California Agriculture

Dairy producers seldom test or examine incoming cattle, although these important biosecurity practices are recommended. This pilot project examined risk management decisions that producers make when faced with test-positive animals in purchased groups of dairy cattle, in order to provide information on disease risks and conditions that could affect animal health and performance. New arrivals to seven herds at dairy farms in four California counties were examined and tested for a range of conditions. The most common findings were bovine leukosis virus (33% of cattle purchased) and male reproductive abnormalities (16% of bulls purchased). Once testing results were known, producers made a variety of risk management decisions. Although testing costs for some conditions outweigh the benefits of finding an infected animal, an individual producer’s decision to test new animals most likely depends on their knowledge of the pros and cons as well as their risk tolerance.