Cattle stressors can be defined as any stimuli that activate the base of the brain (HPA axis) and the sympathetic nervous system to deal with a perceived threat.
Stressors can be classified as physical/physiological or psychological.
Examples of physiological stressors include dehydration, malnutrition, trace mineral deficiencies, weather, transport, pathogens, and pain.
Examples of psychological stressors include confinement, relocation, social disruption, unfamiliar environments, transport, and predator threats.
Prey animals including cattle are blessed with two defense systems to respond to threats real or perceived.
The primary defense system is to first respond to external threats originating from the environment or from caregiver activities.
The brain’s response to cattle anxiety is to ask the adrenal glands to release stress hormones like cortisol, adrenalin, and epinephrine to enhance animal flight and defense.
These hormones enhance survival by improving flight and masking signs of lameness, injury, or disease so predators fail to select weak members of the herd.
Herd behaviors that indicate anxiety include panic motion, vocalization, lack of water intake, and crowding into corners of a pen.
Although hormones released during periods of anxiety and confusion enhance external defense mechanisms, secondary internal defense mechanisms suffer.
These defense stress hormones are very immunosuppressive and increase disease susceptibility, especially to the BRD complex.
The presence of cortisol inhibits white blood cell function by inhibiting antigen detection and protective antibody production.
The presence of stress hormones is a powerful signal to the existing resident gram-negative bacteria population including Mannheimia and Histophilus to colonize in the lung leading to devastating pneumonia lesions.
Relocation stress can lower disease resistance and contribute to morbidity and mortality.
Beef production managers need to focus caregiver activities on shifting brain-induced hormone production of cortisol to production of health hormones like serotonin, dopamine, oxytocin, and norepinephrine.
These activities should include every step of cattle movement and need to result in rehydration, nutrition, rest, and cattle confidence soon after arrival.
Keys to success include understanding the creation of voluntary cattle flow. “Reading” cattle and working from the front of the herd so cattle can see their source of guidance simultaneously with their destination is a requirement for cattle to perceive to belong where we intend.
Greeting arrival cattle during unloading and learning to “lead” new arrivals to their new home reduces cattle anxiety and enhances acclimation activities.
Proper receiving pen management includes pen surface sanitation, palatable forage availability in the bunk, bedding near bunk aprons, and adequate, clean water availability.
Bedding is a powerful message to tired arrivals that their destination is an improvement over their previous home.
An important measure of cattle confidence in their new home is willingness to drink with purpose.
Dream about flow meters in receival tanks to monitor water intake just like we measure dry matter intakes.
Consider delaying arrival processing until cattle are full of water, nutrition, rest, and confidence.
Spend a few minutes with new cattle creating counterclockwise herd movement completely around the pen.
Teach cattle to move as a family and be willing to walk by handlers and travel straight to the bunk or tank. Realize that herds are comprised of individual animals.
Degrees of stress are determined by previous experiences, genetics, and sensory inputs. What upsets a sentinel animal may not be noticed by a herd mate.
Watch for sensitive individual cattle that deserve special care. Inviting timid, sensitive cattle to travel in an orderly fashion to the bunk or tank will encourage the rest of the herd.
Three simple cattle behaviors signal the presence of reduced cortisol and an increase in dopamine and serotonin hormone levels.
These behaviors include REM sleep, active cud chewing, and willingness to pass by handlers with trust, exuberance, and play.
Learning to create these behaviors soon after arrival is an exciting opportunity to reduce disease, improve health, and enhance cattle well-being.
Dr. Tom Noffsinger is a founding partner of Production Animal Consultation and an expert in low-stress animal handling and staff development. He received his DVM from Colorado State University and completed the Beef Production Management Series at the Great Plains Veterinary Education Center. He is a member of American Association of Bovine Practitioners, Academy of Veterinary Consultants, American Veterinary Medical Association, and Nebraska Veterinary Medical Association. Dr. Tom has received multiple honors, including the 2001 AVC Consultant of the Year, the 1999 NVMA Distinguished Service Award, and the 2008 AABP Merial Preventative Medicine Award for Beef. He and his wife Diane reside on their ranch outside beautiful Benkelman, Nebraska.
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