Full-time staff have also been forced to take a 20% cut in hours.
Auctioneers Frank Marshalls made the decision after the spread of foot-and-mouth disease suspended livestock sales.
Only two agricultural auctions are now held each week.
"It is bleak already but it will get bleaker," said Alan Lane, partner in Frank Marshalls.
"It is too early to tell what further action we will have to take."
Two workers were made redundant this week and the 50 remaining staff are now working a four-day week.
Horticultural sales still continue on Wednesday and Thursday evenings, including the sale of bedding plants, potted plants and vegetables.
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