The effect on egg-shell thickness of the inclusion of the calcinogenic plant Solanum malacoxylon in the diet of laying hens.

The leaves of the plant Solanum malacoxylon contain 1,25 dihydroxycholecalciferol, the active form of vitamin D. The effect on egg-shell thickness of supplementing the diet of laying hens with a dry powdered preparation of the leaves (DLSM) has been studied. A significnat increase in shell thickness was evident for eggs laid on the second and subsequent days of the DLSM-regimen but nor for those laid during the first 24 hours. It is suggested that the provision of high doses of the vitamin D metabolite in the form of a DLSM supplement may restore calcium binding protein levels in birds approaching the end of the first laying year and hence improve dietary calcium absorption and consequently egg-shell quality.