STUDY 1 - BODY CONDITION SCORING
OBJECTIVES
- To evaluate overall animal health condition
- To ensure positive effects and system efficiency
SCORING
5: Obese; bones cannot be felt at all
4: Well-fleshed; bones barely felt
3: Optimal; bones palpable but not prominent
2: Thinner; bones prominent
1: Advanced muscle wasting; fats gone; bones very prominent
APPLICATION TO ML 1
Used for submissions
Objective
To assess the benefits of ML system through regular exercise to the hamsters
Hypotheses
H1 = Hamsters playing ML (exercising) will not have a change in BCS
H2 = Hamsters playing ML (exercising) will have a BCS closer to 3 after the 6th week
Subjects
- 20 Phodopus roborovskii hamsters aged 1-2 years
- Viral antibody and parasite free
Procedures
- 1st and 6th Week: Hamsters’ BCS were taken by 3 observers and the mean was taken
- Assessment: Hamster is placed on a flat surface. Exception for roborovskis which need to be caught .
- Scoring of flesh and fat at the sacroiliac area (back and pelvic area)
Sacroiliac Area of roborovski Hamster
BCS Assessment on Hamster
Controls
- For 6 weeks, food amount are monitored. Food consumption: 10% of hamster weight = 10-15g (inclusive of food used during training)
- Cages in room with controlled lighting and optimal temperature and humidity
- Hamsters play ML for 1 hour each on every weekday. Usual training can lasts a maximum of 15 minutes per hamster.
Graph: Result of BCS Observation on the 20 Hamsters
Statistical Analysis and Conclusions
Using Wilcoxon signed-rank test for paired data (normal distribution: more than 15 samples)
For Hypotheses 1,
Test statistic: z = -3.8, p = 0.0006
Hypotheses was rejected.
ML was found to be able to change the BCS of the subject hamsters over the study period.
For Hypotheses 2,
Test statistic: z = -1.4, p = 0.16
Hypotheses is accepted.
After 6 weeks of playing ML, the hamsters' body condition tends to optimal score.
APPLICATION TO ML 2
Objective
Further experiments are carried out to determine whether BCS assessment on roborovski hamster has an impact on their training results and behavior.
Hypothesis
H1 = There is no difference between Meena's median change in BCS and that of Nora's
Subjects
Meena and Nora
Procedures
- BCS was measured daily for 2 weeks (excluding Sunday).
- Scoring: degree of flesh and fat covered
- Experimental: Meena; She was allowed to play ML for 15 minutes each on every weekday in that period
- Control: Nora; She was not allowed to play ML
Graph: Result of BCS Observation on Meena and Nora
Statistical Analysis
Using Wilcoxon rank-sum test for independent samples (normal approximation version as n ≥10)
Test statistic: 4.503
Hypothesis rejected.
Conclusion
There is a difference in BCS between Meena and Nora.
Problems
Before we can conclude that ML actually has a positive effect on Meena's health and body condition, we need to consider a few points.
- Roborovskis are frightened of being chased and grabbed → misleading results
- Meena's BCS assessment was done inside the tank. She runs around in vain to escape from being caught. This stresses her and makes her exert energy as well. Hence a drop of BCS from 4 to 3 and a difference of BCS from Nora's (4 or 5 score).
- Her training result was disrupted - she lost interest in chasing the attractor and instead tries to escape from the tank. To her, the tank = being chased, caught and examined.
- Positive reinforcement (food) was not effective on her and negative reinforcement (knocking) had to be done to make her chase the attractor. This has a negative impact on her and would be against the Duncan method (hamsters are supposed to like choosing to play the game and enjoy it).
- Her behavior also changes - runs a lot on the wheel, climbs throughout her cage
NEXT EXPERIMENT
1.) Assess Meena's and J's BCS in a separate location (i.e. a box) twice a week
- To avoid confusion and stress on them in the tank
- To avoid disrupting training results which are at satisfactory level now
2.) Get a different hamster breed (Winter Whites) which are friendly and can be touched/held
