Reproductive efficiency

Sheep have the potential for multiple births.

Therefore, select #twins for replacements when possible.

With good management, mortality of twins should not be much higher than that of singles.

Measures of reproductive efficiency include age at puberty, fertility, #lambing rate, and #length of the breeding season. #Reproduction in sheep is strongly influenced by the environment. By most estimates, the heritability of reproductive rate is low, but breed differences exist. Fine-wool breeds are highly fertile and have been used successfully in crossbreeding programs to improve reproductive rate. Breeds that have been used under intensive management systems to increase lambing rate include the Finnish Landrace, Border Leicester, and Suffolk as well as Merinos, Dormers and Dohne Merinos.