Broom and Fraser's Domestic Animal Behaviour and Welfare

Donald Broom

• Publisher: CAB International
• Year: 2021
• ISBN:
  9781789249859
• Edition: 6
• Topic: Ciencias biológicas
• Subtopic: Zoología

Completely updated and revised, and synthesizing the recent explosion in animal welfare literature, the sixth edition of this best-selling textbook continues to provide a thorough overview of behaviour and welfare of companion and farm animals, including fish.The introductory section has been completely revised, with all following chapters updated, redesigned and improved to reflect our changing understanding.This edition includes: - New and revised chapters on climate change and sustainability, ethics, and philosophy to ensure that the book provides the latest information in a changing world;- New information on human interactions with other animal species, big data, modern technologies, brain function, emotions and behaviour; - Solutions and advice for common abnormal behaviours.Written by a world-leading expert and key opinion leader in animal behaviour and welfare, this text provides a highly accessible guide to the subject. It is an essential foundation for any veterinary, animal science, animal behaviour orwelfare-focused undergraduate or graduate course.

1 One Biology, Ethics, Sentience and Sustainability

1.1 One Biology

Earth is inhabited by a wide range of organisms, many of them sentient beings. Some of these sentient beings are human but there is only one biology for all of the species and almost all mechanisms in humans are identical with those in many other species. As a consequence, although many writers have striven to emphasize the uniqueness of humans, it is very difficult to find any human quality that is not shared with some other species. Those qualities that some people present as exclusive to humans, such as language, emotions, the notion of culture or society, cooperation, altruism, tool use and a concept of the future, are described in scientific publications about various groups of animals (Broom, 2003, 2014b; Premack, 2007; Clayton and Emery, 2015; de Waal, 2016; McBride and Morton, 2018). Humans have hardly any ability that is not also possessed by other animal species, at least to some degree. It is for this reason that other species can be used to better understand humans. Homberg (2013), writing about neuropsychiatry research aimed at producing therapeutic medicines, emphasizes that ‘rodents, whose brains and behaviour share striking functional similarities with those of humans, are essential’ for this work.

The human frontal and pre-frontal cortex have some more complex processing capacity than that of other animals. Humans have better mathematical logic, perception of time, complex reasoning, analytical capacity and prediction of events than most other species. But these are differences in degree, not in absolute capability (Falk and Hofman, 2012).

Each species has differences from all others and the DNA of more and more species has been sequenced and described. This shows that the genetic differences among species, including humans, are small and the similarities are large (Boffelli et al., 2004). In addition, each complex organism has within its body many microorganisms, most of which have positive or neutral effects on it. Each human has, intermingled among their organs and cells, numbers of bacterial cells similar to the numbers of cells with human DNA, so half of the cells in your body are bacteria (Sender et al., 2016). Given all of the above information, although unsurprisingly humans favour their own species, the ideas that humans are special, or very different from all other animals, or more important than other animals, are not scientifically logical.

The concept of ‘one biology’ mentioned above, like those of one health and one welfare discussed in Chapter 2, merely emphasizes that biological processes in humans and non-humans are the same, just as the concepts of health and welfare mean the same in humans and all other animals (Tarazona et al., 2020). At present, the greatest problem for life as a whole in the world is climate change caused by human activities. The greatest problem for humans and domestic animals is antimicrobial resistance, since many major bacterial diseases, such as tuberculosis, formerly controlled by antimicrobial drugs, may soon be uncontrollable. Mycobacterium tuberculosis could kill a high proportion of humans, just as it did before antibiotics were developed. The numbers of deaths from tuberculosis in most years are likely to be much higher than those due to SARS-CoV-2 that caused COVID-19 and there are several other bacterial diseases with strains resistant to existing antibiotics (Broom and Johnson 2019; Broom, 2020b; https://www.who.int/health-topics/antimicrobial-resistance, accessed18 June 2021).

This book is about animals, living beings with a nervous system and other complex mechanisms for obtaining energy, using energy and reproducing. Animals derive energy by consuming other organisms and most have an effective means of locomotion and a range of sense organs. Only animals have a true nervous system. The word ‘animal’ elicits different images and concepts for different people, who may erroneously use it to mean farmed animals, owned animals, mammals, or warm-blooded animals. It is logically incorrect to say ‘humans and animals’ when humans are animals. Sometimes when people refer to an animal, they imply a being that is more aggressive, less controlled, or more subject to lust than the average human. However, it is now known to be quite wrong that humans control their emotions but non-humans never do so (Broom, 1998; Hofman, 2014).

1.2 Genes and Environment

For many years, some scientists have emphasized that every characteristic of humans, and of every other animal, results from interactions between genetic and environmental information. For example, Broom (1981) referred to the ‘universality of environmental effects on behaviour’. However, a few scientists and most of the general public still believe that some qualities of themselves and other individuals are independent of environmental effect. Research results now show that each step in the translation of genetic information into proteins, and hence characteristics of individuals, can be altered by environmental factors (Alexander, 2017; Broom and Johnson, 2019). Some characteristics are affected by epigenetic effects that can be passed from one generation to another by routes that do not involve DNA (Tatemoto and Guerrero-Bosagna, 2018). This means that no aspect of anatomy, physiology or behaviour of an animal is genetically determined, instinctive or innate, as these terms mean independent of environmental effects. All characteristics are affected by genetic information in the DNA but it is incorrect for a person to excuse their own antisocial behaviour as being in their genes and so unavoidable. Neither is it correct to say that any breed of dog is always aggressive. Whilst probabilities of characteristics related to gene complement differ amongst individuals, all qualities also depend on the environment during the expression of genes and some qualities are affected by non-genetic factors passed from one generation to another. An important consequence of such mechanisms is that when parents are stressed, for example during gamete production, their offspring, and sometimes further generations, can be affected. Poor welfare in domestic animals that results from difficult living conditions or treatment can have effects later in life and effects on offspring.

Adult phenotype can be altered by the conditions in which an embryonic animal develops. Not only can starved embryos develop abnormally but also embryonic conditions can alter growth and there may sometimes be ‘developmental origins of adult health and disease’ (Hammond, 1932; Gluckman and Hanson, 2004; Gardner et al., 2009). The behaviour of offspring can be affected; for example, a high-fibre diet in mother pigs was associated with less aggressive behaviour in the offspring (Bernardino et al., 2016). Offspring can be affected by adverse or enriched conditions during sperm or egg production. Exposure to adverse conditions in utero can lead to DNA methylation and other epigenetic effects that affect offspring development, disease risk and brain pathology (Cao-Lei et al., 2017; Delgado-Morales and Esteller, 2017). An epigenetic trait is a stably heritable phenotype resulting from changes in a chromosome without alterations in the DNA sequence (Berger et al., 2009). An interesting aspect of some recent work is that the effects on offspring of poor welfare of the parent during early development and gamete production can be as great as, or greater than, in fathers as in mothers. Semen quality in mammals is adversely affected by high temperatures and poor nutrition (Wilson et al., 2004; Kunavongkrit et al., 2005; Sinclair et al., 2016). Boars with a high fear of humans have worse growth, immune responses and reproductive performance (Paterson and Pearce, 1992) but socialized boars with good welfare had better semen quality (Flowers, 2015). Stressed male mammals have different DNA methylation that is preserved in the zygote, in the adult offspring and in the following generation (Jeong et al., 2007; Østrup et al., 2013). Adverse conditions during sperm production in boars affect offspring emotionality (A.J. Zanella, personal communication). The occurrence of these paternal effects indicates epigenetic inheritance whereby epigenetic variation, mediated via DNA methylation, post-translational histone modifications, or small non-coding RNAs induced in the male germline, is transmitted to subsequent generations with consequences for a broad range of phenotypes, such as metabolism, behaviour and neurobiology (Braun and Champagne, 2014; Bohacek and Mansuy, 2015). Some effects on the fathers involve glucocorticoids altering small RNA molecules in sperm and cause increased anxiety or depression and effects on glucocorticoids in offspring (Dietz et al., 2011; Short et al., 2016; Chan et al., 2018a). The seminal fluid microbiome can also have an effect on offspring (Javurek et al., 2016). Effects such as these, involving male and female parents, have been reviewed by Chan et al., 2018b).

1.3 Ethics

Something is moral if it pertains to right rather than wrong and ethics is the study of moral issues. Humans and other animals, especially social animals, have many biological mechanisms that enable them to behave in a moral way. It is not possible to live successfully in a social group unless the individuals have the ability to avoid harming others (Fig. 1.1) and perhaps to collaborate. As a consequence, morality has evolved and natural selection has favoured genes that promote abilities such as recognition of individuals and memory of moral and immoral actions (de Waal, 1996; Ridley, 1996; Broom, 2003, 2006c, 2019c). Two other biological mechanisms that may promote moral actions are empathy and compassion (Würbel, 2009). People are more likely to feel empathy with fellow humans and with other animals perceived to have a capacity for feelings similar to those of humans. They are likely to show compassion to those whom they perceive to need compassion (Davis, 2018). Most domestic animals, like humans, are social species well adapted to living in groups. Caring behaviour by cows, other domestic animal mothers and other social group members has long been used in human societies as an example of moral behaviour that should be copied, so it is a longstanding idea that there is a moral structure in some non-human societies and a capacity for empathy in individuals (Broom, 2019c). Since it is clear that individual domestic animals frequently avoid causing harm and sometimes help others, it seems logical to say that the individuals concerned are moral agents. Even for people who do not think of non-humans as being moral agents, each individual can be the subject of moral actions and so has moral value.

Two underlying approaches in thinking about how to behave towards people or other animals are known as deontological and consequentialist. The deontological approach to the organization of human conduct is one in which the structure is a set of duties pertinent to all individuals. Hence, the individual should assess what action duty dictates, using rational thought, and carry out that action.

Consequentialism in ethics implies that the extent to which an act is morally right is determined solely by the goodness of the act’s consequences. This approach was extended into utilitarianism by J.S. Mill (1843), who argued that the right act or policy is that which will result in the maximum utility, or expected balance of satisfaction minus dissatisfaction, in all the sentient beings affected.

Although many aspects of utilitarianism are helpful when deciding what is morally right, as a general approach it may be viewed as incomplete (Broom, 2003). Acting in such a way that general happiness or general good is promoted will be entirely desirable in some circumstances, but following such a philosophy implies that decisions are taken only on the basis of the average or overall good of collections of individuals. This view does not take account of the fact that humans and other animals interact with and have concerns for individuals. The mechanisms underlying moral codes are based on effects on individuals as well as on collections of individuals. An example of the flaw in the extreme utilitarianism approach is that, following this approach, an individual could be caused extreme pain or other poor welfare, or could be killed, if the overall effect on a collection of individuals was good. This individual might be a dangerous criminal or an entirely innocent person, but should they be tortured, caused prolonged misery or killed? Most people would not wish an innocent person to be killed, however great the resulting good, and those who hesitate on the issue might be swayed towards that view if the person were their neighbour, their mother or themselves.

Fig. 1.1. These Longhorn cattle carry dangerous weapons and spend much time close together but they are very careful not to harm one another (photograph D.M. Broom).

Criticisms of the u...