Effects of Ca and P levels in the feed on serum calcium, phosphorus, alkaline phosphatase, hydroxyproline and 25-hydroxycholecalciferol levels, and on the ash content of the third metacarpal bone in pigs.

The material in the present study considered of 42 pigs. The pigs received different amounts of Ca and P in the feed. Observations were made on the blood serum Ca, P, AP, HP, and 25-OH-D3 levels, the ash content of the Mc III, and on the clinical behaviour of the pigs. The pigs were divided into 6 groups (3 X 6 Finnish Landrace and 3 X 8 Large White). The piglets used in each case were from the same sow, sired by the same boar, ensuring similar genetic backgrounds. The duration of the experiment was 85 to 100 days. The Ca and P contents of the feed were 1.24/ 1%, 0.41/0.49%, 0.48/0.76%, 1.3/0.7%, 0.41/0.74%, 0.44/1.83%. The declared content of D3 in the feed mixture was 2 000 IU/kg. At the end of the experiment, SCa levels were normal, but SP levels had risen in the groups fed 0.41/0.74% and 0.44/1.83%. SAP and SHP levels were normal. The 25-OH-D3 levels were within the same range for all groups investigated. The groups receiving low levels of Ca developed an osteodystrophia fibrosa, which, together with osteochondrosis, resulted in a leg weakness syndrome. The ash contents of the Mc III were lowest in the groups receiving a feed poor in Ca.