Kamau, Kevin2023-02-162023-02-162022-12https://hdl.handle.net/11299/252474University of Minnesota M.S. thesis. December 2022. Major: Animal Sciences. Advisor: Isaac Salfer. 1 computer file (PDF); vii, 86 pages.Dairy cows consistently exhibit patterns of feeding and milk synthesis. These patterns can be entrained by environmental cues and management practices. The study of behavior of cows is an essential practice to enhance cow well-being and milk production. Two studies were conducted to better understand the relationship between cow behavioral patterns, physiology, and performance. First, we investigated the effect of season on daily rhythms of body temperature, milk production and milk components. In this experiment, daily rhythms were observed in fall, summer, and spring but winter did not fit a rhythm (P < 0.05). Season also tended to affect the AM to PM ratio of milk yield (P = 0.09). However, season did not affect the AM to PM ratio of fat and protein concentration in milk. The effect of season on daily rhythms of temperature is significant while season’s effect on daily rhythm of milk yield is minimal. Secondly, we examined the effect of using automated feeding robots on cow performance (milk production and milk components), cow behavior and total mixed ration consistency at the feed bunk. The use of feeding systems did not affect milk production and milk components except for lactose (P = 0.02). However, the use of automated feeding robot reduced variability in feed ration at the feed bunk. Ration consistency is an important factor in maintaining proper rumen health. Further research on the effects of automatic feeding systems on rumen health, ration consistency and dairy performance is recommended. Keywords: Daily rhythms, Automated feeding systems, ration consistencyenAutomated feeding systemsCircadian rhythmsCow behaviorCow performanceThesis or Dissertation