CD79A and digestive system infectious disorder: IgA is known to be associated with the immune response against gastrointestinal infections in ruminants, particularly nematodes (Arsenopoulos, Symeonidou, and Papadopoulos 2017; Claerebout and Vercruysse 2000; de la Chevrotière et al. [2012]), however, fecal antibody testing is still a relatively new method in cattle.