The Animal Health: Intervention and Management session of JAM 2013 focused on antibiotic treatment in dry cows, clinical ketosis and standing behavior in transition cows.
The first presentation was entitled “Does every cow need antibiotic treatment at dry-off,” and was presented by the author, P.J. Rajala-Schultz. She informed the audience about how mastitis and mastitis management has been changing in recent years.
In the 1950s and 1960s, mastitis was caused by more contagious pathogens and all cows were treated at dry off whether they were infected or not. Now the practices are being to changed both due to mastitis being caused by minor, environmental, pathogens and concern for antimicrobial resistance.
In a recent study performed by Rajala-Schultz and her colleagues, they treated cows selectively based on past somatic cell count (SCC) and clinical mastitis history. A cow was treated if she had a SCC over 200,000 in the last three tests and if she has a clinical case of mastitis within the current lactation.
Cows with a low SCC were split into two groups with half treated and half not. Non-treated cows were shown to have more infections at calving but there were no significant differences in clinical mastitis cases at 30 and 120 days in milk. In conclusion, Rajala-Schultz explained that dry cow treatment needed to be adapted to individual farms certain needs.
In the presentation entitled, “Clinical ketosis and standing behavior in transition cows,” co-author J.M. Huzzey described how the transition period (three weeks before and after calving) is a very critical time for dairy cattle. She explained that ketosis can be a major problem for these vulnerable cows. Huzzey and her colleagues posed the question of whether or not they could detect early stages of ketosis by looking at standing and lying time in transition cows. Cattle usually do not show clinical signs of ketosis until after 11 days in milk, but they found when looking at two dairy herds in Washington state that cows that were ketotic stood more in the week before calving. They also noticed that the cows also had less lying bouts than cows that were not ketotic.
Derek Nolan holds a bachelor’s degree in dairy science from Iowa State University. His interest in milk quality led him to the University of Kentucky where he is currently researching mastitis economics.