Warning: Article contains images and details that some may find distressing
Injured and bloodied piglets forced to live among rotting corpses are just some of the horrors revealed by undercover investigators on British pig farms.
The footage released by People for the Ethical Treatment of Animals (PETA) UK shows the "hell holes" that some livestock are forced to live in.
Dead newborn piglets can be seen on film still attached to their mother's placenta.
The undercover investigator who filmed the footage, who asked to remain anonymous, spoke to the Huffington Post UK about what he found on the three farms he visited in Norfolk and Yorkshire, all of which feature in the video.
"They are all hell holes and the vast majority of them are really bad. If the average person were to visit a typical British farm they would be appalled," he said.
"It's so disgusting - the industry marketing. After we have been to a farm and compare it to the happy, colourful images of the animals on the website, it's just horrendous."
"The animals live in their own filth."
The investigator, who has visited a number of farms over the course of many months, said that the hygiene he has seen in the facilities is "horrendous".
Speaking about what he found on the farms he visited, he said: "There were numerous dead pigs.
"We first noticed them when we first walked next to the pig sheds and the pigs were startled... the pigs moved but we noticed some that didn't; some that were dead.
"Then we noticed that some were injured and there was blood. We found another one that was partially immersed in the waste.
"In total we saw around half a dozen dead in that one farm and we didn't even have time to check all the sheds."
The footage, which was released by PETA, shows pigs living in enclosures with deceased animals.
Elisa Allen, PETA's Associate Director, said: "The appalling neglect and abuse documented at these farms is rampant in today's industrialised meat industry.
"The only way for consumers to avoid contributing to the systematic suffering of animals on factory farms and in slaughterhouses is to leave animals off their plates and instead choose from the abundant vegan options available in supermarkets today."
PETA reports that many piglets have their teeth clipped or ground down and their tails cut off without being given any painkillers on British farms.
Before they give birth, mother pigs are confined to farrowing crates so small that they are often unable to turn around.
The footage was passed on to the RSPCA who has raised concerns about the welfare of the animals.
An RSPCA spokesman said: “We have concerns over the health and welfare of some the pigs shown in the footage we received.
“In any farming system, animals can become sick and injured but when this occurs they should receive prompt and effective treatment. We are currently investigating this issue.
“We would always urge anyone with concerns about animal welfare to contact us on our Cruelty and Advice Line 0300 123 4999 as soon as possible so we or the relevant authority can act on the information and alleviate any potential suffering.”
Zoe Davies, chief executive of the National Pig Association, told The Mirror: “Accidents, injuries or infections can happen in any type of pig accommodation. What matters is the skill, expertise and care exercised by the stockman in identifying problems and dealing with them appropriately.
“Whenever welfare allegations are made about a pig unit, an immediate independent inspection is automatically triggered.”