Key issues in dairy herd health management

Dairy herd health management benefits dairy farmers, the environment, dairy cows and citizens. It is an important part of modern dairy farm veterinary care. Dairy herd health management is assessing, monitoring and improving the health of dairy cows at a population level. Good herd health management takes a holistic approach and is ongoing and cyclical. All members of the dairy farm team and their advisors are involved, decisions are informed by data generated by the herd. These data may come from numerous sources. The data are processed and analysed to monitor cow health, target investigations and evaluate progress. To make lasting change on farms, advisors must communicate appropriately with farm managers to understand behaviour and motivate change. This chapter reviews these aspects of dairy herd health management, giving practical suggestions on how to get started, how to incorporate herd health management into business models and how to maintain momentum.

Optimising reproductive management to maximise dairy herd health and production

Reproduction is central to the operation of a dairy herd through initiating lactation and providing replacement animals and offspring for sale. This chapter outlines the steps required to detect reproductive problems and limitations in cows and herds. It then elaborates some strategies to overcome limits to reproductive health and production concentrating on detecting cows requiring attention through record monitoring, analysing herd records to monitor reproduction and identify areas that limit performance and providing strategies to deal with these limits. The main limits addressed are anoestrus and inadequate oestrus detection that are addressed through education of farm workers, aids to oestrus detection and the use of planned breeding programs to induce and control oestrus and breeding. Nutritional causes of limited reproductive performance are also considered as well as strategies to limit abortion.

Managing dry cow udder health

The dry period lays a foundation for a successful next lactation, especially from the udder health perspective. It is a high-risk period for acquiring new intramammary infections (IMI), but it also provides an excellent opportunity for eliminating existing subclinical infections. The way cows are dried off and milking is halted at the end of lactation impacts the involution process, mammary health and cow comfort. Antibiotic dry cow therapy (DCT) has played a crucial part in mastitis control, but due to global concerns about increasing antibiotic resistance, the approach to DCT is evolving. This chapter reviews the current knowledge about the impact of milk cessation methods (abrupt vs. gradual dry-off) on mammary involution, udder health and cow comfort. The importance of dry cow therapy is discussed, especially in the light of current global concerns related to antibiotic resistance.

Preventing bacterial diseases in dairy cattle

A paradigm shift in the management of bacterial diseases of food animals is needed; a shift from pharmacologic interventions to disease risk identification and mitigation. The interaction between disease and its risk factors follows the disease triangle, a conceptual model that incorporates host, pathogen, and environmental factors as a tool to understand different aspects that influence disease. A sustainable approach to bacterial disease mitigation in production settings includes a comprehensive assessment of host, pathogen, and environmental factors of disease to build a prevention platform for multiple syndromes of bacterial disease in cattle. Using bovine respiratory disease as a model, the current chapter will focus on the state of the art of disease prevention in dairy cattle, and investigations into interactions between the host, environment and pathogen which can provide robust information on which to build a prevention platform for multiple syndromes of bacterial disease in cattle.

Dairy cattle welfare and health: an intimate partnership

This chapter discusses the intimate partnership between dairy cattle welfare and health. It begins by examining the welfare implications of common dairy cow diseases such as lameness, mastitis, metritis, acidosis, ketosis and other production-related diseases. It also addresses the impact of subclinical diseases as well. Stress and immune function is also discussed, followed by a review of how mental health can impact the welfare of dairy cattle. A case study on the health and welfare of cows in Indian shelters is also included.

Optimising foot health in dairy cattle

This chapter examines optimising foot health in dairy cattle. The chapter begins by reviewing the importance of lameness then goes on to discuss claw horn disruption. It also reviews aetiopathogensis of white line bruising and lesions, which is then followed by a section on aetiopathogensis and control of digital dermatitis. A case study on an 800 cow Holstein herd with a sudden rise in sole ulcers and white line lesions is also included. The chapter concludes with an overview of the emerging diseases in dairy cattle.

Advances in understanding immune response in dairy cattle

From the beginning, cattle have made important contributions to the field of immunology, including the development of the first Mycobacterium bovis BCG vaccine for human tuberculosis in 1921. In 1981 the first report of a biosynthesized polypeptide vaccine against Foot and Mouth Disease Virus (FMDV) using the VP3 protein expressed in Escherichia coli (E. coli) was made for cattle. Cattle also possess a substantial proportion of T cells expressing the γδ T-cell receptor which helped to elucidate the role of these unique cells in host defence. More recently, it was discovered that cattle produce antibodies with ultra-long Complementarity Determining Region (CDR) - 3. This seminal finding has allowed the production of bovine therapeutic broadly neutralizing antibodies with ultra-long CDRs to passively treat various virial infections in humans and play a key role in protecting cattle. This chapter will review advances in bovine immunology, particularly as it relates to dairy cattle.

Key issues and challenges in disease surveillance in dairy cattle

This chapter provides an overview on the different aspects concerning disease surveillance programs. The chapter also describes a specific and conceptual framework related to disease surveillance of production diseases within the individual herd, including both animals and farmers. Regarding farmers, this chapter focus on the justification and purposes for doing disease surveillance as well as the possible decisions and actions they can take to enhance the efficiency of the disease surveillance programs. It also discusses some of the most novel biomarkers that can be potentially used to identify pre-clinical disease states, which will have the potential to minimize the negative effects of production diseases. Finally, the chapter looks into the future perspectives and possible challenges that future automated disease surveillance systems will need to face in order to keep an optimal animal health, performance and welfare within the individual herd.

Managing replacement and culling in dairy herds

Approximately one third of dairy cows are replaced every year. Replacement of dairy cattle is an important part of the cost of dairy production and an environmental sustainability concern. Primary culling reasons are reduced health and fertility. Reduced welfare often proceeds culling. This chapter focuses on factors that affect replacement and culling in dairy herds with a focus on cows. The act of culling is simple, but the risk factors and economic considerations are complex. The chapter first presents some data on culling risks and reasons, explores more in depth the effects of poor health on culling, and presents aspects of economic decision making regarding culling and replacement decisions.

Advances in techniques for health monitoring/disease detection in dairy cattle

Livestock production has been characterized by the intensification and specialization of production leading to larger farms and, hence, to fewer farmers per animal. Thus, the animal-to-stockman ratio is increasing and the available time for monitoring an individual animal is reducing. In the same time period, the focus in the veterinary profession has shifted from treatment of acutely diseased animals to more proactive management, which includes the use of epidemiological tools to identify risk factors for animal health, welfare and production. As part of a modern herd management, reliable data on animal health are provided e.g. by routine and standardized testing of animals for the presence of disease. For this, traditional and increasingly sophisticated diagnostic tools are available. Recently, farmers have increasingly been using sensor technologies, allowing continuous and automated health monitoring of livestock. This aims in establishing an early warning system to optimize herd health management and fostering decision making.