What You Will Learn Basic pathogenesis of viruses. Runting and Stunting syndrome in broilers and what we’ve learned over decades of research. Effect of viral infection on production parameters. How Clostridium perfringens causes both clinical and subclinical disease. How to recognize subclinical effects of Clostridium perfringens early in the disease. How to prevent or treat both clinical and subclinical necrotic enteritis (N.E.) without antibiotics. The influence of coccidial infection on: Intestinal pH and digestive enzyme activity, Nutrient absorption, and energy utilization.