Scientific Basis to SRS®
SRS® breeding of alpacas involves the direct selection for low primary fibre diameter and for high levels of fibre density and fibre length.
This approach is adopted mainly because the genetic regulation of fibre diameter is known to differ between primary follicles and secondary follicles.
Primary fibres are produced by the first-formed follicles in the unborn alpaca's skin at about day 214. The secondary fibres, which outnumber primary fibres by about 10 to 1, develop later from about day 343.
The fact that alpacas worldwide still have primary fibres that are on average, 10 microns coarser than the secondary fibres, is a sign that effective breeding strategies to reduce guard hair are not yet in place.
The mean diameters of the primary fibres and secondary fibres need to reduced to less than 17 microns in order to remove all guard hair and fibre medullation.
Another compelling reason for adopting the SRS® breeding approach arises from research work indicating that fibre density, fibre length and fibre fineness are likely to be regulated genetically by the number, distribution pattern and activity of pre-papilla cells in the foetal skin.
The working hypothesis for maximising fibre density and length is:
- pre-papilla cells regulate wool follicle formation and fibre size
- a large starting population of pre-papilla cells need to be available in the foetal skin to create the potential for a large number of wool follicles to be formed
- pre-papilla cells need to be distributed as small clusters to form a high density of wool follicles
- because all the clusters are small, the fibres, whether originating from primary follicles or secondary follicles, will be fine in diameter and non-medullated
- these small clusters need to emit strong signals from the base of the wool follicles to stimulate the growth of long fibres
Laboratory tests show that the density of different alpacas vary from 20 to 90 follicles per square millimetre of skin and the fibre length from 0.20 to 0.60 millimetres per day. Doubling the density and length of fibres on an alpaca would change it from producing a fleece of 3 kilograms of 25microns to the equivalents of 7.5 kilograms of 20 microns or 4.2 kilograms of 15 microns.
So, how do we breed an advanced alpaca producing high fleece weight of fine diameter wool of exquisite quality?
Several things need to happen simultaneously.
- the mean primary fibre diameter needs to reduced to less than 17 microns in order to remove all guard hair and fibre medullation
- the density and length of the fibres need to be increased
13/06/13 - New England Alpaca Show
Four subscribers were represented at the New England Alpaca show consisting of fleeces and lead animals over the long weekend of the 8th & 9th of June. They were Glen Waverly Alpacas (Betty & Adrian Whitten), Sunline Alpacas (Jeff & Jill Willis), Towarri Alpacas (Stuart & Fiona Marshall) and Glenhope Alpacas (Bronwyn & David Mitchell). Everyone took home some ribbons from the event which attracted 44 fleeces and 136 animals. In the fleece section Glenhope entered 7 fleeces and received 3 Championships, 2 Reserve Championships and the Supreme Champion. Glen Waverly received a Reserve Championship. The judge commented on the weight of the fleeces and the quality of the presentation which is encouraging. In the animal classes Sunline received 2 Championships and a Reserve Champion and Glenhope received a Championship and 2 Reserve Champions.
24/04/13 - Castle Hill Alpaca Show
Castle Hill Show, near Sydney, Australia, on the 9 March was another great show for SRS(R) studs. Walkley Fields (Richard Brennan) and Gunnamatta Alpacas (Sue Maynard and John Hay) had a very succesful day collecting 7 out of 10 Champions, with Walkley Fields taking out Supreme Huacaya Alpaca and Sire's progeny.
Judge Joanne Ham commented on the "super softness" of the animals.