Wool fibre quality, the care and welfare of livestock, ethical farming practice and the external chain-of-custody certification, underpin both the growing and supply of the SRS® brand of merino wool from non-mulesed sheep.

Animal health, farm health, human health - and documented protocols for ethical and environmental outcomes - are central to our product and supply chain commitment.

Finest quality

SRS® fibre is simply the best quality sheep fleece available to the market. It is naturally comfortable for wearing against the skin and is lustrous and luxurious. Itochu Wool Limited (Japan) described SRS® wool fabrics as feeling like cashmere, with excellent drape, a natural ability to stretch, less creasing and a rich appearance after dyeing. SRS® fibre-based designs have won the Australian DesignMark Award and product is held in the Art Institute of Chicago permanent collection. Presentations of apparel have been made to the Crown Princes Victoria of Sweden and the Danish Royals.

Chain of custody

SRS® markets wool fleece exclusively through e-wool® using the NewMerino® certification system and processing chain of custody. This approach provides brands and retailers with access to Australian wool - with high quality integrity, special attributes and trace-back to supplying SRS® farms. SRS® believes supply-cycle factors are also of increasing importance to the purchasing decisions of customers and consumers.

First ethical agreement

In Australia's first-ever ethical wool supply agreement for the furnishings industry, The SRS® Company Pty Ltd has signed an exclusive worldwide agreement with INSTYLE Contract Textiles to provide non-mulesed wool, to be released by INSTYLE under the brand of EthEco™, to the furnishing industry around the globe.

SRS® breeding qualities

Plain-bodied (wrinkle free) Merino sheep are bred for high levels of fibre density and fibre length. They produce high quality wool with improved processing efficiencies and end product qualities shown in commercial processing trials in six (6) global markets.

Revolutionary agriculture

SRS® founder, Dr. Jim Watts says, “this breed is a superior overall animal for meat, wool and fertility and is unparralleled in its performance, ahead of all other breeds. Plain-bodied and wrinkle-free, they grow faster, breed more lambs of better quality and are more comfortable in their environment.”

SRS® is now a secure, permanent fixture in the supply of non-mulesed wool to the market, capable of producing significant qualities of fibre in an increasing customer demand situation.

Farm to factory: holistic commitment

The SRS® Company is committed to a documented audit process for ethical and environmental outcomes. From paddock to manufacturer, sustainable practice and the NewMerino® certification system provide confidence in terms of:

* Animal health: eg; non-mulesed, low stress, ease of handling

* Farm health: eg: ethical management practice, regenerative agriculture

* Human health: eg: low/no chemicals use. natural fibre, lasting comfort.

Testimonial

Major wool customers are taking a keen interest in “the story behind the label” and the environmental conditions in which wool product is grown. Michael Fitzsimons, Managing Director of INSTYLE, in anouncing the SRS®/INSTYLE agreement said “Holistic farming strategies such as rotational stock movements, integrated pest management, enhancing ecosystems, improving soil health and biodeiversity, increasing natural groundcover and optimising water cycles all lead to healthier, happier animals, improved environment and farmlands and more profitable operation long-term.”

No-mulesing

The SRS® sheep breed is naturally resistant to flystrike and related pesticides are not required to be used. Unlike wrinkly Merino sheep this breed is not mulesed, which makes a significant contribution to the animal's overall health. SRS® wool growers are “non-mulesing certified” under a common regime which ensures compliance with SRS® breeding and NewMerino® supply criteria.

SRS® position

We are committed to the following objectives:

* the continuous development & improvement of high value, exclusive wool product

* a progressive program of legitimate animal welfare assurance

* regenerative and progressive farm management practices

* the protection of supply-chain management protocols via NewMerino®

* the design, implementation & monitoring of ram breeding programs to ensure predicted outcomes are realised (external audit certification)

* continued education of and assistance to committed SRS® wool growers and and the improvement of grower returns

* fostering relationships with wool customers for whom SRS® product atrributes provide an exclusive market offer and which command a market premium

* the pursuit of creative, effective customer relationships which create demand for SRS® product

Thank you for your interest in SRS® wool. The SRS® Company Pty Ltd invites further enquiry and is happy to arrange customer inspection of SRS® farms. Enquire here.

The SRS® Company Pty Ltd promotes and develops premium markets for wool produced by SRS® growers.

SRS® Merino sheep are the result of selecting for low primary fibre diameter and high density and length of wool fibres. The breeding system was developed by Dr. Jim Watts, a research veterinarian who specialises in skin and fleece biology. It is based on Moore’s pre-papilla cell hypothesis of follicle formation and fibre growth (Moore, 1984; Moore et al, 1989, 1996, 1998; Wynn et al, 2010).

By selecting sheep this way, exceptional wool quantity and quality, processing performance and end product quality are realized.

Low primary fibre diameter ensures that more of the pre-papilla cells are channelled into producing more wool follicles on the animal's body.

High fibre density occurs when there are many wool follicles populating each follicle group in the sheep’s skin, and these follicle groups are packed closely together. When this happens, the wool fibres become highly aligned, evenly sized and are visible in the fleece as multitudes of “fibre bundles”, each growing from a follicle group in the skin.

High fibre length is expressed most clearly in fleeces that have high crimp amplitude (deep crimp) and low crimp frequency (bold crimp).

The sheep in SRS® Merino flocks are plain-bodied with wrinkle free skins. The animals are never mulesed. We are selecting for naturally short tails so that the sheep do not need to be tail docked.

Figure 1. SRS® Merino rams (recently shorn) in a commercial Merino flock at Brewarrina, New South Wales, Australia. photo: courtesy of The Land newspaper, Rural Press Group.

The SRS® breeding system has designated selection protocols and specific animal and fleece standards that are quantifiable at both genetic and phenotypic levels. The breeding system has been applied to Merino flocks, alpaca herds (www.srsalpacas.com), and Angora goat herds in Australia, New Zealand and Europe.

The Fleece and Skin

Figure 2. SRS® sheep are totally plain-bodied.

The wool on the underside of the neck drapes freely without any horizontal skin wrinkles or folds. There is also no skin wrinkling over the poll (no 'broken poll'), topside of the neck (no 'collars'), body trunk (no 'tiger stripes'), topline (no 'scribble'), tail (no 'fan tails') and no cross-folds down the back legs.

The fleece surface is distinctive (Figure 3). It is long and floppy, deeply crimped and lustrous. Staples are replaced by 'fibre bundles'. The ends of the fibre bundles are very thin, about 1.5 millimetres in diameter (equivalent to the width of the follicle group in the skin), and remarkably uniform in size over the entire fleece surface.

Figure 3. The fleece surface has a 'moppy' and lustrous appearance formed by the ends of very long fibre bundles.

On parting the fleece of an SRS® sheep, a densely packed arrangement of very long and thin fibre bundles is seen (Figure 4).

Figure 4. SRS® sheep have fleeces characterised by high density of fibre bundles and high numbers of fibres per bundle. This adult animal grew 150 millimetres of 19.5 microns wool for 10 months wool growth.

The fleece is: very soft with a resistance to compression of no more than 6.5 kilopascals; adequately nourished with a wax content between 15% to 20% of clean wool weight; white in colour with a suint content no greater than 3% of clean wool weight; lustrous; and has a high crimp amplitude with a fibre length to staple length ratio of greater than 1.3 to 1; and a low crimp frequency of no more than 3.0 crimps per centimetre.

At least 80% of the fibres are circular in cross-section with a mean scale height of no more than 0.3 microns and a mean scale length of no less than 12.0 microns. The orthocortex comprises 40% to 50% of the fibre volume.

The skin is able to be extended manually using gentle force by at least 5.0 centimetres (Figure 5).

Figure 5. The thin and loose skin of an SRS® sheep.

The skin of an adult SRS® sheep has at least 85.0 wool follicles per square millimetre and wool fibres that grow, on average, at the rate of at least 0.50 millimetres per day.

The mean diameter of the primary fibres is 2.0 to 6.0 microns finer than that of the secondary fibres. Secondary fibres do not exceed a mean diameter of 20.5 microns and have been observed to be as fine as 10.5 microns in individual animals. The standard deviation of fibre diameter does not exceed 3.0 microns for either fibre population.

The wool follicles in the skin of SRS® sheep are closely packed, highly aligned and evenly seated but never deeply seated (Figure 6).

Figure 6. Vertical skin section (magnified view) of the ordely and closely packed wool follicles and fibres of an SRS® Merino sheep.

Conventional Merinos have a mean primary fibre diameter that is similar to or up to 4.0 microns coarser that that of the secondary fibres. Wool follicle density is, on average, about 55 wool follicles per square millimetre and mean fibre length is about 0.30 millimetres per day. The wool follicles are usually deeply seated in the skin as a consequence of the skin being thick (see Figure 9).

Important Biological Considerations

For both density and length to increase in tandem, and reach the exceptionally high levels that are achievable, the sheep’s skin can not be thick. The skin must be thin and loose. When the skin is thin, the animal is plain bodied and free of wrinkle, thereby being naturally resistant to fly strike and not mulesed.

These biological relationships are critically important to understand and to observe when designing and implementing Merino breeding programs. Two key factors to recognise are:

1. that there is a strong and negative genetic correlation between fleece length and breech (and body) wrinkle. In other words, if Merino sheep are bred for long wools, the animals will be plain bodied (free of skin wrinkle) and will not need to be mulesed to protect them from fly strike. Conversely, if Merino sheep are bred for short wools, the animals will be wrinkly and susceptible to fly strike. This, in turn, has meant that sheep are being mulesed to prevent fly strike in countries like Australia where the blowfly pest is found.
   
   For many years, Merino producers worldwide, and especially those breeding fine wools and superfine wools, have bred high crimp frequency wools (Figure 7), usually in the belief that such wools are fine in diameter, have high spinning performance and produce end products of superior quality. However, the scientific evidence is to the contrary.
   
   
   
   Figure 7. High crimp frequency of low crimp amplitude wool at 16.0 microns.
   
   
   
   Figure 8. Low crimp frequency wool with high crimp amplitude at 16.0 microns.
   
   High crimp frequency is an unreliable indicator of fibre fineness (Bosman, 1934; Lang, 1944, 1947,1961). Bastawisy et al (1961) found that high crimp frequency wool did not spin as well as wool of the same diameter with lower crimp frequency. Lipson and Walls (1962) also showed that wool with fewer crimps per inch processed better and produced better cloth. In more recent work, Stevens (1994) and Stevens and Crowe (1994) showed that wools of low crimp frequency and high crimp amplitude make tops of 8 to 16 millimetres longer Hauteur, with approximately half the noil and card waste of wools of finer and less defined crimp – these beneficial effects of low crimp frequency and high crimp amplitude were found to be separative and additive.
   
   Yang (1993) and Lamb and Yang (1996) showed that longer Hauteur tops spin more efficiently and produce yarns that are more even and break less often. McGregor and Postle (2002, 2006) found that fabrics produced from low crimp frequency superfine wool were thinner, more compressible (softer), lighter and more permeable and had greater spirality, and less pilling compared with fabrics produced from high crimp frequency superfine wools. McGregor and Postle (2008) also showed that the physical properties of low crimp frequency superfine wool fabrics were closer to the properties of pure cashmere fabrics than were knitted fabrics made from high crimp frequency superfine wool.
   
   The indicators are that if Merino producers breed sheep with longer wool, that wool will process more efficiently and make better quality end-products whilst the animal will produce more wool, will be plain-bodied, free of breech wrinkle and likely to be naturally resistant to fly strike.
   
   
2. that the genetic regulation of fibre diameter differs between primary wool follicles and secondary wool follicles in the sheep’s skin.
   
   Selection experiments have shown that when sheep are bred for increased follicle depth (mimicking thick skins), the primary fibres increased markedly in diameter (by about 3 to 4 microns), wool follicle density decreases and secondary fibre diameter remains largely unchanged. As a result, the sheep are born with “hairy birthcoats”, and grow fleeces that are harsh handling, yellow from high suint content and susceptible to fleece rot and fly strike.
   
   

Figure 9. Vertical skin section (magnified view) of the disorderly and entangled arrangement of wool follicles and fibres in the skin of a thick skinned (wrinkly) Merino sheep.

A detailed explanation of the biological and genetic relationships that need to be considered is given in the Subscribers Section. Ignoring these relationships can lead to unacceptable breeding outcomes that can adversely affect the health, reproduction and welfare of Merino sheep.

The Animal

SRS® Merino sheep are long and deep bodied with a 'triple-wedge' shape (Figure 10).

The sheep have open faces with the wool margins ending at or behind the poll and behind the jaw. The muzzle is long, wide and deep often with a 'Roman nose' and has a smooth, silky and ripple free appearance. The nostrils are wide. The teeth are correctly aligned, long and chunky. In Merino rams, the horns are wide-set and deep, being well clear of the horns, and set wide of the face and curve below the jaw line.

The ears and neck are long. The shoulders are correctly positioned and not set forward. We strive for a loin length of about 60% of the body length (when measured from the shoulders to the point of the hips). Wide hindquarters with full muscling on the inside and outside of the thighs are important. The hindlegs are naturally curved and not straight. Wool ends at the hocks and knees and does not carry down to the points. Feet structure must be correct with no uneven wearing on the undersoles of the hooves. We look for no pigment on the face, ears, legs, perineum, and hooves. Belly wools need to be white and remain so on wet, long pastures.

Figure 10. SRS® Merino ram in 3 months wool.

Increasingly, we are breeding SRS® sheep with long ears and long necks (Figure 11). This is deliberate. Long ears, open faces and bare points appear to be adaptations to hot and humid environments which allow the sheep to cope better with low water intake than conventional Merinos do. The long necks and tall frame of the sheep also appear to assist the animal forage more efficiently, especially when feeding on tall plants under drought conditions.

Figure 11. Eight months old mixed sex Merino lambs in drought, note the long necks and long ears.

SRS® sheep all have wrinkle free breeches. This means that the animals are naturally resistant to breech strike and are never mulesed.

In addition, there are a high proportion of SRS® sheep with no wool growing on the crutch, scrotum, pizzle, and udder (Figure 12). This is an important genetic development for enhanced protection against fly strike which may eliminate the need for crutching.

Figure 12. Wool free zones have been bred on the crutch, scrotum, pizzle and udder of SRS® Merino sheep.

We have been breeding for naturally short tails. This has been done so tails do not need to be docked. Already we are seeing encouraging results (Figure 13).

Figure 13. SRS® Merino lambs (third and fourth from left) with naturally short tails and better muscular control alongside Merino lambs with long tails.

Maximising lamb numbers and minimising lamb losses

Our Merino flocks are now averaging weaning rates of 120% lambs. Some are as high as 160%. At the same time, we are reducing lamb losses to low levels (Figure 14).

Figure 14. SRS® Merino ewes with 8 week old lambs of high growth rate, high fat cover and good body muscling.

How have we set about achieving this in SRS® breeding flocks?

Briefly, it has involved:

* identifying the sires with minimal lamb losses in their progeny.

* identifying the ewes which rear multiple lambs repeatedly throughout life.

* breeding ewes which produce more milk and are able to nurture more lambs by having four (rather than two) milking teats (Figure 15).

* preferentially retaining and breeding from sheep with long, fine and soft birthcoats as lambs in order to ensure good protection of lamb progeny from rain, wind and cold (Figure 16),

* selecting sires and dams with high breeding values for: body weight at weaning; scrotal circumference; fat cover and eye muscle depth.

Figure 15. Breeding SRS® Merino ewes with 4 milking teats has lifted weaning percentage and weaning body weight by 10% to 15%.

Figure 16. These 5 month old SRS® Merino ram lambs were born with long, soft and fine outer coats, which provide excellent weather protection for the newborn lamb and are also an early indicator of high fibre density and length. This excellent trait is unfortunately mistaked by many Merino breeders as being undesirable.

High lifetime wool production

In 10 trials conducted across Australia, SRS® Merino sheep grossed $67 per fleece compared to $29 per fleece for non-SRS® Merino sheep, producing 10% more wool that was 2.5 microns finer. These results are shown in Figure 17.

Figure 17. Comparisons of fleece value, fibre diameter and fleece weight differences between plain-bodied SRS® Merino sheep and thick-skinned and wrinkly Merino sheep.

Figure 18 shows the exceptionally productive fleece that is produced on the plain-bodied SRS® Merino from an early age.

Figure 18. A nine month old SRS® Merino ewe (unshorn). Because SRS® Merino sheep are genetically equipped with high fibre density and length, the animals produce high fleece weights of fine diameter, high quality wool from early in life onwards Note that the fleece is already about 140 millimetres long.

Easy to shear

Figure 19. The plain bodies and no skin wrinkling of SRS® Merino sheep make them easy to shear.

No fly strike and minimal chemicals

The sheep are difficult to wet and dry rapidly, even during periods of prolonged and heavy rain. Consequently, fleece rot and body strike are rarely seen.

No body strike means no insecticides are needed as a preventative.

Our 40 studs can provide over 10,000 rams annually to breed millions of sheep that do not need to be mulesed.

Bounce back quickly after tough times

Being plain-bodied with good muscle patterning, high fat cover and reared with minimal supplementary feeding, SRS® Merino sheep bounce back quickly after drought and other stressful times, saving a fortune in handfeeding costs.

References

• Bastawisy, A.D., Onions, W.J. and Townend, P.P. (1961). Some relationships between the properties of fibres and their behaviour. Journal of the Textile Institute, 50, T1-20
  
  
• Bosman , V. (1934). Fibre fineness of S.a. Merino wool. Onderstepoort J. Vet. Sci. 3, 1, 223-231.
  
  
• Lamb, P.R. and Yang, S. (1996). Choosing the right top for spinning. In TOPTECH 96. Papers presented at Geelong, Australia, 11-14 November 1996. CSIRO Division of Wool Technology and International Wool Secretariat. Pp. 258-276.
  
  
• Lang, W.R. (1944). A survey of the fineness of Australian Merino wool. Publs Gordon Inst. Technol. No. 5
  
  
• Lang, W.R. (1947). Crimp-fineness relationship in Australian wool. J.Text. Inst. 38, T241-270.
  
  
• Lang, W.R. (1961). Fibre thickness, crimp frequency and quality number of Australian wool. Wool Technol. Sheep Breed. 8, 11-20.
  
  
• Lipson, M. and Walls, G.W. (1962). Processing of wool from a flock selected for high fleece weight. J. Text. Inst. 53, P416-422.
  
  
• McGregor, B.A., and Postle, R. (2002). Single yarn knitted fabrics produced from low and high curvature superfine Merino wool. Wool Tech. Sheep Breed., 50 (4), 691-697.
  
  
• McGregor, Bruce A. (2006). A comparison of the ICI Pillbox and the random tumble methods in assessing pilling and appearance change of worsted spun cashmere and cashmere-wool blend knitwear. International Journal of sheep and Wool Science, 54 (3)
  
  
• McGregor, B.A. and Postle, R. (2008). Mechanical properties of cashmere single jersey knitted fabrics blended with high and low crimp superfine Merino wool. Textile Research Journal 78, 399-411.
  
  
• Morley, F.H.W. (1955a). Selection for economic characters in Australian Merino sheep. V. Further estimates of phenotypic and genetic parameters. Aust. J. Agric. Res. 6, 77-90.
  
  
• Morley (1955b). Selection for economic characters in Australian Merino sheep. VI. Inheritance and interrelationships of some subjectively graded characteristics. Aust. J. Agric. Res. 6, 873-881.
  
  
• Moore, G.P.M. (1984). Growth and development of follicle populations and critical stages of growth. Proceedings of a seminar on wool production in Western Australia. (ed. S.K. Baker, D.G. Masters and I.H. Williams). Australian Society of Animal Production (WA Branch).
  
  
• Moore, G.P.M., Jackson, N. and Lax, J. (1989). Evidence of a unique developmental mechanism specifying both wool follicle density and fibre size in sheep selected for single skin and fleece characteristics. Genet. Res. Camb. 53, 57-62.
  
  
• Moore, G.P.M., Jackson, N., Issacs, K., and Brown, G. (1996). Development and density of wool follicles in Merino sheep selected for single fibre characteristics. Aust. J. Agric. Res. 47, 1195-1201.
  
  
• Stevens, D. (1994). Handle: Specification and Effects. In WOOLSPEC 94. Specification of Australian wool and its implications for marketing and processing. Papers presented at the seminar held by CSIRO Division of Wool Technology and International Wool Secretariat. Sydney, 23-24 November 1994. Pp. H1-H10.
  
  
• Stevens, D. and Crowe, D.W. (1994). Style and processing effects. In WOOLSPEC 94. Specification of Australian wool and its implications for marketing and processing. Papers presented at the seminar held by CSIRO Division of Wool Technology and International Wool Secretariat. Sydney, 23-24 November 1994. Pp. E1-E12.
  
  
• Turner, H. N. (1958). Relationships among clean wool weight and its components. Aust. J. Agric. Res. 9 (4), 521-552.
  
  
• Wynn, P.C., Watts, J.E., Thomson, P.,and Moore, G.P.M .(2010). Analysis of fleece and wool follicle traits of sheep selection based on visual markers (in preparation).
  
  
• Yang, S. (1993). The effect of fibre length distribution on yarn evenness and tensile properties. Restricted Investigation Report, CSIRO Division of Wool Technology, Ryde”

Further reading:

• Ferguson, Ken. (1995). The evidence for selecting sheep the Watts way. Australian Farm Journal WOOL. November issue. pp. 28-31.
  
  
• Ferguson, Ken and Watts, Jim. (1999). Biology of the SRS Merino package. Australian Farm Journal WOOL, May issue. pp. 22-23.
  
  
• Ferguson, K.A., and Watts, J.E. (2000). Index measures productivity of wool growing enterprise. Australian Farm Journal. September issue. pp. 67-69.
  
  
• Francis, Pat (1994). Get skin right and wool cut follows. Australian Farm Journal. December issue. pp. 12-15.
  
  
• Jackson, N., Lax, J., and Maddocks, I.G. (1988). Selection criteria for wool growth: significance of primary fibre types and their diameter distributions. In AWC review of CSIRO Division of Animal Production Project: Genetic and phsiological determinants of wool growth and quality. CSIRO Division of Animal Production.
  
  
• Watts, J.E., Nay, T., Merritt, G.C., Coy, J.R., Griffiths, D.A., and Dennis, J.A. (1980). The significance of certain skin characteristics in resistance and susceptibility to fleece-rot and body strike. Aust. Vet. J. 56, 57-63.
  
  
• Watts, J.E., Merritt, G.C., Lunney, H.W.M., Bennett, N.W., and Dennis, J.A. (1981). Observations on fibre diameter variation of sheep in relation to fleece-rot and body-strike susceptibility. Aust. Vet. J. 57, 372-376.
  
  
• Watts, Jim. (1990). Staple structure reflects wool quality. FARM. March issue. pp. 36-37.
  
  
• Watts, J.E. (2002). The Practical Guide to SRS® Breeding of Merino Sheep. (published by Esther Price Promotions and iikon). 23. pp.
  
  
• Watts, Jim. (2003). Celebrating SRS®. Australian Farm Journal / SRS® Company special publication. April issue. 37 pp.
  
  
• Watts, J.E. (1995a). Elite wool - from fibre to fabric. (WRIST and DPIE: Melbourne).
  
  
• Watts, Jim (1995b). The secret of wool cut quality. Australian Farm Journal WOOL. April issue. pp. 32-35.
  

Introduction

Since Soft Rolling Skin (SRS®) Merino breeding began in 1988, the objective has been to breed a plain-bodied sheep with high levels of wool fibre density and wool fibre length and the best quality wool possible (Figure 1).

The logic here is that if a sheep has many wool fibres on its body and these fibres are long, then the sheep will produce a high fleece weight (Figure 1). Also, the fleece will be fine in diameter (high density is closely associated with low fibre diameter) and the fibres will be highly aligned, smooth-surfaced and uniform in size and shape.

Today, 40 Merino and Poll Merino studs across Australia are implementing the SRS® breeding system and supplying over 11,000 rams to commercial Merino breeders. These studs produce sheep that have high fleece weights and low fibre diameter, high lambing percentages and excellent body growth rates.

All of these studs have stopped mulesing as the sheep are plain-breeched (Figure 2) and naturally resistant to breech strike. Some of these stud breeders stopped mulesing four to eight years ago.

It is important to say that while Merino sheep have been bred that are naturally resistant to fly strike, the main focus of our sheep breeding programs has been to improve fleece quantity and quality, feed conversion efficiency, early body growth, muscle patterning and fecundity. Fly strike resistance comes as a bonus when selecting for a plain bodied sheep with high quality wool.

No mulesing

SRS® sheep are totally free of any skin wrinkling (Figure 2). When the sheep's skin is like this it remains dry at all times. Urine is not trapped in the breech regions and rain droplets are not trapped along the sheep's back. Mulesing is not required and neither is preventative insecticidal treatment.

It is when sheep have breech wrinkle and body wrinkle (Figure 3) that the weeping dermatites that produce conditions such as urine scald and fleece rot (from prolonged rain) occur and the sheep are predisposed to fly strike of any kind.

This fact is not new. In 1931, HG Belschner and HR Seddon studied different body types of non-mulesed Merino sheep and found that plain-breeched sheep were far less susceptible to breech strike.

Table 1. Incidence of breech strike in non-mulesed Merino ewes from a 1931 trial. A - plain-breeched, B - wrinkly, C - very wrinkly.

An important opportunity was lost at this time. Breeding plain-bodied sheep for fly strike resistance might have become accepted practice throughout Australia from the 1930s onwards.

Fleece weight

Wool producers often say they are unwilling to change the Merino sheep type from one with thick skin and body wrinkle to a plain-bodied type because they fear losing fleece density and fleece weight.

Many public demonstrations to wool producers have been conducted over the past 15 years to show that plain-bodied Merino sheep with thin and loose skins can produce more weight of fleece per animal at a lower fibre diameter than thick-skinned, wrinkly sheep.

Figure 9 shows the typical results of such demonstrations. In each comparison, the sheep were from the same mob and were of the same age, sex, shearing time and reared under the same nutritional and environmental conditions.

The sheep were assigned to either group on subjective assessment of the animal and its fleece structure. The fleeces were then weighed and tested for fibre diameter and the fleeces valued by experienced wool buyers, notably from Itochu Wool Limited.

Figure 9. Comparisons of fleece value, fibre diameter and fleece weight differences between plain-bodied SRS® Merino sheep and thick-skinned and wrinkly Merino sheep.

A sheep can be plain-bodied and have a high density of wool follicles in its skin, or have a low density.

If a plain-bodied sheep has high follicle density and high fibre output (length) from each wool follicle, the skin will be thin and loose. SRS® Merino sheep have thin and loose skins with follicle densities above 80 follicles per square millimetre and fibre length above 0.50millimetres per day. Average values for traditionally bred Merino sheep are much lower - namely about 55 follicles per square millimetre and 0.30 millimetres per day respectively.

If a plain-bodied sheep has low follicle density, the skin is thin but not loose. Often, the wool is long but the density is too low to allow the sheep to produce high fleece weights.

The photographs in Figure 4 show cross-sections of the wool follicles and fibres, as seen under a microscope. in the skin of two plain-bodied Merino sheep.

The high density sheep is from an SRS® Merino flock. It has 97.0 wool follicles per square millimetre of skin and produces a high fleece weight of fine diameter wool.

The other sheep is a plain-bodied sheep that has a low density of 53.0 wool follicles per square millimetre and a low fleece weights. It is often referred to as a 'flat skin' sheep. While it also does not need to be mulesed, the 'flat skin' sheep is light-cutting and does not pay the bills.

In a glance it is possible to see from Figure 4 that fleece weight of Merino sheep can be improved greatly by genetically improving the density and length of wool fibres on the sheep.

Wool quality

In plain-bodied Merino sheep with high levels of fibre density and fibre length, the fleece consists essentially of fibres that are highly aligned cylinders of uniform diameter and length.

The fibres are smooth surfaced (due to the long, cuticular scales of low scale height) and have a high crimp amplitude (deep crimp) and usually low crimp frequency (bold crimp). These fibre properties create a fleece composed of fibre bundles (not staples) of superb fineness, softness, lustre, high elasticity of deep and well-defined crimp (Figure 5).

In thick-skinned sheep, which have lower levels of fibre density and fibre length, the fleece consists of entangled fibres of uneven size and shape and low crimp amplitude. Thus, thick staples rather than thin fibre bundles are formed in the fleece.

Wool quality measurements were conducted on the sheep listed in Figure 9. In the 1995 comparison at Marnoo, Victoria, the plain-bodied ewes produced 1.2 kilograms more weight of fleeec and were 1.3 microns finer than the thick-skinned ewes. Also, the plain-bodied ewes had higher follicle density (92.5 versus 78.0 follicles per square millimetre), higher fibre length (0.43 versus 0.37 millimetres per day), better fibre alignment (71.2% versus 54.8%), more cylindrical fibres (86.5% versus 69.0%) and more orthocortex in the fibre substance (42.0% versus 30.0%).

In the 1999 and 2000 comparisons at Cooma, New South Wales, the plain-bodied ewes produced a mean of 0.1 kilograms more weight of fleece (for 8.0-8.5 months wool growth), higher wool yield (76.2% versus 68.6% in 1999 and 74.2% versus 70.2% in 2000), were 2.7 microns finer than the thick-skinned ewes, and longer fleeces (96mm versus 76mm in 1999 and 125mm versus 101mm in 2000). Also, the plain-bodied ewes in the Cooma trials had lower coefficient of variation (CV) of fibre diameter (17.1% versus 21.3% in 1999 and 16.0% versus 20.4% in 2000), and higher comfort factor (99.7% versus 98.8% in 1999 and 99.5% versus 97.1% in 2000).

In the 2000 comparison at Badgingarra, Western Australia, the SRS® ewes produced one kilogram more wool than the thick-skinned ewes, and the wool was 2.5 microns finer in diameter. The diameter variation along the length of the fibres was much lower in the SRS® sheep than in the thick-skinned sheep (means of 1.0 micron and 5.2 microns respectively).

In the 2002 comparison at Mungindi, New South Wales, a more detailed investigation of group differences was carried out (Figure 9). This data shows the SRS® sheep have higher follicle density and fibre length, and finer fibre diameters, than the thick-skinned Merino. The number of dermal papilla cells in each folicle was significantly lower in the SRS® sheep; a feature which is fundamentally important for producing fine diameter wool.

Bare breech

Bare breech is a different trait to the plain breech. It is a wool-free area that surrounds the perineum and can extend down onto the udder (Figure 6) or scrotum, on the inside of the back legs and also around the pizzle.

Sheep with this trait are a low risk of developing breech strike and may not need to be crutched.

However, if the sheep are also wrinky, such animals will remain susceptible to other forms of fly strike, especially body strike, and are likely to pass this susceptibility on to their progeny.

It follows that bare-breeched rams will need to be plain-bodied. It is an easy trait to select for in plain-bodied Merinos.

Breeding mules-free Merinos within five years

Andrew Michael, an SRS® Poll Merino breeder from 'Leahcim', Snowtown, SA, says that 25 of his ram-buying clients, all commerical wool producers, have converted their flocks to being unmulesed and resistant to breech strike within 3 to 5 years.

None of the 130,000 Merino lambs on these commercial properties were mulesed in 2008.

The same short transition period was achieved in Michael's “Leahcim” Poll Merino flock which has not been mulesed since 2004.

He calculates that stopping mulesing has added $9.90 per lamb to the value of each lamb at 9 months of age. The calculations are conservative estimates based mainly on the improved body weight gains and labour savings.

His ewes produced an average fleece weight of 5.4 kilograms at 19.5 microns fibre diameter and a length of 80 to 85 millimetres when shorn in only 7.5 months wool.

This is one example which indicates that wool producers should be relaxed and confident about their ability to be able to select productive Merino sheep that do not need to be mulesed, especially in the knowledge that the transition period can be brief.

Within the SRS® breeding system, all 40 Merino and Poll Merino studs, which are located in all mainland states of Australia, have ceased mulesing, some as long as eight years ago.

A survey Dr. Watts conducted in 2005 of about 300 commercial wool producers implementing the SRS® breeding system indicated that 30% had ceased mulesing and 33% were intending to stop the following year. These respondents considered that their Merino lambs had sufficiently smooth and wrinkle free breeches to no longer warrant mulesing.

The procedure for achieving this rapid transition from mulesing to no mulesing is specific. It can be done within five years if Merino breeders understand the skin and body traits that need to be selected for, and how much change is required for a particular flock.

Industry demonstrations

In July 2008, Dr. Watts and his colleagues held two industry days with Landmark in South Australia to demonstrate to wool producers how to breed a plain-bodied Merino sheep that did not need to be mulesed. The workshops were attended by about 280 wool producers.

Wool producers were presented with two groups of one year old Merino ewes, one the had been recently shorn and one that were in 10 months wool.

They were asked to class the sheep into those animals that could have been safely left unmulesed and those that could not. Both groups of sheep appeared to be plain-bodied, particularly as long-woolled sheep.

With guidance, nearly all of the large gathering of wool producers were able to select the animals correctly.

In short wool, the focus was on ensuring that the whole body surface of the sheep was wrinkle free, thin and loose. The tail had to be smooth and rounded and the breech and hindlegs free of any cross folds of skin.

The fleece tip was distinctive, consisting of small staple ends, resembling the heads of matchsticks, arranged as closely packed and beaded array with obvious lustre, all over the sheep's body.

In long wool the wool producers were able to pick the sheep types on their fleece structure.

The sheep with wrinkle free skins that did not require mulesing and appeared to produce high fleece weights of low fibre diameter wool, grew fleeces consisting of long and thin staples of high crimp amplitude (“deep crimp”) , softness and lustre.

Another type of sheep with wrinkle free skin that did not require mulesing but were likely to produce low fleece weights, had taut skins and shorter stapled fleeces with low crimp amplitude (less “character”) and lacking lustre.

And there was another sheep type which outwardly appeared to be plain-bodied but still had wrinkly skins, much like the shorn sheep shown in Figure 7.

These sheep grew fleeces consisting of thick and shorter staples that lacked softness, lustre and whiteness and were often black tipped. The “ribbiness” or skin wrnkled extended to the breech region, indicating that these sheep would be susceptible to breech strike if left unmulesed or unprotected.

Take Home Messages

It is not difficult to breed a plain-bodied Merino sheep that does not need to be mulesed, has superior meat traits and produces high fleece weights of low diameter wool.

Large gatherings of Merino wool producers at recent SRS® industry days clearly demonstrated that they have the capacity to do this, and were reassured that the process can occur within five years.

Two white Huacaya alpacas guarding Merino ewes and their lambs.

Why alpacas?

* can increase lambing and kidding percentages by about 20%.
* natural dislike for foxes
* easy to handle
* intelligent
* eat the same pasture as sheep and goats
* are relatively low care
* live for 15 – 20 years

Relatively low care

* soft padded feet
* dung in a communal pile (reduces the incidence of worms). Although when run with sheep and goats need to be on the same drenching regime.
* don’t require docking
* not prone to footrot or fly strike
* do require shearing and toenail cutting
* don’t shed their fleece

Nutrition

* alpacas are efficient feed converters
* carrying capacity, in terms of dry sheep equivalents, similar to sheep (wether = 1 dse; lactating female =  2.5 – 3 dse)
* susceptible to plant toxins
* require 4 – 5 litres of water per day
* eat 2% of body weight per day
* food ration should consist mainly of forage (pasture or hay) rather than concentrates
* most pastures contain everything an alpaca needs

Husbandry

* vaccinations - 5 in 1 – twice per year
* drenching. “Less is best” approach reduces likelihood of resistance. However they need to be drenched on the same regime as sheep and goats
* toenail cutting – maybe twice a year depending on the hardness of the ground
* teeth trimming – maybe required in older animals

Choosing an alpaca wether

* buy animals that are well grown and at least 18 months of age and reasonable conformation
* never buy an entire male as a guard. They have been know to attempt to mate ewes
* buy animals that have been ‘humanised’, that is, handled. It makes it easier for mustering, vaccinations and shearing.
* ensure animals come from areas that are not prone to disease such as Johne’s or some coastal areas where liver damage can be a problem.

Farm management

* best to be kept with their mob
* should not run alpacas in different mobs that have a common boundary
* effective if  two or more are with the same mob
* can be difficult for farm dogs but get to know the dogs soon enough, especially when with humans

Cost Effective

* cost $300 - $400 plus GST (depends on location)
* live 15 – 20 years. Average cost over 15 years is $20 - $25 per year
* can increase lambing and kidding percentages significantly. For example. Instead of 80% marking having 98% marking. With 500 ewes this is an increase of 90 lambs @ $60 per head or $5400 per year. A return of 700% on investment in the first year

Breeder Comments

“I think they’re pretty good. I had an 80% marking and my neighbour had 30%” “I’ve got alpacas and he hasn’t”.

“You don’t think they are working but at the end of the season the lambs are on the ground”

“Takes a while to get used to them but I wouldn’t be without them now”

“We bought 12 last season. A great investment”

Contacts

David & Bronwyn Mitchell
'Glenhope'
Red Gum Lane
Amidale NSW 2350
T: 02 6772 1940
M: 0422 969 310
e: mitch@glenhopealpacas.com

John & Julie Lawry
'Bonnie Vale'
7963 Mitchell Highway
Wellington NSW 2820
T: 02 6846 7292
M: 0438 467 292
e: jlawrie@bonnievalealpacas.com

Jim Watts
PO Box 2604
Bowral NSW 2576
T: 02 4862 2050
M: 0409 364 864
e: srs@hinet.net.au

Numbers can be sourced and white are usually the preferred colour for wool growers. Give contacts plenty of time to fill the order for you.