The ICSA has called on the Road Safety Authority to urgently reverse the decision to reduce maximum vehicle heights to 4.65m.
Under these new restrictions, the vast majority of lorries transporting fodder will have their loads significantly cut.
Only two rows of 4x4 round bales will be legal on lorries, while large square bales, typically three feet high, will only be legal when loaded three high on most trailers.
ICSA president Gabriel Gilmartin said: “These restrictions, which come into force on November 1, will reduce a typical load of straw by one third. Haulage costs will remain constant, so the cost of bales will inevitably rise. Early indications suggest that this could be between €5 and €10 per bale.
“This change will have dire implications for farmers buying fodder this winter, particularly those dependent on straw being transported long distance from the east and south of the country. It is a restriction that is unworkable in practice and must be reversed as soon as possible.”