Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 23, 2007
Publication Date: July 8, 2007
Citation: Stabel, J.R. 2007. Pasteurization of Colostrum Reduces the Incidence of Paratuberculosis in Neonatal Calves [abstract]. American Dairy Science Association. Technical Abstract: Feeding colostrum from infected dams to neonatal calves is one mode of transmission of paratuberculosis (Johne’s disease). Recent studies have demonstrated improved morbidity and mortality rates in calves fed colostrum replacers or pasteurized colostrum. In the present study, the potential benefits of feeding pasteurized colostrum was demonstrated in calves born to dams naturally infected with <i>Mycobacteirum avium</i> subsp. <i>paratuberculosis</i>. Calves were separated at birth from their dams and randomly allocated into a group fed the dam’s colostrum, followed by feeding the dam’s milk for 3 weeks (DC; n = 6), or into a group fed pooled pasteurized colostrum and milk replacer (PC; n = 5). After 3 weeks, calves were then weaned onto calf starter and housed and fed in a similar manner throughout the rest of the study. Blood and fecal samples were taken at birth and monthly throughout the 12-month study. Calves were necropsied at the end of the study and tissues were cultured for <i>M. paratuberculosis</i>. Twenty-five tissues were taken at necropsy and cultured for <i>M. paratuberculosis</i>. Sixteen of the 25 tissues were positive across treatment groups, with 14 of 16 tissues positive for DC calves and 9 of 16 tissues positive for PC calves. The degree of colonization within a tissue was low and varied between calves even within a treatment group. Fecal shedding was minimal during the study with 2 calves from each treatment group shedding negligible amounts of <i>M. paratuberculosis</i>. As a measure of early immune response to infection, blood obtained from calves was stimulated in vitro with <i>M. paratuberculosis</i> antigen preparations and IFN-gamma secretion was measured. Antigen-specific IFN-gamma was consistently higher throughout the study in calves fed colostrum and milk from their infected dams (0.95 vs 0.43 Abs540nm). These results indicate that feeding a source of clean colostrum to neonatal calves may reduce their exposure to <i>M. paratuberculosis</i>. Key Words: <i>Mycobacteirum avium</i> subsp. <i>paratuberculosis</i>; calves; colostrum.