Developing Management Options for Staph aureus on Organic Dairies

View the project final report

Commodities

• Animals: bovine
• Animal Products: dairy

Practices

• Animal Production: animal protection and health, herbal medicines, preventive practices, milking hygiene
• Production Systems: organic agriculture

Staph aureus is a common contagious mastitis organism worldwide, causing significant economic losses on both organic and conventional dairy farms. Decades of research have developed extensive knowledge about this antibiotic resistant organism, but successful treatment and prevention through vaccination remains low, and the challenge remains for farmers. Management of the problem relies heavily on culling infected cows and on cultural practices to prevent new infections of healthy cows. In the summer of 2018, we experienced an outbreak of Staph aureus on our organic dairy. About one third of our herd tested positive, including several young cows, making it cost prohibitive to cull of all the infected cows. This proposal seeks to test recommendations from New Zealand that may help prevent new infections, and that show potential to help cows overcome existing cases. For this study, we will adopt a set of rigorous milking hygiene and cattle management practices as part of our day to day operations, and trial new dry cow treatments and management approaches. We will culture milk samples of Staph aureus positive and negative cows on a frequent testing schedule to evaluate the efficacy of the dry cow treatments and aim for 100% prevention of new cases in mid-lactation cattle during the study period. We will share our findings electronically through frequently used online dairy forums, as well as through a presentation at a milk quality workshop in cooperation with the Maine Organic Milk Producers and UMaine Cooperative Extension.

Our project seeks to test staph aureus management in the practical setting of a working organic dairy:

1) To test the effectiveness of milking hygiene and preventative management protocols from the US and New Zealand. We will monitor staph aureus negative cows to determine if the adoption of the protocols results in zero new infections during the one year study period. Results will guide us toward development of a clear, written set of protocols for milking hygiene practices that are effective in preventing new infections for mid-lactation cattle.

2) To trial Manuka honey therapy as a dry cow treatment that would be approved under the National Organic Standards to replace antibiotic dry cow treatments typically used in conventional production.

3) To trial long dry periods (105+ days) as suggested by experts in New Zealand, that could allow a staph aureus infected cow to “self cure”.

4) Trial dry off strategies. Cold-turkey dry off and New Zealand once a day dry off will be compared for staph aureus negative cows to see if one strategy is preferable for preventing new infections.