By Dr Clive Dalton
In the old days, depending on how much (or how little) preparation was preparation done on the farm, wool went as greasy wool to a “wool merchant” with massive woolstores. Here staff and "wool classers" unpacked the bales, and classed the fleece wool into similar lines before it was repacked and offered for sale by auction.
The exception was in the larger clips where the wool was classed and sorted at the time of shearing in the woolshed on the farm. So if wool growers offered poorly-prepared wool for sale, the wool merchant’s staff sorted it out - at a charge.
When the lines of wool were valued prior to auction, the bales were laid out in rows in the week before the sale. Buyers dug deep into a sample of opened bales with their hands and pulled the wool out to make sure they saw a good representative sample. All these opened bales then had to be repacked by the staff immediately after the sale. It was a very costly business and things had to change. Here's a brief summary of what happens today:
Wool's journey to market
The first big change was driven by wool importing countries not wanting New Zealand grease and dirt with their purchase, as with freight being charged on a weight basis it cost more to transport greasy wool.
- There was also increasing concern over the effluent from the wool scours polluting the waterways of the destination country, as well as a bonus of New Zealand weed seeds.
- So now about 90% of our exported coarser wools are scoured after being sold and before being shipped.
- The wool is generally put into "fadges" (often by the shearer).
- Everything goes in except the dags and it is either given to the shearer to pay the costs, or is taken to a wool merchant who pays the grower on greasy weight - usually the lowest possible price commensurate with the lowest value wool in the mix!
- The wool merchant sorts it along with wool from other sources and bales it for direct sale to a buyer or through the auction system described below.
- The wool is shorn and prepared (to whatever standard) in the farm woolshed, pressed into bales and branded with the farm brand and the wool's specification (see later).
- It may be purchased in the shed by a wool merchant who will take a hand-grab sample from a number of bales to be sent to a wool measurement laboratory for testing. The grower may then be offered a price based on the test results and this is often seen as the easiest option for the farmer these days.
- If the farmer sends the wool through a stock and station agent, the wool is transported to their wool broker's store where a number of actions are taken in preparation for sale.
- On arrival each bale of a straight type of wool is compressed and four sharpened tubes are forced into it from the top to draw out a "core sample" under pressure. This sample results in short pieces of cut fibres.
- The core samples are used to measure yield, fibre diameter, fibre curvature, colour and sometimes core bulk.
- Then the bale is turned over and a hole cut in the side from which a mechanical grab draws a sample producing full-length staples.
- This grab sample is used to check the wool type against the documented specifications sent in with the wool. It measures staple length and in the case of fine wools, staple strength.
- The grab samples from the line are then sent to the wool selling centre (currently Napier and Christchurch), put together into a box for display along with the testing certificate for the buyers to inspect and value before the auction sale.
- After it is sold, most of the wool is transported to a wool scour where it is blended with other wools to meet the purchaser's specifications and is then scoured.
- Wool due for export is pressed into high-density bales, wrapped and bound with steel straps to reduce its volume for shipping in a container.
Here are some important points to remember when deciding how much work to put into preparation of your clip:
- Do nothing and your wool will be valued according to its lowest common denominator!
- Core sampling and grab sampling are very accurate and will expose anything you have tried to hide in the bale.
- Disasters can happen by negligence in the woolshed resulting in damage to modem high-speed combing machines. This results in claims back on wool exporters who set their prices accordingly.
- Only wool should go into a wool bale. You need systems to make sure nothing else does (see later).
- Things that have been found in wool bales are amazing - from shearers' moccasins, parts of hand pieces, black singlets, towels, steel needles, grinder plates, sand paper, baler twine, wire, sheep skins and cigarette butts. Metal detectors will only find some of these.
- Synthetic fibres from baler twine are an exceptionally serious contaminant.
- Valuable fine wool Merino clips should be packed in nylon packs to minimise contamination from polypropylene packs.
Here are some important principles to consider before you decide how much work to put into wool preparation. Decide how far you want to go based on experience from previous sale returns. Little will have changed since then.
- The main return comes from “body wool” which is the wool from the main body of the sheep, minus the "oddments" (wool that is not body wool) which may well lose you money in a sale.
- The oddments include necks and backs, bellies, bulky pieces, very short pieces (called locks or lox), and stains. The debate is mainly over how many of these items you take out to meet the final very important objective of "putting like with like and taking out what does not match".
- Necks and backs are taken out if they contain seeds and bits of hay. Bellies and pieces are taken out because they are greasy and the wool is usually yellow.
- Make a good job of preparing the woolshed (see later).
- Sheep should not have been treated for external parasites for at least 60 days for strong ols, 90 days for mid-micron wool, and 120 days for fine wools.
- Make sure sheep are dry before shearing - never shear sheep where you can feel the slightest sensation of dampness or coldness from the wool.
- Dag all sheep before shearing and do a proper job removing all dirty wool.
- Shear sheep of different breeds and wool types separately.
- Don't put wool of different types in the same pressed bale unless it is going to be resorted by the merchant or broker. Separate different types with a sheet of newspaper.
- If sheep vary in staple length, draft them into lines of similar staple length and shear them separately.
- Separate the belly wool which is short and greasy. Bellies from rams and wethers will also be urine stained so remove them. This is very important as the stain cannot be scoured out and has no value.
- Separate yellow-stained wool from white wool.
- Keep all cotted (matted) fleeces separate.
- Remove any wool that has raddle (coloured) marks on it. Any raddle used should be approved as "scourable" where the dye can be washed out. Even so, it’s not worth sending it away these days. Use it as garden mulch!
- Remove any wool stained by dung (pen stain) caused by penning sheep too tight before they have emptied out, and where dung could not escape from their holding area.
- Remove short greasy pieces around the edges of the fleece unless the fleece is yellow.
- Shear lambs separately.
- Extra care is needed with lambs' wool. Take out all discoloured or dirty wool.
- Keep all pigmented (black, grey and brown) wool well away from white wool as this can be a serious contaminant with high penalties.
- Wool bales must be clearly and correctly branded (see later).
- For small flocks shorn outside, shear on a board (e.g. an old door) or tarpaulin to keep grass and rubbish out of the wool.
- Take out dags, urine stains, and bacterial stains and raddle marks.
- If you put different wool types (e.g. from different breeds) in the same fadge, then separate the layers with sheets of newspaper to help the wool merchant when resorting it.
There are many options and combinations to choose from so the answer to this question is often confusing. Here are some key points:
- Ideally with today's high-speed computerised processing machinery, wool should be 75-125mm long before shearing, so let this be your main guide in deciding when to shear. Finer wool can be shorter than coarser wool.
- The most common shearing regime was (and still is) to shear the whole flock once-a-year, usually in late spring/early summer before it gets too hot. Fleece wool shorn once a year is called "full wool".
- Wool grows faster and is coarser during the summer than during the winter.
- Leaving a long fleece on sheep during the summer results in it turning yellow and becoming cotted or matted.
- Breeds with long coarse fleeces such as the Romney, Border Leicester, English Leicester and Lincoln are best shorn twice a year in spring and autumn.
- Winter shearing is still common but shearing at this time has a poor image with the public who are concerned about its animal welfare implications.
- To meet these concerns winter shearing should be done with cover combs to leave more wool on the sheep than with conventional combs. Shelter and good feed must be provided immediately after shearing.
- Shearing lambs at weaning at 4 months old helps to prevent flystrike, and is done for this reason more than intending to make money from the wool.
- Shearing when there is adequate green feed available to the sheep (high in energy and protein) can result in increased body and wool growth, whereas shearing when feed is short or mature and dry (low energy and protein), can result in decreased body and wool growth.
- Key point: Shear as early as possible in the season to coincide with the time when the wool fibre is at its finest, and before yellow discolouration develops.
- When first choosing wool for hand spinning, it can be alarming to find the large variation between sheep of the so-called same breed, and equally enormous variation within the fleece from a single sheep.
- This variation is seen in staple length, coarseness of the fibres over the body, the extent of entanglement between fibres, crimp and the all-important “feel” of the wool as well as the extent of discolouration (mainly water stain yellow).
- Some of these qualities still exist after the wool has been spun into yarn so greatly affects its end use. So the two extremes would be coarse wools for rugs and fine wools for baby wear.
The main things to look for
When choosing a fleece for spinning, or selecting sheep to produce one, then look for:
- Good long staples – the longer the better.
- Clearly-defined staples making the fleece “free-opening”.
- Sound wool free of break (tenderness). Test this by pulling on each end of the staple and if it’s tender you will feel it break. If you keep pulling you’ll end up with two short staples!
- Free from cotting.
- Good colour – especially free of yellow water stain. Other possible stains are pink tips on the staples or bands of green, brown, apricot, purple and blue. Only the blue is readily scourable. Faecal green stains should also be avoided.
- Free of vegetable matter.
This material is provided in good faith for information purposes only, and the author does not accept any liability to any person for actions taken as a result of the information or advice (or the use of such information or advice) provided in these pages.