Interpretive Summary: Association of residual feed intake with growth performance, carcass traits, meat quality, and blood variables in native chickens
By: Anne Wallace
Finding ways to improve feed efficiency in chickens is crucial to maintaining sustainable and economically viable poultry systems. Feed efficiency is in general determined from the growth of an animal based on their feed intake. One common way to determine feed efficiency is through calculation of residual feed intake (RFI).
In this July 2020 Journal of Animal Science study, researchers evaluated phenotypic relationships with RFI in native Wannan Yellow chickens. Their goal was to find measurable physiological markers such as growth performance, carcass traits, meat quality, or blood markers (hormone, metabolic, and enzymatic) to see if such markers could be used to select for RFI.
Chickens were separated into three groups based on RFI: low, medium and high RFI. There was a positive correlation of RFI with feed conversion ratio (FCR), abdominal fat yield, average daily feed intake (ADFI) and blood levels of T3, LDL-C and cortisol. Plasma insulin-like growth factor 1 (IGF-1) was consistently higher in the low RFI group and lower in the medium and high RFI groups.
Overall, this study confirms that there are measurable ways to select chickens for RFI based on phenotype, specifically though measured blood levels of IGF-1, T3, cortisol and LDL-C. More studies that further elaborate on these findings and evaluate how these blood factors impact feed efficiency are potential areas of future study.