Genetic and phenotypic relationships of reproduction with live weight and wool traits in a Mediterranean environment

Abstract

An additive genetic variance ratio (h2) for total weight of lamb weaned per breeding ewe over three reproduction opportunities (TWW3) was estimated in a medium wool resource flock. TWW3 was highly variable, with a coefficient of variation of 50 %. The between bloodline variance ratio for TWW3 was significant (P < 0.05), but failed to exceed 5 % of the across bloodline phenotypic variation. Within bloodline h2 (± s.e.) was estimated at 0.154 ± 0.040 for TWW3. Within bloodline genetic correlations of TWW3 amounted to respectively 0.58 ± 0.11, 0.26 ± 0.11, -0.24 ± 0.11 and 0.17 ± 0.10 with hogget live weight, clean fleece weight, clean fleece weight/kg live weight and fibre diameter. It was concluded that TWW3 would respond to selection in Western Australian Merinos. Genetic correlations with hogget live weight and fleece weight were favourable.