Studies of face cover in the New Zealand Romney Marsh sheep. I. The relationships between face cover, wool blindness, and productive characters.

Abstract

Forty open-faced and 80 woolly-faced Romney sheep were selected from a flock of about 500 18-month-old ewes so as to represent extremes of face cover. Half the woolly-faced group were left wool-blind and the remainder were wigged at regular intervals. No differences in liveweight, fertility, or fleece weight resulted from the wigging treatment. Over the subsequent 5 years the open-faced sheep had 30% more live lambs and averaged 0.3 1b greater clean fleece weight annually than the wool-blind and wigged sheep. The open-faced ewes had the greater liveweight over the whole period. It was concluded that wool blindness was not the basic cause of the observed differences between open- and woolly-faced sheep.