Effect of Temperature Stress on Growth, Reproduction, and Adrenocortical Function of Mice

Performance of mouse lines divergently selected for heat loss when exposed to different environmental temperatures. I. Reproductive performance, pup survival, and metabolic hormones1

“…Similar conception rates between different environmental temperatures are therefore contradictory to the findings of Barnett and Manly (1956) and Wettemann et al (1976), who obtained significantly lower conception rates as a result of either cold or heat exposure. The results are, however, consistent with the findings of Wilson et al (1972), who reported no significant differences in conception rate among the cold (12°C), normal (21°C), and hot (30°C) environments (84, 88, and 83% conception rates, respectively) in a four-way composite strain of mice. Similar conception rates between the three environmental temperatures may also be indicative of the high fertility and adaptive capabilities of this particular strain of mice to cold and heat stress.…”

“…The above findings are consistent with those reported by Biggers et al (1958), who observed that growth of mice in the cold environment (5°C) was more depressed than in the hot environment and also noted very small and nonsignificant differences between mice in the hot (28°C) and temperate (21°C) environments. Wilson et al (1972) reported 3-wk body weights of 9.49, 12.07, and 12.14 g in a four-way composite strain of mice in the cold (12°C), normal (21°C), and hot (30°C) environments, respectively, also confirming more depressed growth in the cold than in the hot environment.…”

“…Preweaning mortality rate (dead pups per litter) in the C57BL and GFF strains at −3°C was 3.1 and 2.8, respectively, compared with 2.2 and 0.9, respectively, at 21°C. Wilson et al (1972) reported a higher preweaning mortality in the cold (12°C) than in the normal (21°C) and hot (30°C) environments in two composite strains of mice and attributed the higher mortality in the cold environment to mortality of whole litters rather than consistently high mortality within litters. Barnett (1965) pointed out that one of the adverse effects of cold on female reproduction might be the death of young, hairless pups, especially in the first few days after birth.…”

“…Barnett and Manly (1956) reported slight reductions in litter size in the C57BL and GFF strains as a result of cold exposure (−3°C) and no effect on litter size in the A strain. Wilson et al (1972) reported litter sizes of 7.94, 7.74, and 8.12 in one four-way composite strain of mice, and litter sizes of 8. 55, 8.34, and 8.04 in another four-way composite strain in cold (12°C), normal (21°C), and hot (30°C) environments, respectively.…”

Population Genetics

“…For example, ambient temperature affects tail length in mice, animals grown in higher temperatures having longer tails (Wilson et al 1972). Some understanding of the nature of this noise is necessary, however, if only to avoid or combat its effects.…”