05 16 2007



  • To evaluate overall animal health condition
  • To ensure positive effects and system efficiency


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


Used for submissions


To assess the benefits of ML system through regular exercise to the hamsters


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


  • 20 Phodopus roborovskii hamsters aged 1-2 years
  • Viral antibody and parasite free


  • 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


  • 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.



Further experiments are carried out to determine whether BCS assessment on roborovski hamster has an impact on their training results and behavior.


H1 = There is no difference between Meena's median change in BCS and that of Nora's


Meena and Nora


  • 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.


There is a difference in BCS between Meena and Nora.


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


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

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-Share Alike 2.5 License.