Effects of guanidinoacetic acid on the growth performance, meat quality, postmortem energy metabolism and muscle fibre types of finishing pigs

Abstract

Context Meat quality is increasingly being paid more attention by customers and enterprises. However, the modern pursuit of pork production has led to a decline in pork quality. Muscle fibre type is one of the important factors affecting meat quality that can be used as a key control point. Aims This study set out to assess the effects of dietary guanidinoacetic acid (GAA) on the growth performance, meat quality, postmortem energy metabolism, and muscle fibre types of finishing pigs. Methods In total, 180 healthy Duroc × Landrace × Meishan cross castrated male pigs with the similar weight (average 90 kg) were randomly divided into three treatments, with five replicates (pens) per treatment and 12 pigs per pen, including a GAA-free basal diet and basal diet with 0.05% or 0.10% GAA for 15 days. Key results In longissimus thoracis muscle, the results indicated that GAA supplementation decreased the drip loss and the cooking loss in 0.10% GAA group. Meanwhile, in semitendinosus muscle, 0.10% GAA addition increased pH45 min, and decreased the cooking loss. Additionally, GAA addition increased the content of ATP and AMP in semitendinosus muscle. The mRNA expressions of MyHC-I and MyHC-IIa were increased, whereas MyHC-IIx and MyHC-IIb were decreased. Moreover, in longissimus thoracis muscle, GAA addition promoted the mRNA expressions of CaM and NFATc1; in semitendinosus muscle, dietary GAA up-regulated the CnA and NFATc1 mRNA expressions. Conclusions GAA addition improved the meat quality, enhanced postmortem energy metabolism and promoted the conversion of fast-muscle fibre to slow-muscle fibre via activating the CaN/NFAT signalling. Implications The addition of GAA can improve the meat quality of post-slaughter finishing pigs and provide a theoretical basis for the application of GAA in livestock production.