ECONOMIC CONSEQUENCE OF PARASITE LOADS AND SELECTION OPPORTUNITIES FOR PARASITE RESISTANCE IN ORGANIC DAIRY CATTLE

Organic production systems provide natural environments that confer animal wellbeing advantages. However, antimicrobial and pesticide restrictions coupled with grazing requirements create challenges related to both internal and external parasites, some of which are also a zoonotic risk. We will collect fecal samples to determine internal parasites and record horn flies and other external parasites on approximately 3,225 organic dairy animals from multiple breeds. This data will facilitate estimation of losses due to compromised animal health, particularly for calves, and subclinical reductions in milk yield. All animals will be genotyped so that we can conduct genomic analyses and identify regions of the genome associated with parasite susceptibility. A citizen science mobile app will also be developed to allow public contribution of parasite data. We will deliver information about parasite control through a wide variety of outreach events and a web platform that will include herd-specific economic selection indexes. This effort directly addresses OREI priorities related to selection of animal breeds and genotypes adapted to organic systems and demonstration of educational tools for Cooperative Extension personnel and other professionals who advise producers on organic practices. The long-term goal of this project is to reduce economic losses from parasites and through development of genomic selection and crossbreeding programs designed specifically for organic production.