This conditions is becoming more common in modern pig producing systems particularly in the first litter gilt where the skeleton is still growing and there are heavy demands on calcium for milk production which result in demineralisation of bone..
Bones affected with OP are quite normal in their structure but they become thinner particularly in the dense parts and shafts of the long bones. As a result they become more prone to fracture. OP can arise due to a shortage of calcium in the diet and imbalance of calcium and phosphorus, poor or inadequate absorption from the diet, with heavy losses during lactation and where there is a lack of exercise.
Symptoms
Sows
- Pigs show pain / discomfort.
- Sudden lameness
- Fracture of long bones.
Piglets, Weaners & Growers
- Rare
Causes
- Loss of calcium and phosphorous during lactation.
- Faulty nutrition.
- Age of sow.
Diagnosis
This is based on clinical signs, a history in lactating and newly weaned sows and evidence of fractures of the long bones. If the herd has a problem it is necessary to examine the bones of an affected animal by x-ray to differentiate between OP and OM. Calcium and phosphorus levels may be normal.
Similar diseases include:
- Leg weakness or osteochondrosis.
- Spinal fractures.
- Torn muscles at their insertions into the bones.
- Mycoplasma hyosynoviae infection.