Central regulation of drinking water in divergently selected high-water-efficient young broiler chickens: A minireview.

Poultry production is confronting real challenges, including a lofty projected high demand for animal proteins to feed the future, and the need to adapt to planetary boundaries (global warming) with limited natural resources (land, energy, water). Among the most challenging stressors to poultry production sustainability are heat stress (HS) and water uncertainty, that need extensive fundamental and applied research to identify effective strategies. In that regard, our group has recently developed a high-water-efficient broiler (meat-type) chicken line using water conversion ratio (WCR) as a phenotypic trait and defined the hypothalamic molecular mechanisms controlling drinking water under heat stress conditions. In response to the invitation from the Organizing Committee of the 13th International Symposium on Avian Endocrinology (ISAE 2024), the present review summarizes these data and closes the chapter by asking questions for future investigations. Data showed that HS exposure increased core body temperature (CBT) of both lines, with higher degree in HWE than in LWE counterparts. Despite this increase in CBT, HWE line drank less water but had superior performance with better feed conversion ratio (FCR) and WCR than LWE line. Molecular analyses showed that hypothalamic drinking-related neuropeptides (arginine vasopressin system, aquaporin system, renin, and angiotensin system) are affected in line- and/or environmental-dependent manner. Together, our research outcome indicates that the divergent selection for water efficiency could be an effective strategy to preserve water while maintaining optimal growth performance and could be applied to other poultry species and livestock.