The presence of high concentrations of branched-chain fatty acids in lamb fat results in soft discoloured tissue and objectionable flavours and odours. However, the factors regulating their synthesis and deposition are Incompletely understood. In some studies, but not others, excessive deposition is associated with high cereal diets. Their concentrations may be higher in rams than wethers and there is circumstantial evidence for differences between breeds. We have Investigated their concentration in ewe and ram lambs of three breeds: East Friesland, Oxford and Texel.

Ten lambs of each breed and sex, born in March, were fed to appetite twice daily a concentrate (barley 683 g/kg, crude protein 170 g/kg DM ME 12.1 MJ/kg D.M) with hay available ad libitum. Animals were slaughtered together, by conventional procedures, at 27 weeks of age (± 4 days) and the hind loin was removed and dissected. The subcutaneous fat was analysed for fatty acid composition by capillary gas-liquid chromatography on Chrompack CP Sil 88 and CP wax 57 CB.