Effects of inbreeding on four families of Peppin Merinos. II. The influence of inbreeding on age trends

Abstract

The effect of inbreeding on age trends in lambing performance and fleece characters is discussed. Inbred ewes take longer to reach their peak reproductive performance (5 years as against 4 pears for non-inbred ewes) and maximum fleece weight (4–5 years against 3–4 years). For fleece components, age trends and differences between inbred and non-inbred sheep do not appear to be large. In this material, differences between normal and inbred sheep exist only in characters which normally show big changes with increasing age. Dry ewes, in both groups, grow more wool than those rearing a lamb. This appears to be mainly due to the greater staple length in dry ewes. Differences in fibre diameter may be present, but would be masked by the flock sampling procedure.