Milk cortisol concentration in automatic milking systems compared with auto-tandem milking parlors

Gygax, L; Neuffer, I; Kaufmann, C; Hauser, R; Wechsler, B (2006). Milk cortisol concentration in automatic milking systems compared with auto-tandem milking parlors. Journal of dairy science, 89(9), pp. 3447-54. Savoy, Ill.: American Dairy Science Association

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Milk cortisol concentration was determined under routine management conditions on 4 farms with an auto-tandem milking parlor and 8 farms with 1 of 2 automatic milking systems (AMS). One of the AMS was a partially forced (AMSp) system, and the other was a free cow traffic (AMSf) system. Milk samples were collected for all the cows on a given farm (20 to 54 cows) for at least 1 d. Behavioral observations were made during the milking process for a subset of 16 to 20 cows per farm. Milk cortisol concentration was evaluated by milking system, time of day, behavior during milking, daily milk yield, and somatic cell count using linear mixed-effects models. Milk cortisol did not differ between systems (AMSp: 1.15 +/- 0.07; AMSf: 1.02 +/- 0.12; auto-tandem parlor: 1.01 +/- 0.16 nmol/L). Cortisol concentrations were lower in evening than in morning milkings (1.01 +/- 0.12 vs. 1.24 +/- 0.13 nmol/L). The daily periodicity of cortisol concentration was characterized by an early morning peak and a late afternoon elevation in AMSp. A bimodal pattern was not evident in AMSf. Finally, milk cortisol decreased by a factor of 0.915 in milking parlors, by 0.998 in AMSp, and increased by a factor of 1.161 in AMSf for each unit of ln(somatic cell count/1,000). We conclude that milking cows in milking parlors or AMS does not result in relevant stress differences as measured by milk cortisol concentrations. The biological relevance of the difference regarding the daily periodicity of milk cortisol concentrations observed between the AMSp and AMSf needs further investigation.

Item Type:

Journal Article (Original Article)


05 Veterinary Medicine > Department of Clinical Veterinary Medicine (DKV) > Clinic for Ruminants

UniBE Contributor:

Kaufmann, Christine




American Dairy Science Association




Factscience Import

Date Deposited:

04 Oct 2013 14:45

Last Modified:

04 May 2014 23:13

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Web of Science ID:


URI: (FactScience: 819)

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