Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: July 28, 1998
Publication Date: N/A
Efficient dairy operations require that animals adapt to routine management procedures. Modern dairy operations are increasingly mechanized, and the impact of mechanization on animals is not well understood. Traditionally, acclimation of animals to novel environments has been examined in terms of adrenal stress responses or behavioral changes. However, these methods are often not sensitive enough to detect a response, and duration of responses often precludes associating responses with discrete aspects of environmental changes. In this study, to determine which aspects of a robotic milking system might cause anxiety in animals, movement of the rear legs of 6 heifers were monitored while animals stood in the robotic milking system. Heart rates were monitored every 30 s throughout the day. Non-milking heifers were used to allow for incremental addition of procedures to the normal routine of the animals over time. Small increases in heart rates were seen before animals became acclimated to entering the milking system (essentially a side-opening stall). Subsequently, forcing animals to remain in the stall for 1 min did not alter heart rates. Dramatic increases in heart rate and leg movement were seen only when positioning of the rear legs was instituted. For 5 of the 6 cows, heart rates, averaged over 10 min intervals, increased 13.0 +/- 3.9 bpm relative to leg positioning while peak heart rates increased 26.2 +/- 6.9 bpm for periods of 2 to 6 min. The sixth cow was in heat during this period of testing. These results clearly show that a critical aspect of the robotic milking system which the animals found objectionable was leg positioning, and confirm the value of using changes in heart rate and movement as measures of anxiety.