Influence of dietary osteolathyrogens on the ultrastructure of shell and membranes of eggs from laying hens

Laying hens were fed osteolathyrogens, either semicarbazide hydrochloride at 0.3 g/kg or beta-aminopropionitrile fumarate at 0.6 g/kg, to examine their effects upon the ultrastructure of shell and shell membranes by scanning electron microscopy. 2. Effects of the 2 lathyrogens were similar. Compared with the highly-branched network of fine fibres in normal membranes, there is widespread lack of separation of fibres in lathyritic specimens and hence, uneven distribution of nucleation sites. Pores are also uneven in size and distribution, which can account for increased permeability. 3. Establishment between shell and membranes is reduced. Within the cone layer both type A and type B mammillary bodies occur. Large interstitial spaces and late fusion of the palisade layer indicate reduced resistance to fracture.