Lecture 5: Physiological indicators of animal welfare
1. Homeostasis is crucial for animal welfare, influenced by environment, handling, health, and other factors. Disruption of homeostasis activates physiological responses in the central nervous system (CNS), including the autonomic nervous system (ANS) and neuroendocrine system.
2. Stress occurs when animals perceive a threat to their homeostasis, leading to two types:
- Acute stress: short-term stress.
- Chronic stress: long-term stress, which can lead to distress when the animal can no longer return to homeostasis.
3. Animals cope with stress through:
- Behavioral responses (e.g., avoidance).
- ANS responses: Sympathetic activation results in a fight-or-flight response, while prolonged activation can lead to death.
- Neuroendocrine responses: The hypothalamic-pituitary-adrenal (HPA) axis is activated, causing cortisol release, which has long-term effects on metabolism, reproduction, and immunity.
- Immune suppression due to prolonged stress, leading to a burden on the animal’s body.
4. The General Adaptation Syndrome (GAS) describes three stages of stress:
- Alarm: fight-or-flight response.
- Resistance: recovery with the body still on high alert.
- Exhaustion: depletion of the body’s resources due to chronic stress.
5. Physiological indicators of welfare include heart rate, respiratory frequency, body temperature, blood count, glucocorticoids, adrenal volume, acute-phase proteins, blood lactate, and oxytocin levels.
6. These indicators, however, are not perfect due to individual variability, human error, and the lack of optimal parameters for every species, so they should be used alongside behavioral indicators.
Lecture 6: Assessing Animal Welfare
Animal Welfare Application:
Codes of Practices: Set by public agencies or professional associations to ensure ethical treatment of animals. It includes transportation practices, animal care commitment, facilities, handling, nutrition, health management, euthanasia, and neglect prevention.
Criteria Evaluation:
Clinical records (diseases, diagnosis)
Physiological parameters (hormones, heart, respiratory rates)
Behavioral records
Production system (facilities, equipment, interactions)
Domains Model: Evaluates welfare in five categories – nutrition, environment, health, behavior, and mental state.
Resource-Based Measures:
- Nutrition: Food availability, quality, cleanliness of feeders, etc.
- Environment: Access to outdoor spaces, stall conditions, hygiene, animal density, etc.
- Management: Handling methods, castration, dehorning, mortality, morbidity, etc.
Animal-Based Measures:
- Behavioral: Normal and abnormal behaviors (stereotypy, environment-directed, self-directed).
- Human-Animal Interaction Indicators: Flight distance, voluntary approach tests, milking reactivity, flight speed.
- Physiological: Body temperature, blood lactate levels, oxytocin levels, immunosuppression.
- Health: Clinical signs (discharge, coughing), integument alterations (hairless patches, lesions).
- Performance: Milk production, weight gain, sports, and reproduction performance.
Steps in Assessing Animal Welfare:
1. What should be evaluated?: Define objectives and hypotheses.
2. What is important for the animal?: Understand species biology and welfare needs.
3. Methods: Decide indicators, evaluation tools, timing, and personnel for assessment.
4. Data Collection: Observations, laboratory tests, and facility evaluations.
5. Data Analysis: Analyze quantitative data for animal states.
6. Balance of Welfare Conditions: Analyze positive and negative welfare experiences.
7. Defining Welfare Status: Establish minimum standards and balance variables.
8. Decisions on Results: Objectively define the welfare condition (good or poor).
Lecture 7: Observing and Measuring Animal Welfare
1. Steps in Studying Behavior
Question Definition: Begin by clearly defining a problem based on curiosity, previous knowledge, or specific objectives (e.g., “Why is the hen without feathers?”). This is not a hypothesis but the foundation for formulating hypotheses and predictions.
Preliminary Observations: Used to understand the subject's behavior before collecting hard data. They allow for the refinement of questions, hypotheses, and methods.
2. Choosing Behavioral Categories and Variables
Behavior Categories: It's essential to divide behavior into distinct categories (e.g., feeding, walking) to allow for precise measurement. This can be done based on:
Structure
Consequences
Spatial relations
Ethogram: A catalog describing the species-typical behaviors.
Clear Definitions: Behavioral categories must be clear, comprehensive, and unambiguous to ensure reliable results.
3. Types of Measures
Events: Behaviors of short duration, like a blink or a smell.
States: Behaviors with longer duration, such as sleeping or eating.
Variables: Measures include frequency, duration, latency, intensity, and velocity. For example, the frequency of piglet vocalization or the time a calf takes to touch its mother.
Measurement Scales:
Nominal: Categorical data (e.g., male/female).
Ordinal: Rank order of data.
Interval: Numeric data with meaningful intervals
Ratio: Numeric data with a true zero, like time or duration.
4. Sampling Rules
Ad Libitum: Observing and recording everything visible without constraints.
Focal Sampling: Observing one individual for a set period and recording all behaviors.
Scan Sampling: Scanning a group at regular intervals and recording behaviors at that specific time.
Behavior Sampling: Recording specific behavior occurrences across a group.
5. Recording Rules
Continuous Recording: Capturing every instance of behavior for accuracy.
Time Sampling: Dividing observations into intervals, such as:
Instantaneous Sampling (noting behaviors at a specific moment)
One-Zero Sampling (noting whether behavior occurred in the last interval)
6. Hypotheses and Predictions
Hypotheses: Formulated to explain the defined question:
"Why is the hen suffering from feather pecking?”
The hen is suffering from feather pecking because…
- Predictions: Specific expectations derived from the hypothesis (e.g., "Hens with insufficient space show more feather pecking").
7. Testing Methods for Reliability and Validity
- Test recording methods for inter- and intra-observer reliability. Drop unreliable categories and refine methods as needed.
Lecture 8: Animal Ethics
Importance of Observing Animal Behavior
Observation: A scientific method to collect data and evaluate animal behavior. This process begins with preliminary observations, followed by categorization of behaviors and developing a hypothesis.
Why Observe?: Understanding behavior helps answer specific research questions. Observing behaviors can either be direct (in real-time) or indirect (using equipment or observing consequences of behaviors).
Developing a Research Method
Research Process: Start with a broad question, refine it with preliminary observations, formulate hypotheses, and make predictions. For example, to understand why a hen lacks feathers, one might hypothesize feather pecking, and then observe specific behaviors.
Preliminary Observations: These are crucial for understanding the subjects, forming reliable questions, and training the observer.
Defining and Categorizing Behavior
Behavior Categories: Should be clear, comprehensive, and unambiguous. Behavior can be classified into:
States: Long-duration behaviors like eating or resting.
Events: Short-duration behaviors like blinking or vocalizing.
Structure: How the behavior looks (e.g., "pressing a switch").
Consequence: The outcome of the behavior (e.g., "turning on a light").
Spatial Relations: Emphasis on where the subject is relative to other objects (e.g., "approaching the feeder").
Ethograms
Ethogram: A catalog of behavior patterns typical to a species. Ethograms are helpful but can vary in detail. Not all animals in a species behave the same way, but it is a guide for identifying behaviors.
Types of Measures
Nominal Scale: Assign names to categories (e.g., male/female, awake/sleeping).
Ordinal Scale: Rank behaviors in order of occurrence.
Interval Scale: Quantify the difference between behaviors.
Ratio Scale: Assign values with a true zero point (e.g., time spent eating).
Variables:
Frequency: How often a behavior occurs.
Duration: How long the behavior lasts.
Latency: Time between a stimulus and the behavior.
Intensity: Strength or force of the behavior.
Velocity: Speed of the behavior.
Sampling and Recording Rules
Sampling Rules:
Ad Libitum Sampling: Observing whatever is visible.
Focal Sampling: Observing one individual for a set period.
Scan Sampling: Observing a group at regular intervals.
Behavior Sampling: Recording a specific behavior whenever it occurs.
Recording Rules:
Continuous Recording: Capturing every occurrence of the behavior.
Time Sampling: Dividing the observation into intervals and recording whether behaviors occur within those periods (Instantaneous or One-Zero sampling).
Testing the Methodology
Reliability and Validity: The methods chosen should be reliable (consistent results) and valid (measure what they are intended to measure). Categories should be tested and refined to ensure data accuracy.