Culling guidelines
Assuming an adequate number of maiden gilts of suitable weight, age and
size are available on a unit the following guidelines should be used in
deciding on culling a sow at weaning.
- Two successive small litters – there may be some exceptions e.g. gilts which were first served when they were too light, were overfed during pregnancy, lost excessive weight while suckling and were weaned in poor condition.
- Failure to come on heat despite hormone treatment. Allow a maximum of 18 days after weaning, including 7 days after hormone therapy.
- Second repeat – farrowing rate is less than 50% for sows which have repeated for a second time.
- Six or seven litters produced – sow and litter performance tends to deteriorate after 6 to 7 litters. Litter size falls, due mainly to an increase in stillbirths. Piglet size becomes uneven, with smaller piglets dying due to chilling or failure to suckle. Older sows have more udder problems and tend to be clumsy, both factors which lead to higher pre-weaning mortality.
- Locomotor Disorders – attention to legs at selection/purchase along with good floors and slats, will reduce the need to cull for this reason. Also preventing sows from becoming overweight will reduce culling for locomotor problems.
- Ill-health e.g. infectious vaginal discharges.
Once the decision to cull has been made the sow should be immediately
removed from the herd and replaced as soon as possible by a served gilt.
Holding on to a sow to try to restore condition prior to sale is not
economically justifiable as sows have an FCE of about 7:1.
