23rd August 2019

Most producers are well into or have completed lambing for the year and will be looking at marking lambs over the next month or so. As such we thought it topical to look at available pain relief options.

Why use pain relief?

There are a number of reasons why using some sort of pain relief at lamb marking is beneficial but these can be broken down into 2 broad categories:

1. Welfare:

In this day and age, animal welfare and animal rights are becoming increasingly prominent social issues. With the advent of camera phones and social media, gone are the days where agricultural producers can go about their business with no fear of ending up in the center of a media storm. The continuously growing disconnect between producers and their major markets in metropolitan areas has allowed various animal welfare & rights groups to heavily influence these consumers with a bombardment of emotive messaging. The end result is that our consumers have become, as a whole, much more socially conscious of how their foods are produced.

As such, it is vital that the industry get on the front foot and act proactively rather than reactively in the face of increasing activism. We all need to be doing everything we can to improve the welfare of the animals under our care where ever practically possible and remove ammunition that activists can use against us. One of the simplest changes that can be made is the increased use of pain relief whenever performing procedures on animals that are likely to cause pain – as mulesing and marking undoubtedly do.

2. Production:

The production benefits of using pain relief for lamb marking are difficult to boil down to a reliable $$ figure. Subjectively, many producers who use pain relief (whether Tri-Solfen or meloxicam) say that they notice a marked difference in the behavior of lambs in the immediate period post marking. This is noted in a reduced number of lambs sitting down, increased lambs straight back with their mothers and fewer stragglers when walking away from yards. This is particularly important in the first 2-3 days post marking when pain is at its greatest. Many lambs will fail to follow their mothers when they head off for feed or water, resulting in mis-mothering of a percentage and death of some lambs. This issue is going to be exacerbated for mobs in larger paddocks or particularly hilly country. In a couple of anecdotal cases, producers who have routinely lost up to 10% of lambs between marking and weaning have reduced those losses to just 1-2% through the introduction of pain relief at marking.

There have been multiple studies performed which have conclusively proved that pain relief provided at the time of marking has a significant impact on lamb weight in the weeks following marking. Whilst the few studies that have followed these lambs long term have shown that the difference between the groups lessens several months down the track, the real impact is the positive benefits in lamb strength and survival in the immediate term post marking.

What options are available?

The options available for pain relief at lamb marking fall into 2 classes based on active ingredients:

1. Local Anaesthetics:   Trisolfen

Local anaesthetics block the transmission of pain stimuli from travelling along nerves to the spinal cord, thereby preventing pain perception in the brain. They are very effective in the short term and work best when injected prior to a painful procedure. Various local anaesthetics provide differing lengths of analgesia – lignocaine works very quickly but wears off after a couple of hours, whilst bupivacaine has a slower onset but lasts for up to 8 hours. The addition of adrenalin helps to extend the duration of action of local anaesthetics.

2. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs):   Metacam, Buccalgesic

NSAIDs are anti-inflammatory drugs which include ibuprofen (humans) and phenylbutazone (horses) along with many others. The most common NSAID registered for use in sheep is meloxicam which is also used in humans, dogs, cats, horses & cattle. NSAIDs work by inhibiting the inflammatory cascade initiated by the mulesing or marking procedure, thereby reducing the amount of pain stimulus sent from the affected area to the brain. NSAIDs can be administered in a number of ways, in sheep the 2 major options are injectable or transbuccal (similar to oral but absorbed from the gums). The onset of action is not immediate (around 15 minutes) and therefore ideally it is given prior to the procedure for maximum benefit.

It is important to note that NSAIDs will not completely remove all pain like local anaesthetics potentially can, however the duration of action of products registered in sheep is typically around 48 hours – much longer than that of local anaesthetics.

Within these categories, the main products available registered in sheep are:

Trisolfen:

• Is a combination of a short acting and long acting local anaesthetic combined with adrenalin in a gel spray to extend its duration of action (plus antiseptic)
• Is a topical local anaesthetic so will not be as effective as injectable options but much easier to apply
• Rapid onset of action but with much shorter duration of action than NSAIDs
• Unlikely to absorb through skin very effectively when using rings on tails and scrotums therefore much better suited to mulesing and surgical castrations
• Approximately $1.00-1.40/head depending on pack size + size of lambs

Metacam 20:

• Is an injectable formulation of meloxicam (NSAID) injected under the skin which provides analgesia within approximately 15 minutes and lasts for approximately 48 hours
• Will be as effective for non-surgical operations (rings) as it is for surgical procedures (mulesing/castration)
• Approximately $0.70-0.90/head

Buccalgesic:

• Is a transbuccal formulation of meloxicam (NSAID) which is deposited inside the cheek to be absorbed through the mucous membranes
• Effectiveness very similar to Metacam (same active ingredient)
• Trickier to administer correctly (need to ensure that it is not swallowed) than injectable formulations
• Approximately $0.70-0.90/head

In summary, local anaesthetics will provide superior analgesia in the immediate aftermath of marking (0-10 hours) however NSAIDS will provide much longer acting analgesia (up to 48 hours). With this in mind, the gold standard of analgesia would be to use both products in conjunction with each other, however given cost constraints many producers will be making a decision of one or the other.

As an adjunct, the use of analgesia is also topical for beef producers when marking or dehorning calves with the above products all being registered for use in cattle as well. In New Zealand it has recently become mandatory to use some form of analgesia when performing these procedures on calves and there is a likelihood Australia will follow suit at some point in the future.

If you have any queries about the use of pain relief products at lamb marking (or calf marking) please don’t hesitate to give us a call at the clinic.