Behavior is shaped by both genetics and experience--nature and nurture. This book synthesizes research from behavioral genetics and animal and veterinary science, bridging the gap between these fields. The objective is to show that principles of behavioral genetics have practical applications to agricultural and companion animals. The continuing domestication of animals is a complex process whose myriad impacts on animal behavior are commonly under-appreciated. Genetic factors play a significant role in both species-specific behaviors and behavioral differences exhibited by individuals in the same species. Leading authorities explore the impact of increased intensities of selection on domestic animal behavior. Rodents, cattle, pigs, sheep, horses, herding and guard dogs, and poultry are all included in these discussions of genetics and behavior, making this book useful to veterinarians, livestock producers, laboratory animal researchers and technicians, animal trainers and breeders, and any researcher interested in animal behavior. - Includes four new chapters on dog and fox behavior, pig behavior, the effects of domestication and horse behavior - Synthesizes research from behavioral genetics, animal science, and veterinary literature - Broaches fields of behavior genetics and behavioral research - Includes practical applications of principles discovered by behavioral genetics researchers - Covers many species ranging from pigs, dogs, foxes, rodents, cattle, horses, and cats

Research in behavioral genetics is important for pig welfare. Consequences of the ongoing selection for high production on pigs’ behavior need to be studied, as well as possibilities to select directly for changed behavior. The Farm Animal Welfare Council’s definition of welfare is based on five freedoms related to hunger and thirst, discomfort, pain, injury or disease, fear and distress and normal behavior. All these freedoms are associated with pig behavior. Maternal behavior related to piglet survival and aggressive behavior of pigs kept in groups are especially important for welfare. Pig breeding programs could be further developed by including behavioral traits relevant for welfare.

The domestic dog has many phenotypic and behavioral forms. In this chapter we describe five different kinds of dogs and how each has been derived. We trace the background village dog adapting to the age of agriculture, with the coincident transformation of human behavior to permanent settlement. Over centuries, this village dog has changed, adapting to its different geographies and to local agricultural activities. In tandem, people began sorting through the village populations for dogs with appropriate behaviors, and these eventually became the founding stock for breeding programs. In recent centuries, samples of these working and hunting breeds have been collected by kennel clubs, and sexually isolated, becoming at best historic representations of the working or hunting breeds. More commonly they are used as pets, or household dogs, sometimes with sport competitions in the show or agility ringl

In this chapter, we begin by defining domestication as a genetic process, whereby animals change phenotypically and genetically as a response to living under human supervision. This has caused a convergent set of phenotypic modifications across numerous different species, through a combination of relaxed natural selection, increased human selection, and correlated responses. The genetic mechanisms underlying these processes are discussed in addition to genetic drift and inbreeding. The driving types of mutations are dealt with, as is the way in which genes are organized in the genome to give rise to a specific genetic architecture facilitating selection responses. The different methods used to discover genes and mutations are divided into either top-down approaches, where one starts with the phenotype and uses mapping methods to find the causative genes, or bottom-up, where the genetic polymorphism is the starting point and the phenotype the desired response variable. A number of examples of single genes and mutations that have been coupled to behavioral variation are given, among them genes showing pleiotropic effects on pigmentation, and genes involved in regulation of the effects of neuropeptides. Finally, the relatively novel area of behavioral epigenetics is examined, in particular with its possible relation to domestication effects.

Dog domestication involved long-term genetic selection for behavior. The genetics-centered view of domestication is supported by experimental selection of farm-foxes (Vulpes vulpes) that began in the 1950s. Selection of foxes, separately, for tame and for aggressive behavior, has yielded two strains with markedly different, genetically determined behavioral phenotypes. Tame-strain foxes communicate with humans in a positive manner and are eager to establish human contact. Foxes from aggressive strains are aggressive to humans and difficult to handle. Although selected solely for behavior, changes in physiology, morphology, and appearance with significant parallels to characteristics of the domestic dog, were observed in tame-strain. Ongoing research is focused on identification of molecular genetic mechanisms associated with selection of foxes for behavior. Identification of behavioral loci in the fox genome in the region which is homologous to the region in the dog genome that differentiates dogs from wolves lead to the hypothesis that domesticated behavior in dogs and foxes may have similar genetic bases.

This chapter provides an overview of the current behavioral and cognitive aspects of emotions in animals and explore the impacts of emotional experiences on the animal's adaptation to its current challenging circumstances. There is evidence that animal welfare results from the animal's perception of its environment and its background. The chapter is structured in four complementary sections. The first one addresses the nature of emotions that the animals can feel which is validated from commonalties in physiological and behavioral responses to dangers across and within species. The second section presents advanced features of the relationships between cognition and emotions originally studied in humans, which are now developed in animals to better access their affective states. The third section is devoted to the relevance of the personality concept, as resulting from both genetics and developmental experience, for assessing animal individuality in emotional behaviors and stress. The last section explores some approaches that can alleviate fear and induce positive affective states, with the potential to mitigate detrimental stress-induced effects on the welfare and health status by eliciting positive emotions in animals.

In these classic experiments, quail chicks were selectively bred for the behavioral traits of fear and social reinstatement. Over a period of 20 generations, four separate genetic lines were created. They were high and low fear and high and low social re-instatement. The duration of tonic immobility was used as a measure of fear and social reinstatement was measured with a treadmill test. In this test, the time that a bird will walk on a treadmill to stay close to its flockmates is measured. Since the publication of this chapter in 1998, many scientists have carried out with these genetic lines. Duration of tonic immobility does not all measure all types of fear. Fear maybe multidimensional because selection for tonic immobility has little effect on behavioral reactions to novelty. More recent research has also discovered linked traits such as low social reinstatement birds have stronger ultradiam rhythms.

The partnership between humans and domestic animals is natural. The human brain is hard-wired to emotionally respond to animals. Beginning with the domestication of wolves, this chapter covers the process of domestication and reviews the early work of behaviorists and ethologists who refused to accept emotional states in animals. Modern behavior research employs methods developed by behaviorists and ethologists combined with neuroscience and genetics. Emotional systems in the brain drive behavior. Confusion between different emotional systems may explain conflicting findings in the behavior literature. Behavior in an open-field test may be motivated either by fear, separation distress, or novelty seeking. Each emotion is controlled by separate subcorticol systems. A novel open-field arena can frighten a prey species, but it may activate seeking in a predator. Genetics affects the strength of fear, novelty seeking, and separation distress. Behavior is shaped by a complex interaction between genetics and experience.