Last update: April 14, 2011 09:07:30 AM E-mail Print

 

DIFFERENCES IN LINEAR SCORED TRAITS BETWEEN GENETICALLY FINE AND STRONG WOOLLED MERINO SHEEP

 

A G Bezuidenhout & A C Greyling

Cradock Experimental Station, Cradock  5880

J J Olivier

Grootfontein Agricultural Development Institute, Middelburg 5900

 



 

A genetically fine wool flock was established at Cradock Experimental Station during 1988. One of the aims of this project was to distribute fine wool rams to the industry. Subjectively assessed wool and body traits play an important role during purchasing of rams. Since 1989, 5 wool and 6 body conformation traits were scored on a linear scale by two experienced sheep classers for all fine wool animals as well as for a strong woolled group (average 26 micron). The data were transformed to have a mean of zero and a standard deviation of one. The transformed data were analyzed by means of a fixed effect model, which included the effects of year 9f birth, genetic group, sex, weaning status and all insignificant interactions for each individual trait. All animals were also classed into three categories namely top, average and cull. The fine wool animals were inferior (P<0.01) to the strong wool animals for quality, yolk, staple formation, belly and points, head, forequarter, hocks and conformation. The fine wool animals had less (P<0.01) fleece variation and colour than the strong wool animals. Of the fine wool animals, 31.4% was classed in the top class in comparison to 70.1 % of the strong wool animals. Only 23.7% of the strong wool animals were culled compare to 55.3% of the fine wool group. The most important traits contributing towards the category in which the animal was classed, were conformation, wool quality and hocks. These results suggest that fine wool animals were inferior to strong wool animals as far as most of the linear scored traits are concerned. To make a significant impact on the wool industry, the superiority as far as genetic fine wool is concerned, must be maintained but a concerted effort must be made to improve general conformation, wool quality and hocks in these animals. The correlation of linear traits with production traits needs to be investigated to assess the possible correlated responses.


 

Published

Proceedings 34th SASAS congress