Ref Code: SHE18

Objective

Dye bands are placed in the wool at skin level to mark specific times in the growth of wool.

This can be for two purposes:

• To calculate wool growth rates over specific periods within the annual fleece, and
• To enable wool grown during a specific period to be sampled for predetermined measurements.

Alternatives to animal use for teaching

There are no practical alternatives.

Details of procedure

The dye solution must be prepared immediately before use. Dye bands should not be applied to damp wool or if rain is likely to wet the bands within 6 hours of application.

Walk the sheep into the handling crate, secure the adjustable side of the crate and tip the crate.

With the sheep lying on its side, part the fleece at the midside position in a straight dorso-ventral (ie. back to belly direction) line. N.B. It is much easier and quicker if a second operator can hold the fleece open.

Half fill a disposable plastic pipette with the dye solution. Apply the dye sparingly to the fibres at the skin level, removing excess solution but at the same time ensuring that the fibres are wetted. (Dye will run along the skin level towards the belly when the animal is released if the excess is not removed.) The band should be 10-15cm long.

Close the fleece and mark the position of the band with a scourable stock marker applied to the surface of the fleece.

Return the crate and sheep to the upright position.

Release the sheep.

This procedure may be repeated at intervals of 3 weeks or more, depending on the rate of wool growth.

Dyed staples must be removed before the sheep are shorn.

Drugs, chemicals or biological agents

1,4-phenylenediamine (Durafur black R flakes or Nako H powder) is the most commonly used chemical to dye the wool. This dye (0.8% w/v) will dye greasy wool black/brown in 4 hours. Body warmth and hydrogen peroxide (0.8%) enhance the oxidation process required to dye the wool.

Note: 1,4-phenylenediamine is a hazardous substance. The MSDS must be consulted and Departmental procedures for handling hazardous chemicals must be followed.

Impact of procedure on wellbeing of animals

Dye banding has no impact on animals other than the restraint required to place the dye band on the animal's flank. Handling by experienced operators and use of an appropriate restraining device will minimise that impact.

Reuse and repeated use

Usually each sheep is dye banded at intervals of 3 weeks or greater, depending on wool growth rate and the needs of the investigation.

Care of animals during/after the procedure

These procedures have no after-effect on sheep. There should not be any need for special care after dye banding.

Pain relief measures

Not needed.

Qualifications, skill or training necessary to perform this procedure

Competence in handling sheep. Observation and understanding of the procedure.