More than 46 billion chickens are killed worldwide every year. Chickens are usually either bred and raised directly for their flesh (broilers) or for egg production (layers). Most chickens used for egg production spend their lives in overcrowded sheds filled with tens of thousands of other chickens with no room to move around or perform behaviors that come naturally to them. It’s not uncommon for stressful conditions to induce heart attacks in chickens. Since chickens are viewed by the industry as expendable and veterinary care isn’t cost efficient, ailing chickens go without treatment and the decomposing bodies of dead chickens left in their sheds further contributes to an unsanitary environment. As a means to prevent chickens from pecking at one another (unusual behavior they display only in extremely painful circumstances), factory farms use a hot razor to sever the tips of their beaks. Many layers are so malnourished that their bones break when they’re picked up. When they’re no longer able to lay eggs, they’re typically sent to the slaughterhouse at around a year old (they have a natural lifespan of around 7 years). Since males can’t lay eggs, they are immediately killed at birth, normally by being thrown into a grinding machine, suffocation, being shocked by electrified plates or sent, fully conscious, through macerators. Broilers have slightly more space to move around than layers do, they aren’t shoved into crates but instead live on the ground of barns. Broilers are fattened up, through selective breeding and being given a diet of high fat feed with antibiotics, and grow at a drastically more rapid pace than chickens in the wild do. Since their bodies can’t naturally support the weight, they’re often incapable of walking. Contrary to popular belief, the conditions for ‘free range’ and ‘cage free’ chickens aren’t much better. Legally, the claim that chicken derived products are ‘free range’ only requires a small, narrow opening in a shed housing tens of thousands of chickens which can’t accommodate all of them. ‘Free range’ chickens are ultimately killed in the same way that other factory ‘farmed’ chickens are, being hung upside down while their throats are slit before being scalded in boiling water to remove their feathers.
Cattle are also divided into two groups when it comes to human use, those exploited for milk production and those for their flesh. Worldwide, around 300 million cows are raised for their flesh and around 200 million for milk production (I’m assuming this is limited to cows in organized, modern Western style factory farms). Because bulls behave aggressively in restricted, tight quarters, they are dehorned and castrated without anesthesia. Like the male offspring of chickens used for egg production, male calves are separated from their mothers a few days after birth, in the ‘wild’, they would normally stay with their mothers for around 9-12 months. As fellow mammals, cows have the same maternal-offspring bonding need that human mothers and their small children have (the same is also true for chickens who have an empathetic response to the distress of their chicks). These male calves are restricted to tiny stalls for almost half a year and are fed a low protein/iron diet to prevent their muscles from developing so their flesh (‘veal’) remains soft. This is actually illegal in the E.U and some U.S states. Like chickens, cows are fattened up and made to support more weight than they can, their bones are also brittle and weak as a result of poor nutrition. Cows used for milk production are made to produce 9.5 tonnes of milk a year, after around 4 years of having been milked painfully by machines and constantly separated from their offspring, it’s not uncommon for them to drop dead from exhaustion before being sent to the slaughterhouse. If they can survive that, they are electrically stunned and, like chickens, tied upside down and cut open until they bleed to death. They have a natural lifespan of around 20 years.
Around 1.3 billion pigs are killed worldwide every year. Pigs, who, like cats and dogs, make affectionate and friendly companions ( although more intelligent, as chickens and probably cows are as well), are kept in tiny, unsanitary cages with chains tied around their necks. Piglets are separated from their mothers at around 3-4 weeks, they require around 13-19 weeks of weaning. Pigs naturally have around 6-8 piglets a year, on factory farms, they’re constantly impregnated and made to have around 20 piglets a year. In frustration, pigs will bite at the tails of other pigs near them, to deal with this, factory farms use metal pliers to clip their teeth and the tips of their tails, without anesthesia. Like other factory ‘farmed’ animals, pigs can literally die from the stress of their lives alone.
Around a month before I became a vegan, when PETA’s ‘Meet Your Meat’ video convinced me to stop eating the flesh of chickens (I had stopped eating ‘red meat’ months earlier), I rationalized my continuing to eat fish and marine invertebrates by claiming that they lacked nervous systems complicated enough to feel pain. I don’t think any modern scientist would take seriously the idea that humans are the only sentient animals on the planet, there’s virtually irrefutable evidence that all mammalian nervous systems (as well as avian nervous systems) are too similar to ours for humans to be the only sensitive, feeling animals, we also have good reason to believe that all vertebrates are sentient and to give the benefit of the doubt to ‘simple’ invertebrates as well. Fish have physiological and behavioral responses that indicate pain and their brains fire neurons in the same way that human brains do when humans feel pain. This isn’t ‘proof’ but it’s evidence. As a pescetarian I claimed that fish can’t feel pain because they lack a neocortex but different species use different brain structures to handle the same functions (even in humans, in cases where an entire hemisphere, or certain regions, of the brain have been removed or impaired, other regions of the brain will compensate). Not only do fish respond as though they feel pain but they actually alter their behavior as a result, they’ll avoid nets if they remember having seen another fish being caught in one, for example. An estimated 90-100 million “tonnes of fish” are killed each year so even more so than chickens, human dietary preferences might victimize fish and other marine creatures more than any other group of animals besides maybe insects. Hundreds of thousands of birds, turtles and marine mammals like dolphins and whales are also killed in fishing nets every year.
Like vertebrates, many invertebrates produce natural opiates and substance P and they show less of a reaction to noxious stimuli when given morphine which suggests that they can feel pain and morphine helps to alleviate that pain. Fruit flies avoid odors they associate with having been electrically shocked and pursue odors they associate with rewards like sugar. Cockroaches who underwent similar differential conditioning trials also associated the smell of peppermint with sugar and vanilla with saline and pursued and avoided both accordingly. Bigger brains do not necessarily indicate a greater capacity for complicated functions. Vertebrate neurons project a single axon whereas invertebrate neurons have several axons that are each capable of functioning independently, I’m not sure how this might relate to sentience but invertebrate neurons aren’t as primitive as we’d assume. Consciousness is just the processing of information and neurons are specialized information processing cells that all ‘animals’ have.The nervous system of every animal on the planet descends from a common ancestry. If insects and other ‘primitive’ invertebrates are sentient, then they make up the majority of sentient beings on this planet and it’s possible that most of the suffering (or enjoyment) felt in the (this) world is felt by them.
Tens of millions of non-human animals are dissected, gassed, burned, infected, electrocuted, blinded, poisoned etc. by scientists every year, often for almost certainly unnecessary things like testing the safety or effectiveness of cosmetic products or household cleaners. I won’t get into vivisection or deforestation (and the displacement of ‘wild’ animals by humans), zoos, circuses, commercial pet breeding, poaching etc. There’s also a strong ecological argument for veganism and I won’t get into how surprisingly intelligent non-human animals we exploit for food and other purposes are as well intelligence and non-‘instinctive’ behavior in animals like honeybees, wasps, . I don’t see intelligence as having any direct moral relevance, if a person (being) can suffer or enjoy, then their suffering or happiness should be given the same consideration that any other being’s would. There should be no moral hierarchy.
Although I became a vegan based on the idea that all sentient beings are equal, it wasn’t explicitly on the basis of hedonistic utilitarian reasoning (although I did think that sentience was the only morally relevant criterion), which I would now use to justify veganism and to criticize unnecessary mistreatment of non-human animals. A utilitarian argument for prescribed animal rights would have to concede that factory farming, vivisection, and other exploitation of non-human animals can be theoretically justified but not giving non-human interests the same consideration we would give human interests isn’t even hypothetically justifiable. Giving all animals equal consideration means that if causing a great deal of suffering to humans (or depriving them of happiness) was the only way to prevent a greater amount of suffering in non-human animals or produce a greater amount of pleasure for them, the utilitarian actor would be just as willing. If they aren’t then they aren’t giving non-humans equal consideration. The cost of factory farming clearly outweighs the benefit, the minor pleasure that affluent people who can afford a healthier plant based diet gain from eating the body or bodily products of factory farmed animals doesn’t outweigh the unimaginable, constant agony of the victims. Affluent humans don’t need to eat meat for their well-being. It’s easier to take a utilitarian argument for vivisection seriously when you consider how much suffering a cure for AIDS, cancer and other medical illnesses could alleviate but there’s no direct reason to prefer that the victims be non-human (if vivisection is a necessary evil to begin with). There’s the issue of humans living in fear if they knew they could be abducted and used for experimentation but that could be dealt with by using orphaned infants, some mentally retarded adults or prisoners, not because the suffering of these humans would count for less but because the general population could assure themselves that it won’t happen to them or their loved ones as long as they avoid committing serious crimes. Results from experimentation carried out on humans would be more applicable which would make the pain caused less likely to have been for nothing. Animal rights theorists who take a deontological stance against animal testing but view the killing of non-human animals for food in times of famine should be consistent. Also unlike deontological animal ‘rights’ supporters, I no longer see the exploitation (‘use’) of humans or non-humans as necessarily bad if the exploited are neither harmed or deprived of happiness.
Easily refuted arguments against veganism include “animals have no moral code and kill other animals, ” (infants and some retarded humans can’t morally reason either, and some humans also kill other animals, but moral consideration doesn’t have to be earned and it can’t be forfeited, veganism only requires that humans have a moral code, never mind that most non-humans kill to survive and the ones we eat are primarily herbivorous), “what about plants” (there’s no evidence for sentience in plants, even if there were, we need plant food to survive, we don’t need animal flesh), “animals die in the production of agriculture, everything from ink to roads and things which are virtually unavoidable contain animal products or are the result of exploiting non-human animals” (this is true but causing some pain is unavoidable in life, it’s better to cause less suffering than more), “animals don’t have souls and/or are less intelligent than humans” (either an animal can experience some degree of pleasure/pain or they can’t, how intelligent they are or whether or not they have souls is irrelevant to that), etc.
Preference utilitarians typically argue that most non-human animals can not be considered as ‘persons’ because they lack self-awareness and a(n illusory) concept of being the same being who exists over extended periods of time, they don’t have an interest in continuing to live because their desires are moment to moment and they can’t conceive of their lives in an abstract way. It may (or may not?) be true that most non-human animals do not have extended future oriented desires or an abstract desire to continue living since most non-human animals lack episodic memory and the self-awareness it requires but I view desire and (non-felt) desire fulfillment as being of neutral value. You can’t practically produce meat, dairy or eggs for millions of consumers without causing pain to the animals these products come from, I think most preference utilitarians would admit to this, but even if we could painlessly kill pigs for food, if pigs enjoy their lives then their deaths would deprive them of something beneficial, whether or not they have a future oriented desire for what they’re being deprived of or can appreciate this in some abstract way is irrelevant, we can. It’s also been pointed out that the happiness of a being can be ‘replaced’ by bringing another equally happy being into existence but if you can avoid killing one and bring more relatively happy beings into existence, there would be more well-being in the world than there would otherwise have been. I think pleasure, and not the realization of preference, is what makes a life worth living. Desire is consciously felt, if the realization or thwarting of a desire isn’t consciously felt, which would be pleasing or distressing and good or bad on that basis, in what meaningful way has that desire been satisfied or frustrated?