The use of farrowing crates in intensive pig production has come to be a highly controversial and emotional issue. Their continued use has polarised opinions. According to the "Protecting Animals in Democracy" campaign, farrowing crates are "a profound welfare insult" and "a severe curtailment of..natural behaviour". However, despite the actions of groups like these, farmers continue to use and support crate systems. One American farmer says "I thought they might be cruel. Boy, was I wrong! Instead of carrying out buckets of dead baby pigs, I now have a 95-98 percent survival rate." According to a report by the British Pig Executive, in 2002 around 95% of indoor pig production in the UK was based on farrowing crates.
This report will look at both the advantages and disadvantages of crate systems, the alternatives available and the future of farrowing crates in the EU. But first, an explanation of what farrowing crates are is necessary.
Developed in the nineteen sixties, farrowing crates are metal cages that are used to contain sows for eight weeks between the late stages of gestation and the weaning of piglets at four weeks of age. The term is often used, however, to also describe gestation crates or sow stalls, which contain the pregnant sows until just before farrowing. Sows can be in these crates for their entire gestation, which is around 3 months, 3 weeks and 3 days, or 115 days.
The crates are just a few inches wider and longer than the sow herself. This means that the sow cannot turn around, or walk about, and her movement is restricted to sitting or lying down and standing up. Feeding and water will most likely be automated and piglets will be provided with a warm "creep" area in which to sleep.
So Why Use Crates?
The first reason that farrowing crates were adopted was, in fact, sow welfare. By confining the sow in individual pens, it stopped fighting and bullying amongst sows. However, this was superseded by more financial benefits the crates offered.
An on-farm study conducted in Minnesota showed that crate systems consistently gave higher numbers of piglets weaned per sow per litter. This is the main advantage that crate systems offer a farmer, and of course any system that reduces piglet mortality increases the gross margin attainable per sow.
The reason for this reduction in piglet mortality, and therefore increased profitability, is the restricted movement of the sow. The confining nature of farrowing crates mean that it is virtually impossible for sows to stand on or to lie on piglets, which is a considerable problem in other systems.
There are other, secondary, advantages to crate systems. Because the space allocated to each sow and litter is limited, less space is required per sow than in other systems.(This reduces costs and increases the profitability per hectare of the enterprise. The fact that the animals are all inside allows the temperature of the farrowing house to be carefully controlled and monitored.
The sows and piglets live on slatted floors which allow faeces and other waste products to fall through into a waste canal. This means that pen hygiene is increased as the animals are not living in their own muck. Also, due to the ease of supervision that crate systems allow, they can provide excellent working conditions for the farm staff.
So Why Not Use Crates?
Whilst the advantages of farrowing crates are based on financial benefits, the disadvantages are based on welfare issues. There is considerable evidence to suggest that farrowing crates have adverse metal and physical effects on the sows within them.
Like any animal, a sow needs to exercise her muscles in order for them to remain physically healthy. It has been shown that sows in farrowing crates spend "significantly more time standing inactively" (Boyle et al., 2001) than those loose housed. This inactivity can lead to joint problems, muscular weakness in the legs and eventually impaired mobility.
Crated sows are unable to demonstrate normal behaviours such as nest building or rooting. This deprivation can lead to a number of disorders including "chronic stress, depression and frustration, aggression, and abnormal and neurotic coping behaviours called stereotypies." Stereotypies are repetitive, seemingly purposeless movements and have been compared to the symptoms of obsessive compulsive disorder in humans: "They (neuroses) have been reported to have anxiety-reducing effects, a very similar finding to the stress-reducing effects of stereotypies in pigs. The parallel is sufficiently close to warrant the view that sows performing stereotyped behaviours are not so much coping' as suffering clinical neuroses".
In conclusion, farrowing crates offer an economically attractive system of pig production to farmers. They consistently provide higher weaning percentages than other systems, higher stocking densities and therefore higher gross margins per pig.
However, these advantages are counter-acted by the low standards of sow welfare. There is evidence to show that sows experience numerous discomforts and injuries whilst in farrowing crates, a fact which has been picked up on by various vociferous animal rights movements.
Just as veal crates and sow stalls have gone before, it is my opinion that the life span of farrowing crates is drawing quite quickly to a close as the consuming public become more aware of, and concerned with, the animal welfare standards of the meat they buy.