Associate Professor

Animal Breeding and Genetics, Dairy

Research Interests

Dairy Cattle Genetics and Management

Goals are to reduce incidence of mastitis, especially in first lactation heifers, and to improve disease resistance of dairy cattle and milk quality for consumers.

The current focus of research is to determine the relationships among mastitis, somatic cell counts in milk, and milk yield in first-calf heifers. Somatic cells in milk consist primarily of leukocytes and neutrophils secreted in response to invasion by an infectious pathogen. Somatic cell counts in milk serve as an indicator of udder health and are elevated during mastitis infections. Research has indicated that somatic cells in milk are elevated when heifers first freshen, although clinical symptoms may or may not be present. The relative roles of pre-calving infections, or even calfhood infections, environmental stressors, or onset of lactation in causing elevated cells counts is not clear. We are attempting to model lost milk production following mastitis infection by studying patterns of daily somatic cell counts and milk yield. The dilution of cell counts by varying milk volume is also being studied. Economic losses accruing from medical treatment costs, discarding of milk from treated cows, foregone milk production, and lower milk quality incentive payments will be modeled to demonstrate the benefits of selections against mastitis susceptibility. Research methods integrate statistical modeling, quantitative genetics, mixed model statistical analyses, and fundamentals of immunology. Other research interests include conformation and health traits in breeding programs, investigation of disease prevalence in dairy heifers.

Research Techniques

• Mixed model statistical techniques
• Methods to predict lactation and age production curves
• Best Linear Unbiased Prediction (BLUP)
• Genetic modeling
• Evaluation of dairy management practices

Current Research Projects

• Relationships among test-day milk yields and somatic cell scores (in cooperation with R.H. Miller, USDA Animal Improvement Programs Laboratory).
• Pre-partum milking and parlor acclimation effects on stress indicators and behavior of primiparous dairy cows (in cooperation with S. Pruiett, USDA Livestock Behavior Research Laboratory).
• Patterns of test-day somatic cell scores to improve genetic evaluation of dairy cattle for mastitis resistance.
• Identifying optimum genetics for pasture-based dairy production.

Representative Publications

Schutz, M. M., and G. R. Wiggans. 1998. Current status of genetic evaluations for somatic cell scores of dairy cattle in the United States. Proceedings of the sixth World Congress on Genetics Applied to Livestock Production 25:15.

Schutz, M. M., P. M. VanRaden, G. R. Wiggans, and H. D. Norman. 1995. Standardization of lactation means of somatic cells scores for calculation of genetic evaluations. Journal of Dairy Science. 78:1843.

Schutz, M. M. 1994. Genetic evaluation of somatic cell scores for United States dairy cattle. Journal of Dairy Science. 77:2113.

Schutz, M. M., A. E. Freeman, D. C. Beitz, C. M. Koehler, and G. L. Lindbergh. 1994. The effect of mitochondrial DNA on milk production and health of dairy cattle. Livestock Production Sciences. 37:283.

Schutz, M. M., P. M. VanRaden, P .J. Boettcher, and L. B Hansen, 1993. Relationship between somatic cell score and type trait evaluations of Holstein sires. Journal of Diary Science. 76:658.

Miller, R. H., M. J. Paape. L. A. Fulton, and M. M. Schutz. 1993. Relation of milk somatic cell count to milk yields for Holstein heifers after first calving. Journal of Dairy Science. 76:728.