Lactating dairy cows adapt quickly to automatic milking system
Transitioning a dairy herd to an automatic milking system (AMS) from a conventional parlor system may be stressful for the cow, as many changes occur during this process. Chronic stress may affect the welfare of the cow, and acute stress during milking can decrease milk yield. Therefore, it is important to quantify if and how long stress during adaptation to an AMS might persist.
In a study from Michigan State University seventy-seven cows with acceptable udder and teat conformation that would not interfere with adaptation to the AMS and that were lactating for the full duration of the project were chosen for observation. All cows had been milked previously in a double-6 herringbone milking parlor.
Four stress-related behaviors [step-kick behavior both before and after attachment of teat cups, elimination (urination and defecation instances), and vocalization] were recorded during milking by trained observers, whereas milk yield was automatically recorded by the AMS. Data were collected for 24-h periods beginning on the day the cows transitioned to milking in the AMS (d 0), and on d 1, 2, 4, 8, 16, and 32 thereafter. Instances of elimination and vocalization were greater on d 0 compared with all other days. Milk yield increased between d 0 and d 1. Primiparous cows were more likely than multiparous cows to display step-kick behaviors both before and after teat cup attachment during milking. Eight days after introducing the cows to the AMS, over 60% of the herd was milking voluntarily and 95% of the herd was milking voluntarily within a month, which suggests that cows did not find the AMS aversive. Greater elimination and vocalization behavior and lower milk yield on d 0 relative to subsequent days indicated initial stress and discomfort with the milking process in the new system; however, the cows appeared to adapt within 24h.
The study was made by J.A. Jacobs and J.M Siegford at the department of Animal Science at Michigan State University and ws published in the Journal of Dairy Science in March 2012.
Journal of Dairy Science, Volume 95, Issue 3, Pages 1575-1584, March 2012