While sales volumes are up, a lot of farmers are choosing to pay a little less for mid range rather than premium feed.
And prices overall have come down because SealesWinslow invested nearly $1 million in the Wanganui plant last year, upgrading production lines and improving efficiency.
"We've been able to lower the price and pass that on," Mr Brown said.
SealesWinslow is owned by Ballance Agri-Nutrients, a farmer-owned co-operative, and it has to weather the ups and downs of the dairy market. Mr Brown said dairy prices had a six to seven-year cycle.
"Farmers that have been through it before know you just need to hunker down and trade through it. We need to support our shareholders through the journey."
Other boosts to SealesWinslow business have come from beef rearers investing in supplementary feed. More people will be rearing beef cattle in the coming season, as farmers keep more bobby (male) calves than usual and grow them on for beef.
They will be keeping more this year to maintain beef production, after a season when dairy farmers have culled more of their unproductive cows than usual.
Poor weather and the lack of grass has meant sheep farmers have been buying feed "for the first time in many, many years".