ABSTRACT
This chapter will focus on disease preventative measures, health monitoring and disease investigation techniques, and the management of sick, meat chicken flocks. Poultry operations vary markedly, not only between countries, but also between integrated operations within the same geographic region. Diseases in intensive poultry flocks may occur due to viral, bacterial, fungal, protozoal, metazoan or arthropod infections or infestations. Non-infective metabolic conditions, nutritional deficiencies and toxicities can also present disease or poor performance manifestations. Genetic change in the broiler, which has become exceedingly rapid over the last three to four decades, have made major changes to the birds’ physiology and anatomy. These changes have often proved unbalanced and resulted in the emergence of disease (typically cardiovascular and skeletal problems) or impaired health states. Technological changes in environmental control of houses, increased stocking densities, shorter batch cycles due to improved growth rate, increased feed intakes, faster turnarounds between batches, growing birds to larger final body weights, multiple pickups for slaughter within a house and regulatory withdrawal of many medications have complicated disease expression and severity. Development of better and expanded vaccines (especially of the immunosuppressive diseases), vaccination technologies and eradication of some diseases from breeding stock have improved bird health and decreased the reliance on antibiotic medication of earlier decades. With shorter grow out time to final weight (now as young as 32 days), the influence of factors during fertile egg incubation assume far greater effects on the growth and health of the
modern broiler. As a result, the occurrence of multifactorial conditions has become much more a feature of the scenario and these issues now dominate veterinary interventions and investigations in intensive poultry. The coverage here will tend to be general in nature.
