Novel insights into heat tolerance: the impact of dwarf and frizzled feather traits on crossbreed chicken performance under thermal stress

Abstract

Heat stress (HS) poses significant challenges to broiler production, negatively influencing growth performance and meat quality. This study explores the resilience and the meat quality of hybrid chickens with dwarf size and frizzled feather traits to HS. We investigated F1 progeny derived from a crossbreed of dwarf yellow chickens (DYCs) with Yuexi frizzled feather chickens. Following a rearing period of 12 weeks, we randomly assigned 72 chickens into two distinct environmental conditions: a HS group subjected to 35 ± 1 °C for 8 h per day, and a control group (CN) maintained at 26 ± 1 °C. Seven days post-HS, multiple tissue samples were collected to assess meat quality attributes and measure expression levels of heat shock proteins (HSPs), muscle growth-related genes and cytokines. The results demonstrated a substantial reduction in weight gain of the F1 chickens exposed to HS, along with decreased expression of insulin-like growth factor-1 (IGF-1) and its receptor (IGF-1R) in the liver. Furthermore, HS exposure significantly increased muscle shear force and the expression of HSP70 in both liver and pectoral muscle tissues (p < .05). Despite these changes, there were no significant alterations in the other meat quality indices, or indicators of splenic and hepatic tissue injury. Likewise, expression levels of growth hormone receptor (GHR) and cytokines remained stable, implying a lack of heightened inflammation. These observations suggest an inherent thermotolerance in the chickens possessing dwarf size and frizzled feather traits, warranting further exploration for their potential in heat-stress-prone poultry production environments. Highlights Dwarf and frizzled feather traits in crossbreed chickens show potential for improved heat tolerance in poultry production. Heat stress had limited impact on meat quality parameters, suggesting resilience of these local chicken traits. Understanding the genetic basis of thermotolerance can inform breeding strategies for climate-resilient chickens.