Nutritional strategies to mitigate broiler breast myopathies

Woody breast (WB) and white striping (WS) in broiler breast meat are emerging issues in the poultry industry worldwide. These conditions are associated with high breast yielding, heavy broilers, and they have negative quality impacts and major economic implications. Nutritional strategies have been studied by researchers in efforts to reduce the prevalence of WB in broilers, without negative impacts on live performance. Dietary inclusion of guanidinoacetic acid (GAA) has been evaluated as a nutritional intervention to reduce the incidence of myopathies. Recent studies have shown that that GAA (0.06% or 0.12% GAA supplementation in diet) had no impact on live weight at processing and no negative impact on FCR compared to the control diet at 55d (P< 0.05). Supplementation of 0.12% GAA reduced (P< 0.05) WB compared to control and supplementation of either 0.06% or 0.12% GAA reduced WS severity compared to control. In a secondary study, GAA (0.08%) was supplemented in diets with reduced energy (control diet less 25 or 50 kcal/kg). At day of processing, no differences (P> 0.05) were noted in final live weight due to energy reduction or GAA supplementation. In addition, no differences (P> 0.05) were noted in breast yield. There were also no statistical differences in frequency of WB severity (P> 0.05). Results of these studies suggest that GAA may reduce myopathies such as woody breast without negatively affecting live performance, but the level of inclusion is important. The inclusion rate should be optimized for effective reduction of myopathies.

Keywords: poultry, myopathy, guanidinoacetic acid, meat quality, broiler.