1. A study on the effects of the type of diet on the histological development of the fore-stomachs of the lamb is presented.
2. The rumen papillae were well developed in a 7-week-old lamb that had been fed solely on milk from birth, but compared to a lamb of the same age that had access to lucerne chaff from birth, they were smaller in size and more conical in shape. There was no difference in the appearance of the rumen mucosal surfaces of two lambs of 13 weeks of age, one of which had access to lucerne chaff from birth and the other access to lucerne chaff for only 4 weeks prior to slaughter.
3. The type of diet appeared to have little effect on the appearance of the reticulum mucosal surface.
4. The appearance of the omasum mucosal surface was only normal when lucerne chaff was fed to lambs.
5. The histology of the rumen wall was normal in the milk-fed lamb. However, compared to the lamb of the same age that had been fed on lucerne chaff, the papillary body formation, stratum granulosum and stratum corneum were less well developed.
6. Apart from a thinner stratum granulosum and stratum corneum, the histology of the reticulum wall of the milk-fed lamb was little different from that of the lamb of the same age that had been fed on lucerne chaff.
7. The histology of the omasum wall of the 7-week-old milk-fed lamb was very similar to that found in the lamb at birth.