Identifying physiological measures of lifetime welfare status in pigs: exploring the usefulness of haptoglobin, C- reactive protein and hair cortisol sampled at the time of slaughter

Abstract

BackgroundPhysiological measures indicative of the welfare status of animals during rearing could form part of an abattoir-based animal health and welfare assessment tool. A total of 66 pigs were used in this study, the aim of which was to assess how serum concentrations of haptoglobin (Hp) and C-reactive protein (CRP) (assessed in 51 pigs), and hair concentrations of cortisol (assessed in 65 pigs), measured at or close to slaughter, reflected welfare-related indicators recorded from the animal during its lifetime. These indicators were recorded at intervals between 7 and 21 weeks of age and included assigning scores for levels of tail and skin lesions, recording the presence or absence of certain health issues, and conducting qualitative behavioural assessments (QBA).ResultsPigs recorded as having tail lesions during their lifetime had higher hair cortisol levels than those with no tail lesions (tail lesions: 47.87 ± 3.34 pg/mg, no tail lesions: 42.20 ± 3.29 pg/mg, P = 0.023), and pigs recorded as having moderate or severe tail lesions had higher Hp levels than those with no or mild tail lesions (moderate/severe: 1.711 mg/ml ± 0.74, none/mild: 0.731 mg/ml ±0.10, P = 0.010). Pigs recorded as being lame during their lifetime tended to have higher hair cortisol levels than non-lame pigs (lame: 52.72 pg/mg ± 3.83, not lame: 43.07 pg/mg ± 2.69, P = 0.062). QBA scores were not associated with any of the physiological measures (P > 0.05). Receiver Operator Curve (ROC) analysis was also carried out to get a better understanding of the usefulness of the physiological measures in discriminating animals that had had welfare-related issues recorded during their lifetime from those that had not. Hair cortisol was determined as having ‘moderate’ accuracy in discriminating pigs that were tail bitten on-farm from unbitten pigs (AUC: 0.748) while Hp and CRP were determined to have no meaningful discriminatory ability (AUC < 0.600).ConclusionThis research should be repeated on a larger scale, but the results suggest that hair cortisol measured at slaughter could provide insight into the welfare status of pigs during their lifetime. Hp may be a useful indicator of tail lesions in pigs. However, further research utilising a greater proportion of severely bitten pigs is required before conclusions can be drawn.

Analysis of Hair Cortisol as an Indicator of Chronic Stress in Pigs in Two Different Farrowing Systems

“…Consequently, at no point in time was HCC found to be influenced by BLS. Also, Carrol et al ( 25 ) did not find any influence of skin lesions on HCC in fattening pigs, whereas HCC was affected by tail lesions and lameness.…”

“…However, several studies on HCC in pigs did not consider the hair growth rate in order to adapt the shaving scheme to the period under investigation, or they did not perform a first shave ( 28 , 32 ). In studies with a non-specific time frame for stress detection ( 25 , 33 , 34 ), prior shaving of the sampling region seems unnecessary. If the stress level should be studied over a certain period of time, shaving should be carried out beforehand.…”

“…Moreover, factors which affected the sows' stress levels in the farrowing systems should be analyzed as well. Since physical damage in pigs can also influence chronic stress levels ( 25 ), the occurrence of skin lesions in sows was investigated using a lesion score and their impact on HCC was also determined.…”

Supering Apis mellifera (Hymenoptera, Apidae) beehives impairs honey production and biomarker genes

“…Consumers appreciate relatively inexpensive and safe food supply; however, size and scale of modern operations may compromise the environment and animal welfare (Boogaard et al, 2011). Various physiological parameters have been used as welfare indicators in livestock production, such as cortisol levels (Carroll et al, 2018). However, there are no well-established biological indicators for measuring welfare in honey bees.…”

Is Magnesium Supplementation an Effective Nutritional Method to Reduce Stress in Domestic Pigs? A Systematic Review

“…Physiological measures of stress, such as heart rate or cortisol, have typically been the most common method of measuring a stress response in animals. For example, hair cortisol has been shown to be a potential marker for chronic stress ( 4 ), whereas blood and salivary cortisol changes much faster in response to acute stressors ( 5 ). However, whilst these measures assess the level of arousal of the individual, they do not indicate valence—the physiological changes observed can be the result of positive (excitement) or negative stress, making interpretation difficult.…”