الفهرس 
AbstractOnly 14 pages are availabe for public view
 |  | from | 163 |  |  |
| | | from | 163 | | |
Abstract
C. perfringens, is widespread in the environment and IS mmonly a part of normal gut flora, is commonly involved In domestic animals and some wildlife, including rses, poultry, birds, rabbits sheep, goats, cattle, mink, ostrich, dogs and cats (Nillo,1993). In humans, C. perfringens can cause gangrene IOd gastrointestinal disorders. It is certainly the most serious cause of clostridial enteric disease in domestic animals (Johansoon, 2006). C. perfringens is also the causative agent of c1ostridiois, one of the most important diseases in broiler and turkey flocks. C. perfringens produces a variety of fatal extracellular toxins, designated as alpha (0), beta (J3), epsilon (s), iota (I) and theta (8), as well as other minor toxins (Songer, 1996; Songer and Meer, 1996). C. perfringens type A is consistently recovered both from the intestinal tracts of animals and from the environment, while others (types B, C, D and E) are less common in the intestinal tracts of animals (Songer, 1996). Poultry must have a healthy and functional intestinal tract to maintain the excellent feed efficiency that is required by modern production standards. It is estimated that feed costs for poultry comprise roughly 66% of the total production costs, whether costs are for a dozen eggs, broiler chickens, or turkeys (Schrader, 1997, Purdue University, Department of Agricultural Economics, Krannert Building, West Lafayette, IN, 47907). Low-grade damage to the intestinal tract by pathogenic bacteria may cause poor feed efficiency and decreased rate of gain to escalate the total production costs.