UTILIZATION OF DIETARY ENERGY IN THE RAT .4. MULTIFACTORIAL INHERITANCE MODULATED BY GENDER

In Wister rats the conversion indexes (CIs) are normally distributed, A conversion index is the amount of food consumed necessary to increas e the body weight by 1 g in a 32-day period, which begins at weaning ( day 21) and ends on the 52nd day of life of the rat. Some experiments have been designed trying to demonstrate that inheritance of energy di etary utilization in Wistar rats may be multifactorial modulated by ge nder, In the study presented here parental males (F1) with CIs below t he male median were paired with females of the same F1 who also had CI s below the female median, It was postulated, if the hypothesis is cor rect, that the offspring (F2) obtained from these pairings would have conversion indexes below the median of the CIs of the parental rats (F 1), The results indicate precisely that both males and females behave as expected, Thus it appears that inheritance of efficiency of dietary energy utilization in the Wistar rat is a multifactorial trait.