Shocking undercover footage has exposed workers punching and throwing chickens before they are slowly drowned in electrified stunning baths at a slaughterhouse.

Non-profit group Compassion Over Killing recorded the footage at an Amick facility in Hurlock, Maryland.

In 2018, a COK investigator worked inside the high-speed facility that kills up to 175 birds each minute - that's as many as over one million birds every week.

Workers were shown punching and throwing the birds as they moved down the kill line

Workers can be seen punching, shoving, and throwing birds down the quickly moving line in the video before the animals are shackled upside down.

Birds are also seen drowning in electrified stunning baths during an equipment break-down and others appear to have been scalded alive in vats of hot water.

Due to the speed at which the slaughter line is allowed to run at Amick Farms and other high-speed plants, animals can endure even greater suffering.

Dr. Sara Shields said: 'Birds can be seen–still hanging from the shackles–in the water bath…it is likely that the birds would have experienced prolonged, possibly painful electrical shock while they died of drowning.

'This situation is totally unacceptable from an animal welfare perspective.'

Hundreds of birds fill the slaughterhouse and up to 175 can be killed each minute at the facility

The shocking footage shows the chickens being shackled upside down by rough workers

Workers also endure the negative impacts of increased line speeds. While working there for a short time, the COK investigator suffered crippling pain and other hand injuries.

The investigator suffered swollen knuckles so severe their hand could not close and the fingers would not touch when extended.

In the filthy and fast-paced assembly-line environment, many workers also removed their shirts in the extreme heat, putting themselves at further risk as they operated dangerous machinery without even basic protection.

COK explained how most facilities operate at the staggering rate of killing up to 140 birds per minute and workers are forced to keep birds moving down the kill line.

Up until last month, 20 plants in the US were allowed to operate at the high-speed rate of killing 175 birds per minute.

Despite alarming problems at high-speed plants — including what COK caught on camera at Amick Farms — the United States Department of Agriculture recently allowed four more chicken slaughter plants to increase their speeds.

The National Chicken Council has urged the federal agency to entirely remove all caps on line speeds.

Shackled birds move towards electrified stunning baths in the powerful undercover footage

Compassion Over Killing's undercover investigator suffered swollen knuckles so severe their hand could not close after working at the Maryland facility

The agency denied this request, but instead of abolishing the program altogether, plans on granting more waivers to individual plants to run up to 175 birds per minute like Amick Farms.

Even before arriving at the slaughterhouse, birds endure severe overcrowding, filthy conditions, and the painful, crippling effects of unnaturally rapid growth.

At Amick and in other slaughterhouses operating with these increased line speeds, birds can endure suffering beyond cruel standard practices.

Erica Meier, Executive Director, Compassion Over Killing said: 'SDA's plan to allow even more slaughterhouses to increase kill line speeds that are already dangerously fast is a reckless step backwards.

The animals are kept in crammed into the slaughterhouse. Workers were filmed roughly handling the birds and throwing them

24 plants in the US are allowed to operate at the high-speed rate of killing 175 birds per minute

'Animals, workers, and consumers need more protection, not less.'

In a statement to the Washington Post, Amick Farms President Ben Harrison says: 'Some of the actions in the video are clear violations of our animal welfare policies and our company values.

'We are taking all appropriate actions including, but not limited to, further training, swift disciplinary action, and a more rigorous approach to ensuring compliance with our policies for the humane handling of our birds.'

This is the second time in just a few years that a COK investigation has exposed the horrors of high-speed slaughter.

In late 2015, a COK investigator worked inside Quality Pork Processors, a high-speed pig slaughter plant supplying Hormel Foods revealing pigs shocked, dragged, and pulled to the kill floor and pigs covered in feces.

COK has since delivered over a quarter million signatures against high-speed pig slaughter to the USDA.