Sunday, 22 November 2009

Lamb Marking

6th October 2009 was Lamb Marking Day here on Ochre Arch. This blog post outlines some of the key steps, equipment and learnings from this significant activity in the annual calendar of sheep management.

1. Sourcing the equipment

Here is a list of the equipment and other bits and pieces needed for the process:

Ear tags, applicator and temporary storage vessel. The ear tags have to at least have the Property Identification Code on them; and are a pre-requisite for selling livestock through public sale facilities. In theory they allow for traceability by end users back to specific producers as part of quality control; and are especially required by export markets. The system is far from infallible given that the tags can fall off or get pulled out during shearing and general incidents. At the domestic level the tags are a bit farcical in that buyers tend to pool their purchases and the identification numbers may or may not be recorded. Ear tags are colour coded – and the 2009 tags are white.

Ear marking pliers. We used the ones that Phillip’s father owned. The pliers are used to take a small patterned section from the ear of the animal. It was necessary for us to have the pliers reconditioned (see a previous blog post) and registered with the local Livestock Health and Pest Authority. Ear marks on sheep tend to be more enduring than tags and are more relevant to neighbours in sorting out stock when they get through fences etc. Ear marks are generally placed in the left ear of a female sheep and right ear of a male. This also assists in identification during drafting.

Shears and sharpening stone. Used in the mulesing process, and supplied on the day by the mulesing contractor. Mulesing is a well known (and in recent times controversial) fly-strike mitigation measure for Merino sheep, and involves the removal of skin from around the tail of the animal. As the wound heals the skin around the area is stretched tighter, removing wrinkles. These skin folds or wrinkles can accumulate moisture, which attracts flies.

• Temporary fencing. The contractor supplied 3 fencing panels which were used to create a temporary ‘catching pen’ for the lambs adjacent to the yards; small enough in size to keep the effort in catching the lambs to a minimum.

Holding cradles into which the lambs are placed and restrained during the actual marking. Four cradles on a stand were supplied by the contractor. They were ‘home made’, extremely simple and very effective.

Elastrator and elastrator rings for castrating (de-sexing) male lambs. Castration is carried out for a few reasons: allows for better management of breeding in that high quality sire number can be kept to a minimum (generally 1 ram to 100 ewes), animals are purportedly much less aggressive and the meat flavour is not as pungent. 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 if placed on the tail, but we opted to use a gas knife for this aspect (see later).

Lamb marking knife with hook on the end, for castration of male lambs on an exception basis. At times it is not possible to place the rubber rings using the elastrator method over both testicles. Reasons can include lamb size (too large or small) and inability to locate both testicles (sometimes one or both of the testicles remains in the body cavity i.e. do not reside within the scrotum). 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.

Vaccine and applicator. Lamb marking is a good time to vaccinate sheep against common diseases. We purchased the vaccine in Forbes. In our case, we injected each lamb with 1 millilitre of ‘5 in 1’. The vaccine has to be kept refrigerated prior, during and after use.

Insecticide and applicator - to prevent flystrike

Antiseptic and anaesthetic and applicator – to mitigate against infections and reduce pain (and stress)

Antiseptic and containers (stainless steel buckets) to sterilise equipment.

Gas knife, holder, connector, bottle and box of matches. A gas-heated de-tailer was used. The heat cauterises the blood vessels, which virtually eliminates bleeding. Studies suggest that there appears to be less stress associated with the operation, as lambs show normal behavioural patterns earlier. Tails are removed to mitigate fly-strike and reduce shearing and crutching times.

Shelving for placement of items during the marking process. We used the underside of an empty 200 litre drum as a small table; on which we placed the container with the ear tags in it, ear marking pliers and ear tag applicator. The mulesing contractor used the back tray of his ute to store antiseptic and many other bits of equipment.

2. Assembling the team
During discussions with the mulesing Contractor it became obvious that we needed more people to assist than we had originally envisaged, due in part to our decision to mules the sheep. In the end, a total of seven people were involved on the day.

3. Getting the sheep on hand and setting up for the activity
We brought the sheep into the Duck Dam paddock the night before the lamb marking so that they could be easily brought into the yards early in the morning. In this way stress could be minimised. When herding the sheep into the yards we (possibly) applied a little too much pressure as many of the lambs moved away from their mothers to form a mob adjacent to the ewes. They were consequently more difficult to manage.

Tim arrived the night before and stayed over. Bruce (mulesing contractor) arrived first thing in the morning with the balance of the equipment, chemicals, and temporary fencing we did not have. Bruce and Tim set up the catching pen off the small gate on the south west of the yards.

Judith and Kevin arrived in time for the commencement of activities.

4. Doing the work on the day
Once the mob of sheep was in the yards we proceeded to draft the lambs from the ewes. This makes for much easier catching of lambs as the ewes are not in the way. Phillip did the actual drafting, with Tim, Bruce and Jan herding the mob into the drafting race. Some drafting errors were made. The correction process is basically to catch the animal that was drafted the wrong way (lamb in with the ewes as an example) and lift it or take it via a gate to where it should be.

Here are a couple of photos of the lambs, taken prior to marking.

After drafting, the ewes were released from the yards into the paddock (Air Strip) where they would stay for a few days, and into which the lambs were released as they were marked.

The lambs were herded into the temporary catching pen in lots. We did find that the lambs were difficult to get into this pen and were unsuccessful in identifying the root cause. The ramifications were that the whole team ended up being involved in the penning-up process; which would not normally be the case. We do not own and did not use sheep dogs. Perhaps dogs would have made for less work?

Below are the first names of those who participated in the lamb marking, together with the activity they carried out.

Inside the catching pen (am):
• Tim – catching the lambs, placing them into to holding crates, and applying the ear tags. Tim, based on many years of prior experience, would lay the lambs on their left / near side in the cradle.
• Phillip – ear marking and release once all activities had been completed. Tim’s action in laying the lambs on their side made the tagging process simpler: if male, tag the ‘upper’ ear, and if female, tag the ‘lower’ ear.

Outside the catching pen (am):
• Judith - vaccinate the lambs
• Kevin – dock the tails
• Bruce – castrate and mules
• Jan – apply chemical

After lunch Judith and Kevin left due to other commitments, and Warren called and provided assistance. Warren took over the catching and ear-tagging, Tim did the castrating, and Bruce vaccinated, tail-docked and mulesed. Phillip and Jan proceeded as before lunch.

We found that some of the lambs jumped through the hinge-joint fencing from the Air Strip Paddock to the Front Paddock as they were released. This delayed re-uniting with the applicable ewes.

When we bought the ewes we had been told that they were all ‘scanned in lamb’ at 164 %. This means that in theory, assuming no losses, we would be marking 164 lambs for every 100 ewes. While the ewes were lambing we did notice what seemed to be quite a few losses (dead lambs). Based on this and our own lack of stock management experience we had purchased for use during the lamb marking event:
• Enough vaccine for up to a 125 % marking rate (125 lambs for every 100 ewes)
• Enough ear tags for up to a 138 % marking rate (138 lambs for every 100 ewes).
It transpired that our lamb marking percentage was 140 (140 lambs for every 100 ewes) which meant that on the day:
• We ran short of vaccine, and Phillip did an un-planned and rushed trip to Grenfell for some more;
• We ran out of ear tags – by about a dozen. The affected lambs still received all of the other treatments.

Two lambs managed to squeeze out of the catching pen and are at this point still not marked / treated.

At the start of the day Phillip was asked by Bruce whether we wanted the ewe and wether lambs to be separated. Due to inexperience Phillip thought this question literally meant we were being offered the option to split the lambs into different mobs and responded ‘No’. After we got going with the marking we realised that Bruce had actually been asking / offering to create two separate piles of lamb tails: one from the ewes and the other from the wethers. By so doing we would then be able to get an accurate count on the number of ewe and wether lambs – to assist in later management decisions. Such is life! We have carried out an estimate on the number of wether lambs based on the number of remaining elastrator rings; however this is not accurate as the rings are counted into the sale containers based on weight – and thus there can be large variations in the actual numbers.

5. Clean-up and concluding remarks
Once all of the lambs had been marked Phillip herded the lambs that had escaped into the Front Paddock and beyond into the Air Strip paddock where they could re-unite with their mothers; and Bruce, Tim and Warren disassembled the temporary yards and packed away the equipment.

It was then time for some rest and recreation … the best part of the day!

First thing on the next day we transported the lamb tails and mulesing off-cuts to the Saddle Paddock and placed them on a patch of bare ground. We are curious to see what the impact of this addition of organic matter to that area will be over time.

Here is a picture of the tails and mulesing off-cuts on the bare ground in the Saddle Paddock.

A couple of days after lamb marking we noticed that one lamb and two ewes had died. Tim mentioned that the separation process for ewes (from their lambs – no matter how short) is extremely stressful and it is common to lose some.

One of the decisions taken during the marking process was to mark ALL of the lambs we could, rather than perhaps leaving a few of the smaller ones to a later date. Whilst this might seem to have been a little harsh it is consistent with one of our goals of running a simple to manage business. Fortunately we did not lose any of the small lambs as a result.

The ear tag applicator we bought and used could have been better designed. The deficiency is that the tags can only be inserted into the tool one way, rather than two ways. We have subsequently provided feedback to the vendor of the applicator.

The key highlight of the overall day was the teamwork and camaraderie from everyone who was involved. We had a common goal and there was a fantastic balance between getting the job done and enjoying the effort.

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