Abstract
Summary: The micro-Kjeldahl technique and paper electrophoresis were used to measure the total protein and γ-globulin concentrations in the sera of 423 2-day-old Finnish Landrace, Scottish Blackface, Merino and Merino × Cheviot lambs, and the total protein concentrations in the sera and colostra of their mothers. The concentrations were higher in Finnish lambs than in lambs of other breeds. The interbreed variations between single lambs were not significant, but the variations between lambs from larger litters were highly significant, because the concentrations in Finnish twins and triplets were as high as in single lambs, whereas the concentrations in Blackface and Merino × Cheviot lambs were negatively correlated with litter size. The differences between the breeds were attributable to the particularly high protein concentrations in the colostra from the Finnish ewes, to the small size of their lambs, and, probably, to a higher rate of production of colostrum by Finnish than by other ewes. There was some evidence of a positive correlation between the lengths of the gestation periods and the γ-globulin concentrations of the lambs.