140 Western Live-stock Management 
All lambing systems, whether shed, tent, or corral, have 
two purposes: first, to prevent ewes and their lambs 
from becoming separated until the lambs are old enough 
that there is no danger of their being disowned ; second, 
in those cases in which lambs are unavoidably disowned, 
to remedy the difficulty by some special means. » Minor, 
although important, considerations in lambing are to 
prevent lambs from becoming chilled or trampled to death 
and to assist ewes that have difficulty in parturition. 
The large size of the range flocks makes the dangers of 
lambing many times greater than with small farm flocks, 
hence the system of lambing on the range is always 
elaborate and painstaking. 
PERCENTAGE INCREASE 
The percentage of increase varies with the climatic 
conditions, and with the care given. Severe weather tends 
to decrease the percentage while good care tends to raise 
it. The percentage usually varies from about 50 to 100; 
that is, there are 50 to 100 lambs for each 100 ewes. 
The average in the western states is between 80 and 85 
per cent. A percentage higher than 100 is not to be de- 
sired, since not many of our ranges are good enough to 
support ewes bearing twins and one good strong lamb is 
better than two weak ones, neither of which may live 
through the summer. The percentage increase is usually 
calculated on the basis of the number of lambs and ewes 
counted at the time of marking. 
MARKING 
The term marking is used on the range to designate 
the operations of docking, castration, and branding lambs. 
