Despite improvements in milk quality management, mastitis continues to challenge herd health and dairies’ profitability goals. Mastitis is the most costly disease in U.S. dairy herds, costing producers $155-224 for each mastitis case and a significant increase in the risk of culling.1,2,3 It has been estimated to cost the dairy industry over $1 billion per year.
According to Gary Neubauer, DVM, senior manager, Dairy Technical Services, Zoetis, quality milk is strongly linked to both the health and genetics of cows. “When coupled with sound milk quality management, improving health and wellness traits with genetic selection offers producers a compelling opportunity to manage mastitis risk and improve profitability.”
Manage milk quality with mastitis wellness trait
To help producers manage and reduce risk for costly health events, CLARIFIDE® Plus provides reliable assessments at an early age for six common dairy health challenges: mastitis, lameness, metritis, retained placenta, displaced abomasum and ketosis. The wellness trait for mastitis goes beyond the indirect measurement of somatic cell count (SCC) that’s available with CLARIFIDE testing through the Council on Dairy Cattle Breeding (CDCB) by offering a direct measurement for mastitis risk. The genetic correlation between mastitis and somatic cell score (SCS) is moderate, putting an even greater importance on directly selecting for mastitis reduction. This also helps explain why the industry has not made more progress on reducing mastitis with indirect genetic selection for SCS.
The genetic risk for mastitis is measured as a standardized transmitting ability (STA), and provides the disease risk of a Holstein female being diagnosed with clinical mastitis one or more times in a given lactation. When producers select for a high STA it will apply selection pressure for reduced risk of mastitis.
The most profitable way to apply a new trait to genetic selection is by identifying its economic value and incorporating it into a selection index. The mastitis trait is included within two indexes: Wellness Trait Index™ (WT$™) and Dairy Wellness Profit Index™ (DWP$™). Using the DWP$ index includes emphasis on mastitis without compromising performance and profitability gain from other traits, such as production. While Net Merit (NM$) may result in some genetic improvement in mastitis from indirect selection on SCS, DWP$ incorporates more emphasis on the direct trait of interest and less from indirect predictor traits. Therefore, DWP$ will approximately double the rate of genetic improvement as compared to NM$ for genetic risk of mastitis.4
Powerful, reliable predictions
CLARIFIDE Plus derives genetic predictions based on data collected from millions of health records within U.S. commercial herds, including over four million lactation records from herds where cases of mastitis were recorded. U.S. producers can be confident CLARIFIDE Plus results will be relevant to their operations with an average reliability of 51% for heifers under two years of age.4
According to Dan Weigel, PhD, Director of Outcomes Research for Zoetis, the reliability level of the mastitis trait is pretty amazing on young CLARIFIDE Plus tested calves. “It is very comparable to CDCB core traits, such as heifer conception rate and daughter stillbirth rate, which have proved to be very useful predictions for producers to make decisions from.”
To help achieve the most progress toward minimizing mastitis incidences, continue to employ best management practices in conjunction with genetic selection. To learn more about managing mastitis risk, watch the educational video Exploring CLARIFIDE Plus Wellness Traits: Mastitis. You can find more information at CLARIFIDEPlus.com or by contacting your local Zoetis representative.
1 Guard, C. 2009. The costs of common diseases of dairy cattle. Central Veterinary Conference Proceedings. Kansas City, MO
2 Cha E, Kristensen AR, Hertl J. Schukken Y, Tauer L, Welcom F, Gibhan Y. Optional insemination and replacement decisions to minimize the cost of pathogen-specific clinical mastitis in dairy cows. Journal of Dairy Science 2014; 07(4): 2101-2117.
3 Cha E, Bar D, Hertl J, Tauer L, Bennett G, Gonzalez R, Schukken Y, Welcom F, Grohn Y. The cost and management of different types of clinical mastitis in dairy cows estimated by dynamic programming. Journal of Dairy Science 2011; 94(9); 4476-4467.
4 Data on file. Zoetis internal data, August 2015, Zoetis, Inc.