Meat quality of heat stress exposed broilers and effect of protein and vitamin E

Abstract

1. This study was designed to determine the effects of heat stress exposure on broiler fattening performance, meat quality and microbial counts.

2. Six groups were established: CHP (24°C + 210 g/kg crude protein (CP)), SHP (34°C + 210 g/kg CP), CLP (24°C + 190 g/kg CP), SLP (34°C + 190 g/kg CP), SHPVE (34°C + 210 g/kg CP + Vitamin E) and SLPVE (34°C + 190 g/kg CP + Vitamin E) groups.

3. It was determined that the body weights of the male animals included in Group CHP displayed statistically significant differences in comparison to those of Groups SHP, CLP and SLP. Furthermore, it was ascertained that the values of Group CLP also displayed statistically significant differences in comparison to those of Groups CHP, SHP and SLP. The feed consumptions in Groups CHP and CLP were significantly different from those of the remaining groups, excluding Group SHP. The highest feed conversion rate was determined in Group SHPVE.

4. When evaluated for chicken drumstick TBA values, Group CHP differed significantly from Groups SHP, SHPVE, CLP and SLP, whilst Group CLP differed significantly from Groups SHP, SHPVE and SLP. On the other hand, when evaluated for breast meat TBA values, Group CHP displayed statistically significant differences in comparison to Groups SHP, SLP and SLPVE, whilst Group CLP differed significantly from Groups CHP, SHP, SLP and SLPVE.

5. The sensitivity of breast meat to colour susceptibility was greater than that of chicken drumsticks. While storage period affected the TBA values and microbial counts of meat significantly, its effect on colour parameters was found to be variable. Trial groups significantly affected total aerobic mesophilic bacteria counts in chicken drumsticks, and Enterobacteriaceae and total aerobic mesophilic bacteria counts in breast meat.

6. In conclusion, heat stress adversely affected final body weights and the lipid oxidation of meat, whilst vitamin E alleviated these adverse effects.

Acknowledgements

The authors would like to thank Ataturk University for financially supporting this study (BAP 2007/184).