By Dr Pat Kluver, Livestock Biosecurity Network regional manager
A recent MLA report investigating the relationship between tail length and arthritis has shown that sheep with short tails are at greater risk of developing arthritis.
Arthritis costs the sheep industry around $39 million each year through slow growth rates, deaths and trimming at the abattoirs.
The work was carried out by veterinary consultant, Dr Joan Lloyd and compared the rate of arthritis in lambs with correct tail length and those with short docked tails, finding the rate of arthritis was significantly higher in lambs with tails that were docked too short.
While there has been plenty of reason to cut tails the correct length before now, this new study has given more reason to get it right.
The recommendation for tail length is the third palpable joint of the tail which is about the length that just covers the vulva in ewes.
There are a number of problems seen with docking tails too short, including increased risk of fly strike, prolapsed rectums and skin cancer of the vulva.
Sheep with short tails are 2-3 times more likely to be affected by breech strike, due to their inability to raise the tail properly while defecating.
As well rectal prolapse is seen in lambs with short tails at around four times the level we see in tails docked at the recommended length.
If tails are cut short enough to expose the bare areas of the vulva this can lead to an increase in skin cancer in older ewes.
Short docked tails can result in a larger wound, slower healing and a higher level of infection. Arthritis is caused by bacteria entering the body usually through a wound and lodging in the joint.
Around 20 percent of sheep in the study had tails shorter than the recommended tail length and in these sheep, the risk of arthritis was 1.5 times that of sheep with correctly docked tails.
This means if you stop docking tails short you’ll reduce the level of arthritis by around a third in your lambs.
Docking tails short accounts for around 10% of arthritis cases in the overall population so if we eliminate this practice it would result in savings to the industry of around $3.9 million annually.
Arthritis affects sheep on farm in a number of ways including poor growth, mortalities and unmarketable sheep which cannot be finished or trucked for welfare reasons.
At the abattoir, legs are trimmed to the next clean joint, resulting in an average loss of 750 gms per carcase with the occasional whole carcase condemned if more than four joints are affected.