Bad concrete can be hard on the pig herd
Bad concrete can be hard on the pig herd
BADLY laid concrete floors and poorly made concrete slats can cause lameness in pigs which in turn may increase risk of infection and carcass condemnation.
Warwicks-based pig vet and researcher Richard Penny says lameness is the third most common cause for culling sows and poor concrete flooring is a main reason for foot injuries.
Injuries can be linked to worn concrete and broken slats which can become infected. Uneven slats can also lead to bruising of the soft tissue under the horn. This damages horn production, which is vital to protect the foot.
Prof Penny suggests broken flooring is often the result of poor concrete laying. "Concrete is frequently laid too wet because wetter concrete is easier to work. When it is too wet, and then overworked, cement and sand rise to the surface and that surface is more prone to wear," he says. Wear and frequent washing exposes the aggregate, which damages the pigs feet. Injuries can then be made worse when local aggregate with sharper edges, such as crushed limestone and hard granite, is used. Prof Penny suggests making concrete using rounded aggregates such as river gravel to lessen the risk of injury when concrete wears.
Overworking concrete may also bring a slurry of water and cement to the surface. As the water evaporates it leaves a white alkaline scum over the concrete surface.
He has recorded pH levels of up to 11.6 on such surfaces. At this level alkaline burns and chaps the foot, exposing it to damage.
"To avoid this, the top surface must be cured well, by allowing the concrete to dry slowly with damp sacking or canvass laid over the surface," advises Prof Penny. Hosing down the surface also reduces the alkaline material.
"A gradual drying process with the right amount of tamping, therefore, creates a stronger floor that is less prone to crumbling. A hardening agent could also be used."
When installing or replacing concrete slats, check that slats were vibrated correctly during production. "There is no British standard governing the production process for concrete slats, and some, if not vibrated correctly, will be more likely to fracture than others.
"Slats that have narrow edges are more prone to breaking, causing jagged edges which can cut the pigs foot." He, therefore, advises choosing slats with a pencilled edge, when its edge is thicker and there is less chance of chipping.
• To help prevent foot injuries, in addition to checking and repairing flooring, Prof Penny advises checking diets for their biotin (vitamin H) levels. This vitamin helps keratin production so hardening the horn at the front of the foot. Sows could be run through a footbath to further harden hoof horn. *
When slats are well made and have been properly maintained they offer comfortable and dry accommodation, causing few foot problems.
FOR GOOD CONCRETE
• Do not overwork when laying.
• Use rounded aggregate.
• Allow new concrete to dry slowly.