Crossing Merino and a coarse wool breed of sheep; a study of the birthcoat of lambs

Abstract

SUMMARYBirthooat fibre types were investigated in Barki, Merino and their crosses. The halo hair grade was high in the Barki breed, in the Merino a wide range of grades occurred but the majority was low. A trend of a decrease in halo-hair grade and an increase in non-hairy birthcoats occurred with the increase of Merino proportion in the crosses. An anterior reduction in halo-hair density was encountered in all groups under study.Fibre type arrays were all coarse in Barki and ¼ Merino, the ¾ Merino had 50% fine arrays and 75% of the Merino arrays were fine. A trend towards a maternal influence on the birthcoat was observed in the ⅜ Merino and ⅝ Merino; more fine arrays were encountered in lambs born to dams with more Merino proportion.Within saddle and ravine arrays, CT/Pre-CT ratio was highly significantly correlated with the pre-natal check as indicated by Merino proportion.It was suggested, from the birthcoat studies, that ⅝ Merino might be the best combination in the Merino crosses as far as the fibre type arrays were concerned.Less coarse arrays were encountered in the birthcoat due to selection against kemp in rams used for breeding.