Assessment of pain responses following castration of lambs using the Elastrator ring with and without midline injections of lignocaine
| Project start date: | 30 October 2015 |
| Project end date: | 15 March 2016 |
| Publication date: | 01 March 2016 |
| Project status: | Completed |
| Livestock species: | Lamb |
| Relevant regions: | National |
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Summary
This study concentrated on the question if and when a single midline injection of lignocaine at the time of castration is effective and whether 1.5 mL or a higher dose of 4.0 mL is required for efficacy. Thirty-six lambs were subjected to 3 treatments (12 lambs per treatment), ring castration with either no pain relief or a single midline injection of 1.5 or 4.0 mL of lignocaine at the time of castration. Lambs were observed continuously for 2 h after castration, when most pain is expected, and instantaneous point sampling every 10 minutes was used until 5 h after castration. In addition blood samples were taken prior to castration as well as 30, 60 and 210 min after castration.
Key findings
Lambs injected with 4.0 ml of lignocaine at the time of ring castration compared to no pain relief or an injection of 1.5 ml showed minor but significant reduction in pain related behaviour. However, other behaviours and the results of the cortisol analysis do not confirm a reduction in pain. The behavioural changes observed do not appear to be biological significant and do not warrant the time and cost involved in administration of this anaesthetic in order to obtain minimal pain relief. It would also not satisfy the expectation of the general public of providing effective pain relief.
More information
| Project manager: | Jim Rothwell |
| Primary researcher: | University of Melbourne |
