Lamb marking

Ref Code: SHE12

Category

Teaching - 3 (Instructor:student ratio 1:3)
Research - 4

Objective

To identify, castrate and dock the tails of lambs.

Alternatives to animal use for teaching

Abattoir specimens, video presentation.

Details of procedure

Lambs can be restrained either by hand or in cradles.

  1. Ear marking

    In NSW it is compulsory to put the owner's registered mark in the off-side ear of ewes and near side for males, using the specially designed ear-marking pliers.

  2. Ear tagging

    The head should be adequately restrained and the tag located in the centre of the ear or slightly towards the end, so that the longitudinal ridges of the ear are avoided.

    Applicators should be kept in good working order. Disinfection of applicator and tag is recommended between animals.

    Replacement tags should be located in the previous site where possible.

  3. Castration
    1. Surgical removal of the testicles involves cutting off the bottom one-third of the scrotum with a sharp sterilised lamb-marking knife. The testicles are then exposed (by squeezing the remaining portion of the scrotum with the thumb and index finger) and removed with a clamp or hook on the end of the knife.
    2. The elastrator method involves the use of a rubber ring, which is expanded using a pair of special pliers and placed over the scrotum just above the testicles. The ring blocks blood circulation, causing the scrotum and testicles to eventually wither and fall off. It induces the same effect when placed on the tail.
  4. Tail docking

    Implements required for castration are also commonly used to remove tails. Tail severance should occur level with the tip of the vulva or below the second palpable tail joint. If lambs are mulesed at marking or later, tails are cut slightly longer - that is below the third palpable joint - as some shrinkage occurs following mulesing.

    1. When using the lamb-marking knife it is important that the bare skin beneath the tail is pushed forward just prior to severance, leaving a flap of skin to heal over the bottom of the cut tail. Any other action is likely to leave wool-bearing skin at the base of the tail, which, on becoming wet from urine, risks blowfly strike. Severance should occur between the tail joints. Cutting through the bone tends to result in slower healing and so a greater risk of fly strike.
    2. A gas-heated de-tailer may be used. The heat cauterises the blood vessels, which virtually eliminates bleeding. There appears to be less stress associated with the operation, as lambs show normal behavioural patterns earlier.
    3. Elastrator Rings are stretched and applied to the tail with the elastrator pliers. The tail withers and falls off about three weeks later. The area is generally attractive to flies for longer than if the knife is used, because of slower healing.

Drugs, chemicals or biological agents

Insecticide to prevent flystrike when necessary.

Antiseptic to sterilise equipment.

Impact of procedure on wellbeing of animals

Marking lambs in an overheated or excited condition causes excessive bleeding. When operations are completed, release the lamb so that it lands on its feet, to avoid the risk of wound infection.

Reuse and repeated use

One demonstration per animal.

Care of animal(s) during/after the procedure

Livestock should be handled quietly before, during and after the procedure.

Lambs should not be held in yards. In extensive areas where paddocks are large, flocks may need shepherding for up to an hour after marking to allow ewes and lambs to mother up. Providing water for ewes during marking may make them less likely to desert the lambs when they are let out of the yards.

Flystrike can be a major problem, so regular monitoring is needed after marking, and the wound should be dressed with insecticide. Tetanus can develop if lambs' mothers haven't been vaccinated with a clostridial vaccine prior to lambing.

Pain relief measures

None required if lambs are under 6 months of age. Lambs more than 6 months of age may only be castrated by a veterinarian.

Qualifications, experience or training necessary to perform this technique

The operator needs to demonstrate proficiency in the technique.