The Effects of Oral Controlled Exposure on Colostrum Characteristics in Swine

The first chapter is composed of a literature review including topics such as basic porcine immunology, placenta physiology, colostrum composition and immunological importance and lastly a general review about Clostridiumperfringens-associated disease in piglets. The objective of this chapter was to build a solid scientific background to support the two following research topics. The second chapter is composed of the oral control exposure trial and the third chapter reviews the Clostridium perfringens transmission in pigs. Oral exposure with herd-derived animal materials has been widely used in swine production over the years to stimulate herd immunity as a method to control and prevent diseases. The process consists of an intentional exposure of breeding age females to feces, tissues, or environmental materials, presumably containing potential pathogens, with the objective of increasing immunity thus decreasing clinical disease. In 1953, Bay concluded that sows fed infective intestinal material with a coronavirus (Transmissible Gastro Enteritis virus) at various intervals before farrowing were capable of transferring passive immunity to their litters. Years later Kohler`s (1974) study demonstrated that feeding back enteropathogenic E. coli to sows during the last month of gestation increased the anti-diarrheagenic value of colostrum and milk. Accurate diagnosis and control of neonatal diarrhea is complicated by interactions of infectious agents and risk factors. Intentional feedback of farrowing house-derived materials (usually feces) given to pregnant females\u27 weeks before farrowing has the objective of bolstering both the pre-farrow immunity and post-farrow passive transfer of protective antibodies to the offspring. This concept is particularly adaptable to swine due in part to species specific attributes and modern confinement housing systems Despite wide use of controlled oral exposure over in swine the past 40 years, there is a general lack of scientific information available supporting this intervention other than E. coli and Transmissible Gastroenteritis (TGE) virus control. This lack of scientific data and mixed results in the field when attempting to control other pathogens has generated much controversy among practicing veterinarians. The objectives of this study were to better characterize the oral controlled exposure (OCE) methodology, to determine the optimal timing of OCE and to evaluate whether or not biological parameters such as total colostral immunoglobulin G, white cells and some specific antibodies are suitable to monitor the efficacy of the OCE process. The shedding of microorganisms was also assessed to identify if this procedure has any influence on the shedding pattern. The third chapter is a literature review about Clostridium perfringens (Cp) disease in piglets. The review focuses on Cp type A and type C which are associated with disease in neonatal piglets. The first part of the review describes the nature of the disease and how the different types are categorized. The second part describes the clinical signs and findings associated with the two different pathogens. The primary focus of the review is transmission of the agent and possible methods of control. Topics such as first colonization, gut microflora succession and shedding are discussed due to their relevance. The last part of the chapter discusses the different possibilities of control including several different methodologies such as vaccination, oral controlled exposure, the use of antibiotics, probiotics and prebiotics, and lastly an emphasis on cleaning and disinfection