@conference {40648,
	title = {Presidential address: some advantages of corporate animal production},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {1-4},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Staple tenacity is an estimate of the peak force to break a staple  of a certain cross-sectional area at the point of break. Staple  strength is a measure of peak force to break a certain weight of staple.  Using the density of wool and the length of staple broken, both  estimates can be converted to force per unit linear density (N/ktex).  The relationship between these two estimates was examined. Midside wool  samples were collected at shearing from 164 ewe hoggets from lines of  New Zealand Romneys that have been selected for or against staple  tenacity, and a randomly selected control line. Five staples from each  sample were measured for staple strength and staple tenacity. This was  accomplished by defining the cross-sectional area at the break point,  breaking the staple to estimate peak force and then cutting the portion  of the staple from between the jaws and determining the weight of clean  wool after scouring. The High staple tenacity line had a significantly  higher staple strength (P<0.001) and staple tenacity (P<0.001).  Although a similar weight of greasy wool was removed from between the  jaws for each selection line (P=0.336), the weight of clean wool was  significantly greater in the High staple tenacity line (P=0.003).  Covariate analysis revealed that the fitted relationships between staple  strength and staple tenacity for the three selection lines had similar  slopes (P=0.822) but significantly different intercepts (P=0.029).  Staple strength is thus biased relative to staple tenacity in these  lines, because of the differences in weight of wool between the jaws,  for staples which are all the same cross-sectional area at the point of  break. Staple tenacity is therefore more useful for some purposes than  staple strength and vice versa, and care should be taken when drawing  comparisons and conclusions and when considering which to use.   },
	issn = {1176-5283},
	author = {Nicoll GB}
}
