Effects of dietary alpha-lipoic acid on anti-oxidative ability and meat quality in Arbor Acres broilers

Abstract

An experiment was conducted to evaluate the effects of dietary alpha-lipoic acid (LA) on growth performance, carcass characteristics and meat quality in Arbor Acres broilers. A total of 240 1-d-old male Arbor Acres broilers were randomly allocated to 4 dietary treatments (0, 300 ppm, 600 ppm, and 900 ppm dietary LA supplementation, respectively). Birds were slaughtered at 42 days old. Live body weight (BW), average daily gain (ADG), average feed intake (AFI), feed conversion ratio (FCR), dressing percentage, breast muscle percentage, thigh muscle percentage, abdominal fat percentage, muscle color (L *, a*, b*), pH values at 24 h postmortem, meat shear force value (SFV) and anti-oxidative ability were measured. Results showed that addition of 600 ppm or 900 ppm LA decreased BW (p<0.01), ADG (p<0.01) and AFI (p<0.05) compared with other diets. FCR was not affected by dietary LA content. LA had no marked effect on dressing percentage, breast muscle percentage or thigh muscle percentage. Abdominal fat percentage was lower (p<0.05) in the 900 ppm LA supplementation group than the control group. Dietary 900 ppm LA increased (p<0.05) breast and thigh muscle pH value at 24 h postmortem compared with the control treatment. Dietary LA increased thigh muscle a* value, though no significant difference was found in thigh muscle a* value among the treatments. Dietary LA significantly decreased breast muscle L* value (p<0.05), breast muscle b* value (p<0.01) and thigh muscle b* value (p<0.05). Broilers fed LA had higher breast muscle a* value (p<0.05) and thigh muscle L * value (p<0.05). All test groups had lower (p<0.05) breast muscle SFV than the control group. Dietary 600 ppm or 900 ppm LA both decreased (p<0.01) thigh muscle SFV compared with the control treatment. Dietary 900 ppm LA significantly increased (p<0.05) TAOC, SOD and GSHPx compared with no LA treatment. Broilers fed LA had lower (p<0.01) MDA compared with the control treatment. These results suggested that dietary LA enhanced the anti-oxidative ability and oxidative stability, and contributed to the improvement of meat quality in broilers.