Abstract:
A total of 23 ram lambs were produced from matings between homozygous polled Merino rams (PP) and heterozygous polled Merino ewes (Pp). The genotype of the ram lambs was established by progeny testing, and a comparison between genotype and phenotype was made. At birth, seven out of nine PP ram lambs showed clean depressions at the horn sites, whereas all of 14 Pp rams showed knobs set in depressions. At 15 months of age, the range of phenotypes with regard to horn growth was: