AWI has recently conducted a project to look at key principles to try and maintain crutching productivity in un-mulesed sheep. Keys are: The use of the Free hand, Entry points, Gear and Cut and finally Position. AWI have developed a series of interactive training DVD’s and innovative hard copy resources.

Assessment of Crutching in Unmulesed Sheep
Key finding to help maintain productivity

Principals and blow patterns
The major aim of this project was to identify principles and blow patterns that will lead to maintaining and/or increasing crutching productivity in unmulesed sheep, when compared to mulesed sheep.

Two professional Shearer Trainers worked through a process of considering each of the 5 Pillars of Shearing: Free Hand, Entry, Gear and Cut, Grip and Position, and identified in relation to each, the technique considered to be necessary to reduce potential productivity losses when crutching unmulesed sheep.

Free Hand
When considering the technique of crutching unmulesed sheep, the Free Hand is seen as the most significant of the pillars. Unmulesed sheep present a higher level of skin area to the crutcher, which is usually associated with additional wrinkles, and these are generally more pronounced. As with all shearing and crutching, the Free Hand is used largely to manipulate the skin to provide a flat surface for which to run the comb over.

With unmulesed sheep this role is increased as more skin is present. This means that additional use of the Free Hand being required. Specifically, the role of the Free Hand is increased in the areas of:

• Stretching the wrinkles that would have been removed if the sheep had been effectively mulesed. Generally, as sheep get older these wrinkles become harder and require more “Free Hand” to stretch. It is important to shear over the top of wrinkles and not down them, so as to avoid unnecessary cutting of the skin.
• Where wrinkles cannot be stretched flat, such as the bottom side of the tail, the Free Hand is used to position the wrinkle so as a blow can be run down either side of the wrinkle. This ensures all wool is effectively cleaned out from around the wrinkle. Wool left around wrinkle is likely to catch urine and dag and lead to the sheep becoming fly struck.
• As unmulesed ewes have wool closer to the vulva than mulesed ewes, the Free Hand plays a critical role in protecting the vulva from being damaged. To do this in conjunction with stretching the skin and positioning the wrinkle, every part of the Free Hand is required including the fingers.
• Providing entry points by opening up the wool. Predominantly done by the thumb of the Free Hand to provide an entry point above the tail, stretching the skin causes the fibres to be spread so as the comb tooth can be easily entered onto the skin. Due to the lack of skin stretch that the mulesing operation results in, the wool of unmulesed sheep in the crutch area generally has higher density, which requires more “Free Hand” to open up.

When sheep have not been mulesed, significantly more “Free Hand” is required to flatten and stretch the skin. In essence, the mulesing shears are being replaced by the Free Hand.

The ‘cleaning up’ of wool around wrinkles to reduce the risk of fly strike is one of the significant factors that results in the loss of productivity between crutching mulesed and unmulesed sheep. Whilst this productivity decline could be reduced by not taking as much care in cleaning up around wrinkles, the effectiveness of the crutch in terms of a tool to prevent fly strike would be severely reduced.

Entry
Also important to the technique of crutching unmulesed sheep are entry points or “Entry”.
The Entry point is similar between mulesed sheep but the Entry on unmulesed sheep needs to be more precise as the gap between fibres is not as pronounced (due to higher density of fibres) and therefore harder to find.

While the Free Hand does aid Entry in stretching out the fibres, more care needs to be taken to identify appropriate and efficient entry points so as the comb can be applied to the skin, which is the most effective location to cut the fibre.

Unmulesed sheep will generally require an additional blow and therefore an additional Entry,
over the tip tail.

Where Bat Wings (large vertical wrinkles that run up from the tail) are present, a different blow is required to shear between the Bat Wings, instead of shearing horizontally across them. When these Bat Wings are large, this will mean making an Entry above the wrinkle in order shear between them. This can result in quite a large crutch being taken, which can result in a loss in wool productivity.

Gear and Cut
Every mob of sheep and situation will require attention to what is the best Gear and Cut for the job.

When crutching unmulesed sheep, selection of combs is critical in order to give effective Entry. Sharper combs, that is, combs with a pointier tip or combs that have been used more, will provide easier access for Entry in denser wool. Combs straight out of the box should be avoided when crutching unmulesed sheep.

Grip
The Grip to be used when crutching unmulesed sheep is similar in all respects to the Grip that should be used when crutching any sheep. The Grip needs to be light and in the form of a “spider”, with an air tunnel between the hand and the handpiece. This Grip provides a great deal of flexibility and allows the free movement of the handpiece around the crutch area.

This flexibility is particularly important when crutching unmulesed sheep as the Grip will need to be adjusted more often to accommodate for the higher level of shearing angles encountered as compared to mulesed sheep. Areas such as the tip of the tail and the wrinkle below the tail, which don’t generally appear on mulesed sheep, lead to more dramatic angles and therefore Grip changes.

Whilst not specifically Grip related, hand speed when operating around the vulva should be
slowed down to reduce the risk of injury. This is more important in unmulesed sheep due to the closeness of the handpiece to the vulva.

Position
The relationship of the sheep to the downtube and the shearer to the sheep and the downtube remains the same regardless of mulesing status. One slight change in Position that may be required is the additional rolling of the sheep to get both under the tail and under the wrinkle below the tail. However, this movement is seen more of an adjustment which is quite natural for a crutcher to make and not something that is necessarily learnt.

A Note on Clipped Sheep
The above principals and blow patterns were identified on unmulesed sheep. Subsequently, the principals and blow patterns were tested on sheep that had been clipped in order to determine their relevance.
It was demonstrated that the same principals and blow patterns that were found to be effective on unmulesed sheep were equally as effective on clipped sheep. The level to which the principals and blow patterns needed to be applied did differ between unmulesed and clipped sheep, with the clipped sheep requiring less attention to the 5 Pillars of Free Hand, Entry, Gear and Cut, Grip and Position, than did unmulesed sheep...