Decision three to predict respiratory rate of piglets submitted to cold conditions

Received: January 16th, 2021 ; Accepted: March 13th, 2021 ; Published: October 5th, 2021 ; Correspondence: [email protected] subjected to thermal conditions outside their comfort zones may show altered physiological and behavioural responses, which may consequently cause productive losses. For these reasons, the aim of this paper is to develop a decision tree for the prediction of respiratory rate (RR, mov min-1 ) of piglets exposed to different thermal situations. The experiment was carried out in an experimental pig farm of the Universidad Nacional de Colombia Campus Medellin, located at the San Pablo Agraria Experimental Station located in the eastern sector of the department of Antioquia, during August 2019. A database containing the raw data for dry bulb temperature - tdb (°C), and relative humidity - RH (%) as input variables, and RR (mov min-1 ) of six piglets were assessed every two hours as output variable for piglets was generated. The experimental database was composed of 78 observed data. The decision trees were developed to conditions of tdb between 19.2 to 29.5 °C and RH between 50.2 to 88.4%. In the experimental period, RR of piglets submitted to tdb higher than 27.1 °C the RR was around 60 mov min-1 , tdb smaller than 27.1 °C the RR varied from 36 to 46 mov min-1 . These low values of physiological responses may indicate that the piglets are not in a comfortable situation, so their development, welfare and production can be affected. The decision tree developed can be useful to provide a quick understanding of the piglet’s welfare condition based on the environmental variables and physiological responses

Systematic review of animal-based indicators to measure thermal, social, and immune-related stress in pigs

The intense nature of pig production has increased the animals' exposure to stressful conditions, which may be detrimental to their welfare and productivity. Some of the most common sources of stress in pigs are extreme thermal conditions (thermal stress), density and mixing during housing (social stress), or exposure to pathogens and other microorganisms that may challenge their immune system (immune-related stress). The stress response can be monitored based on the animals' coping mechanisms, as a result of specific environmental, social, and health conditions. These animal-based indicators may support decision making to maintain animal welfare and productivity. The present study aimed to systematically review animal-based indicators of social, thermal, and immune-related stresses in farmed pigs, and the methods used to monitor them. Peer-reviewed scientific literature related to pig production was collected using three online search engines: ScienceDirect, Scopus, and PubMed. The manuscripts selected were grouped based on the indicators measured during the study. According to our results, body temperature measured with a rectal thermometer was the most commonly utilized method for the evaluation of thermal stress in pigs (87.62%), as described in 144 studies. Of the 197 studies that evaluated social stress, aggressive behavior was the most frequently-used indicator (81.81%). Of the 535 publications examined regarding immune-related stress, cytokine concentration in blood samples was the most widely used indicator (80.1%). Information about the methods used to measure animal-based indicators is discussed in terms of validity, reliability, and feasibility. Additionally, the introduction and wide spreading of alternative, less invasive methods with which to measure animal-based indicators, such as cortisol in saliva, skin temperature and respiratory rate via infrared thermography, and various animal welfare threats via vocalization analysis are highlighted. The information reviewed was used to discuss the feasible and most reliable methods with which to monitor the impact of relevant stressors commonly presented by intense production systems on the welfare of farmed pigs

Infrared thermography in the study of animals’ emotional responses: A critical review

Whether animals have emotions was historically a long-lasting question but, today, nobody disputes that they do. However, how to assess them and how to guarantee animals their welfare have become important research topics in the last 20 years. Infrared thermography (IRT) is a method to record the electromagnetic radiation emitted by bodies. It can indirectly assess sympathetic and parasympathetic activity via the modification of temperature of different body areas, caused by different phenomena such as stress-induced hyperthermia or variation in blood flow. Compared to other emotional activation assessment methods, IRT has the advantage of being noninvasive, allowing use without the risk of influencing animals’ behavior or physiological responses. This review describes general principles of IRT functioning, as well as its applications in studies regarding emotional reactions of domestic animals, with a brief section dedicated to the experiments on wildlife; it analyzes potentialities and possible flaws, confronting the results obtained in different taxa, and discusses further opportunities for IRT in studies about animal emotions

A Review of Pain Assessment in Pigs

There is a moral obligation to minimize pain in pigs used for human benefit. In livestock production pigs experience pain caused by management procedures, e.g. castration, and tail docking, injuries from fighting or poor housing conditions, management diseases like mastitis or Streptococcal meningitis, and at parturition. Pigs used in biomedical research undergo procedures which are regarded as painful in humans, but do not receive similar levels of analgesia, and pet pigs also experience potentially painful conditions. In all contexts, accurate pain assessment is a prerequisite in: a) the estimation of the welfare consequences of noxious interventions; and b) the development of more effective pain mitigation strategies. This narrative review identifies the sources of pain in pigs, discusses the various assessment measures currently available, and proposes directions for future investigation

Exploring the potential of Precision Livestock Farming technologies to help address farm animal welfare

The rise in the demand for animal products due to demographic and dietary changes has exacerbated difficulties in addressing societal concerns related to the environment, human health and animal welfare. As a response to this challenge, Precision Livestock Farming (PLF) technologies are being developed to monitor animal health and welfare parameters in a continuous and automated way, offering the opportunity to improve productivity and detect health issues at an early stage. However, ethical concerns have been raised regarding their potential to facilitate the management of production systems that are potentially harmful to animal welfare, or to impact the human-animal relationship and farmers’ duty of care. Using the Five Domains Model (FDM) as a framework, the aim is to explore the potential of PLF to help address animal welfare and to discuss potential welfare benefits and risks of using such technology. A variety of technologies are identified and classified according to their type (sensors, bolus, image or sound based, Radio Frequency Identification (RFID)), their development stage, the species they apply to, and their potential impact on welfare. While PLF technologies have promising potential to reduce the occurrence of diseases and injuries in livestock farming systems, their current ability to help promote positive welfare states remains limited, as technologies with such potential generally remain at earlier development stages. This is likely due to the lack of evidence related to the validity of positive welfare indicators as well as challenges in technology adoption and development. Finally, the extent to which welfare can be improved will also strongly depend on whether management practices will be adapted to minimize negative consequences and maximize benefits to welfare

Thermoregulation mechanisms and perspectives for validating thermal windows in pigs with hypothermia and hyperthermia: An overview

Specific anatomical characteristics make the porcine species especially sensitive to extreme temperature changes, predisposing them to pathologies and even death due to thermal stress. Interest in improving animal welfare and porcine productivity has led to the development of various lines of research that seek to understand the effect of certain environmental conditions on productivity and the impact of implementing strategies designed to mitigate adverse effects. The non-invasive infrared thermography technique is one of the tools most widely used to carry out these studies, based on detecting changes in microcirculation. However, evaluations using this tool require reliable thermal windows; this can be challenging because several factors can affect the sensitivity and specificity of the regions selected. This review discusses the thermal windows used with domestic pigs and the association of thermal changes in these regions with the thermoregulatory capacity of piglets and hogs

Automatic early warning of tail biting in pigs:3D cameras can detect lowered tail posture before an outbreak

<div><p>Tail biting is a major welfare and economic problem for indoor pig producers worldwide. Low tail posture is an early warning sign which could reduce tail biting unpredictability. Taking a precision livestock farming approach, we used Time-of-flight 3D cameras, processing data with machine vision algorithms, to automate the measurement of pig tail posture. Validation of the 3D algorithm found an accuracy of 73.9% at detecting low vs. not low tails (Sensitivity 88.4%, Specificity 66.8%). Twenty-three groups of 29 pigs per group were reared with intact (not docked) tails under typical commercial conditions over 8 batches. 15 groups had tail biting outbreaks, following which enrichment was added to pens and biters and/or victims were removed and treated. 3D data from outbreak groups showed the proportion of low tail detections increased pre-outbreak and declined post-outbreak. Pre-outbreak, the increase in low tails occurred at an increasing rate over time, and the proportion of low tails was higher one week pre-outbreak (-1) than 2 weeks pre-outbreak (-2). Within each batch, an outbreak and a non-outbreak control group were identified. Outbreak groups had more 3D low tail detections in weeks -1, +1 and +2 than their matched controls. Comparing 3D tail posture and tail injury scoring data, a greater proportion of low tails was associated with more injured pigs. Low tails might indicate more than just tail biting as tail posture varied between groups and over time and the proportion of low tails increased when pigs were moved to a new pen. Our findings demonstrate the potential for a 3D machine vision system to automate tail posture detection and provide early warning of tail biting on farm.</p></div

THE USE OF IMAGE LABELLING TO IDENTIFY PIG BEHAVIOURS FOR THE DEVELOPMENT OF A REAL-TIME MONITORING AND CONTROL TOOL

The behaviour of animals is the most informative indicator of the farm status, reflecting animal responses to the change of their welfare, health or surrounding environment. Complex and continuously changing animal responses could be monitored through automated and real time measurements offered by PLF. The most crucial component of an effective PLF system is a precise real-time algorithm able to detect, quantify or even predict the target behaviour, considering that animals are individually different in their responses. During the process of the development of such an algorithm the input of the expertise in animal ethology and biology is indispensable. Understanding of biological mechanisms is a key element in comprehension of the message given by animal behaviour. One of the most important contributions of the specialist with biological background in algorithm development is labelling.This thesis was particularly dedicated to the labelling and its importance in the process of the development of successful PLF system. The objective of this thesis was application of image labelling technique to contribute to the development of an automatic PLF systems to monitor behaviours of pigs

Affective-autonomic states of domestic pigs in the context of coping and animal welfare

Gaining better insight in affective states of farm animals is of importance for understanding their welfare state. One important step in this context is to establish valid proxy measures to objectively assess and interpret an individual’s subjective perception of its environment. This thesis presents a reliable tool for the objective evaluation of affective-autonomic states in free-moving pigs and gains insight into the neurophysiological mechanisms underlying the individual processing of affective states in relation to their valence and arousal dimensions.Die Untersuchung affektiver Zustände von Nutztieren ist für das Verständnis ihres Wohlbefindens von essentieller Bedeutung. Ein wichtiger Schritt in diesem Kontext ist die Etablierung zuverlässiger Messmethoden zur objektiven Beurteilung und Interpretation individueller subjektiver Wahrnehmung. Diese Arbeit stellt eine valide Methode zur objektiven Beurteilung affektiv-autonomer Zustände bei Schweinen dar und vermittelt einen Einblick in die neurophysiologischen Mechanismen, die der individuellen Verarbeitung affektiver Zustände zugrunde liegen

Comparison of febrile responses, thermoregulation and skin morphology in the local Kolbroek, Windsnyer and exotic Large White breeds of pigs in South Africa

A Thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy Johannesburg, 2017.Smallholder agriculture may be particularly vulnerable to the increased temperatures, reduced water availability and increased risk of disease anticipated under future climate change scenarios. Pigs may be particularly sensitive to the increased heat stress as they do not sweat. Local pigs are said to be better adapted than the exotic breeds and therefore may be better able to withstand some of the negative impacts of climate change however, there is not much scientific support for that claim. I therefore compared the febrile and thermoregulatory responses and skin characteristics of local (Kolbroek, Windsnyer) and exotic (Large White) pigs. Pigs were implanted with intra-abdominal tags for measuring core body temperature and activity. Terminally, skin samples were collected from the interscapular, lateral thoraco-abdominal and ventral abdominal regions. Six week old boars of the (Kolbroek (5.4 ± 1.4 kg; n = 8), Windsnyer (8.1 ± 1.6 kg; n = 8) and Large White (6.0 ± 1.5 kg; n = 8) were used to determine the febrile responses and sickness behaviours. The pigs were injected intravenously with polyinosinic acid: polycytidylic acid (poly I:C) (0.5 mg/kg); lipopolysaccharide (LPS) (2 μg/kg) and Staphylococcus aureus (S. aureus) (1.7 x 1010 cell walls/kg) or saline (control). The exotic Large White pigs had a significantly greater (F2,20 = 13.70; P = 0.0003) Thermal Response Index (TRI) after receiving poly I:C but a lower (F2,21 = 6.22; P = 0.009) TRI in response to LPS than the local pigs. All pigs displayed anorexia and lethargy in response to poly I:C, but only the Large White and Windsnyer displayed anorexia and lethargy to LPS. Febrile temperature responses were similar between the breeds of pigs after injecting S. aureus. The Large White and Kolbroek were more sensitive to S. aureus and had severe clinical signs when compared to the Windsnyer pigs. Following LPS and S. aureus administration, the Large White and Kolbroek pigs showed no body mass reduction 22 h after pyrogen administration unlike the Windsnyer which lost body mass. There were slight differences in febrile responses between the breeds; however the Large White pigs had more severe clinical signs than the local breeds of pigs after injection of the bacterial mimetics. Four month old boars of Kolbroek (n=6; 40 ± 1.3 kg); Windsnyer (n=7; 46 ± 7.7 kg) and Large White (n=7; 60 ± 1.3 kg) pigs (Sus scrofa domesticus) were used to determine thermoregulatory responses. The pigs were exposed to 5°C (92% RH), thermoneutral (20°C) with 40% RH, 30°C with drinking water with 40% RH, 30°C with high relative humidity (60%) and 30°C with 48 h water deprivation except for the cold and thermoneutral treatments where pigs were kept for 48 h. The pigs showed remarkably similar patterns in core body temperature under all the treatments. At 5°C, local pigs employed primitive behaviours to maintain core body temperature while the exotic pigs increased activity. At 30°C compared to TNZ all pigs reduced physical activity, however, the Large White and Kolbroek had higher change in respiratory rates (F4,68 = 14.96; P < 0.0001) than the Windsnyer which maintained constant respiratory rates when compared to TNZ. On exposure to 30°C with 48 h water deprivation, the local breeds conserved their plasma volume unlike the Large White. The lower respiratory rates in the Windsnyer pigs may reflect their being less dependent on panting than the other breeds. Their skin histology provides support for that hypothesis as they had large (F2,13 = 52.48; P < 0.0001) and more superficial (F2,13 = 125.60; P < 0.0001) sweat glands, thin total skin layer, thinner hypodermis than the Large White pigs and Kolbroek pigs. The skin of the Windsnyer also had more melanin visible than the Kolbroek whilst the Large White had none. Although the differences between the breeds were subtle, the Windsnyer pigs had some physiological, behavioural and morphological traits that might make them more adaptable to the changing environmental conditions than the Kolbroek and Large White pigs.MT201