Influence of dietary creatine monohydrate and carcass cooling rate on colour characteristics of pork loin from different pure breeds

Performance Responses and Fillet Quality of Rainbow Trout (Oncorhynchus mykiss) to Increasing Addition Levels of Dietary Supplementation of Guanidinoacetic Acid

Guanidinoacetic acid (GAA) plays an important role in cellular energy use and protein synthesis. The objectives of this study were to determine the optimal level of dietary GAA regarding the growth performance and fillet characteristics of rainbow trout (Oncorhynchus mykiss). A total of 300 trout (initial weight, 66.84 ± 7.82 g) were fed isonitrogenous (34%) and isocaloric (20.6 MJ kg-1) diets with increasing levels of GAA (0.00, 0.06, 0.12, 0.18%) for 90 days. The results showed that trout fed GAA (either 0.06, 0.12, or 0.18%) yielded better (p < 0.05) performance (BW, BWG, FCR, and SGR) than trout fed the control diet (0.00% GAA inclusion). No differences (p > 0.05) were observed for BW, BWG, nor FCR among trout fed GAA. Nonetheless, trout fed a diet with a 0.12% GAA inclusion had the highest (p < 0.01) SGR. Fillet quality was not affected by GAA supplementation (p > 0.05) for cook loss, shear force, nor colour. Trout fed 0.06% GAA inclusion tended (p = 0.08) to have a higher WHC. Moreover, trout fed 0.12 and 0.18% GAA had lower (p < 0.05) pH values than trout fed the control diet and 0.06% GAA. Our findings give insights for the growth promotion and fillet quality of trout fed diets supplemented with GAA, especially at the level of 0.12%.

Post mortem changes in M. iliotibialis lateralis muscle protein profile of emu (Dromaius novaehollandiae)

The available literature lacks information on the metabolic processes taking place in emu muscles after the cessation of circulation. Hence, this study was undertaken to examine the physicochemical characteristics (pH, drip loss, WHC, TBARS, L*, a*, b*) with concomitant changes in protein expression patterns (SDS-PAGE) of femoral muscle (M. iliotibialis lateralis) that occur post mortem and during the first days (0 h, 24 h, 48 h) of its maturation in 1- and 3-year-old emus. Our results indicated that the interaction between emus age and storage time had significant impact on meat pH and all color indicators. Furthermore, we detected 24 differentially expressed protein bands, representing 22 different gene products. ClueGO pathways analysis revealed that these proteins were mainly involved in glycolysis/gluconeogenesis pathway, pyruvate metabolism and pyrophosphate hydrolysis-driven proton transmembrane transporter activity. Based on the results obtained it can be assumed that early post-mortem metabolism of emu muscle is predominantly based on the glycolysis as reflected by the relative abundance alterations of the glycogenolytic and glycolytic enzymes. Moreover, the energy supplies provided by ATP and other high-energy substances degradation is higher in the group of older emus. Our findings also highlighted the complexity of the molecular mechanisms underlying the conversion of muscle to meat.

Does the 1 Gy dose of gamma radiation impact the pork quality?

A nuclear accident (e.g., Fukushima), and, in particular, the transport of animals within a radiation-affected area can lead to a whole-body, or partial external irradiation, followed by oxidative stress, which could result in subsequent meat quality changes. In this experiment, live pigs were exposed to half-body irradiation by an external dose of 1.0 Gy. The caudal half of the animal's body was irradiated. After their slaughter, samples from the muscle tissue of musculus semimembranosus and musculus longissimus lumborum et thoracis at the upper margin of musculus gluteus medius (irradiated body half) and at the 3rd-4th thoracic vertebra (non-irradiated half) were collected to determine the meat quality parameters. A significant difference (P < 0.05) was observed only in the meat colour parameter (a*) in the irradiated group of pigs. If there is no internal contamination, and the half-body exposure to the external radiation dose does not exceed 1 Gy, pigs from an irradiation-affected area may be used for human consumption.

Pork meat quality after exposure to low (0.5 Gy) dose of gamma radiation

Farm animals in the immediate vicinity of damaged nuclear facilities (Chernobyl, Fukushima), may be affected by an external radiation dose and a radiation dose from internal contamination. In the experiment, pigs weighing 30 kg were exposed to a full body irradiation (60Co) at a dose of 0.5 Gy. Samples from longissimus dorsi muscles at the last rib and semimembranosus muscles were collected. No significant differences of monitored meat colour indicators L*, a*, b*, C*, ΔE*, pH value, (45 min and 24 h post mortem) lactic acid concentration, water content and fat content (24 h post mortem) and drip loss indicators (24 and 48 h post mortem between the experimental and control group (10 and 10 pigs, respectively) were observed. If there is no internal contamination, and external radiation dose does not exceed 0.5 Gy, pigs from the affected area may be used for slaughter purposes. The results show that oxidative stress resulting from exposure to this dose of ionizing radiation does not affect the meat quality.

Creatine Monohydrate and Guanidinoacetic Acid Supplementation Affects the Growth Performance, Meat Quality, and Creatine Metabolism of Finishing Pigs

This study aimed to investigate the effects of creatine monohydrate (CMH) and guanidinoacetic acid (GAA) supplementation on the growth performance, meat quality, and creatine metabolism of finishing pigs. The pigs were randomly allocated to three treatment groups: the control group, CMH group, and GAA group. In comparison to the control group, CMH treatment increased average daily feed intake and GAA treatment increased average daily feed intake and average daily gain of pigs. In addition, CMH and GAA treatment increased pH_45 min, myofibrillar protein solubility, and calpain 1 mRNA expression level and decreased the drip loss and shear force value in longissimus dorsi or semitendinosus muscle. Moreover, CMH and GAA supplementation increased the concentrations of creatine and phosphocreatine and the mRNA expressions of guanidinoacetate N-methyltransferase and creatine transporter in longissimus dorsi muscle, semitendinosus muscle, liver, or kidneys and decreased the mRNA expressions of arginine:glycine amidinotransferase in kidneys. In conclusion, CMH and GAA supplementation could improve the growth performance and meat quality and alter creatine metabolism of finishing pigs.

Effect of creatine monohydrate supplementation on carcass traits, meat quality and postmortem energy metabolism of finishing pigs

The objective of this study was to evaluate the effects of creatine monohydrate (CMH) supplementation on meat quality and postmortem energy metabolism of finishing pigs. In total, 48 healthy Duroc–Large White cross castrated male pigs were randomly allocated into two treatments, and fed either a CHM-free basal diet or a basal diet with CMH supplementation (0.8%) for 14 days. At the end of the experiment, six pigs from each treatment were weighed individually and slaughtered. The muscle from longissimus dorsi was collected to evaluate the meat quality and energy metabolism-related parameters. The results showed that CMH supplementation did not affect the loin eye area, back fat depth or dressing percentage (P > 0.05). The muscle pH45 min was higher, whereas drip loss and cooking loss were lower in the CMH supplementation group (P < 0.05). CMH supplementation increased the concentrations of creatine (P < 0.05), adenosine triphosphate (P < 0.05), adenosine diphosphate (P < 0.01) and creatine kinase activity (P < 0.05), and decreased the concentration of lactic acid (P < 0.05), and the activities of lactate dehydrogenase (P < 0.05) and pyruvate kinase (P < 0.05) in muscle postmortem. However, no differences were observed between groups for chemical composition, textural characteristics and glycolytic potential of longissimus dorsi muscle (P > 0.05). These findings suggest that dietary supplementation with CMH during the finishing period in pigs could delay early pH decline and decrease the rate of glycolysis in postmortem longissimus dorsi muscle resulting in a decreased drip loss.

Creatine and creatine kinase in health and disease--a bright future ahead?

Many links are reported or suspected between the functioning of creatine, phosphocreatine, the creatine kinase isoenzymes or the creatine biosynthesis enzymes on one hand, and health or disease on the other hand. The aim of the present book was to outline our current understanding on many of these links. In this chapter, we summarize the main messages and conclusions presented in this book. In addition, we refer to a number of recent publications that highlight the pleiotropy in physiological functions of creatine and creatine kinase, and which suggest that numerous discoveries on new functions of this system are still ahead of us. Finally, we present our views on the most promising future avenues of research to deepen our knowledge on creatine and creatine kinase. In particular, we elaborate on how state-of-the-art high-throughput analytical ("omics") technologies and systems biology approaches may be used successfully to unravel the complex network of interdependent physiological functions related to creatine and creatine kinase.