The 8th US Circuit Court of Appeals backed the three-month jail sentences given last year to Austin "Jack" DeCoster and Peter DeCoster.
The Centers for Disease Control and Prevention (CDC) estimated that about 56,000 people fell ill with salmonellosis in 2010 after consuming contaminated eggs, according to court documents.
In August 2010, officials determined the Salmonella outbreak had originated at Quality Egg's facilities.
Quality Egg recalled eggs that had been shipped from five of its six Iowa farm sites between May and August 2010.
A Food and Drug Administration (FDA) inspection of operations in Iowa in August found live and dead rodents and frogs in the laying areas, feed areas, conveyer belts, and outside the buildings.
They also found holes in the walls and baseboards of the feed and laying buildings.
Quality Egg was sentenced in 2015 to pay a fine of $6.79m and placed on probation for three years.
A year earlier, the firm pleaded guilty to one count of bribery of a public official, one count of introducing a misbranded food into interstate commerce with intent to defraud and one count of introducing adulterated food into interstate commerce.