The influence of calcium, phosphorus and vitamin D supplementation of a pea–barley ration for growing pigs

Abstract

A diet based on field peas and barley can satisfy the mineral requirements of growing pigs provided that calcium is supplemented at least to the level of dietary phosphorus present, and that vitamin D₃ supplementation is greater than Agricultural Research Council recommendations. Bone fragility and lameness observed in pigs on a low calcium-low vitamin D₃ diet was overcome by increasing either of these components, and this was accompanied by increased metacarpal ash and femur breaking strength. A similar response could also be produced by increasing dietary phosphorus levels.

Plasma calcium and phosphate concentrations were significantly influenced by changes in the dietary calcium/phosphorus ratio, whereas vitamin D₃ changes had a minimal influence. Parathyroid activity appeared to reflect the plasma calcium concentration. There did not appear to be any relationship between plasma concentrations and bone fragility or lameness.

In order to ensure adequate bone development in pigs offered a diet of plant origin, vitamin D₃ supplementation and elevation of dietary calcium to the level of total phosphorus present is a minimum requirement.