Do I need to take more than one sample from each sheep?

This depends upon the purpose of the sampling. If the samples are simply for selecting animals or even for classing fleeces, only one sample should be necessary. The sample size is more important. The major proportion of the variation in Mean Fibre Diameter over a fleece is along and between fibres within staples. Hence, in order to obtain a representative result the sample must include more than one staple. AWTA Ltd recommends a sample size of approximately 50 grams, which equates to a good handfull.

However, if the sample is being taken for a ram sale catalogue then you might want to give consideration to taking two samples, from both mid-sides, and testing them separately. This will provide a measure of quality control and by averaging the two results you obtain a more precise estimate of the mean.

Some major ram sales already insist that two samples are taken for each ram.