American dairy scientists have confirmed a direct link between SCC levels in milk and the probability of finding antibiotic residues.
"The risk that producers will violate international regulations with regard to antibiotics in milk increases as their herds' somatic cell counts rise," Wisconsin-based milk quality specialist, Dr Pamela Ruegg, confirmed to Farming Life.
"In fact, a high somatic cell count, or SCC, indicates that a herd has a high prevalence of sub-clinical mastitis."
Recent research has confirmed that dairy farms in the midwest of the United States with serious sub-clinical mastitis problems are up to seven times more likely to have antibiotic residues in their milk than producers with herds that have a low incidence of mastitis. "Milk producers everywhere know that reducing the incidence of sub clinical mastitis leads to higher milk production and valuable premiums for milk quality. This study shows that efforts to reduce sub clinical mastitis may have the additional benefit of reducing the risk of antibiotic residue violations," said Dr Ruegg, a member of staff in the College of Agricultural and Life Sciences at the University of Wisconsin.
She added: "Most dairy farms do an excellent job of preventing antibiotic residues in milk. Our study suggests that a cost-effective way to prevent this problem may be to target programmes to farms with high SCC," says Ms Ruegg, who is currently heading up an educational initiative designed to help farmers improve milk quality.
To look for a relationship between SCC and antibiotic residues, Dr Ruegg obtained data on 805,000 milk tests from the Wisconsin area. Herds were divided into five categories based on their average annual SCC: less than 250,000; 251,000 to 400,000; 401,000 to 550,000; 551,000 to 700,000; and greater than 700,000.
