The association between face cover and the productivity of Merino ewes in twelve NSW flocks

Abstract

The association between the face cover and productivity of more than 3000 Merino ewes has been examined in 12 flocks located in the major sheep producing areas of New South Wales. Each flock was divided into Open (scores 1 and 2), Moderate (scores 3 and 4), and Muffled (scores 5 and 6) groups. A significant negative association between face cover and reproductive performance was apparent in two flocks that contained appreciable numbers of muffled-faced ewes. A similar trend was apparent in another Muffled flock, but in one other Muffled flock and four Open flocks, there was no evidence of such an association. The results from the remaining four flocks were not considered, due to the possibility that the results were confounded by face cover scoring after joining. In one Muffled flock, the body weights of weaner lambs were negatively correlated with their dams' face cover. A relationship between face cover score and total greasy fleece weight, corrected for previous reproductive performance, was absent from most flocks and negative in two, despite evidence of a positive correlation with belly weight. There was a trend to inferior fleeces of finer trade count in Moderate and Muffled groups of several flocks. Excess face cover was found to be an undesirable attribute in Merino flocks. Its importance was greatest in flocks containing appreciable numbers of muffled-faced ewes