The influence of age and breed on the concentrations of serum IgG, IgA and IgM in sows throughout the reproductive cycle.

The influence of age and breed on the concentrations of IgG, IgA and IgM in the sera of sows throughout the reproductive cycle was investigated in 4137 sows which had had 0-20 gestations and representing three breeds: Swedish Landrace, German Landrace and L-12 (= Swedish Landrace x Large White). Data revealed an increase in total immunoglobulins (Ig), IgM and IgG serum levels with increasing gestation number; the latter contributed greater than 80% to total Ig levels. IgG was significantly increased up to the fourth gestation, whereas IgM showed a significant increase only to the third gestation. IgA showed only minor differences. Age-dependent increases in serum IgM were ascribed to the increased probability of antigenic exposure during suckling, while failure to observe this change in serum IgA was ascribed to its role as a local Ig. Breed differences were observed to be significant for all three Ig's. It is concluded that establishment of group norms for serum Ig's should consider age and breed difference as well as stage of gestation or lactation.