The educational information listed in this section has been graciously provided by the American Sheep Industry Association.
Table of Contents
A. Grower Responsibility
A. Preparation Options
B. Clip Preparation Standards
C. Skirting Standards
D. Classing Standards
A. Packaging Options
B. Identification of Wool Packages
E. Other fiber Contaminants
VII. WOOL TESTING
A. Core Sampling
B. Information Available From Testing Wool
C. Larger Lots Larger Savings
D. Benefits of Pre-Sale Objective Measurement
This booklet is prepared for all segments of the U.S. wool industry to offer a set of standards for a self-regulatory approach to clip preparation. It describes the recommended procedures for preparing all wool types and outlines basic wool handling procedures.
It is the intent of this publication to offer guidelines that can be incorporated by any wool producer, regardless of breed type, operation size or geographic location. Specifics must be determined by each individual wool grower as how to best prepare their own clip. The step-wise approach allows anyone to implement improved wool preparation and packaging techniques. Whatever a grower is currently doing, in the way of wool preparation, an additional step can be taken toward higher clip preparation standards.
Wool preparation and marketing are separate issues. Improved wool preparation cannot necessarily change market conditions, but it can increase the number of markets available to the grower. This concept encourages wool growers to know and understand more about their product -- wool. This increased knowledge and understanding can make growers wiser in genetic selection, management practices and marketing strategies.
Wool contamination is covered in this booklet from the approach of identifying potential sources and types of contamination that occur before, during and after shearing. Discussion does not tell the reader why contaminants are detrimental. Suffice to say that wool contamination adds cost to processing raw wool, limits the end uses that raw wool can reach in the retail market and adds labor cost to remove contamination. These costs and limited processor markets are invariably passed back to the grower in reduced prices for American wool.
Wool is a global commodity and is traded worldwide. Producers must build greater respect for the value of their product by taking pride in its production as well as its preparation. As more growers enhance wool quality by proper preparation, confidence will grow from wool buyers and processors for American wool, thus improving market conditions for all U.S. wool growers.
The Code of Practice booklet will be periodically revised and reprinted to fit the ever changing needs of the wool industry.
Adequate labor - Too few or too many people can jeopardize proper wool preparation and shearing.
Adequate space - Shearing floor should accommodate proper shearing with enough space between shearers. Adequate space must be provided for proper wool handling.
Clean facilities - The shearing area must be clean and all contaminants (straw, twine, burrs, etc.) removed before shearing. Make sure adequate light and ventilation are provided.
Equipment - Provide sacking stand, hydraulic baler, skirting table, wool bags, brooms, tarps and offsort containers.
Planning - Contact your shearer or shearing contractor frequently to set dates and discuss what materials he will supply and what you are expected to provide. Marketing representatives and classers must be kept advised of plans.
Classer - Provide classers with full information prior to shearing.
- New sheep brought onto the property since last shearing.;
- Descriptions of all the sorted groups and whether stain has been removed (tagging);
- Order of groups to be shorn, and any changes as they occur during shearing;
- Any special requirements for preparation of the clip.
Grower's presence - With the owner present, shearing crews are more conscientious about their work. Other shed help will follow instructions in the owner's presence.
Objective measurement - Grower should be aware of the availability of pre-sale objective measurements for fiber diameter and clean yield.
Shed and Pen Maintenance - Repairs need to be completed before shearing begins. Planning for this will prevent problems during shearing.
Wool production is a year-round process with quality determined by selection emphasis, management and environment in which the wool is produced. A year is spent growing the product, while only a few minutes is required to harvest it. It is in this brief harvest period that quality is often adversely affected. A grower can improve his returns from wool by following these simple rules.
Breed selection and management are the foundation for wool quality improvement. The grower must determine the type of operation, type of sheep and methods that will be used in preparing the wool clip. A grower must determine the classification which fits the operation. The types of sheep operations in the United States fall into two broad classifications: Farm Flock and Range.
Consideration Must Be Given To:
- Shearing facility must be clean prior to shearing;
- Sheep with wet wool should not be shorn;
- Sheep should be penned at least 4 hours prior to shearing;
- Sheep should be held off feed and water at least 4 hours prior to shearing;
- Avoid holding sheep in dusty and burr infested pens.
Sheep should be chute - cut to separate the following groups prior to shearing: (This sorting is based on wool type, fiber diameter, fiber length and style.)
Black and spotted sheep - Shear these last after all other shearing has been completed;
Different breeds - All different breeds and crossbreds should be sheared separately;
Grades - Sheep of extremely different quality grades (fiber diameter) within the same breed should be kept separate;
Lambs and weanlings - Sheep which have not been shorn previously should always be kept separate from those which have;
One-year-old sheep (if shorn previously) - One-year-old sheep, which have been shorn previously, should be separated from older sheep;
New sheep - Sheep brought onto property since previous shearing should be separated;
Sick and diseased - Separate any sick sheep.
Sweeping- Maintaining a clean shearing board and floor is an important and continuous process. It must be done before, during and after shearing to insure a quality clip.
Whatever growers are currently doing in wool preparation, they can go one step further or increase their efficiency and effectiveness of current practices.
There are two main wool quality preparation options currently practiced in the United States.
Option 1 - Bellies Out Untied (BOU)
Includes belly wool being shorn out and kept separate, with the fleece being carefully rolled flesh side out and classed without table skirting. A BOU type of preparation can include offsorts of locks, bellies and stain. Producers are limited as to the degree of skirting that can be accomplished by this method. However, much can be done to enhance the fleece quality by this preparation method if shed help is conscientious. Sweeping is very critical.
Option 2 - Full Table Skirt
Includes belly wool being shorn out and kept separate, with fleece being thrown on a skirting table, skirted, carefully rolled flesh side out and classed by a certified classer. Sweeping is very important. The skirting guidelines are described under the following headings of Clip Preparation and Skirting Standards.
Recommendation: Contact wool buyers and brokers in your area and follow their advice.
The level of skirting will depend on the quality standard of the clip. All fleeces must be carefully and minimally skirted to ensure that only inferior wool is removed and all good fleece wool remains with the fleece.
Locks- Locks (tags) are removed in several places during shearing. As shearing occurs many second cuts, sweat locks from the front and rear flanks, and heavy dung locks will fall to the shearing board and can be easily swept away, thus preventing these from mixing with fleece wool or other offsorts. These need to be removed from a BOU and full table skirt. Once the fleece is rolled flesh side out it is difficult to remove any inferior wool that might have remained with the fleece. Full table skirting allows additional locks to fall out on the skirting table.
Belly Wool- The belly wool is removed from the sheep in the first phase of shearing. The handler picks up this wool and places it in the line set aside for belly wool. Excessive removal of bellies by the shearer is not recommended. Any belly remaining with the fleece will be detected and removed on the skirting table. With a BOU type preparation this is more difficult.
Picking up and throwing the fleece- When the shearer has completed shearing, the fleece is lying flat on the shearing floor ready to be picked up by a handler. Proper shearing and shearer cooperation is vital to consistently remove the fleece from the shearing board and throw the fleece on the skirting table in a form that allows for fast and proficient skirting.
The handler walks up to the fleece and takes hold of the area of wool from the hind legs and britch area of the fleece, while keeping the neck wool bunched up against the ankles. With a single fold, the handler forms a tight bundle out of the fleece, picks it up and carries it to the skirting tables.
Here the fleece is thrown onto a table so that it lands shorn side down, ready for skirting. Done in this manner allows:
Table skirting is necessary to remove only inferior portions of the fleece that remain at this point. Some inferior wool will have been removed before this point, but any of the following wool types will be removed once on the skirting table. The entire clip and fleece quality must be considered in determining what to skirt.
|Stain||normal crutchings with heavy locks removed|
|Bellies||entire belly with any locks removed|
It may also be necessary to remove:
- clumpy vegetable matter;
- cotted edges;
- hairy britch wool;
- necks (vegetable matter);
- backs (very dusty and tender).
A thorough evaluation of the flock management practices and growing conditions will indicate what is necessary and practical to remove on the skirting table.
Wool Workers' Responsibilities
In most shearing sheds, many functions are combined.
The main objective of the skirter should be:
Each fleece must be carefully skirted so that only inferior wool is removed and all good wool remains with the fleece.
Fleeces must be skirted to remove all stain, tags, skin pieces, crutchings, top knots, shanks, and heavy, clumpy vegetable matter.
Check your pieces bin frequently to ensure good fleece wool is not present. Heavy skirting may bring higher prices per pound for your pieces wool, but generally will not produce a higher return overall, as the table shows.
Example: Fleece 1 - Efficient Skirting
|Weight(lbs.)||Micron V.M. (%)||Yield (%)||Price Clean||Total (dollars/lb.)||Value ($)|
Example: Fleece 2 - Heavy Skirting
|Weight(lbs.)||Micron V.M (%)||Yield (%)||Price Clean (dollars/lb.)||Total Value ($)|
Gain: $.43 per fleece, or $430 per 1,000 fleeces
Note: Price benefit for efficient skirting would double at a 100% incentive payment.
It is important to adequately staff the shed with competent wool handlers during shearing. This helps prevent over skirting, while making sure all inferior wool is removed. Remember: It is the net return for the total clip, not the highest prices for an individual line, that puts the most money in your pocket.
The classers' duties shall be carried out in accordance with this set of standards and with the directions and orders of the grower. The clip must be classed in accordance with each sheep group that was initially separated.
After skirting, the fleeces are separated (classed), into various lines according to these characteristics:
Fineness - mean fiber diameter;
Yield - amount of clean wool obtained from a definite quantity of grease wool, normally expressed as a percentage;
Length - the actual distance of the fiber from tip to base;
Strength - fiber should not break easily by hand;
Color and Style - overall physical appearance with regard to crimp, handle and color.
Besides classing, the classer is responsible for:
Unnecessary fragmentation of a clip does NOT enhance the wool technically, and increases handling costs. It should be avoided in the interest of overall efficiency.
The classer is a team member and should be willing to perform any wool handling task.
Variation in any one line should not exceed the adjacent grades by more than two. For example, typical combinations for fine-wool fleeces are 70s/64s/62s or 64s/62s/60s. Coarser fleeces averaging 58s or coarser should be limited to only two adjacent grades, 58s/56s or 56s/54s for example.
Any wool packaging material can be a source of contamination. Proper handling of packs and sacks will minimize this problem.
Australian Style Square Pack hydraulically packed bales weigh approximately 400-450 lbs. It is an international standard size, saves freight cost due to density and minimizes contamination, Either burlap or polyethylene may be used as long as it is an approved new pack. Previously used packs should not be used.
Burlap Sacks come in two sizes, 6' and 8'. Mills prefer the 6' sack. A minimum of 12 oz. quality burlap is recommended for the construction of all sacks, and only use new sacks.
Each bale or sack should contain the following information:
1. Grower's name or official brand.
2. Official labeling should be used for identification between the grower and warehouse:
|A-1||coarse or larger fiber diameter line|
|A-2||shorter stapled line; might include tender and/or broken wool|
|A-3||additional cast line such as heavy color, low yield, heavier vegetable matter, etc.|
|A-4||additional cast line if needed|
|AA, AAA||additional fleece lines if necessary|
NOTE: In large clips there can be more than one A line if necessary.
3. Bale or sack number, number in sequence.
4. Classer stencil number.
Use approved ink, which dries quickly and will not be absorbed into the packaging material and stain the wool. Do not use branding paint or aerosol paint. Contact the warehouse or a stencil ink manufacturer/distributor for acceptable supplies.
There are several sources of contaminants that reduce the value of our domestic wool clip. If these items are not kept out of the raw wool, they will inevitably show up at the manufacturing level where costly removal must occur. Wool containing high amounts of contamination are discounted to cover the removal expense. Fundamentally, anything that is not wool is a contaminant.
There are three major categories of contamination while the wool is still on the sheep; First is naturally occurring, such as urine, dung and yolk stains. Second is acquired contaminants, which may be animal, vegetable or mineral in nature. Third is applied sources, which are generally manmade in origin and applied by man such as branding fluid, dewormer compounds and external sprays or dips.
Polypropylene contamination has become a very serious problem for American wool growers. This contaminant is subtle in raw wool, but very obvious in finished fabric. Wool mills invest much time and money in processing before the poly contaminant is detected. For this reason, processors have expressed so much concern.
Other contaminants are usually a result of careless housekeeping and can be easily corrected. However, these and other extraneous materials found in wool pose a serious problem to the manufacturer.
Natural contaminants are produced by the sheep themselves. While one cannot prevent this from being produced there are management practices that can minimize their effect on wool quality.
Acquired contaminants are a result of the environment in which the sheep are placed. Many other factors determine how and to what extent these contaminants can be reduced.
If it is impractical to remove the contaminant plants from fields or rangelands, there are several alternatives.
Again, blowing sand cannot be prevented. Any change that will reduce the effects of dirt penetration into the fleece should be considered. Soil does not only reduce yield, but can in some soils actually stain the wool. Shearing is much easier on clean sheep and usually the shearing quality reflects this.
Other livestock run in conjunction with sheep can reduce wool quality. This is not only from cross contamination with other animal fibers, but includes manure. External parasites also contribute to wool contamination from eggs, feces and the parasites themselves, all of which can stain the wool.
These are substances applied by man usually for management reasons. The most notable ones are paint brands, dewormers and topical sprays. While all have an intended purpose, care must be taken to minimize any reduction in wool quality.
Paint free wool should be first consideration, as it has been proven that if marketed accordingly, it will bring a premium.
If sheep must be branded:
Other identification options:
Dewormers and Medications
These compounds should certainly be used in any operation even though there may exist a potential for wool to become stained. Few dewormers used today actually stain the wool; however, if it is a possibility use care to prevent sheep from rubbing these compounds on each other. Stains from wound dressings and such should be removed at shearing.
Most wool proccesors do not consider external spray compounds to be a contaminant. While they do not necessarily affect wool processing performance they can limit lanolin recovery and how the scouring effluent is treated. Lanolin use in cosmetics and creams must meet critical standards for minimal chemical content. Chemical compounds, if used improperly in parasite control, can remain in the recovered lanolin.
While polypropylene contamination could be categorized in one of the previous headings, it is such a subtle and critical problem for processors it is discussed separately. This contaminant can occur before, during and after shearing.
Hay baling twine
Tarps and feed sacks
Most poly is picked up off the ground when sheep lay down. In such cases, skirting of the belly at shearing is beneficial.
These should never be allowed to come in contact with wool. Their presence results in small, non-wool fibers being mixed with wool fibers which cannot be removed, resulting in defective yarn or fabric.
At shearing the potential for contamination increases. All the previously mentioned contaminants can occur as the fleece is shorn and packaged. Steps must be taken to minimize this contamination threat. The shearing floor must be swept clean at all times. A clean floor keeps dust, manure, locks and litter from contaminating fleece lines. Portable shearing plants must be cleaned thoroughly prior to shearing
Objective measurement is an assessment made without being influenced by personal feelings or prejudice. This is accomplished by the use of instruments and laboratory procedures to measure specific characteristics.
Objective qualification and quantification of raw wool is essential for a producer to set appropriate goals in selection programs and measure progress in attaining those goals. It is also essential for the grower to know what his wool is (quality and quantity) in order to effectively market the wool clip.
In order for an objective measurement of any wool characteristic to be meaningful, it is absolutely necessary that the sample being tested be representative of the bulk from which it was drawn. This is accomplished by core sampling when staple length is not required.
Standard practice for sampling lots of grease, pulled or scoured wool in bales and bags for yield and fiber diameter determination is provided in the American Society for Testing and Materials (ASTM) test method D1060. This method provides a description of suitable core sampling equipment, sampling procedure, a method to determine the number of packages to be cored in a particular lot and the number of cores to be taken from each sampled package.
Remember, a core sample must represent the entire wool lot for the integrity of testing and the confidence of using objective measurement in commerce. Sample manipulation or mishandling will affect the test results.
Core Sampling Equipment
General Core Sampling Procedure for 2" Core
1. A minimum number of cores taken from each lot shall be such as to
give a sampling precision of
1% clean wool content at a probability level of 95%. Use the following schedule:
|Small Lots of Domestic Wool Bags
(Not covered by ASTM Standards)
|Large Lots of Domestic Wool Bags
(Commercial Testing Lab Recommendations)
NOTE: Each bag must be cored the same number of times. Each core must be a full tube core.
2. Open the packaging material to provide access to the wool without contaminating the sample. Poly packs should be cut with a heated iron to melt the raw edge and prevent contamination.
3a. The coring tube is inserted into a bag at a 45 degree angle to sample as many fleeces as possible.
3b. The coring tube is inserted into a bale at a 90 degree angle on the compressed bottom end of the bale.
4. Each sample is removed and immediately placed in a sealed container to prevent moisture changes and to keep it clean.
5. Special attention must be made to weigh the wool at or near the time of sampling.
General Core Procedure for 7/8" Automatic Core Machine
New equipment is being used in the U.S. that automatically core samples Australian type bales. Core sampling schedules for this type machine has not been developed for wools in the U.S. Core samples should be taken to provide a minimum of 1000-1500 gram (2-3 lb.) sample. Each bale should be cored and each bale cored the same number of times. Collection and handling of core samples are the same as with the 2" core.
Minimum Number of Cores per Bale*
|Bales In Lot||Number of Cores|
*Schedule based on information from Australia Wool Testing Authority
Samples may be taken from individual animals to run objective measurements. Figure 4 shows the correct area to take samples. Each sample should be 2" square in area to provide adequate test material.
Individual Animal Tests
Increasing the number of bales in a sale lot will help cut costs for growers and the wool industry. However, do not mix lines that are not similar or lines which will reduce a grower's marketing options.
Warehouseman, Cooperative Manager, Wool Buyer
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