On the relative growth and development of various breeds and crosses of sheep

摘要: Records of the live and carcase weights sheep exhibited at Smithfield Show from 1893 to 1913 have been treated statistically. The results show average weights, rates growth, proportions in different breeds 9 months 21 age (see Tables II V). On all rate growth declines 4·7 lbs. per week birth 1·7 age. percentage increases with on 61 cent, 65 it fat 5·7 64 months. other hand pluck, skin alimentary canal (“Unaccounted for”) decrease Ratios early maturity are given for various factors which affect discussed. crosses IX XIII). From a comparison crossbreds pure would appear that crossing leads increase weight probably more maturity. There is an indication carcase, pluck less but greater than sheep. variation Cheviot Blackface Leicester, Southdown, Hampshire Suffolk breeds; latter variability decreases former Variability old has steadily increased there little change. Some parts variable their proportion others. Fat most variable, slightly while even weight. Within breed among animals same heaviest generally highest lowest canal. A high correlated low old. At holds true exception not fat. does be any part body except inversely During period 1893–1913, although individual differences, majority remained practically constant 1840 were very much fatter those shown Carcase Classes to-day comparable present-day Live Classes. Since Leicesters great Southdowns small both decreased during 1893–1913; this attended by influences first year life (store period) ultimate size. seasonal attained dependent rainfall; rainfall through root fodder crops causing