Scanning electron microscopy of the mucosal surface of the forestomachs and abomasa of grey, white and black Karakul lambs.

Homozygous grey and white Karakul lambs suffer from a lethal genetic factor causing death after weaning. Previous studies revealed large milk-filled rumens in the grey and white lambs which was attributed to a significant decrease in the number of myenteric ganglia and neurons in the rumen wall. This study was undertaken to determine the effect of milk on the epithelial lining of the forestomachs of affected grey and white lambs. In the forestomachs of the black lambs the polygonal epithelial cells were tightly packed, seemed to overlie one another and cytoplasmic projections occurred on the cell surfaces. In the grey and white lambs the epithelium had an eroded appearance due to sloughing of the surface cells and the cytoplasmic projections were lower and had a weathered appearance compared to the black lambs. No obvious differences could be detected in the abomasa of grey, white and black lambs. It is concluded that the milk in the forestomachs of the grey and white lambs is responsible for the epithelial changes.