Leitner, G., National Mastitis Reference Center, Kimron Veterinary Institute, Bet Dagan, Israel
Pinchasov, Y., SIAP Lab, Bet Gamliel, Israel, YAMIT Biotechnologies, Kiryat Shmona, Israel
Morag, E., YAMIT Biotechnologies, Kiryat Shmona, Israel
Spanier, Y., YAMIT Biotechnologies, Kiryat Shmona, Israel
Jacoby, S., Institute of Animal Science and Institute of Technology and Storage of Agricultural Products, A.R.O., Volcani Center, Bet Dagan, Israel
Eliau, D., YAMIT Biotechnologies, Kiryat Shmona, Israel
Pitcovski, J., Migal Galilee Technology Center, Kiryat Shmona, Israel, Department of Biotechnology, Tel-Hai Academic College, Israel

The aim of this study was to examine an alternative, immunologically based treatment for mastitis. A microbead carrying specific anti-mastitis bacteria antibodies and an enhancer of phagocytosis, termed Y-complex, was tested in two experiments. In experiment 1, 21 cows were challenged with Streptococcus dysgalactiae and treated with Y-complex, Cobactan LC® or saline. Y-complex cleared the bacteria by day 4 and by day 10 only one cow was positive and remained positive up to day 28. No bacteria were isolated from any of the seven cows treated with Cobactan LC after day 4; however, in two out of the seven cows, the bacteria were re-isolated on day 24. On day 28, cows treated with placebo had still not cleared the bacteria. Experiment 2 was a field study in which cows, naturally infected with Escherichia coli, S. dysgalactiae or coagulase-negative staphylococci (CNS), were treated with Y-complex (32 cows), sulfadiazine+trimethoprim or procaine penicillin+streptomycin (BA) (8 cows), or a non-steroidal anti-inflammatory drug (NSAID) (19 cows). Y-complex was as effective as antibiotics, and superior to NSAID, in eliminating bacteria. Milk quantity and quality following infection and treatment were similar for all treatments, but significantly less milk was discarded from cows treated with Y-complex as compared to antibiotics. Y-complex was proven to be safe and effective, and may serve as a new approach for the treatment of mastitis. © 2013 Elsevier B.V.