Dairy cattle health and welfare: Research highlights 2017-2018


Source: Dairy Farmers of Canada

Dairy Farmers of Canada in partnership with Agriculture and Agri-Food Canada, the Natural Sciences and Engineering Research Council of Canada (NSERC), and provincial partners, is supporting 10 research projects in dairy cattle health, care and welfare under the Dairy Research Cluster 2 and the NSERC Industrial Research Chairs program.

Key Outcomes:

• Canada’s first National Dairy Study led to key findings on milk quality and milking practices, animal care and biosecurity on Canadian dairy farms:

› A new method to calculate the Canadian average somatic cell count (SCC) resulted in a national average of 208,000 cells/ mL.

› Based on bulk tank samples, the most common mastitis pathogens were Staph. aureus (46%), Prototheca spp. (6%), Mycoplasma bovis (<1%), and Strep. agalactiae (<1%).

› Risk factors for Staph. aureus-positive farms included: not fore-stripping cows before milking, milking with a pipeline system and stall bases with a rubber surface (rubber mats, gel mattresses, waterbeds).

› The most important factor associated with lameness and hock injuries was the depth of bedding on top of the lying surface. The odds of lameness increased by 53% when bedding depth was 0-1 inch vs. 3-6 inches.

› Farms with pasture access and farms that used a professional hoof trimmer had less lameness.

› Findings highlight the need for stricter biosecurity, especially in the purchase of animals.

• Quarter-based selective dry cow therapy for mastitis proved to reduce the use of antimicrobials on dairies by 60% on average (range: 32.1 – 74.5% among herds).

• New information, which includes the identification of important Coagulase-Negative Staphylococcus (CNS) species, are improving the accuracy of mastitis diagnosis in Canada and around the world.

• Discovery of antibiofilm molecules produced by CNS generates the potential for a new tool to control/treat bovine mastitis caused by staphylococci and other Gram positive mastitis pathogens.

• The economic model developed for the costs of mastitis on Canadian dairy farms indicated substantial losses due to mastitis with median costs of $662/cow/year. Total costs for Canadian dairies using year 2014 demographic data were estimated at $665 million.

• A research agreement with an option of license was signed with a private company to potentially commercialize a chitosan hydrogel infusion to prevent new intramammary infections at drying-off by stimulating mammary gland immunity.

• Results from an evaluation of alternative therapies for the treatment of clinical mastitis on organic dairies indicate that no alternative or non-antibiotic methods have demonstrated efficacy for the treatment of clinical mastitis. However, the administration of bismuth subnitrate internal teat sealants (approved by Health Canada) used without antibiotics is a very efficient method for the prevention of mastitis at dry-off in organic herds.

• Automated activity monitors measure estrous expression/ intensity and have potential as management tools to improve the efficiency of timed AI programs based on estrous detection and therefore, decrease hormone use.

• New information generated from a survey of producers using AMS was conducted to assess the impact of automatic milking systems on milking labour management, milk production and milk quality