# Fatty acid composition of multigenerational heat stressed adult Japanese quail (Coturnix coturnix japonica)

## TL;DR

This study examines how heat stress and selective breeding affect fatty acid composition in Japanese quail, focusing on differences in various organs.

## Contribution

The study investigates fatty acid composition in heat-stressed quail selectively bred for high fitness, a previously unexplored area.

## Key findings

- Quail livers showed the most variation in fatty acid concentrations under different treatments.
- TN and TNS quail had higher levels of long-chain PUFA and lower saturated fatty acids compared to HS and HSS quail.
- Selective breeding for low FCR in heat stress did not lead to significant fatty acid differences compared to random-bred quail.

## Abstract

As above average heat events are rising across the globe, it is imperative to understand the effects of heat stress on lipids of poultry species. The fatty acid composition of various organs of quail selectively bred for high fitness in heat stress has not been previously investigated. Therefore, this study treated 10 generations of quails with the following (1) random-bred in a thermoneutral temperature (22°C, TN), (2) random-bred in heat stress (31°C, HS), (3) selected for low feed conversion ratio (FCR) in heat stress and not exposed to heat stress (22°C, TNS), and (4) selected for low FCR in heat stress, then exposed to heat stress (31°C, HSS). Fatty acid composition was analyzed in feed, brain, liver, kidneys, and thighs of quail from the 10th generation. It was hypothesized that HS and HSS would have less polyunsaturated fatty acids (PUFA) in all organs due to oxidation and HS would have lower ratios of SFA:PUFA and n-6:n-3 compared to those that were not selectively bred. Data were analyzed using treatment, tissue, and their interaction as the main effects. Significance was determined at P ≤ 0.05. Results showed that of all organs analyzed, livers experienced the most variations in concentrations of fatty acids when compared by treatment. TN brains had less PUFA than that in both TNS and HSS. TN or TNS had more long chain PUFA and less saturated fatty acids than that in HS or HSS across all tissues. Thus, it can be concluded that selection for low FCR in heat stress may reduce oxidation of PUFA or increase retention of PUFA in the brain. However, overall, selectively breeding for low FCR in heat stress did not result in fatty acid differences compared to those that were random-bred in heat stress.