Relationship between Birthcoat Halo-hair and Medullated Fibres in Merino and Damara Crossbred Lambs Wool

Abstract

\"OFDA100 was used to assess the levels of medullated fibres in Merino lambs wool and determine relationships with scores for birthcoat halo-hair. For a contrast, wool from Damara x Merino lambs was also measured. There were relatively few objectionable fibres detected in Merino compared with the crossbred wool (means 0.6 to 1.1 v. 98 to 103 per 10,000 fibre snippets). Little relationship existed between the counts of objectionable medullated fibre and the birthcoat halo-hair score. However, halo-hair score was positively correlated with the levels of flat medullated fibres, standard deviation and coefficient of variation of fibre diameter. At this stage, there is no evidence that substantiates a need for specific selection against medullation in Merino wool. However, it is recognised certain crossbreeding situations lead to wool contamination that requires specific bale branding and declaration to warn wool buyers. \"