Effects of acetylated wood powder on growth performance, hepatic and muscular free amino acid profiles, and inosine 5'-monophosphate concentration of breast meat in broiler chickens.

The present study was conducted to determine the effects of acetylated wood powder (AW) as a new feed additive on performance, liver and muscle metabolism of amino acids and fatty acids and nucleotide-related substances of meat in broiler chickens. It was hypothesised that acetic acid desorbed from AW during intestinal digestion affects tissue metabolism. Two-week-old broiler chicks were divided into four groups and fed on diets supplemented with wood powder (30 g/kg) less than 106 µm in diameter, except for controls. The AW was added to diets at 0, 10 and 30 g/kg to replace the non-acetylated wood powder (NAW) for 26 d. Plasma, liver tissue and breast muscle were taken from half of birds at 40 d of age under the fed condition. After the remaining chickens were fasted for 14 h, breast muscle was taken and refrigerated for 24 h. Consumption of wood powder with or without acetyl groups had no effect on growth performance including tissue weights of abdominal fat and breast muscle and plasma metabolites. Feeding AW decreased total free amino acid concentrations in the liver compared to the group only fed on the NAW. This response was dependent mainly on reduced non-essential and glucogenic amino acid concentrations. However, in breast muscle, alterations of free amino acid concentrations were observed only for histidine and tryptophan. In addition, the fatty acid composition of liver and breast muscle was not affected by feeding AW. In breast meat obtained from fasted chickens, the higher level of AW increased the concentration of inosine 5'-monophosphate, a taste-active compound, and in contrast, decreased the subsequent catabolites (inosine and hypoxanthine). However, the concentration of glutamic acid, a taste-active compound, was lowered at this level of AW ingestion. Therefore, this study suggested that feeding AW as a new feed additive regulates ante-mortem amino acid utilisation in the liver and contributes to retard post-mortem degradation of inosine 5'-monophosphate as a taste-active compound in chicken meat.