Impact on mother sow
The average weaning age for piglets in Britain is between three and four weeks, which means the sow would be restrained in a farrowing crate for this time, plus a week before giving birth. Research has now shown however that peak nesting behaviour occurs during these days (16). Husbandry practices of fostering and batch farrowing (every few weeks rather than weekly) can extend the time in the crate even further. An individual sow may rear a second consecutive litter as a foster sow, thus remaining restrained for up to nine weeks in total (16).
According to the FAWC: “Skin, shoulder, hock and foot lesions are relatively common in sows. These may … be due to … the hard nature of the environment. Several of these injuries are particularly linked with farrowing crates, and there were claims from those consulted/visited of reduced shoulder sores in free farrowing systems. With reduced restriction, lower incidences of skin lesions and lameness are also likely… Restriction of nest building is stressful” (16).
The constraint of the farrowing crate prevents the sow from fulfilling any of her natural maternal instincts. Studies of wild or semi-wild pigs show that sows actually become more active before giving birth. The standard practice of confining sows in the farrowing crate a week before they give birth not only restrains them at a time of increased restlessness but also denies them the privacy they desire by forcing them into close proximity with other sows. Pregnancy should be a time of restless activity, of collecting sticks and leaves, of nest building. The act of nest building, which is so important for sows, is also denied. With not a strand of straw for comfort, her natural instincts are utterly frustrated. The animals have nothing but a hard floor; sows still attempt to build a nest, pawing at the floor, nuzzling the bars and attempting to turn around.
Sow stalls also increase abnormal behaviour such as sham chewing in which the sow chews the air, and bar-biting, indicating severe frustration and stress, and sows in crates can exhibit behaviour likened to clinical depression. There is certainly no joy of motherhood for today’s breeding sow.
Dr. I. Lean, Animal Production Dept., Wye College states (45):
“Under intensive conditions, the sow has little opportunity to exhibit the behaviour patterns which occur in more natural situations before and during parturition. The extreme restlessness commented on by many workers has led to a re-evaluation of the type of accommodation provided for this time but has not so far led to any changes in common commercial practice”.
A scientific report by the European Food Safety Authority (EFSA) has concluded that keeping sows in stalls for the first four weeks of pregnancy (which is still permitted ‘post-service’ in many EU nations) is damaging to their health and welfare. The impact of potentially long-term, close restraint of sows, in terms of both behavioural and physiological stress, is not fully understood, but it is thought to be ‘considerable’ (16). For most sows, the issues extend beyond a single litter, with repeated farrowings and lactations across their productive life.
At around three to four weeks old, the piglets are suddenly removed. The sow is given no treatment for drying her milk supply – except for reduced feed. She is made pregnant again a few days after having her babies removed, and taken to another pen where the ordeal begins all over again until her production drops or until she is killed through disease or lameness.