The decision to offer only oat milk smoothies on a stand at the National Eisteddfod has been criticised, as the event is taking place on a dairy farm.
The event hosted by Ceredigion council in Tregaron, with the local authority giving the smoothies on its Pentref Ceredigion stand.
But a farmers' union complained, calling the move "perplexing".
Ceredigion council is now offering a dairy and non-dairy option to visitors at the cultural festival.
It said oat milk smoothies were originally the only option due to so many children being allergic or having intolerance to dairy milk.
NFU Cymru President Aled Jones said: "The National Eisteddfod is a celebration of Wales' language, culture and heritage and agriculture is an integral part of the fabric of rural communities in Wales.
"We were extremely disappointed to learn that Ceredigion County Council was only offering children visiting its Pentref Ceredigion stand oat drink smoothies."
He described the decision not to offer milk "perplexing" considering the fact the National Eisteddfod is at "a prominent dairy farm in the heart of a rural community".
NFU Cymru representatives met council officials at the National Eisteddfod on Wednesday, with a follow-up meeting planned for after the event.