title: Application of a handheld Pressure Application Measurement device for the characterisation of mechanical nociceptive thresholds in intact pig tails.
abstract: The assessment of nociceptive thresholds is employed in animals and humans to evaluate changes in sensitivity potentially arising from tissue damage. Its application on the intact pig tail might represent a suitable method to assess changes in nociceptive thresholds arising from tail injury, such as tail docking or tail biting. The Pressure Application Measurement (PAM) device is used here for the first time on the tail of pigs to determine the reliability of the methods and to provide novel data on mechanical nociceptive thresholds (MNT) associated with four different age groups (9, 17, 24 and 32weeks) and with proximity of the target region to the body of the animal. We recorded an overall acceptable level of intra-individual reliability, with mean values of CV ranging between 30.1 and 32.6%. Across all age groups, the first single measurement of MNT recorded at region 1 (proximal) was significantly higher (P<0.05) than the following two. This was not observed at tail regions 2 and 3 (more distal). Age had a significant effect (P<0.05) on the mean thresholds of nociception with increasing age corresponding to higher thresholds. Furthermore, a significant effect of proximity of tail region to the body was observed (P<0.05), with MNT being higher in the proximal tail region in pigs of 9, 17 and 24weeks of age. There was also a significant positive correlation (P<0.05) between mechanical nociceptive thresholds and age/body size of the animals. To the best of our knowledge, no other investigation of tail nociceptive thresholds has been performed with the PAM device or alternative methods to obtain mechanical nociceptive thresholds in intact tails of pigs of different age/body size. The reliability of the data obtained with the PAM device support its use in the measurement of mechanical nociceptive threshold in pig tails. This methodological approach is possibly suitable for assessing changes in tail stump MNTs after tail injury caused by tail docking and biting.
authors.affiliation: School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom. Electronic address: Pierpaolo.Di-Giminiani@newcastle.ac.uk.
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Di Giminiani
authors.affiliation: Aarhus University, Department of Animal Science, AU-FOULUM, Tjele, Denmark.
authors.forename: Dale A
authors.initials: DA
authors.lastname: Sandercock
authors.affiliation: School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors.forename: Emma M
authors.initials: EM
authors.lastname: Malcolm
authors.affiliation: School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Leach
authors.affiliation: Animal and Veterinary Science Research Group, Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH16 4SA, United Kingdom.
authors.forename: Mette S
authors.initials: MS
authors.lastname: Herskin
authors.affiliation: School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Edwards
mesh_terms: D000375:Aging / Q000473:pathology / Q000502:physiology; D000818:Animals; D049628:Body Size / Q000502:physiology; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D059225:Nociception / Q000502:physiology; D010147:Pain Measurement / Q000295:instrumentation*; D017288:Pain Threshold / Q000502:physiology; D010812:Physical Stimulation / Q000295:instrumentation; D011312:Pressure; D015203:Reproducibility of Results; D034421:Sus scrofa / Q000033:anatomy & histology / Q000502:physiology; D013623:Tail / Q000033:anatomy & histology / Q000254:growth & development
keywords: Mechanical nociceptive thresholds; Pig; Pressure algometry