TORONTO -- A Canadian meat processor must pay a $6,000 penalty for allowing thousands of free-range hens on their way to slaughter to suffer in frigid conditions, the Federal Court of Appeal has ruled.

In its decision, the court sided with the Canadian Food Inspection Agency and a review tribunal that Maple Lodge Farms -- already on probation for a similar offence -- had violated anti-animal suffering laws as well as its own procedures.

"Maple Lodge Farms held compromised spent hens in unheated lairage as part of their transportation for 12 hours," the Appeal Court said. "The spent hens experienced prolonged, undue suffering due to Maple Lodge Farms' omissions."

The case concerning 7,680 spent hens -- those no longer of use for their eggs -- arose on a frigid January in 2013 when an organic egg farmer in Chazy, N.Y., south of Montreal, shipped the birds to Maple Lodge Farms in Brampton, Ont.

It initially took several hours to load the hens in frigid conditions in New York onto an unheated trailer for a 12-hour journey that went through Quebec, where it was a "really cold" minus 18 degrees, before the hens arrived at about midnight in Brampton, court records say. On arrival, their trailer was taken to an unheated barn, which was around minus three degrees, and left there for a further 12 hours -- a period known as 'lairage.'

Because of their age and their tendency to peck each other in close quarters, spent hens are fragile and often have missing feathers. As a result, they are more susceptible to the elements.

By the time they were offloaded, at least 860 hens were already dead -- about 12 per cent of the total.

The inspection agency fined Maple Lodge $7,800 -- increased from $6,000 -- because of the seriousness of the offence and the company's prior history, including that it was on probation stemming from a 2013 criminal conviction for causing undue suffering to chickens that resulted in an $80,000 fine.

Maple Lodge Farms turned to the Canadian Agricultural Review Tribunal, which, after a 13-day hearing, upheld the citation in March last year but reduced the penalty to $6,000.

In turning to the courts, the company argued the tribunal hadn't given enough weight to, or ignored, evidence. The Appeal Court, however rejected those submissions, saying the tribunal's fact finding was entitled to deference. Maple Lodge also attacked expert testimony from a veterinarian -- to no effect.

"Dr. Appelt testified that the spent hens would have been shocked from the extreme cold at the outset of the transport -- from the four-hour process of rounding up and catching the spent hens and the further multi-hour wait at the farm," the court noted. "They would never have fully recovered during the drive from New York to Brampton."

As such, the load should not have been transported at all for which Maple Lodge has to be held accountable, the court noted.

"Omissions in its practices and procedures nevertheless prolonged the undue suffering of the spent hens due to undue exposure to the weather," the Appeal Court ruled.

The court also ordered the company to pay $5,000 in costs.