CULLING FOR FERTILITY IN SHEEP FLOCKS IN WESTERN AUSTRALIA

Summary Two methods of culling for fertility were studied in Western Australian flocks. Individual lambing records of 6,178 ewes in 12 flocks were studied over two successive years to determine whether the proportion of ewes which lambed in the second year could be enhanced by culling ewes which were dry in the first year. Only two of the 12 flocks were significantly improved by this method of culling. Mating records on 3,718 ewes in seven flocks were used to determine the effect on lambing performance of culling those ewes which returned to service. A significant improvement was seen in two of the flocks. The practicability of either method is questionable because, in most cases, very large proportions of the flocks have to be culled to attain significant improvement.