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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Cell Wall Biology and Utilization Research » Research » Publications at this Location » Publication #412725
Research Project: Developing Strategies to Improve Dairy Cow Performance and Nutrient Use Efficiency with Nutrition, Genetics, and Microbiology

Location: Cell Wall Biology and Utilization Research

Title: Behavioral and hair cortisol responses of heifers raised in barn or on pasture

Author
item Hall, Mary Beth
item Jaramillo, David
item Kalscheur, Kenneth
item CAMISA NOVA, CARLOS HENRIQUE - University Of Wisconsin
item DISALVO, ALEXA - Collaborator

Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/18/2024
Publication Date: 6/16/2024
Citation: Hall, M., Jaramillo, D.M., Kalscheur, K., Camisa Nova, C.P., Disalvo, A. 2024. Behavioral and hair cortisol responses of heifers raised in barn or on pasture. Journal of Dairy Science. 107 (Supplement 1):155.

Interpretive Summary:

Technical Abstract: We assessed behavior and hair cortisol responses of heifers raised in barn and fed a total mixed ration or on pasture rotationally stocked on cool-season pastures and given grain with a vitamin and mineral mix. Holstein heifers (N = 64) aged 4.8 ± 0.45 months were assigned to 8 groups; 4 on pasture and 4 in the barn (8 heifers/group). A barn-housed animal died due to causes unrelated to the study. Hair samples were obtained in May before treatments began and in June and August, 6 and 14 wk after imposing treatments. Hair cortisol was analyzed via an enzyme-linked immunosorbent assay. Behavioral observations were recorded every 10 min for 12 h during daylight on 1 d in June and 1 d in July by trained observers. Behavior data were converted to minutes or incidents per animal by dividing observations by number of heifers in a group. Data were analyzed as repeated measures in a model with treatment, sampling date, the interaction, and with group as a random variable and the experimental unit. For cortisol, May data was used as a covariate, and also analyzed separately with treatment and group in the model. Eating/grazing time was greater for animals on pasture than in the barn (403 and 243 min/heifer, standard error (SE) = 6.6; P < 0.0001) as were incidents of vocalization (0.96 and 0.15 times/heifer, SE = 0.173, SE not back transformed; P < 0.001). Incidents per heifer of drinking, grooming, and stereotypy were greater for animals in the barn (pasture and barn results, SE, P, respectively: 3.92 and 5.75, 0.47, P = 0.03; 4.59, 9.79, 0.73, P < 0.01; 0.17 and 2.15, 0.27, P < 0.01). Time spent standing (491 on pasture and 468 in barn min/heifer, SE = 7.7; P = 0.07) or laying (229 on pasture and 252 in barn min/heifer, SE = 7.8; P = 0.08) tended to differ between treatments. Hair cortisol picograms/milligram of hair did not differ between treatments in May (7.2 for animals assigned to pasture and 6.8 for animals assigned to barn, SE = 0.51; P = 0.62) but was higher for pastured heifers than for those in the barn in later months (June: 19.2 for pasture and 5.3 for barn; August: 17.3 for pasture and 5.5 for barn, SE = 0.48; treatment, P < 0.001, treatment x date, 0.08). Vocalization seemed inquisitive or related to feeding, not due to distress. Stereotypy for heifers in the barn may be a time budget rather than stress response. Based on hair cortisol, heifers in the barn were less stressed than those on pasture, though the latter appeared to adapt.