GENOTYPE BY DIET INTERACTION IN MICE SELECTED ON THREE DIETARY REGIMENS
The effect on 10-wk body weight of seven generations of selection in three nutritional regimens (corn, rye and wheat) for two growth related traits, adjusted body weight (ABW) or adjusted feed efficiency (AFE) was evaluated. Selected mice were 3.2 g heavier (P < 0.01) than mice from the diet control (DC) lines. No effects of selection regimen or differences between the two selected lines for 10-wk weight were significant (P > 0.05). During generation 8 a crossover study was undertaken. Mice from each line (ABW, AFE or DC) from each selection regimen were fed the corn, rye and wheat diets. Response was estimated as a deviation from the DC line fed the same diet. No significant (P > 0.05) regimen by diet interactions were detected in either the ABW or the AFE lines. However, mice in the ABW line tended (P = 0.18) to have higher final weights on test (approximately 1 g) when fed the selection diet compared to the two alternative diets. Key words: Mice, genotype by diet interaction, body weight, feed efficiency