Can roosters′ head ornaments serve as a criterion for their selection as a valuable reproducers?

It is widely practiced that before mating the roosters are selected as reproducers mainly on the basis of head ornaments appearance. Relationship between males secondary sexual traits (comb and wattles) with testes size, as all of them are testosterone-dependent traits, were examined. Measurements of head ornaments and testes from two broiler breeder lines and two laying lines of chicken were correlated. The value of fluctuating asymmetry (FA) of bilateral traits was also measured. Positive correlations were found for head ornaments and testes weight in one of broiler breeder lines. No correlations were found for males of laying lines. The degree of FA did not differ between lines, except for FA of wattle length, which was higher (P≤0.05) for one of the broiler lines. Results obtained indicated that head ornaments cannot be used as the only criterion for rooster selection as reproducers.