Pain evaluation in dairy cattle

Pain compromises the welfare of animals. A prerequisite for being able to alleviate pain is that we are able to recognize it. Potential behavioural signs of pain were investigated for dairy cattle with the aim of constructing a pain scale for use under production conditions.

Forty-three cows were selected and fifteen different behaviours were scored, subsequently a clinical examination was performed to allocate the cows to a pain and non-pain group. The animals were then treated with an analgesic or a placebo and after a resting period the cows were re-scored by two observers blinded to the treatment.

Six behaviours were found to be significantly different between the pain and non-pain group and robust enough to be included in the pain scale: 'attention towards the surroundings' 'head position', 'ears position', 'facial expressions', 'response to approach' and 'back position' (a seventh, piloerection, was also significant but seemed difficult to use as it changed rapidly; p < 0.05 for all measures).

The Cow Pain Scale is the sum of the score for the aforementioned behaviours. For each individual animal before and after treatment, it was significantly lower after analgesic treatment (p = 0.003) in the ClinPain group but not after placebo treatment (p = 0.06); the pain score did not differ significantly before compared to after treatment with analgesic or placebo for the non-pain group (p = 0.2; p = 0.1).

A second study was conducted to further validate the Cow Pain Scale. Cows from two herds were randomly selected (n = 119) and their behaviour scored by two observers. Subsequently the cows were clinically examined and allocated to a pain and non-pain group (n = 96, 23 cows were excluded because of incomplete examination). The cows from the pain group scored higher on The Cow Pain Scale compared to the non-pain group for both observer I (p < 0.0001) and observer II (p = 0.0001). For the two observers the sensitivity of the Cow Pain Scale was calculated to 0.61/0.75 and the specificity to 0.75/0.75 with a weighted Kappa of 0.62.

In conclusion the Cow Pain Scale has the potential to be applied for the assessment of pain in dairy cattle under production conditions.

Link to the article:

http://www.sciencedirect.com/science/article/pii/S0168159115002269

Reference:

Karina Bech Gleerup, Pia Haubro Andersen, Lene Munksgaard, Björn Forkman. Pain evaluation in dairy cattle. Applied Animal Behaviour Science. Volume 171, October 2015, Pages 25–32. doi:10.1016/j.applanim.2015.08.023