Impact of dietary spray-dried bovine plasma addition on pigs infected with porcine epidemic diarrhea virus

Duffy, Mark A; Chen, Qi; Zhang, Jianqiang; Halbur, Patrick G; Opriessnig, Tanja

An intact intestinal mucosa, which prevents the entrance of agents across the epithelium, is a first line of protection with great importance in weaned pigs that, due to separation from their dam and comingling with other pigs, are under high stress and exposed to numerous pathogens they have not encountered before (Pitman and Blumberg, 2000; Boudry et al., 2004; Pie et al., 2004; Bailey et al., 2005; Moretó and Pérez-Bosque, 2009 ). Producers commonly add spraydried plasma (SDP) of porcine or bovine origin to weaned pig diets as it has been shown to promote growth (Grinstead et al., 2000) and aids in combating common postweaning pathogens such as Escherichia coli (Torrallardona et al., 2003; Bosi et al., 2004) . It is well recognized that the addition of SDP to pig feed enhances the immune response and decreases pathogen loads compared with pigs without plasma access through feed. For instance, plasma protein supplements modulated the mucosal immune response in organized and diffuse gut-associated lymphoid tissue, which is accompanied by a reduction of proinflammatory cytokine production (Bosi et al., 2004; Nofrarias et al., 2006; Pérez-Bosque et al., 2008) .