How Well Does Australian Animal Welfare Policy Reflect Scientific Evidence: A Case Study Approach Based on Lamb Marking

The development and substance of animal welfare policy is subject to a range of social, cultural, economic, and scientific influences that commonly vary within and between countries. Discrepancies in policy can create confusion and mistrust among stakeholders and consumers and limit the ability to create a uniform minimum level of requirements to safeguard animal welfare, as well as create a level 'playing field' for farmers when trading with other jurisdictions. The livestock sector is receiving growing scrutiny globally for real and perceived violations of animal welfare, for example, the practice of mulesing in Australia. This article explores animal welfare legislation within Australia and how it reflects the scientific evidence surrounding routine husbandry practices in sheep, including tail docking, castration, and mulesing. While there is some variation between state and territory legislation, the most notable concern is the lack of enforceable recommendations surrounding the evidence-based use of analgesia and anaesthesia for painful husbandry procedures. The age at which these procedures are recommended to be performed is relatively consistent across Australian jurisdictions, but there is a marked difference compared to international legislation. The global context of animal welfare legislation, public perception, and producer perception of these procedures are also discussed, highlighting the difficulty of creating robust animal welfare legislation that promotes a good standard of welfare that is respected worldwide whilst being practical in an Australian setting given our unique geography and climatic conditions.

Analgesia for Sheep in Commercial Production: Where to Next?

Simple Summary

Increasing societal and customer pressure to provide animals with ‘a life worth living’ continues to apply pressure on industry to alleviate pain associated with husbandry practices, injury and illness. Although a number of analgesic solutions are now available for sheep, providing some amelioration of the acute pain responses, this review has highlighted a number of potential areas for further research.

Abstract

Increasing societal and customer pressure to provide animals with ‘a life worth living’ continues to apply pressure on livestock production industries to alleviate pain associated with husbandry practices, injury and illness. Over the past 15–20 years, there has been considerable research effort to understand and develop mitigation strategies for painful husbandry procedures in sheep, leading to the successful launch of analgesic approaches specific to sheep in a number of countries. However, even with multi-modal approaches to analgesia, using both local anaesthetic and non-steroidal anti-inflammatory drugs (NSAID), pain is not obliterated, and the challenge of pain mitigation and phasing out of painful husbandry practices remains. It is timely to review and reflect on progress to date in order to strategically focus on the most important challenges, and the avenues which offer the greatest potential to be incorporated into industry practice in a process of continuous improvement. A structured, systematic literature search was carried out, incorporating peer-reviewed scientific literature in the period 2000–2019. An enormous volume of research is underway, testament to the fact that we have not solved the pain and analgesia challenge for any species, including our own. This review has highlighted a number of potential areas for further research.

Facial action units, activity and time spent with dam are effective measures of pain in response to mulesing of Merino lambs

Repeatable measures of pain in ruminants following husbandry procedures are required to validate responses to pain relief. This study tested the hypotheses that facial action units, activity and time spent with dam can be used to assess the efficacy of pain relief in lambs following mulesing. Merino lambs (n = 120) were allocated to one of six treatments implemented at mulesing: (1) lambs that were not mulesed or lambs that were mulesed and administered (2) no pain relief, (3) meloxicam 15 min before mulesing, (4) Tri-Solfen®, (5) a combination of meloxicam 15 min before mulesing and Tri-Solfen after mulesing and (6) meloxicam at mulesing. Facial action units detected a difference in pain between mulesed and non-mulesed lambs at 1 and 5 h post-mulesing (P = 0.005 and <0.001) but not at 26 h post-mulesing. Lambs that were not mulesed were more active and spent more time with their dams than mulesed lambs (P < 0.001). No differences were observed between lambs that were mulesed with or without pain relief. Therefore, facial action units, activity of the lamb and time spent with dam can detect pain in response to mulesing in Merino lambs but cannot detect any changes associated with pain relief.

Preliminary Findings on a Novel Behavioural Approach for the Assessment of Pain and Analgesia in Lambs Subject to Routine Husbandry Procedures

Simple Summary

The identification and assessment of pain in sheep are important but, due to their stoic nature, are difficult. In the present study, we evaluated the use of qualitative behavioural assessment to assess pain in lambs caused by routine husbandry procedures performed at lamb marking (ear tagging, castration, mulesing, and tail docking). To do this, video footage of control lambs and of lambs subject to these procedures that were either administered analgesics (Tri-Solfen and meloxicam) or a placebo, was captured 1.5 h post-procedure and assessed by 19 observers. Results showed that the observers agreed in their assessment of the lambs and, as expected, the pain caused by the husbandry procedures altered the behavioural patterns and demeanour of the lambs in a way that was captured by observers using this approach. At the time of assessment, it also appears that the analgesics administered did not reduce the pain experienced by those lambs that received them. These results suggest that qualitative behavioural assessment may be useful in identifying pain in lambs; however further work is needed to test this methodology with lambs given effective analgesic pain relief.

Abstract

The identification and assessment of pain in sheep under field conditions are important, but, due to their stoic nature, are fraught with many challenges. In Australia, various husbandry procedures that are documented to cause pain are routinely performed at lamb marking, including ear tagging, castration, mulesing, and tail docking. This study evaluated the validity of a novel methodology to assess pain in lambs: qualitative behavioural assessment (QBA) was used to compare the behavioural expression of control lambs (CONTROL) with that of lambs subject to these procedures that received either a saline placebo 15 min before procedures (PLACEBO), or were administered meloxicam 15 min before procedures in addition to the standard analgesic Tri-Solfen at the time of procedures, as per the manufacturer’s recommendations (ANALGESIC TREATMENT; AT). In terms of behavioural expression, it was expected that: CONTROL ≠ PLACEBO, AT = CONTROL, and PLACEBO ≠ AT. Video footage of the 6−8-week-old lambs (n = 10 for each treatment) was captured approximately 1.5 h postprocedure and was presented, in a random order, to 19 observers for assessment using the Free-Choice Profiling (FCP) approach to QBA. There was significant consensus (p < 0.001) among the observers in their assessment of the lambs, with two main dimensions of behavioural expression explaining 69.2% of the variation. As expected, observers perceived differences in the demeanour of lambs in the first dimension, scoring all lambs subject to the routine husbandry procedures as significantly more ‘dull’ and ‘uneasy’ compared to the control lambs (p < 0.05). Contrary to expectations, the results also suggested that analgesic treatment did not provide relief at the time of observation. Further investigations to validate the relationship between behavioural expression scores and pain are necessary, but these results suggest that painful husbandry procedures alter the behavioural expression of lambs and these differences can be captured using QBA methodology.

Behavioural measures reflect pain-mitigating effects of meloxicam in combination with Tri-Solfen® in mulesed Merino lambs

Flystrike costs the Australian industry $173 to 280 M per annum and 70% to 80% of Merino lambs are currently mulesed to reduce the risk of flystrike. To alleviate welfare concerns there has been widespread adoption of analgesics to mitigate the pain associated with mulesing. The objective of this experiment was to determine the effectiveness of Tri-Solfen® and meloxicam (Metacam® 20) at reducing pain-related behavioural responses to mulesing in Merino lambs. One hundred and forty Merino lambs were allocated to one of seven treatment groups: (1) non-mulesed (Control); (2) mulesed with no pain relief; (3) subcutaneous (s.c.) meloxicam administered 15 min before mulesing; (4) Tri-Solfen® administered at time of mulesing; (5) Tri-Solfen® and saline injection (s.c.) 15 min before mulesing; (6) Tri-Solfen® and meloxicam (s.c.) 15 min before mulesing; and (7) meloxicam (s.c.) at time the of mulesing. Behavioural responses such as standing, walking and lying were measured every 15 min for 6 h on the day of marking and for up to 2 h for 4 days thereafter. Standing (hunched v. normal) and walking (stiff v. normal) behaviours were then categorised into pain- and normal-related behaviours while lying remained in its own category. Mulesed lambs with no pain relief displayed significantly more pain-related behaviours than Control lambs during the 6 h post-mulesing (1.22 v. 0.22 out of a total score of 3; RSD=1.15). Lambs that received a combination of pain relief displayed significantly less pain-related behaviour than mulesed lambs with no pain relief on the day of mulesing (0.85 v. 1.22 out of a total score of 3; RSD=1.15). Administration of meloxicam or Tri-Solfen® on their own had minimal if any significant effect on pain-related behaviours on the day of mulesing. The results of this experiment support the use of pain-related behaviours to measure the efficacy of analgesics and the use of multimodal analgesia during mulesing of lambs.

Breech-strike on mulesed, clipped and unmulesed Merino ewes and hoggets in south-eastern Australia

OBJECTIVE

Compare breech-strike on Merino ewes and hoggets that were mulesed, had breech and tail clips applied ('clipped') or left unmulesed and treated strategically with long-acting insecticide.

DESIGN

A cohort study on two farms in southern Victoria.

METHODS

Three treatment groups were established at lamb marking in 2008 and 2009 on each farm. The unmulesed group was treated with a long-acting insecticide in early spring. The prevalence of breech-strike and key risk factors, including presence of dag, urine stain and breech wrinkle, were compared between groups.

RESULTS

Breech-strike was detected from October to December on 1.9% and 7.2% of mulesed, and on 14.8% and 12.5% of clipped ewes, respectively, on each farm. Thus, clipped ewes had a relative risk of breech-strike 7.8- and 1.7-fold that of mulesed ewes. Unmulesed ewes treated with insecticide had similar or less breech-strike compared with mulesed ewes (3.4% and 1.4%), but significantly more dag, stain and breech wrinkle. From January, breech-strike on unprotected unmulesed ewes was 8.5% and 2.8%, compared with 3.5% and 0% on mulesed ewes.

CONCLUSION

Early-season treatment of unmulesed sheep prevented most breech-strikes during spring and early summer on both hoggets and breeding ewes, confirming it as a short- to medium-term option for the control of breech-strike. Some benefits were associated with the use of clips but, to control breech-strike, clipped sheep should be treated the same as unmulesed sheep. Genetic selection to reduce the prevalence of dag will be required for future strategies to control breech-strike on Merino sheep in south-eastern Australia.

Trial of human laser epilation technology for permanent wool removal in Merino sheep

OBJECTIVE

To assess whether human laser epilation technology can permanently prevent wool growth in sheep.

DESIGN

An observational study.

METHODS

Two commercial human epilation lasers (Sharplan alexandrite 755 nm laser, and Lumenis LightSheer 800 nm diode laser) were tested at energies between 10 and 100 J/cm2 and pulse widths from 2 to 400 ms. Wool was clipped from flank, breech, pizzle and around the eyes of superfine Merino sheep with Oster clippers. After initial laser removal of residual wool to reveal bare skin, individual skin sites were treated with up to 15 cycles of laser irradiation. Behavioural responses during treatment, skin temperature immediately after treatment and skin and wool responses for 3 months after treatment were monitored.

RESULTS

A clear transudate was evident on the skin surface within minutes. A dry superficial scab developed by 24 h and remained adherent for at least 6 weeks. When scabs were shed, there was evidence of scarring at sites receiving multiple treatment cycles and normal wool growth in unscarred skin. There was no evidence of laser energy level or pulse width affecting the response of skin and wool to treatment and no evidence of permanent inhibition of wool growth by laser treatment. Laser treatment was well tolerated by the sheep.

CONCLUSIONS

Treatment of woolled skin with laser parameters that induce epilation by selective photothermolysis in humans failed to induce permanent inhibition of wool growth in sheep. Absence of melanin in wool may have contributed to the result.