Metabolic and Digestive Strategies in Rodents Under Food Restriction: Insights for Adaptation to Arid Environments

Arid environments characterized by rising temperatures, reduced precipitation and increasing food scarcity, significantly challenge ecosystems and species worldwide. This study investigates the bioenergetic and digestive adaptations of three rodent species—field voles (herbivorous), white mice (omnivorous), and desert-adapted spiny mice (omnivorous)—under conditions of ad libitum feeding and 50% food restriction. These species were not selected for their direct economic value but serve as valuable biological models for understanding mammalian adaptation to nutritional stress. Such insights can inform strategies to enhance the resilience of livestock and other species in arid and resource-limited environments. Feed restriction resulted in notable body mass reductions across all species: 26.0% in voles (p < 0.01), 33.0% in white mice (p < 0.01), and 22.0% in spiny mice (p < 0.01). Feed restriction did not significantly impact oxygen consumption in social voles and white mice, but spiny mice experienced a 36% reduction (p < 0.01). Upon transitioning to food restriction, the mean retention time increased in voles by 48% (p < 0.05) compared to the control group. A similar trend was observed in white mice, with an increase of 21% (p < 0.05) due to food restriction. The highest increase under food restriction was recorded in common desert spiny mice, which exhibited an increase of about 56% (p < 0.05). Significant differences were observed in digestive system morphology. Voles exhibited reductions in digestive tract length (17.9%, p < 0.05), while white mice demonstrated a 22.13% decrease in tract length (p < 0.05). In contrast, desert-adapted spiny mice showed no significant change, highlighting their superior efficiency in resource utilization under scarcity. These findings emphasize the role of physiological adaptations in desert rodents, such as adjustments in metabolic rates and expansion of the digestive system, as key mechanisms for survival during food shortages. These adaptations contrast sharply with the responses of non-desert rodents, providing insights into species resilience in extreme environments. Furthermore, the study underscores the importance of desert rodents as model organisms for understanding adaptation strategies relevant to livestock systems in arid regions. The results suggest avenues for future research, including the exploration of metabolic modulation and digestive efficiency in other species. Such studies could inform sustainable agricultural practices in the face of ongoing ecological stress. Key words: Resource scarcity, digestive system, adaptation, rodents, Climate change