Noninvasive assessment of autonomic activity for evaluation of pain in calves, using surgical castration as a model

Heart rate (HR) measurements have been used to determine stress in livestock species since the beginning of the 1970s. However, according to the latest studies in veterinary and behaviour-physiological sciences, heart rate variability (HRV) proved to be more precise for studying the activity of the autonomic nervous system. In dairy cattle, HR and HRV indices have been used to detect stress caused by routine management practices, pain or milking. This review provides the significance of HR and HRV measurements in dairy cattle by summarising current knowledge and research results in this area. First, the biological background and the interrelation of the autonomic regulation of cardiovascular function, stress, HR and HRV are discussed. Equipment and methodological approaches developed to measure interbeat intervals and estimate HRV in dairy cattle are described. The methods of HRV analysis in time, frequency and non-linear domains are also explained in detail emphasising their physiological background. Finally, the most important scientific results and potential possibilities for future research are presented.Keywords: heart rate, heart rate variability, stress, welfare, dairy cattle ImplicationsHousing and milking technology, health status and way of handling of animals influence the well-being of animals in intensive dairy farming. Non-invasive methods of assessing stress include heart rate and heart rate variability measurements that involve the monitoring of the autonomic nervous function by digital, high frequency, 24 h multi-channel electrocardiographic recorders. As high-producing cattle breeds are very sensitive to environmental factors, monitoring and decreasing stress is of major importance in terms of both animal welfare and production. IntroductionIn intensive dairy farming, housing and milking systems are main factors in determining the welfare of animals, as adaptation to environmental changes can be challenging for high-producing breeds.Important aspects in the improvement of dairy cattle management systems in respect of animal welfare are the recognition and evaluation of stress. The stressfulness of the technological environment has been examined in many different contexts. Certain welfare studies proved that for intensively farmed cattle, the milking technology (Rushen et al., 2001;Wenzel et al., 2003), fear from given routine treatments (Holst, 1998) and pain (Broom, 1991;Mellor et al., 2000) mean such load that may cause stress (Dantzer and Mormède, 1983;von Borell, 2001) having a negative impact also on milk production (Rushen et al., 2001). Effects of technology and of social interactions can be described not only by classical descriptive behavioural observations (e.g. Milmann, 2013;Theurer et al., 2013), but with physiological measures as well (Hopster and Blokhuis, 1994;Rietmann et al., 2004). Most dairy cattle studies have focused on the stress reactions of animals expressed in neuroendocrine changes that are considered to be reliable indicators of stress and pain in livestock species (...

Section: Effect Of Painmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Welfare implication of measuring heart rate and heart rate variability in dairy cattle: literature review and conclusions for future research

Kovács

Jurkovich

Bakony³

et al. 2014

“…This leads to several consequences such as the increase of ACTH and plasma cortisol up to 60 min after castration (MarchantForde et al, 2009;Keita et al, 2010;Sutherland et al, 2012) with a possible second peak 3 h later (Moya et al, 2008), the increase of lactate owing to glycogen mobilisation (Prunier et al, 2005), and the rapid and transient increase of epinephrine followed by a longer lasting increase in plasma noradrenaline (Prunier et al, 2002;Mühlbauer et al, 2010). Moreover, variations of sympathetic and parasympathetic systems seem to alter eye temperature in animal subjected to painful practice, as recently described in cattle by Stewart et al (2010a and2010b). Surgical castration also causes behavioural changes (Taylor et al, 2001;Hay et al, 2003).…”

Section: Introductionmentioning

confidence: 84%

“…Stewart et al (2010a and2010b) and Dockweiler et al (2013) described an increase of eye temperature in calves right after castration (up to 10 min) due to an increase in parasympathetic nervous system activity associated with deep visceral pain. Results from these studies suggest that it would be beneficial to investigate eye temperature in a closer time interval to castration increasing the number of samplings but at the same time avoiding repeated handling that would not allow discrimination between pain and handling stress.…”

Section: Discussionmentioning

confidence: 99%

Can novel methods be useful for pain assessment of castrated piglets?

Lonardi

Scollo

Normando

et al. 2015

Given that surgical castration is a painful practice performed on millions of pigs every year, a need to identify novel reliable pain assessment tools exists in order to test anaesthetic and analgesic protocols that may reduce related pain. Two treatments were considered: handling (H) and surgical castration (C). Physiological (cortisol, lactate, glycaemia, rectal and eye temperature) and behavioural variables (latency to move after treatment and alterations in posture and walking) were analysed. Cortisol showed the greatest level in C piglets within 20 min after the surgical procedure and a positive correlation with glucose concentration. Eye temperature was higher in C piglets, and the same difference was detected for rectal temperature 3 h after castration. Behavioural parameters revealed that C piglets had longer latency to move and a higher percentage of them showed alterations in posture and walking. Results of this study showed that, in castrated piglets behavioural and physiological alterations occur mainly in the first 3 h from treatment. Latency to move, alterations in posture and walking, and eye temperature appear to give additional and useful information in piglet pain assessment. However, differently from the behavioural parameters considered, eye temperature involves several manipulations of the animals and a long process to acquire the data.

“…Calves with the head blocked in a restraint system and submitted to various treatments showed a transient decrease in eye temperature after disbudding without local anaesthesia followed by a prolonged increase, whereas only the prolonged increase was observed after disbudding with anaesthesia (Stewart et al, 2008). Similarly, a prolonged increase was observed in calves after surgical castration (Stewart et al, 2010). Acute phase proteins may be used as markers of an inflammatory state susceptible to generate pain.…”

Section: Physiological Indicatorsmentioning

confidence: 94%

Identifying and monitoring pain in farm animals: a review

Prunier

Mounier

Neindre³

et al. 2013

103

One important objective for animal welfare is to maintain animals free from pain, injury or disease. Therefore, detecting and evaluating the intensity of animal pain is crucial. As animals cannot directly communicate their feelings, it is necessary to identify sensitive and specific indicators that can be easily used. The aim of the present paper is to review relevant indicators to assess pain in several farm species. The term pain is used for mammals, birds and fish, even though the abilities of the various species to experience the emotional component of pain may be different. Numerous behavioural changes are associated with pain and many of them could be used on farms to assess the degree of pain being experienced by an animal. Pain, as a stressor, is associated with variations in the hypothalamic-pituitary-adrenal axis as well as in the sympathetic and immune systems that can be used to identify the presence of pain rapidly after it started. However, most of these measures need sophisticated equipment for their assessment. Therefore, they are mainly adapted to experimental situations. Injuries and other lesional indicators give information on the sources of pain and are convenient to use in all types of situations. Histopathological analyses can identify sources of pain in experimental studies. When pronounced and/or long lasting, the pain-induced behavioural and physiological changes can decrease production performance. Some indicators are very specific and sensitive to pain, whereas others are more generally related to stressful situations. The latter can be used to indicate that animals are suffering from something, which may be pain. Overall, this literature review shows that several indicators exist to assess pain in mammals, a few in birds and very few in fish. Even if in some cases, a single indicator, usually a behavioural indicator, may be sufficient to detect pain, combining various types of indicators increases sensitivity and specificity of pain assessment. Research is needed to build and validate new indicators and to develop systems of pain assessment adapted to each type of situation and each species.