Assessment of Welfare

Welfare

• The concept of welfare has moved away from just providing feed, water, and a clean cage.

• We are now charged with providing for the psychological wellbeing of our animals.

• Why?• Assessment?

– Behavioral tests– Biochemical analyses

Behavioral Assessment

• Behavioral signs of stress

Interpreting ResultsWhich mouse is more fearful?

Biochemical Assessment

• Biochemical measures of stress

Interpreting Results• Biochemistry varies with

– Circadian Rhythm

– Social status

– Animal gender

– Observer gender

– Line or breed

Biochemistry varies with Line and Sex

Example only—don’t memorize

Comparative Biochemistry

Mice at 8 weeks of age Balb/cJ C57Female Male Female Male Units

WBC 3.24 2.86 3.48 2.62 103 cells/ulPercent Monocytes 0.80 0.90 0.70 1.40 %Percent Neutrophils 14.80 23.10 7.40 18.50 %B cells 53.43 51.06 56.13 57.80 %T cells 16.95 20.82 15.51 13.60 %

Information from the Jackson Laboratory website

Interpreting Results• Does NE increase more during breeding or

transport?

• Does corticosterone increase more during movement of home cage or seeing another rat decapitated?

• Does corticosterone increase more during the entrance of a male technician into its room or a 15-minute restraint in a plastic tube?

Gender affects on Research Results

• A recent study looked at the effects of olfactory exposure to men on stress and related analgesia in rodents– Pain levels were determined using the grimace test.– It was noted that when the observer, seated ~0.5 m away)

was male, there was a significant decrease in facial grimacing relative to no observer

– This effect was not noticed with a female observer– The effect was short-lived. Within 30 minutes, the rodent

had habituated to the presence.– It is a result of “Stress-Induced Analgesia” – It calls into question studies in which a male technician

was used to determine pain or stress levels in rodents.

Stress vs Distress (Dr. Moberg)Normal Function

Altered biological function

Pre-pathological state

Pathology

Stimulus

Stimulus

Stimulus

Relief from stimulus Stress

Distress

Stress vs Distress, An ExampleNormal Function

Altered biological function

Pre-pathological state

Pathology

Stimulus

Stimulus

Stimulus

StressSAMS

↑ NE and EpiHPA

↑ ACTH and GC

Winning male

Male mice fighting

DistressSubordinate male repeatedly attacked

Inability to Cope

• Breakpoint stress—no longer able to respond or adapt to stress

• Affected by– Severity– Predictability– Duration– Interval

Breakpoint Stress

• Indicators– Change in weight or body condition– Change in organ weight and size

• Hypertrophy: • Hypotrophy:

– Suppressed reproduction– Gastric ulceration– Self-mutilation– Suppressed immune function disease

Individual Response

• Same conditions don’t lead to same response in all animals.

• Don’t rely on a single indicator to identify stress.

• Always get baseline levels

• Not all stress is bad.

Control of Variables

• Housing

• Nutrition

• Health

• Genetics

Positives of Enrichment

Negatives of Enrichment

Sources of Enrichment• Positive human interaction

• Interaction with conspecifics

Mouse Enrichment

Rat Enrichment

Rabbit Enrichment