A COMPARISON OF THE REDUCTION IN IMMUNOGLOBULIN (IGG) CONCENTRATION OF FROZEN EQUINE PLASMA-TREATED BY 3 THAWING TECHNIQUES

The IgG concentration of plasma from 13 mares was measured by radial i mmunodiffusion when fresh and after storage at -4-degrees-C and thawin g by 3 methods. There was no significant (P > 0.05) reduction in the I gG concentration when plasma was thawed over 6 hours at 22-degrees-C ( 1352.9 +/- 101.6 mg/dL) (mean +/- SEM) compared with the fresh sample (1369.5 +/- 88.1 mg/dL). In contrast, there was a significant (P < 0.0 5) reduction in the IgG concentration of plasma that was rapidly thawe d at 57-degrees-C over 50 minutes (1142.9 +/- 66.2 mg/dL), or placed i n a microwave oven for 20 to 25 minutes (1093.4 +/- 74.4 mg/dL). When plasma is administered to hypo-gammaglobulinaemic newborn foals, a lar ger volume is required when thawing is rapid than when thawing is slow or when fresh plasma is administered.