ABSTRACT
Mammary glands are particularly susceptible to new infections during the dry and early lactation periods. Dry cow antibiotic therapy in all quarters of all cows has been a traditional method to reduce the effect of these new infections. The objective of this study which was done for the first time in Iran was to determine the effect of infusion with Masti-Seal at dry off. Eighty Holstein Frisian dairy cows parity of 2 to 5 in 7 month of pregnancy were selected from a commercial dairy farm. All cows didn't show clinical mastitis in last month. The cows of group A [n=10] were randomly assigned to be treated in two quarters [LF/RR or RF/LR] with the sealant while two quarters in each cow remained as untreated controls. The cows of group B [n=10] were randomly treated with the dry cow therapy [DCT] and sealant. The cows of group C were randomly assigned to be treated in two quarters [LF/RR or RF/LR] with the DCT and sealant while two quarters were treated just with antibiotic DCT. In group D the effect of Masti-seal and Orbiseal in rear quarters were compared. Milk samples were collected for bacterial culture and somatic cell count [SCC] at dry off, 10-15 DIM. At calving, the Mastiseal was manually stripped from each quarter prior to collecting of colostrum. The clinical evaluations of teats were done in all groups at days 7, 14 and 28 after treatment. No changes in teats of cows were seen. Corynebacterium bovis and one yeast were isolated from 2 and 1 samples, respectively. The SCC of cows in group B increased significantly after parturition compared with cows treated by DCT. In other groups there were no significant differences between dry period and after parturition. Results revealed that using of Masti-seal in combination with DCT is useful. However, use of Masti-seal is a necessity even without antibiotics