Foals with the Ca blood group antigen on their RBC were given colostrum with anti-Ca antibodies (6 foals) or colostrum without anti-Ca antibodies (6 foals). The PVC were determined at birth and 2, 4, and 6 days after birth for the foals in each group. Significant differences were not observed for the PCV between the 2 groups, indicating that foals were not adversely affected by ingesting colostrum with the anti-Ca antibody. Standardbred mares without the Aa blood group antigen were evaluated to determine whether production of anti-Ca antibodies influenced production of anti-Aa antibodies. Of 266 mares without the Aa antigen, 3 of 61 (5%) mares without the Ca blood group antigen produced anti-Aa antibodies and 43 of 205 (21%) with the Ca blood group antigen produced anti-Aa antibodies. These 2 groups of mares were significantly (p = 0.006) different; Ca-negative mares were less likely to produce antibodies to Aa than were mares with the Ca blood group antigen. This observation was consistent with a hypothesis of antibody-mediated immunosuppression of immune response to the As blood group antigen by antibodies to the Ca blood group antigen, ie, when a mare is exposed to her foal's RBC and already has antibodies to the Ca blood group antigen on the foal's RBC, then she is less likely to initiate an immune response to the Aa blood group antigen also on the foal's RBC.

This work was carried out to get some informations about blood types and their researches, involved blood stock and genetic identification. Horses examined were total 55 heads of sire, mare and their progeny in Korean Horse affairs Association. Albumin and phenotypes of 26 mare were examined. The appearance of phenotype AA, BB, AB, was 1, 18, 7 respectively. The gene frequency of albumin A was 0.17 and albumin B was 0.76. The appearance of phenotype AA, BB, Ab in 29 progeny was 1, 16, 12 respectively. The gene frequency of albumin A was 0.24 and albumin B was 0.76. The gene frequency of gene A was higher than their parents. Identification of the relationship between parents and their progeny was also examined. 4 of type AB between AA and BB, 4 of type BB between BB and BB, 13 of type AB between BB and AB were borned. In third case, all of progeny was type AB. This results suggest positive relationship between them