Effects of dietary supplementation with creatine monohydrate during the finishing period on growth performance, carcass traits, meat quality and muscle glycolytic potential of broilers subjected to transport stress

Effects of guanidino acetic acid and betaine supplementation on growth, dietary nutrient digestion and intestinal creatine metabolism in sheep

BACKGROUND

The intestine of young ruminants is in the developmental stage and has weaker resistance to the changes of external environment. Improving intestinal health is vital to promoting growth of young ruminants. This study investigated effects of guanidino acetic acid (GAA) and rumen-protected betaine (RPB) supplementation on growth, dietary nutrient digestion and GAA metabolism in the small intestine of sheep.

METHODS

Eighteen healthy Kazakh rams (27.46 ± 0.10 kg of body weight and 3-month old) were categorized into control, test group I and test group II, which were fed a basal diet, 1500 mg/kg GAA and 1500 mg/kg GAA + 600 mg/kg RPB, respectively.

RESULTS

Compared with control group, test group II had increased (p < 0.05) average daily gain, plasma creatine level, ether extract (EE) and phosphorus digestibility on day 30. On day 60, the EE apparent digestibility, jugular venous plasma GAA, GAA content in the duodenal mucosa and GAA content in the jejunal and ileal mucosa of test group II were higher (p < 0.05) than other groups. Transcriptome analysis revealed that the differentially expressed genes (DEGs) involved in the duodenal pathways of oxidative phosphorylation and non-alcoholic fatty liver disease were significantly altered in test group II versus test group I (p < 0.05). Moreover, in the jejunum, the MAPK signalling pathway, complement and coagulation cascade and B-cell receptor signalling pathway were significantly enriched, with ATPase, solute carrier transporter protein, DHFR, SI, GCK, ACACA and FASN being the significantly DEGs (p < 0.05).

CONCLUSION

Dietary supplementation of RPB on top of GAA in sheep diets may promote sheep growth and development by improving the body's energy, amino acid, glucose and lipid metabolism capacity.

Inhibition of mtDNA-PRRs pathway-mediated sterile inflammation by astragalus polysaccharide protects against transport stress-induced cardiac injury in chicks

Transport stress (TS) not only weakens poultry performance but also affects animal welfare. Additionally, TS can evoke cardiac damage by triggering sterile inflammation in chicks, but the underlying mechanism is not fully understood. Here, we aimed to elucidate how TS induces sterile inflammation and heart injury and to clarify the antagonism effect of astragalus polysaccharides (APS). We randomly divided 60 chicks (one-day-old female) into 5 groups (n = 12): Control_0h (Con_0h) group (chicks were slaughtered at initiation), Control group (stress-free control), TS group (simulated TS exposure for 8 h), TS plus water (TS+W) group, and TS plus APS (TS+APS) group. Before simulation transport, the chicks of TS+W and TS+APS groups were, respectively, dietary with 100 μL of water or APS (250 μg/mL). H&E staining was employed for cardiac histopathological observation. ELISA assay was used to measure oxidative stress marker levels (GSH, GPX, GST, and MDA). A commercial kit was used to isolate the mitochondrial portion, and qRT-PCR was employed to measure the mitochondrial DNA (mtDNA) levels. Furthermore, we evaluated the activity of mtDNA-mediated NF-κB, NLRP3 inflammasome, and cGAS-STING inflammatory pathways and the expression of downstream inflammatory factors by Western Blotting or qRT-PCR. Our findings revealed that APS notably relieved TS-induced myocardial histopathological lesions and infiltrations. Likewise, the decrease in proinflammatory factors (TNF-α, IL-1β, and IL-6) and IFN-β by APS further supported this result. Meanwhile, TS caused severe oxidative stress in the chick heart, as evidenced by decreased antioxidant enzymes and increased MDA. Importantly, APS prevented mtDNA stress and leakage by reducing oxidative stress. Interestingly, TS-induced mtDNA leakage caused a series of inflammation events via mtDNA-PRRs pathways, including TLR21-NF-κB, NLRP3 inflammasome, and cGAS-STING signaling. Encouragingly, all these adverse changes related to inflammation events induced by mtDNA-PRRs activation were all relieved by APS treatment. In summary, our findings provide the first evidence that inhibition of mtDNA-PRRs pathway-mediated sterile inflammation by APS could protect against TS-induced cardiac damage in chicks.

Resveratrol improves meat quality traits by activating the lncRNAs-KEAP1-NRF2 axis in pigs

This research aims at uncovering the effects and investigating the molecular mechanisms of dietary resveratrol (RES) supplementation on antioxidant capacity and meat quality of pigs. In this study, 20 μM RES could activate the KEAP1-NRF2 antioxidant defense pathway in response to oxidative stress in porcine skeletal muscle satellite cells was firstly found. Then, twenty-four healthy crossbred castrated boars were allocated to 4 treatments that were fed with a basal diet (control) and a basal diet supplemented with 200 mg, 400 mg or 600 mg RES per Kilogram (kg) of feed for 41 days, respectively. 400 and 600 mg/kg RES-supplemented diet can effectively improve the meat quality traits and activities of antioxidizing enzymes via the KEAP1-NRF2 signaling pathway of pigs. The molecular dynamic simulation further revealed that RES could directly binding to KEAP1 to reduce the tightness of KEAP1-NRF2 protein-protein interaction. More importantly, dietary supplementation of RES also improves antioxidant capacity through a series of KEAP1-NRF2 pathway-related lncRNAs were found by RNA sequencing (RNA-seq). Altogether, this study demonstrated that RES improves meat quality traits by effectively increasing antioxidant levels via the lncRNA-KEAP1-NRF2 axis in vivo and/or in vitro. These results provide new insights into the molecular mechanisms by which RES, as a nutritional agent, regulates antioxidant capacity and improves meat quality in pigs.

The antioxidative influence of dietary creatine monohydrate and L-carnitine on laying performance, egg quality, ileal microbiota, blood biochemistry, and redox status of stressed laying quails

The experiment was implemented to assess the influence of dietary supplementation of laying quails with creatine monohydrate (CrM), L-carnitine (CAR) and their mixture (CrMCAR) as antioxidants against oxidative stress (OS) induced by 2.5 ppm lead acetate (LA) in drinking water on productive, physiological and microbial aspects. In total, 400 laying quail females at 10 wk of age were divided into a randomized design with 5 groups and 4 replicates of 20 birds each. Birds were fed ad libitum with a balanced diet for 8 wk. The control group was kept under no-stress conditions and was given fresh water without any additives (G1). While birds in other groups were exposed to OS induced experimentally by 2.5 ppm LA in drinking water with no feed additive (G2) or supplemented with 500 mg/kg CrM (G3) or 500 mg/kg CAR (G4) or combination of 250 mg/kg each of CrM and CAR (CrMCAR, G5) to feed mixture. Compared to G2, G5 demonstrated the reduction (P ≤ 0.05) of feed conversion ratio, feed intake, mortality and ileal total coliform, as well as serum and egg malondialdehyde and serum lipid hydroperoxide, uric acid, glucose, cholesterol, enzymatic activities (alanine aminotransferase, aspartate transaminase, alkaline phosphatase, creatine phosphokinase, γ-glutamyl transferase), and heterophils/lymphocytes ratio. In the meanwhile, there was an increase (P ≤ 0.05) in egg production, egg mass, and weight with the improvement of egg quality, serum sex hormones level and ileal lactic acid bacteria for G5 followed by G4 and G3. Moreover, G5 enhanced (P ≤ 0.05), the total antioxidant capacity of egg and serum glutathione, superoxide dismutase, catalase, glutathione peroxidase, protein and calcium levels. Therefore, dietary CrMCAR, CAR and CrM have analogous influence to control by improving the antioxidant and physiological parameters which resulted in better productive performance and egg characteristics of stressed quails. These antioxidants, especially in their equal combination, are beneficial to alleviate oxidative stress incidence and can be recommended for poultry feeding under various aspects of environmental stresses.

Muscle growth affects the metabolome of the pectoralis major muscle in red-winged tinamou (Rhynchotus rufescens)

The aim of the present study was to identify and quantify the metabolites (metabolome analysis) of the pectoralis major muscle in male red-winged tinamou (Rhynchotus rufescens) selected for growth traits. A selection index was developed for females [body weight (BW), chest circumference (CC), and thigh circumference (TC)] and males [BW, CC, TC, semen volume, and sperm concentration] in order to divide the animals into 2 experimental groups: selection group with a higher index (TinamouS) and commercial group with a lower index (TinamouC). Twenty male offspring of the 2 groups (TinamouS, n = 10; TinamouC, n = 10) were confined for 350 d. The birds were slaughtered and pectoralis major muscle samples were collected, subjected to polar and apolar metabolites extractions and analyzed by proton nuclear magnetic resonance (1H NMR) spectroscopy. Analysis of the polar metabolomic profile identified 65 metabolites; 29 of them were differentially expressed between the experimental groups (P < 0.05). The TinamouS groups exhibited significantly higher concentrations (P < 0.05) of 25 metabolites, including anserine, aspartate, betaine, carnosine, creatine, glutamate, threonine, 3-methylhistidine, NAD+, pyruvate, and taurine. Significantly higher concentrations of cysteine, beta-alanine, lactose, and choline were observed in the TinamouC group (P < 0.05). The metabolites identified in the muscle provided information about the main metabolic pathways (higher impact value and P < 0.05), for example, phenylalanine, tyrosine and tryptophan biosynthesis; alanine, aspartate and glutamate metabolism; D-glutamine and D-glutamate metabolism; β-alanine metabolism; glycine, serine and threonine metabolism; taurine and hypotaurine metabolism; histidine metabolism; phenylalanine metabolism. The NMR spectra of apolar fraction showed 8 classes of chemical compounds. The metabolome analysis shows that the selection index resulted in the upregulation of polyunsaturated fatty acids, unsaturated fatty acids, phosphocholines, phosphoethanolamines, triacylglycerols, and glycerophospholipids. The present study suggests that, despite few generations, the selection based on muscle growth traits promoted changes in metabolite concentrations in red-winged tinamou.

1H NMR Metabolic Profiling and Meat Quality in Three Beef Cattle Breeds from Northeastern Thailand

The increasing need for effective analytical tools to evaluate beef quality has prompted the development of new procedures to improve the animal sector's performance. In this study, three beef breeds-Thai native (TN), crossbred Brahman × Thai native (BT), and crossbred Charolais × Brahman (CB)-were compared in terms of their physicochemical and metabolic profiles. The findings demonstrated that TN beef was lighter and tougher than other beef. Beef odor was stronger in BT. In addition, CB beef was the most tender and had the highest intramuscular fat content. Twenty-one different metabolites were found overall through NMR and chemometric approaches. The primary factors contributing to the difference in OPLS-DA loading plots were acetylcholine, valine, adenine, leucine, phosphocreatine, β-hydroxypyruvate, ethanol, adenosine diphosphate, creatine, acetylcholine, and lactate. The multivariate analysis indicated that these metabolites in beef cattle breeds could be distinguished using NMR spectroscopy. The results of this study provide valuable information on the quality and meat metabolites of different breeds. This could help in the development of a more accurate assessment of the quality of beef in future research.

Dietary Se-Enriched Cardamine enshiensis Supplementation Alleviates Transport-Stress-Induced Body Weight Loss, Anti-Oxidative Capacity and Meat Quality Impairments of Broilers

The aim of this experiment was to explore the effects of a new selenium (Se) source from Se-enriched Cardamine enshiensis (SeCe) on body weight loss, anti-oxidative capacity and meat quality of broilers under transport stress. A total of 240 one-day-old ROSS 308 broilers were allotted into four treatments with six replicate cages and 10 birds per cage using a 2 × 2 factorial design. The four groups were as follows: (1) Na2SeO3-NTS group, dietary 0.3 mg/kg Se from Na2SeO3 without transport stress, (2) SeCe-NTS group, dietary 0.3 mg/kg Se from SeCe without transport stress, (3) Na2SeO3-TS group, dietary 0.3 mg/kg Se from Na2SeO3 with transport stress, and (4) SeCe-TS group, dietary 0.3 mg/kg Se from SeCe with transport stress. After a 42 d feeding period, the broilers were transported by a lorry or kept in the original cages for 3 h, respectively. The results showed that dietary SeCe supplementation alleviated transport-stress-induced body weight loss and hepatomegaly of the broilers compared with the broilers fed Na2SeO3 diets (p < 0.05). Furthermore, dietary SeCe supplementation increased the concentrations of plasma total protein and glucose, and decreased the activities of aspartate aminotransferase and alanine aminotransferase of the broilers under transport stress (p < 0.05). Dietary SeCe supplementation also enhanced the anti-oxidative capacity and meat quality in the breast and thigh muscles of the broilers under transport stress (p < 0.05). In summary, compared with Na2SeO3, dietary SeCe supplementation alleviates transport-stress-induced body weight loss, anti-oxidative capacity and meat quality impairments of broilers.

The effect of water shower spray on stress physiology and mortality in broiler chickens subjected to road transportation under the hot and humid tropical condition

This study was performed to investigate the effect of water shower spray on rectal temperature (RT), serum levels of corticosterone (CORT), heat shock protein (HSP) 70 and creatine kinase (CK) in broiler chickens road transported at different times of the day. A total of 320 male broiler chickens (35 days of age) were crated and subjected to either water shower spray (WS) for 10 min or no water shower (control). The WS and control broilers were then loaded into an open truck and transported either from 0900 to 1100 h (29.0 °C and 89.0% RH) (AM) or 1900 h to 2100 h (26.0 °C and 94.0% RH) (PM) with an average speed of 80 km/h. The CORT of AM birds were significantly reduced by WS, but the treatment had negligible influence on the PM group. Transportation during AM significantly elevated RT, CORT and HSP70 compared to the PM group. Water shower spraying of birds before transit significantly reduced RT and HSP70 compared to controls. Neither water shower treatment nor transportation time had a significant on CK and mortality rate of broilers. In conclusion, water shower spray is beneficial to alleviate the physiological stress response in road-transported broilers under the hot and humid tropical environment.

Dietary creatine nitrate enhances muscle creatine loading and delays postmortem glycolysis of broilers that experienced preslaughter transport

This study investigated the attenuating effects of dietary creatine nitrate (CrN), a novel form of creatine, on energy expenditure and rapid glycolysis in pectoralis major (PM) muscle of broiler induced by preslaughter transport. A total of 288 Arbor Acres broilers (28 day old) were randomly assigned into five dietary treatments, including a basal diet or the basal diet supplemented with 600 mg/kg guanidinoacetic acid (GAA), 300, 600, or 900 mg/kg CrN for 14 d, respectively. On the day of transportation, the broilers from basal diet group were divided into two equal groups: one group was transported for 0.5 h (Control group) and the other group was transported for 3 h (T3h group). Meanwhile, the birds from GAA and CrN supplementation groups were transported for 3 h (identified as GAA600, CrN300, CrN600, and CrN900 group, respectively). The results demonstrated that dietary supplementation of GAA or CrN from 28 to 42 d of age did not significantly affect the growth performance, carcass traits, and textural characteristics (P > 0.05) in PM muscle of transported broilers. Compared with T3h group, GAA600, CrN600, and CrN900 groups increased the pH45min (P < 0.01), and CrN600, CrN900 groups decreased the cooking loss (P < 0.05) of PM muscle. Meanwhile, the muscle of GAA600, CrN600, and CrN900 groups showed a higher glycogen content (P < 0.01) and a lower lactic acid content (P < 0.01). GAA600 and all CrN treatments enhanced muscle Cr content and reduced AMP/ATP ratio (P < 0.01). In addition, GAA600 and all CrN treatments downregulated the relative mRNA expression levels of LKB1 and AMPKα2 (P < 0.001) and the protein expression of p-AMPKαThr172 compared with the T3h group (P < 0.01). All CrN treatments showed lower protein expression levels of LKB1 and p-LKB1Thr189 than those of the T3h group (P < 0.05). In summary, dietary supplementation with GAA and CrN enhanced the content of muscle creatine, and inhibited transport-induced activation of LKB1/AMPK pathway, which is beneficial for delaying rapid muscle glycolysis and improving meat quality.

Dietary live yeast supplementation alleviates transport-stress-impaired meat quality of broilers through maintaining muscle energy metabolism and antioxidant status

BACKGROUND

This experiment was to investigate the effect of dietary live yeast (LY, 1 × 10¹⁰  CFU g^-1 ) supplementation on serum metabolic parameters, meat quality as well as antioxidant enzyme activity of transported broilers. A total of 192 one-day-old broilers were randomly assigned to four treatments with six replicates and eight chicks per replicate: a basal diet without transportation (CON), a basal diet containing 0 (T), 500 (T + LY₅₀₀ ) and 1000 mg kg^-1 (T + LY₁₀₀₀ ) LY with 3 h of transportation after feeding for 42 days, respectively. The serum and muscle samples of broilers were collected immediately after 3 h of transportation.

RESULTS

A higher (P < 0.05) final body weight and average daily weight gain were observed in T + LY₁₀₀₀ group compared with CON and T groups. The T + LY₁₀₀₀ group reduced (P < 0.05) the serum lactate contents and improved (P < 0.05) the pH_24h and decreased (P < 0.05) the drip loss in muscles of transported-broilers. Also, the T + LY₁₀₀₀ group enhanced (P < 0.05) the total-antioxidant capacity and reduced (P < 0.05) the malondialdehyde in serum and muscles. Besides, the messenger RNA (mRNA) expression of avian uncoupling protein (avUCP) in muscles was down-regulated (P < 0.05) of T + LY₁₀₀₀ group compared with T group.

CONCLUSION

Dietary LY supplementation alleviates transport-stress-impaired meat quality of broilers through maintaining muscle energy metabolism and antioxidant status. Therefore, LY may serve as a potential protector for broilers under transport stress in the future. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of yeast hydrolysate on growth performance, serum parameters, carcass traits, meat quality and antioxidant status of broiler chickens

BACKGROUND

Yeast hydrolysate (YH) has multiple salutary biological activities. Nevertheless, the application of YH in broiler production is limited. This study was conducted to evaluate the protective effects of YH derived from Saccharomyces cerevisiae by exploring growth performance, serum parameters, organs relative weight, carcass traits, meat quality and antioxidant status of broilers.

RESULTS

Supplementing YH linearly and quadratically improved (P < 0.05) body weight gain and gain-to-feed ratio compared to that in the control group. Triglycerides, low-density lipoprotein cholesterol and total cholesterol in serum, the decline in pH and cooking loss of breast muscle, and malonaldehyde concentration in serum and liver were decreased linearly and/or quadratically by YH (P < 0.05), whereas high-density lipoprotein cholesterol in serum, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in serum, GSH-Px activity in liver, glutathione content in serum and liver, eviscerated yield rate and chest muscle yield, and the relative weight of spleen and liver were linearly and/or quadratically increased (P < 0.05). Moreover, YH enhanced the mRNA levels of nuclear factor erythroid 2-related factor 2, heme oxygennase-1 (HO-1), GSH-Px1 and SOD1 (linear and/or quadratic, P < 0.05).

CONCLUSION

Dietary YH beneficially affected growth performance, serum parameters, organ relative weight, carcass traits, meat quality and antioxidant status in broilers, indicating its potential application as a promising feed additive in broiler production. © 2021 Society of Chemical Industry.

Creatine nitrate supplementation strengthens energy status and delays glycolysis of broiler muscle via inhibition of LKB1/AMPK pathway

This study aimed to evaluate the effects of dietary creatine nitrate (CrN) on growth performance, meat quality, energy status, glycolysis, and related gene expression of liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) pathway in Pectoralis major (PM) muscle of broilers. A total of 240 male Arbor Acres broilers (28-day-old) were randomly allocated to one of 5 dietary treatments: the basal diet (control group), and the basal diets supplemented with 600 mg/kg guanidinoacetic acid (GAA), 300, 600, or 900 mg/kg CrN (identified as GAA₆₀₀, CrN₃₀₀, CrN₆₀₀, or CrN₉₀₀, respectively). We found that dietary GAA and CrN supplementation for 14 d from d 28 to 42 did not affect broiler growth performance, carcass traits, and textural characteristics of breast muscle. GAA₆₀₀, CrN₆₀₀, and CrN₉₀₀ treatments increased pH_24h and decreased drip loss of PM muscle compared with the control (P < 0.05). The PM muscles of CrN₆₀₀ and CrN₉₀₀ groups showed higher glycogen concentration and lower lactic acid concentration accompanied by lower activities of phosphofructokinase (PFK), pyruvate kinase (PK), and lactate dehydrogenase (LDH) (P < 0.05). Simultaneously, GAA₆₀₀ and all CrN treatments increased concentration of muscle creatine, phosphocreatine (PCr) and ATP, and decreased AMP concentration and AMP/ATP ratio (P < 0.05). Meanwhile, the concentrations of muscle creatine, PCr, and ATP were increased linearly, while muscle AMP concentration and AMP/ATP ratio were decreased linearly and quadratic as the dose of CrN increased (P < 0.05). GAA₆₀₀, CrN₆₀₀, and CrN₉₀₀ treatments upregulated mRNA expression of CreaT in PM muscle, and CrN₆₀₀ and CrN₉₀₀ treatments downregulated GAMT expression in liver and PM muscle compared with the control or GAA₆₀₀ groups (P < 0.05). The mRNA expression of muscle LKB1, AMPKα1, and AMPKα2 was downregulated linearly in response to the increasing CrN level (P < 0.05). Overall, CrN showed better efficacy on strengthening muscle energy status and improve meat quality than GAA at the some dose. These results indicate that CrN may be a potential replacement for GAA as a new creatine supplement.

The effect of Cu, Zn and Fe chelates on the antioxidative status of thigh meat of broiler chickens

The studies aimed to verify the effect of Cu, Zn and Fe glycine chelate on the antioxidative status in the thigh meat of broiler chickens. The study assumption was that due to the antioxidative or prooxidative effect of Cu, Zn and Fe, these elements supplemented to chickens in an easily assimilable form would modify the antioxidative status of meat and those having a prooxidative effect could deteriorate the quality of meat. The experiment involved three hundred and fifty Ross 308 chickens divided into seven equipotent experimental groups. Over 42 days of the experiment, the chickens were administered Cu, Zn and Fe glycine chelates in an amount corresponding to 50% of the requirement (experimental factor I) or 25% of the requirement (experimental factor II). The level of oxidative stress indicators such as superoxide dismutase, catalase, glutathione, glutathione peroxidase and malondialdehyde was determined in the muscles and blood. The groups receiving Zn or Cu chelate showed statistically confirmed higher activity of superoxide dismutase, catalase, and a higher level of glutathione in comparison to the group receiving Fe chelate. In order to increase the antioxidative stability of thigh meat, it is sufficient that broiler chickens receive Zn or Cu in the form of glycine chelate in an amount covering 25% of their requirement of such minerals. On the other hand, the use of Fe glycine chelates decreased antioxidative stability due to an increase in the level of malondialdehyde, so it should be considered whether the administration of pro-oxidative Fe chelate to broilers is advisable.

Effects of guanidinoacetic acid and complex antioxidant supplementation on growth performance, meat quality, and antioxidant function of broiler chickens

BACKGROUND

This study was conducted to evaluate the effects of adding guanidinoacetic acid (GAA), or complex antioxidant (CA), or their combination, in diets on the growth performance, carcass traits, meat quality, and antioxidant capacity of broilers. A total of 192 25-day-old broilers were assigned to a 2 × 2 factorial design including two dietary supplements at two different levels, in which the main effects were the addition of GAA (0 or 600 mg kg^-1 ) and CA (0 or 150 mg kg^-1 ). This trial lasted for 18 days.

RESULTS

Compared with the control group, the GAA group, CA group, and GAA + CA group, decreased feed conversion ratio by 7.02%, 6.58%, and 11.40%, respectively. Guanidinoacetic supplementation increased eviscerated yield, pH_24h (P < 0.05). Complex antioxidant supplementation increased the a* values (P < 0.05). The combination of GAA and CA did not affect the carcass traits and meat quality. Guanidinoacetic acid alone and CA alone and combined with GAA and CA decreased the reactive oxygen species (ROS) level and malonaldehyde (MDA) content (P < 0.05), and the GAA + CA group had the lowest ROS level and MDA content of broilers.

CONCLUSION

Dietary supplementation of GAA, CA or their combination had beneficial effects on growth performance and breast antioxidant capacity, and the combination of GAA and CA could exert a synergistic effect in improving antioxidant capacity. © 2020 Society of Chemical Industry.

Thai Native Chicken as a Potential Functional Meat Source Rich in Anserine, Anserine/Carnosine, and Antioxidant Substances

This study identified anserine and anserine/carnosine in chicken breast of Thai native chicken (TNC; 100% Thai native), Thai synthetic chicken (TSC; 50% Thai native), and Thai native crossbred chicken (TNC crossbred; 25% Thai native) compared with commercial broiler chicken (BR; 0% Thai native) using nuclear magnetic resonance (NMR) spectroscopy and the effect on antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl assay (DPPH). We conducted experiments with a completely randomized design and explored principal components analysis (PCA) and orthogonal projection to latent structure-discriminant analysis (OPLS-DA) to identify the distinguishing metabolites and relative concentrations from 1H NMR spectra among the groups. The relative concentrations and antioxidant properties among the groups were analyzed by analysis of variance (ANOVA) using the general linear model (GLM). This study revealed seven metabolites alanine, inositol monophosphate (IMP), inosine, and anserine/carnosine, lactate, anserine, and creatine. Lactate, anserine, and creatine were major components. In terms of PCA, the plots can distinguish BR from other groups. OPLS-DA revealed that anserine and anserine/carnosine in the chicken breast were significantly higher in TNC, TSC, and TNC crossbred than BR according to their relative concentrations and antioxidant properties (p < 0.01). Therefore, TNCs and their crossbreeds might have the potential to be functional meat sources.

Tryptophan in poultry nutrition: Impacts and mechanisms of action

Many studies have shown that productivity, immune system, antioxidant status, and meat and egg quality can be optimized by dietary supplementation with amino acids that are not usually added to poultry diets. Understanding the effects of these amino acids may encourage feed manufacturers and poultry producers to include them as additives. One of these amino acids is tryptophan (Trp). The importance of Trp is directly related to its role in protein anabolism and indirectly related to its metabolites such as serotonin and melatonin. Thus, Trp could affect the secretion of hormones, development of immune organs, meat and egg production, and meat and egg quality in poultry raised under controlled or stressed conditions. Therefore, this review discusses the main roles of Trp in poultry production and its mode (s) of action in order to help poultry producers decide whether they need to add Trp to poultry diets. Further areas of research are also identified to address information gaps.

Guanidino-Acetic Acid: A Scarce Substance in Biomass That Can Regulate Postmortem Meat Glycolysis of Broilers Subjected to Pre-slaughter Transportation

The different substances in biomass can regulate the metabolism and reproduction of broilers. Guanidino-acetic acid (GAA) is a natural feed additive that showed a potential application in dietary for broilers, while its amount is scarce in biomass. The objective of the present study was to investigate the effects of dietary supplemented with GAA on muscle glycolysis of broilers subjected to pre-slaughter transportation. A total of 160 Qiandongnan Xiaoxiang chickens were randomly assigned into three treatments, including a basal control diet without GAA supplementation (80 birds) or supplemented with 600 mg/kg (40 birds) or 1,200 mg/kg (40 birds) GAA for 14 days. At the end of the experiment, the control group was equally divided into two groups, thus resulting in four groups. All birds in the four groups aforementioned were separately treated according to the following protocols: (1) no transport of birds of the control group fed with the basal diet; (2) a 3-h transport of birds of the control group fed with the basal diet; (3) a 3-h transport of birds fed with diets supplemented with 600 mg/kg GAA; and (4) a 3-h transport of birds fed with diets supplemented with 1,200 mg/kg GAA. The results demonstrated that 3-h pre-slaughter transport stress increased corticosterone contents and lowered glucose contents in plasma (P < 0.05), decreased pH_{24 h} (P < 0.05), and resulted in inferior meat quality evidenced by elevating the drip loss, cooking loss, and L^∗ value (P < 0.05). Meanwhile, 3-h pre-slaughter transport stress decreased the contents of Cr and ATP in muscle (P < 0.05) and elevated the ratio of AMP:ATP and the glycolytic potential of muscle (P < 0.05). Moreover, 3-h pre-slaughter transport resulted in a significant elevation of mRNA expressions of LKB1 and AMPKα2 (P < 0.05), as well as the increase in protein abundances of LKB1 phosphorylation and AMPKα phosphorylation (P < 0.05). However, 1,200 mg/kg GAA supplementation alleviated negative parameters in plasma, improved meat quality, and ameliorated postmortem glycolysis and energy metabolism through regulating the creatine-phosphocreatine cycle and key factors of AMPK signaling. In conclusion, dietary supplementation with 1,200 mg/kg GAA contributed to improving meat quality via ameliorating muscle energy expenditure and delaying anaerobic glycolysis of broilers subjected to the 3-h pre-slaughter transport.

Effects of chitosan oligosaccharides on meat quality, muscle energy metabolism and anti-oxidant status in broilers that have experienced transport stress

Context Pre-slaughter transport, exposed broilers to various stressors, which resulted in detrimental effects on animal welfare, live bodyweight loss, mortality and meat quality. There was growing interest to explore effective ways to reduce the stress response and improve meat quality of transported broilers by using dietary feed additives. Aims The purpose of the present study was to investigate the effect of chitosan oligosaccharides (COS) on meat quality, muscle energy metabolism and anti-oxidant status of broilers having 3-h transport stress. Methods In total, of 144 35-day-old broilers were randomly allocated to two dietary treatments, including a basal diet (96 broilers), or basal diet supplemented with COS at 200 mg/kg (48 broilers). There were eight broilers per cage, and 12 replication cages in the basal diet group and six replication cages in the basal diet with 200 mg/kg COS group. At the end of the experiment, after a 12-h fast, broilers in the basal diet group were randomly divided into two groups, with six replication cages in each group; then, the broilers were transported as per the following protocols: broilers in the basal diet group (CON group) were without transport stress; broilers in the basal diet group with 3 h of transport stress (TS group), and broilers in the basal diet with 200 mg/kg COS supplementation and 3 h of transport stress (TSC group). The serum corticosterone concentration, serum, liver and muscle anti-oxidant status, as well as meat quality and muscle energy metabolism were analysed. Key results Compared with the CON group, TS group showed increased bodyweight loss, serum corticosterone concentration, breakdown of muscle glycogen, increased muscle lactate dehydrogenase activity, as well as some changes of body anti-oxidant status (higher serum, liver and muscle MDA concentrations, lower serum SOD and GSH-Px, liver SOD and CAT, and lower muscle SOD, GSH-Px, and CAT activity), accompanied with lower pH45min and pH24h. Nevertheless, compared with the TS group, dietary COS supplementation reduced bodyweight loss, decreased muscle MDA concentration, increased muscle SOD and CAT activity, and was accompanied with improving pH24h. Conclusions The results suggested that the positive effects of dietary COS supplementation in maintaining meat quality were mainly due to the improved muscle anti-oxidant status. Implications Dietary supplementation with 200 mg/kg COS could serve as a beneficial and effective way to alleviate transport-impaired meat quality of broilers.

Stress Associated with Simulated Transport, Changes Serum Biochemistry, Postmortem Muscle Metabolism, and Meat Quality of Broilers

Simple Summary

The objective of this study was to investigate the effects of the transportation on broilers through the use of a vibration and motion simulation machine. Short-term transport stress induced significant physiological changes in broiler chickens. Simulation of the vibration and motion associated transport for 2 h altered hormonal secretion and blood biochemical characteristics. However, after 4 h, the birds appear to regain homeostatic equilibrium. Despite this, the stress activated antioxidant defenses, acidified muscles and increased peroxidation, as well as decreasing the meat quality of broilers. This study supports and extends previous work that identified transportation as a major risk in relation to bird welfare and meat quality.

Abstract

Many factors contribute to the stress of transporting broilers from the farm to the processing plant. Using a motion simulation machine, a total of 144 male broilers were employed to determine the effect of motion, vibration, and feed withdrawal during transportation on serum biochemical parameters, postmortem muscle metabolism, and meat quality of broilers. The results indicated that transportation did not affect the activity of lactate dehydrogenase, γ-glutamyl transferase, aspartate aminotransferase, creatine kinase, and glucose in the serum, glutathione peroxidase in the breast and thigh muscle, nitric oxide synthase (NOS) in the breast, and heat stress protein 70 mRNA expression level in the liver (p > 0.05). Serum triiodothyronine, thyroxine, and insulin concentration declined with 2 h transportation (p < 0.05) and recovered with 4 h transportation (p < 0.05). NOS concentration in the thigh increased with 2 h transportation (p < 0.05) and recovered with 4 h transportation (p < 0.05). Two-hour and 4 h transportation increased the activity of superoxide dismutase in both muscles. Malondialdehyde, lactic acid, and drip loss_{24 h} in both thigh and breast muscles increased, and glycogen in both muscles decreased with increasing transportation times (p < 0.05). Two-hour transportation did not influence pH_{45 min} and pH_{24 h} in the breast and thigh muscle, but these indexes decreased with 4 h transportation. This experiment supports and extends previous work that identified transportation as a major risk in relation to bird welfare and meat quality.

Chitosan oligosaccharide as an effective feed additive to maintain growth performance, meat quality, muscle glycolytic metabolism, and oxidative status in yellow-feather broilers under heat stress

This study investigated the effects of dietary chitosan oligosaccharides (COS) supplementation on growth performance; corticosterone, growth hormone, and insulin-like growth factor-1 concentration; relative organ weight; liver function; meat quality; muscle glycolytic metabolism; and oxidative status in yellow-feather broilers under heat stress. A total of 108 35-day-old Chinese yellow-feather broilers (BW, 470.31 ± 13.15 g) was randomly allocated to 3 dietary treatments as follow: control group, basal diet and raised under normal temperature (24°C); HS group, basal diet and raised under cycle heat stress (34°C from 10:00 to 18:00 and 24°C for the rest time); and HSC group, basal diet with 200 mg/kg COS supplementation and raised under cycle heat stress. Each treatment had 6 replication pens and 6 broilers per pen. Results indicated that heat stress decreased ADG, ADFI, gain:feed ratio, the relative weight of thymus, bursa of Fabricius, pancreas, proventriculus, gizzard, and liver, growth hormone concentration, pH_24h, muscle glycogen content, muscle superoxide dismutase and glutathione peroxidase activity, as well as increased corticosterone, alanine aminotransferase and aspartate aminotransferase level, cooking loss, muscle lactate and malondialdehyde content. Compared with the HS group, broilers in the HSC group had higher ADG, the relative weight of thymus, bursa of Fabricius, and liver, growth hormone concentration, pH_24h, muscle glycogen content, muscle superoxide dismutase and glutathione peroxidase activity, and lower serum corticosterone, alanine aminotransferase and aspartate aminotransferase level, cooking loss, and muscle lactate and malondialdehyde content. In conclusion, the results suggested that COS could be used as an effective feed additive to maintain growth performance, liver function, meat quality, muscle glycolytic metabolism, and oxidative status of yellow-feather broilers under heat stress. The improved meat quality is possibly through reducing muscle glycolysis metabolism and improving muscle oxidative status by dietary COS supplementation in broilers under heat stress.

Dietary betaine supplementation improves meat quality of transported broilers through altering muscle anaerobic glycolysis and antioxidant capacity

BACKGROUND

To investigate the effect of dietary betaine supplementation on growth performance, meat quality, muscle anaerobic glycolysis and antioxidant capacity of transported broilers, 1-day-old partridge-shank-broiler-chickens (n = 192) were randomly divided into three groups for a 50-day feeding trial. The broilers in the control group were fed a basal diet, and experienced 0.75-h transport before slaughter. The broilers in the other three groups were fed a basal diet supplemented with 0, 500 or 1000 mg kg^-1 betaine, respectively, and experienced 3-h transport before slaughter (T, T + BET₅₀₀ or T + BET₁₀₀₀ groups).

RESULTS

Dietary betaine supplementation increased (P < 0.05) average daily gain of broilers, and feed conversion ratio was also improved (P < 0.05) by 500 mg kg^-1 betaine supplementation. Compared with the control group, 3-h transport increased (P < 0.05) live weight loss, serum corticosterone and cortisol concentrations, as well as muscle lactate and malondialdehyde (MDA) contents, and decreased (P < 0.05) muscle pH_24h , glycogen content and total superoxide dismutase activity. Compared with the T group, betaine supplementation decreased (P < 0.05) serum corticosterone and cortisol concentrations and muscle MDA content, and increased (P < 0.05) muscle a*_24 h . In addition, 1000 mg kg^-1 betaine supplementation further decreased (P < 0.05) muscle drip loss, lactate content and lactate dehydrogenase activity, and increased (P < 0.05) muscle glutathione content and glutathione peroxidase activity.

CONCLUSION

Betaine supplementation not only improved growth performance of broilers, but also alleviated meat quality deterioration of transported broilers through altering muscle anaerobic glycolysis and antioxidant capacity. © 2020 Society of Chemical Industry.

L-theanine attenuates transport stress-induced impairment of meat quality of broilers through improving muscle antioxidant status

This study was to investigate the effect of dietary L-theanine (THE) supplementation (0, 600 mg/kg) on growth performance, carcass traits, immune organ indexes, meat quality, and muscle antioxidant status of transported broilers. A total of 180 one-day-old male Ross 308 broilers were randomly allotted to 2 treatment groups including a THE-free group with 12 replicates of 10 birds each and a THE group with 6 replicates of 10 birds each. On the morning of day 42, after a 9-h fast, the birds of THE-free group were divided into 2 equal groups, and then all birds in the 3 groups were placed into 18 crates and were transported according to the following protocols: 0-h transport of birds in the THE-free group (control group), 3-h transport of birds in the THE-free group (T group), and 3-h transport of birds in the THE group (T + THE group). Results showed that dietary THE supplementation improved feed conversion ratio and birds' final body weight (P < 0.05), while transport and dietary THE supplementation did not affect carcass traits of broilers (P > 0.05). Transport increased bird live weight loss, drip loss, L*24 h, muscle malondialdehyde (MDA), protein carbonyl (PC) and lactate contents, while it decreased thymus, spleen, and bursa of Fabricius indexes, pH24h, a*, and muscle total antioxidant capacity (T-AOC), catalase (CAT), and glutathione peroxidase (GSH-PX) activities and glycogen content (P < 0.05). Nevertheless, compared with birds in the T group, birds in the T + THE group exhibited increased thymus, spleen, and bursa of Fabricius indexes, pH24h, a*24 h, and muscle T-AOC, CAT, and GSH-PX activities and glycogen content, and decreased drip loss, L*24 h, and muscle MDA, PC, and lactate contents (P < 0.05). This study provided the first evidence that dietary THE supplementation prevented transport-stress-impaired immune organ indexes and meat quality of broilers, and the reason for maintenance of meat quality by supplementation of THE may be partly ascribed to the changed muscle glycolysis metabolism and antioxidant status.

Thermotolerance of Broiler Chicks Ingesting Dietary Betaine and/or Creatine

The present study aimed to assess the effect of dietary betaine (B) and/or creatine (C) on performance and thermoregulatory responses of broiler chicks. Indian River broiler chicks, fitted with compact thermosensors, were reared to market age (five weeks). The chicks were randomly distributed into four treatment groups, in a 2 × 2 factorial arrangement of treatments-basal control diet (Control group: CONT; B-/C-); 1 g betaine/kg feed (Betaine group: BETA; B+/C-), 1.2 g creatine monohydrate/kg feed (Creatine group: CRET; B-/C+), and combination (Betaine and Creatine group: COMB; B+/C+) of both supplements. At 31 days of age, 20 chicks from each group were exposed to acute heat stress (A-HS) for 3 h (34.45 ± 0.20 °C), and hemogramic profiles were screened before and after. Performance parameters (feed intake, body weight gain, and feed conversion ratio) were reported on a weekly basis, and carcass meat quality was evaluated at the end of experiment. Redness of breast was higher due to B and C treatments separately than the CONT group (B by C interaction; p < 0.05). Compared to the CONT, dietary supplements alleviated hyperthermia responses, with B alone being more efficient than C or COMB treatments. The mitigation of hyperthermia is likely mediated by enhancement of water balance indicators. Although not efficient in improving growth performance, dietary B and/or C are efficient in improving thermophysiological performance and survival of finishing broiler chicks under A-HS.

Attenuating effects of guanidinoacetic acid on preslaughter transport-induced muscle energy expenditure and rapid glycolysis of broilers

This study evaluated the effects of dietary guanidinoacetic acid (GAA) supplementation on growth performance, plasma variables, muscle energy status, glycolytic potential, and meat quality of broilers experiencing transport stress during the summer. A total of 320 28-day-old male Arbor Acres broilers were randomly allotted to 3 dietary treatments, including a GAA-free basal control diet (160 birds) and basal diet supplementation with 600 (80 birds) or 1,200 mg/kg (80 birds) GAA for 14 D. On the morning of day 42, after an 8-h fast, the birds fed basal diets were divided into 2 equal groups, and all birds in the 4 groups of 80 birds were transported according to the following protocols: 1) a 0.5-h transport of birds on basal diets (as a lower-stress control group), 2) a 3-h transport of birds on basal diets, and a 3-h transport of birds on basal diets supplemented with either 3) 600 or 4) 1,200 mg/kg GAA. The results revealed that dietary supplementation with GAA at 600 and 1,200 mg/kg for 14 D prior to slaughter did not affect growth performance, carcass traits, and most textural characteristics and chemical composition of the pectoralis major (PM) muscle (P > 0.05). In the GAA-free group, a 3-h transport increased the broiler live weight loss, elevated the plasma corticosterone concentration, decreased the plasma glucose concentration, muscle concentrations of ATP, creatine and energy charge value, increased the muscle AMP concentration and AMP/ATP ratio, and accelerated glycolysis metabolism, which resulted in inferior meat quality (lower pH and higher drip loss, P < 0.05). However, dietary addition of GAA at 1,200 mg/kg increased the mRNA expression of S-adenosyl-l-methionine: N-guanidino-acetate methyltransferase in the liver and creatine transporter in both the liver and PM muscle. It also elevated muscle concentrations of creatine and phosphocreatine (P < 0.05), which helps improve meat quality by ameliorating the 3-h transport-induced muscle energy expenditure and delaying anaerobic glycolysis of broilers.

Stability of creatine monohydrate and guanidinoacetic acid during manufacture (retorting and extrusion) and storage of dog foods

The stability of creatine monohydrate (CrMH), crystallised guanidinoacetic acid (GAA-C) and granulated GAA (GAA-G) in a moist retorted and a dry extruded dog food formulation during production and storage was investigated. Commercial food mixtures were supplemented with CrMH, GAA-C or GAA-G. Uniformity after mixing and retorting or extrusion was determined based on replicate samples (moist n = 8, dry n = 10). Storage stability was evaluated at 25°C/60% relative humidity for 15 months and 40°C/75% for 6 months. Foods with CrMH were analysed for creatine (Cr) and creatinine (Crn), whereas GAA-C and GAA-G foods were analysed for GAA concentrations. Coefficients of variation (CV) for uniformity of the additives after mixing of moist and dry pet food formulations were below 15%, and the CV was lower in processed mixtures. Recoveries after retorting and extrusion were higher for GAA-G (79 and 99%) and GAA-C (89 and 86%) compared to CrMH (36 and 85%) foods. In moist CrMH food, Cr concentrations re-increased by 54% whilst Crn concentrations decreased by 39% after storage at 25°C for 15 months. With total molar Cr + Crn remaining stable throughout storage, Crn and Cr appeared to effectively interconvert. Storage of the extruded CrMH food at 25°C for 15 months resulted in a 63% decrease in Cr and a 39% increase in Crn concentration. The decrease in Cr concentration was larger at 6 months storage at 40°C compared to 15 months storage at 25°C. Both GAA-C and GAA-G moist and dry foods were stable during storage (<10% decrease). This study showed that GAA is highly stable during production and storage of moist and dry canine foods whilst CrMH is relatively unstable, particularly during storage. The latter makes it difficult to establish a guaranteed Cr content in finished moist retorted and dry extruded foods with CrMH.

Enterococcus faecium NCIMB 10415 supplementation improves the meat quality and antioxidant capacity of muscle of broilers

The present study was conducted to investigate the effects of Enterococcus faecium (E. faecium) on the meat quality and antioxidant capacity of muscle in broilers. A total of 600 Arbor Acre broiler chickens (1-day-old, male) were randomly divided into five treatments with six replicates (20 chickens per replicate) for each treatment. The five treatments were the control treatment (CON, basal diet), antibiotic treatment (ANT, basal diet supplemented with 0.1% chlortetracycline) and E. faecium-supplemented treatments (LEF, MEF and HEF, basal diet supplemented with 50, 100 and 200 mg/kg of E. faecium respectively). The experiment lasted 42 days in two periods of 21 days. Results showed that there were no differences in breast meat quality among different treatments (p > 0.05). Compared with the CON and ANT treatments, the yellowness of thigh meat in E. faecium-supplemented treatments was significantly increased (p < 0.05); the shear force of thigh meat in the LEF and MEF treatments was lower than that of the CON treatment (p < 0.05). In addition, the concentration of the inosine monophosphate (IMP) in the breast and thigh meat of the MEF treatment was significantly higher than that of the other treatments (p < 0.05). At 21 days, the total antioxidant capability (T-AOC) level and glutathione peroxidase (GSH-Px) activity of breast meat and superoxide dismutase (SOD) in the thigh meat of the MEF treatment were greatly increased (p < 0.05). At 42 days of age, the catalase (CAT), GSH-Px and T-AOC activities in the breast meat of the MEF treatment were increased (p < 0.05) and the CAT activity of thigh meat in the LEF and MEF treatments was increased (p < 0.05). In conclusion, E. faecium supplementation increased the meat quality of the thigh muscle, increased the IMP content and the activities of CAT, SOD, T-AOC, and GSH-Px of muscle in broilers. Supplementation with 100 mg/kg E. faecium had the greatest effects.

Forsythia suspensa extract protects broilers against breast muscle oxidative injury induced by corticosterone mimicked pre-slaughter acute stress

Broilers were used to determine the protective effects of Forsythia suspensa extract (FSE) against breast muscle oxidative injury induced by corticosterone (CS) mimicking pre-slaughter acute stress. A total of 144 male Arbor Acre broilers was randomly allotted to one of 4 treatments in a 2 × 2 factorial arrangement that included FSE supplementation (0 or 100 mg/kg) and subcutaneous injection of CS (0 or 4 mg/kg) at 3 h before slaughter. Corticosterone increased live BW loss, and the adverse effect was attenuated by FSE in broilers subjected to CS (P < 0.05). Serum levels of CS, uric acid, and glucose were increased, and postmortem breast muscle pH values at 45 min and 24 h were decreased for CS-challenged broilers (P < 0.05). Corticosterone increased lightness and yellowness values and decreased redness of breast muscle (P < 0.05), and FSE decreased yellowness and increased redness of breast muscle (P < 0.05). Drip loss was increased by CS for birds supplemented without FSE (P < 0.05) and decreased by FSE for birds under CS challenge (P < 0.05). Corticosterone increased monounsaturated fatty acid (FA) and decreased polyunsaturated FA in breast muscle (P < 0.05), and saturated FA was decreased and polyunsaturated FA was increased by FSE (P < 0.05). Malondialdehyde and carbonyl contents in breast muscle were increased by CS and decreased by FSE (P < 0.05). Inhibition of 1,1-diphenyl-2-picryl-hydrazyl was decreased by CS and increased by FSE (P < 0.05). The activities of total-antioxidant capacity, glutathione peroxidase, and superoxide dismutase in breast muscle were lower in birds subjected to CS (P < 0.05) and were greater in birds supplemented with FSE (P < 0.05). Collectively, live BW loss and breast muscle oxidative injury were increased by CS in broilers, and these stress-related adverse effects could be attenuated by FSE supplementation via enhanced scavenging ability of free radicals and antioxidant capacity. Therefore, FSE could protect broilers against breast muscle oxidative injury when acute stress happens.

Dietary resveratrol supplementation prevents transport-stress-impaired meat quality of broilers through maintaining muscle energy metabolism and antioxidant status

This experiment was to evaluate the effect of dietary resveratrol (Res) supplementation (0, 400 mg/kg) on growth performance, meat quality, and muscle anaerobic glycolysis and antioxidant capacity of transported broilers. A total of 360 21-day-old male Cobb broilers was randomly allotted to 2 dietary treatments (Res-free group and Res group) with 12 replicates of 15 birds each. On the morning of d 42, after a 9-hour fast, 24 birds (2 birds of each replicate) were selected from the Res-free group and then equally placed into 2 crates, and the other 12 birds (one bird of each replicate) were selected from the Res group and then placed into the other crate. All birds in the 3 crates were transported according to the following protocols: 0-hour transport of birds in the Res-free group (control group), 3-hour transport of birds in the Res-free group (T group), and 3-hour transport of birds in the Res group (T + Res group). The results showed that Res not only improved feed conversion ratio (P < 0.05) but also tended to improve birds’ final body weight (P < 0.10). In the Res-free group, a 3-hour transport increased serum corticosterone concentration, muscle malondialdehyde (MDA) and lactate contents, and muscle lactate dehydrogenase (LDH) activity, while it decreased muscle glycogen content, total superoxide dismutase (T-SOD), and glutathione peroxidase (GSH-PX) activities (P < 0.05), which induced decreased breast meat quality (lower pH_24h and higher drip loss and L*_24 h, P < 0.05). Nevertheless, compared with the T group, Res increased muscle glycogen content and T-SOD and GSH-PX activities (P < 0.05 or P < 0.10), while it decreased muscle MDA content and LDH activity (P < 0.05), which is beneficial to the meat quality maintenance of transported broilers (lower drip loss, L*_24 h, and higher pH_24h, P < 0.05 or P < 0.10). This study provides the first evidence that dietary resveratrol supplementation prevents transport-stress-impaired meat quality of broilers, possibly through decreasing the muscle anaerobic glycolysis metabolism and improving the muscle antioxidant capacity.

Effect of dietary resveratrol supplementation on meat quality, muscle antioxidative capacity and mitochondrial biogenesis of broilers

BACKGROUND

The naturally occurring polyphenol resveratrol has been acknowledged with many beneficial biological effects. The aim of this study was to evaluate the influence of dietary resveratrol supplementation on meat quality, muscle antioxidative capacity and mitochondrial biogenesis of broilers. One hundred and eighty 21-day-old male Cobb broilers were randomly assigned to two groups and fed on a 0 mg kg^-1 or 400 mg kg^-1 resveratrol-supplemented diet for 21 days. Then, chickens were slaughtered and pectoralis major muscle (PM) samples were collected for analysis.

RESULTS

The results showed that resveratrol not only tended to increase (P < 0.10) PM pH_24h but also significantly decreased (P < 0.05) PM L*_45min , pH decline, drip loss and lactate content. Meanwhile, PM total antioxidative capacity and catalase activity were significantly increased (P < 0.05) by resveratrol, while malondialdehyde content was decreased (P < 0.10). Moreover, resveratrol significantly increased (P < 0.05) PM peroxisome proliferator-activated receptor γ coactivator 1α and nuclear respiratory factor 1 mRNA levels, along with increased (P < 0.05) citrate synthase activity.

CONCLUSION

Resveratrol can be used as a feed additive to improve meat quality of broilers, which may be associated with improved muscle antioxidative status and mitochondrial biogenesis. © 2017 Society of Chemical Industry.

Preslaughter Transport Effect on Broiler Meat Quality and Post-mortem Glycolysis Metabolism of Muscles with Different Fiber Types

Preslaughter transport has been reported to decrease the quality of breast meat but not thigh meat of broilers. However, tissue-specific difference in glycogen metabolism between breast and thigh muscles of transported broilers has not been well studied. We thus investigated the differences in meat quality, adenosine phosphates, glycolysis, and bound key enzymes associated with glycolysis metabolism in skeletal muscles with different fiber types of preslaughter transported broilers during summer. Compared to a 0.5 h transport, a 3 h transport during summer decreased ATP content, increased AMP content and AMP/ATP ratio, and accelerated glycolysis metabolism via the upregulation of glycogen phosphorylase expression accompanied by increased activities of bound glycolytic enzymes (hexokinase, pyruvate kinase, and lactate dehydrogenase) in pectoralis major muscle, which subsequently increased the likelihood of pale, soft, and exudative-like breast meat. On the other hand, a 3 h transport induced only a moderate glycolysis metabolism in tibialis anterior muscle, which did not cause any noticeable changes in the quality traits of the thigh meat.

Creatine Monohydrate Enhances Energy Status and Reduces Glycolysis via Inhibition of AMPK Pathway in Pectoralis Major Muscle of Transport-Stressed Broilers

Creatine monohydrate (CMH) contributes to reduce transport-induced muscle rapid glycolysis and improve meat quality of broilers, but the underlying mechanism is still unknown. Therefore, this study aimed to investigate the molecular mechanisms underlying the ameliorative effects of CMH on muscle glycolysis metabolism of transported broilers during summer. The results showed that 3 h transport during summer elevated chicken live weight loss and plasma corticosterone concentration; decreased muscle concentrations of ATP, creatine, and energy charge value; increased muscle AMP concentration and AMP/ATP ratio; and upregulated muscle mRNA expression of LKB1 and AMPKα2, as well as protein expression of p-LKB1^Thr189 and p-AMPKα^Thr172, which subsequently resulted in rapid glycolysis in the pectoralis major muscle and consequent reduction of meat quality. Dietary addition of CMH at 1200 mg/kg ameliorated transport-induced rapid muscle glycolysis and reduction of meat quality via enhancement of the energy-buffering capacity of intramuscular phosphocreatine/creatine system and inhibition of AMPK pathway.

Effect of dietary creatine monohydrate supplementation on muscle lipid peroxidation and antioxidant capacity of transported broilers in summer

This experiment was to evaluate the effect of dietary supplementation with creatine monohydrate (CMH) during the finishing period on the muscle lipid peroxidation and antioxidant capacity of broilers that experienced transport stress in summer. A total of 320 male Arbor Acres broilers (28 d in age) were randomly allotted to 3 dietary treatments including a basal control diet without additional CMH (160 birds), or with 600 (80 birds) or 1,200 mg/kg (80 birds) CMH for 14 d. On the morning of d 42, after an 8-h fast, the birds fed the basal diets were divided into 2 equal groups, and all birds in the 4 groups of 80 birds were transported according to the following protocols: 1) a 0.75-h transport of birds on basal diets (as a lower-stress control group), 2) a 3-h transport of birds on basal diets, 3) a 3-h transport of birds on 600 or 4) 1,200 mg/kg CMH supplementation diets. The results showed that the 3-h transport decreased the concentration of creatine (Cr) in both the pectoralis major (PM) and the tibialis anterior (TA) muscles, increased the concentration of phosphocreatine (PCr) and PCr/Cr ratio in PM muscle, and elevated the concentrations of thiobarbituric acid-reactive substances and the activities of total superoxide dismutase and glutathione peroxidase in both the PM and TA muscles of birds (P < 0.05). In addition, transport also upregulated mRNA expression of avian uncoupling protein and heat shock protein 70 in both the PM and TA muscles, as well as avian peroxisome proliferator-activated receptor γ coactivator-1α in the TA muscle (P < 0.05). Dietary supplementation with 1,200 mg/kg CMH increased the concentrations of Cr and PCr in PM muscle, and Cr in TA muscle than those in the 3-h transport group (P < 0.05). However, contrary to our hypothesis, dietary CMH did not alter the measured parameters in relation to muscle lipid peroxidation and antioxidant capacity affected by 3-h transport (P > 0.05). These results indicate that dietary CMH supplementation does not provide any significant protection via directly scavenging free radicals or increased antioxidant capacity of transported broilers.