Abstract

In previous work, one mouse line was selected for resistance to fescue toxicosis (R) and a second line was selected for susceptibility (S). Post-weaning growth of R mice was less severely depressed by a toxic fescue-containing diet than was growth of S mice. The current experiment was conducted to determine whether long term reproduction of mice on a toxin- containing (+) versus non-toxic (-) diet was more severely depressed in S than in R mice. Twenty-eight mating pairs per line x diet combination were cohabited continuously for 36 weeks. Percentage changes in reproductive traits of mice on the toxin-containing diet, for R and S pairs respectively, were -11 and -28 for total number of offspring bom, -7 and -24 for total number of offspring weaned, -11 and -13 for total number of litters produced per pair, -29 and-41 for grams of offspring weaned, and +1 and -1 for pup survival percentage to weaning. Selected lines differed in adaptation to the toxic diet as measured by its effect on several components of long term reproduction.

C. R Wagner, W. D Hohenboken

Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume 27: Reproduction; fish breeding; genetics and the environment; genetics in agricultural systems; disease resistance; animal welf, , 307–310, 1998