The Effects of Common Square Meal vs. Advanced Nutrition Diet on Mean Wheel Revolutions in House Mice
I tested whether house mice (Mus musculus) exhibited more wheel revolutions on diets of common square meal or Advanced Nutrition Diet meal. There was no difference in mean wheel revolutions between the females fed common square meal and the females fed Advanced Nutrition Diet meal. There was also no difference in mean wheel revolutions between the male groups fed the differing diets of common square meal or Advanced Nutrition Diet meal.
Keywords: Mus musculus, mean wheel revolutions, square meal, Advanced Nutrition Diet meal
“Wheel running, at the genetic level, is a largely independent axis of behavior” (Pawel et al. 1999). Another factor that can influence the amount of activity is the time of day, which affects the responses of mice in relation to their phases of active behavior (Sherwin and Nicol 1997).
Many scientists have debated whether mice complete more wheel revolutions just prior to being fed or when being deprived from food and water for specific periods of time (Sherwin 1998). In addition, the variances in sex, time of day, and presence of food might have, whether individually or collectively, had an affect on the wheel running outcomes.
This experiment was designed to test whether house mice completed more wheel revolutions after being fed common square meal or Advanced Nutrition Diet meal. If the mice fed Advanced Nutrition Diet meal complete more wheel revolutions than the mice fed common square meal, then my hypothesis would be supported. If the mice fed common square meal complete more wheel revolutions, then my hypothesis would be falsified.
On February 18, 2002, house mice (8 total) were randomly chosen to become part of the common square meal group or the Advanced Nutrition Diet meal group. Each type of food was purchased at Pet World, in Milwaukee, Wisconsin. Both the square meal and the Advanced Nutrition Diet meal (made by 8 in 1 Pro) contained common, basic ingredients of ground wheat, wheat middlings, soybean meal, ground corn, meat and bone meal, dried yeast, fish meal, and corn gelatin meal. However, in comparison, there were five major differences between the two types of food. The Advanced Nutrition Diet meal contained beet pulp (a source of vitamin), higher amounts of ground oats, cheddar cheese powder, 2% more fiber, and slightly higher amounts of vitamins or vitamin supplements.
Each test group was composed of 2 females and 2 males; I made sure that each test group had approximately 23 grams of test group-specific meal each day. Both types of food had been autoclaved 2 days prior to being given to the mice and then weighed on an Ohaus electronic balance. Food mass was measured every two days and necessary food, in addition to water, was added when needed. The cages were cleaned very Friday and water was added as needed to their cages. The mice were allowed one week (Feb. 18-22) to adjust to the food types.
On February 25, 2002, actual wheel testing began and continued through 20 March 2002. The tests were randomly run between the hours of 8:00a.m. and 7:30p.m. Each mouse only completed one wheel test per day; each test was timed for 3 minutes by an Armitron stopwatch. The timing began immediately after each mouse was placed into the wheel. Two self-counting wheels that the lab provided were used, one for the males and one for females. The metal running wheels contained an area of .21 square meters. At the end of each time segment, total wheel revolutions were tallied. On the final day of testing the mice were weighed on an Ohaus electric balance to determine their final masses. I analyzed the data by determining the means, standard deviations, and P-values from T-tests on Microsoft Excel.
There was no difference in mean wheel revolutions between the females fed common square meal (Mean =20.17, Standard deviation =14.87) and the females fed Advanced Nutrition Diet meal (Mean =23.0, Standard deviation =8.15). There was also no difference in mean wheel revolutions between the male groups fed different diets; the common square meal group (Mean =64.04, Standard deviation =28.44) did not exhibit more mean revolutions than the Advanced Nutrition Diet group (Mean =49.54, Standard deviation =33.33).
When the total female and male
values were compared in a T-test, the females had a P-value of 0.3758 and the
males a value of 0.3402. In comparison,
neither P-value depicted a significant value.
However, this might have been due to a smaller sample size than would be
present in a larger experiment. The
effects of differing food types may be present in my experiment, but just not
detectable. At the conclusion of this
experiment, the average mass of the female house mice was 27.5 grams. The average mass of the male house mice was
Fig. 1. The effects of common square meal vs. Advanced Nutrition Diet meal on mean wheel revolutions per 3-minute trials in each test group. Reg. Food Female =common square meal for female test group, Reg. Food Male =common square meal for male test group, Exp. Food Female =Advanced Nutrition Diet meal for female test group, Exp. Food Male =Advanced Nutrition Diet meal for male test group.
House mice in this experiment ate regularly and completed at least 6 revolutions per trial. However, the mice did show a difference in the amount of mean wheel revolutions per sex-test group. The males fed the common square meal had the highest mean of 64.04 wheel revolutions. The lowest mean, 20.17, was present in the female group fed the common square meal. These results might suggest that the stimulation or action of wheel running may differ between sexes (Pawel et al. 1999). Between the individual groups, there was no difference in mean wheel revolutions between the females fed common square meal and the females fed Advanced Nutrition Diet meal. There was also no difference in mean wheel revolutions between the male groups fed different diets.
In reference to my findings, my hypothesis was falsified. The males fed differing diets did not show a significant difference. There was also no evidence to support my hypothesis in relation to the females fed differing diet meals. In another experiment with a much larger sample size, there might be a chance that a specific type of food affects the total wheel revolutions that mice complete, however my experiment does not show this. There were also chances that my data could have been affected during my experiment.
During my experiment unknown outside sources would constantly add food to my test subjects’ dishes. The food, which was often the wrong kind in relation to the Advanced Nutrition Diet meal, was added in extreme/unequal amounts that could have affected the amount(s) and type(s) of food ingested. In reference to the differing diets that the mice were fed, the main elements in each type of food might have influenced their eating behaviors and/or their activity levels. The constant presence of food and water could also have had an affect on the mice and their overall performance.
In a controlled laboratory setting, it is important to separate the differences between the average feeding behaviors of the mice and the distinctions in individual feeding behaviors of each mouse (Georgios et al. 2000). At the conclusion of this study, not all the mice weighed the same. Therefore, a slight increase or decrease of 2-3 grams might have affected the total number of wheel revolutions the mice completed.
Another aspect that could have influenced my data was the death of a male mouse on the common square meal diet regime. I had to substitute the mouse with another mouse, which was older and larger in size. Since he was added at a later date, he was therefore one day behind in the testing schedule and had to be run during an extra testing day. This change in test subjects and the unauthorized addition of food to test subjects could have affected my data enough to possibly alter the final outcomes.
Pawel, K., T. Garland, J. Sax, J. Swallow, and P. Carter. 1999. Behaviour of house mice artificially selected for high levels of voluntary wheel running. Animal Behaviour, 58:1307-1318.
Sherwin, C., M. and Nicol, C., J. 1997. Behavioural demand functions of caged laboratory mice for additional space. Animal Behaviour, 53:67-74.
Georgis, A., G. Emmans, I. Kyriazakis. 2000. Variation between individuals and the consequences of diet selection by groups of animals. Animal Behaviour, 60:811-820.
Sherwin, C., M. 1998. Voluntary wheel running: a review and novel interpretation. Animal Behaviour, 56:11-27.