13/01/2013 17:38 GMT | Updated 15/03/2013 05:12 GMT

Do Farm Animals and Humans Have Anything in Common? A Case for the Vegan Option Continued

Farmers who rear animals on an industrial scale often justify their welfare standards by claiming that animals are not like us.

In so saying they seem to imply that animals do not mind being kept in conditions totally alien to their needs and closely confined in vast sheds. Sows in gestation stalls. Piglets reared on slatted floors. Ducks without water except to drink. Poultry on stinking bedding rank with ammonia fumes. Cows and calves separated at birth. Is it a stretch too far to suppose that these animals - motherless, sick, filthy; trapped, afraid and defenceless - do not suffer fear, anxiety and distress as they live out their utterly wretched lives, their spirits broken, in conditions that are akin to torture?

Some people equate intelligence with sentience. Yet we do not believe that our own babies are incapable of feeling pain or fear or all the other reactions associated with sentient beings.

If we look at the similarities between us and the animals we farm, it seems there are a raft of ways in which we are not so very different at all. We share the same instincts and behave in similar ways although we give them other names. We make nests - but call it home. We suckle our young - but term it breast feeding. Our bonds with our offspring are no more - or less - strong. We too defend our territory. We too like to have friends and be in groups of people we trust. And, like sheep in a flock, we follow where others go - as sports fans or followers of fashion or members of clubs. Neither is our instinct to escape from danger or to protect our young different from any other mammal. When our backs are against the wall, our fear and anxiety, our terrified, panic-stricken reaction, are just the same. How must animals feel when they are rounded up for slaughter and rushed up ramps onto lorries?

Also, like us, animals have their own characters and personalities. Some might be boisterous or irritating. Some crave affection. Others are playful. Some like cuddling up with others. Others like their own space. Some are aggressive, others cowardly. All have their own personal likes and dislikes. Pet owners know this. Yet we seem not to recognise that animals reared for food have any individuality at all.

If common sense does not tell us that animals suffer in factory farm conditions then the science might. There are a plethora of studies that make clear that all animals share instinctive emotional behaviour like joy and happiness; depression and suffering; affection and irritation; rage and terror. The Cambridge Declaration on Consciousness, signed by an international group of prominent scientists, is one of the most recent.

But where farming is on an industrial scale animals have no choice. Every aspect of their lives is controlled. They do not choose their surroundings. Or the animals they mix with. Or what they eat. Or when they eat. Or when or whether (given hormones and artificial insemination) they mate.

Factory farm conditions are, by design, violent, cruel and unfeeling. Do we have a moral obligation to the animals we use for food?