Analysis of records of a Perendale flock V. Repeatabilities and genetic correlations between ages

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Abstract
Repeatabilities of greasy fleece weight (FW), staple length (SL), mean fiber diameter (FD), quality number (QN), fleece character (FC) and number of lambs weaned (NLW) were calculated by regressing older records on younger records in data collected from a flock of Perendale ewes. Average repeatabilites of the wool traits were: FW, 0.62; SL, 0.50; FD, 0.71; QN, 0.46; and FC, 0.18. The repeatabilites of the various components of NLW were low. Genetic correlations between records of each trait collected at different ages were also calculated. With quality number, fleece character and fleece weight there were indications of genotype .times. age interactions. A low genetic correlation between hogget and lifetime average fleece weight, coupled with earlier estimates of lower heritability of fleece weights in hoggets, suggest that selection on hogget fleece weight is considerably less effective than selection on 2-yr-old fleece weight in terms of lifetime average response.