**Contents**



## **About the Editor**

**Bianca Castiglioni** is a senior research scientist at the National Research Council (CNR) of Italy, Institute of agricultural biology and biotechnology. She has expertise in livestock genomics, transcriptomics, epigenetics and metagenomics. She has participated as scientific coordinator and WP or Task leader in several European and national research projects. She published over 100 peer-reviewed papers (WoS Researcher ID: G-9856-2013). Her activities span from the study of genes and mechanisms that control the livestock production traits to the study of animal microbiome, with special focus on animal health, and the traceability and food safety of animal products.

## **Preface to "Genetics of Animal Health and Disease in Livestock"**

Livestock diseases adversely affect animal production throughout the world. Although there are some examples of genetic resistance to disease in livestock, disentangling the genetic effects is a compelling task. Indeed, in most cases, animals are not resistant to a disease, but they vary in their susceptibility to the disease agents. Therefore, it is still difficult to demonstrate the potential of the genetic approach and to be able to identify genetic variation that accounts for disease resistance and/or tolerance.

An additional issue is that resistance is measurable only in the presence of the disease-causing pathogen. Moreover, for most livestock, the genes and products of the innate and adaptive immune system are not fully known or functionally annotated. Many immune-related genes exist as multiple copies within an individual animal, and their number, sequence, and regulation are difficult to characterize. The lack of methods to follow specific genes or to functionally measure outputs at a cellular or animal level reduces our ability to fill the knowledge gaps. Many diseases are complex, and their causative pathogens are unknown. Furthermore, the influence of a healthy microbiome on pathogen virulence is only now beginning to be understood.

Nevertheless, the role of genetics in improving animal health will become increasingly important as the focus on tackling antimicrobial drug resistance increases. This research will result in greatly reduced direct and indirect costs associated with animal disease, maintenance of a secure, and safe food supply, improved animal welfare, production efficiency, and resilience to environmental changes, and reductions in antimicrobial use and improved vaccines or other measures that can mitigate or prevent existing, new, and re-emerging infectious pathogens.

> **Bianca Castiglioni** *Editor*
