Date of Award
Program or Major
Master of Science
Milk from pastured cows contains more beneficial fatty acids than milk from total mixed ration (TMR) fed cows. No studies have been done comparing health status in cows from each system. This study used pastured vs. TMR fed Jersey cows to measure levels of cortisol, haptoglobin (Hp), somatic cells, and production within and between farms over time.
Cortisol was significantly different between farms with means of 126.78 and 93.64 ng/ml for pastured and TMR groups, respectively. Levels in pastured cows trended with temperature and humidity. There was no significant difference in Hp levels between farms though levels did change over time within farms. All animals had Hp levels considered normal. Somatic cell counts were not significantly different, yet the pastured group had a numerically lower average, 57.7 vs. 113.8 x 103 cell/ml. Results indicated that environment caused added stress to pastured cows but feeding TMR vs. grass did not.
Seneca, Megan Lee, "Markers of health status in pasture-fed versus total mixed ration-fed Jersey dairy cattle" (2012). Master's Theses and Capstones. 767.