Stress Effects on Meat Quality: A Mechanistic Perspective

PSE condition is associated with increased apoptotic potential in broiler pectoralis major muscle

This study compared the meat quality and sensory quality characteristics of broiler pectoralis major (PM) muscle between meat quality classes, including reddish, firm, and non-exudative (RFN) and pale, soft, and exudative (PSE) conditions. Additionally, we also investigated the associations between the meat quality classes and expression levels of cytochrome c, initiator (caspase 9), and effector caspases (caspase 3 and 7) at the early postmortem period. A total of 135 PM muscles from broilers were used, and meat quality classes were determined according to the pH_{24 h} and lightness values and classified into the RFN (N = 81) and PSE (N = 54) conditions. The PSE breasts showed lower muscle pH_{15 min} and pH_{24 h} values compared to the RFN breasts (P < 0.05). A lower lightness value was observed in the RFN group compared to the PSE group (P < 0.001), whereas there were no significant differences in redness and yellowness between the groups (P > 0.05). The PSE group exhibited higher extent of water loss, including drip loss and cooking loss, compared to the RFN group (P < 0.05). For these reasons, samples from the RFN group required less force to breakdown the cooked meat with more moisture in the mouth after chewing compared to samples from the PSE group (P < 0.001); however, flavor intensity did not differ between the groups (P > 0.05). At 15 min postmortem, all apoptosis-related molecules, including cytochrome c, caspase 9, caspase 3, and caspase 7, were present at higher levels in the PSE group than in the RFN group (P < 0.05). These results indicated that higher apoptotic potentials were associated with the development of PSE chicken breasts. Therefore, the variation of meat quality in chicken breast can be explained as being affected by the expression levels of apoptosis-related factors at the early postmortem period.

Overexpression of Heat Shock Protein 70 Ameliorates Meat Quality of Broilers Subjected to Pre-Slaughter Transport at High Ambient Temperatures by Improving Energy Status of Pectoralis Major Muscle and Antioxidant Capacity

The induction of heat shock protein 70 (HSP70) potentially mediates meat-quality development under stress conditions. To investigate the effects and mechanism of HSP70 on the meat quality of the pectoralis major (PM) muscles of broilers exposed to pre-slaughter transport, a total of 168 broilers were intraperitoneally injected with L-glutamine (Gln) or saline. Twenty-four hours later, broilers were subjected to transport or held under normal living conditions. The results indicated that acute Gln supplementation significantly increased HSP70 expression in the PM of transported broilers (p < 0.05). The overexpression of HSP70 significantly alleviated the decreases in muscle pH and water-holding capacity and improved the shrinking of muscle fibers induced by transport (p < 0.05). HSP70 induction increased ATP content, decreased the activities of glycolytic enzymes, and lowered the phosphorylation level of AMP-activated protein kinase in transported broilers (p < 0.05). In addition, the overexpression of HSP70 greatly increased total superoxide dismutase and the total antioxidant capability and decreased the levels of reactive oxygen species, malonaldehyde, and carbonyls in the PM of transported broilers (p < 0.05). Overall, this work indicated that HSP70 could effectively improve the meat quality of transported broilers by improving the energy status, inhibiting glycolytic influx, and restoring redox homeostasis.

Influence of Processing Steps on Structural, Functional, and Quality Properties of Beef Hamburgers

In hamburger manufacturing, meat is subjected to four main processing steps (pre-grinding, mixing, grinding, and forming), whereby muscle fibers are disintegrated. In this study, the influence of these process steps was characterized by structural (amount of non-intact cells (ANIC), CLS-Microscopy), functional (drip loss) and qualitative (soluble protein content, lactate dehydrogenase (LDH) activity, myoglobin content (Mb)) parameters of the meat. Therefore, meat samples were analyzed after each process step. Histological analyses revealed an increased ANIC with progressive processing. Thereby, the first and second grinding steps caused the strongest increases (factors 2.43 and 2.69). Comparable results were found in the relative LDH activity (factor 2.20 and 1.62) and the Mb concentration (factor 2.24 and 1.33) of the extracted meat solution. The findings suggest that the disintegration of the meat structure increases with progressive processing, causing more vulnerable structures which result in increased leakage of intramuscular substances. Further, the type of stress acting on the meat determines the extent of the changes. The presented findings enable manufacturers to precisely adjust their process towards more gentle production parameters and thus, to meet the legal regulations.

Influence of meat batter addition in ground beef on structural properties and quality parameters

The determination of the amount of non-intact cells (ANIC) in ground beef products is usually performed using a time-consuming and subjective histometric approach neglecting structural properties, which is why more objective and faster methods including evaluation of quality parameters are needed. To determine, whether the addition of meat batter increases the histologically determined ANIC ground beef samples containing increasing shares of meat batter (non-intact cells) were investigated histologically and results were compared to other methodological approaches, namely lactate dehydrogenase activity (LDH), soluble protein content, metmyoglobin content, drip loss, firmness, and cooking loss. Histological measurements showed that ANIC increased linearly with the addition of meat batter to ground beef. The quality parameters drip loss (r = − 0.834, p < 0.01) and firmness (r = − 0.499, p < 0.01), and the structural parameter metmyoglobin content (r = 0.924, p < 0.01) revealed significant correlations with the amount of added meat batter, and detected differences between ground beef samples when the difference in the amount of added batter-like-substance was ≥ 25%. Therefore, those methods might be useful to estimate and extrapolate ANIC, and assess product quality of ground beef samples in a faster and simpler way. The cooking loss was not affected by meat batter addition, whereas LDH activity revealed non-repeatable results. Taken together, histometric methods are useful to measure ANIC, nevertheless, it is limited in terms of characterization of morphological and structural changes in the meat. However, other parameters were correlated and could, in addition, be used for assessing the quality of ground meat.

Alteration of Mitochondrial Lipidome and Its Potential Effect on Apoptosis, Mitochondrial Reactive Oxygen Species Production, and Muscle Oxidation in Beef during Early Postmortem

Lipid molecules are important participants in mitochondria-mediated apoptosis. This study explored the effect of mitochondrial lipids on mitochondria-mediated apoptosis, mitochondrial reactive oxygen species (ROS) production, and muscle oxidation of beef longissimus lumborum (LL, n = 6) and psoas major (PM, n = 6) during 24 h postmortem. A total of 432 lipid species matched with 21 lipid classes were identified. Remarkably, at 12 h postmortem, the levels of cardiolipin and phosphatidylserine in PM and ceramide, cardiolipin, phosphatidylserine, and sphingosine in LL increased significantly compared with 1 h postmortem, indicating that mitochondria-mediated apoptosis in beef muscle was accelerated during early postmortem. Moreover, PM had higher levels of cardiolipin and phosphatidylserine than LL, also suggesting a higher degree of apoptosis in PM during postmortem. Lipid molecules may assist the production of mitochondrial ROS and decrease the mitochondrial membrane potential (MMP) during postmortem apoptosis, resulting in muscle oxidation and the damage of antioxidant system. Notably, compared with LL, PM had higher abundance of apoptosis-related lipid molecules, a higher amount of ROS, faster diminishment in MMP, and then a higher degree of apoptosis. These findings provided new insights into the apoptosis and muscle biochemistry in beef during early postmortem.

Contributions of energy pathways to ATP production and pH variations in postmortem muscles

The roles of energy pathways in postmortem muscles are still debated. In this study, the contributions of different pathways to ATP production and pH variations were analyzed by using a kinetic model based on data from beef longissimus lumborum. Phosphocreatine represents over 92% of the initial ATP production but, after 24 h, glycolysis, phosphocreatine, myokinase reaction, and aerobic respiration contribute, respectively, 89.44%, 5.26%, 4.44%, and 0.86% of the cumulative amount of ATP produced. ATP hydrolysis and glycolysis result in 0.52 and 0.6 units of pH decline, respectively, at 24 h with ATP hydrolysis accounting for most of the early decline. Phosphocreatine, myokinase reaction, and aerobic respiration lead to, respectively, 0.08, 0.07, and 0.004 units of pH increase after 24 h though phosphocreatine is depleted within the first 30 min. Furthermore, electrical stimulation affects pH primarily through ATP hydrolysis and glycolysis. The initial muscle oxygen saturation level and phosphocreatine content affect pH but the influences are small.

Acute stress deteriorates breast meat quality of Ross 308 broiler chickens by inducing redox imbalance and mitochondrial dysfunction

This study investigated the effects of acute stress on breast meat quality, redox status and mitochondrial function in pectoralis major (PM) muscle of broilers. A total of 168 broiler chickens (42-day-old, Ross 308) were randomly divided into control (CON) and pre-slaughter transport (T) treatments. A broiler was an experimental unit. Each treatment consisted of 84 broilers, and they were put in 12 crates with 7 broilers each. Broilers in the T group were transported according to a designed protocol, and the CON broilers were kept in crates under normal living conditions before slaughtering. Based on the meat quality traits assessed at postmortem 24 h, all PM muscles of the transported broilers were further classified into normal (T-NOR) and pale, soft and exudative (PSE)-like (T-PSE) groups for the determination of redox status in PM muscle and isolated mitochondria, energy metabolites, mitochondrial electron transport chain complexes activities, as well as mitochondrial function-modulating genes expression. Compared with CON, the extent of lipid peroxidation as well as protein oxidation were significantly increased in both PM muscles and mitochondria in T-PSE (P < 0.05), whereas not in T-NOR. Higher activities of glutathione peroxidase, total superoxide dismutase and Cu-Zn superoxide dismutase were observed in PM muscle of T-NOR broilers as compared with CON (P < 0.05). Pre-slaughter transport increased the generation of reactive oxygen species, as well as enhanced antioxidant capacity in PM mitochondria of broilers (P < 0.05). Compared with CON, the ATP content, activities of complex I and III, as well as relative mitochondrial membrane potential and swelling were significantly decreased in T-PSE (P < 0.05), whereas no significant changes in either ATP content or complex I activity were observed in T-NOR. Pre-slaughter transport enhanced the mRNA expression of regulators involved in the glutathione system, thioredoxin 2 system and mitochondrial biosynthesis in PM muscle of broilers (P < 0.05). Moreover, we noticed a more evident enhancement effect in T-NOR than in T-PSE (P < 0.05). Overall, this work indicates that acute stress-induced redox imbalance and mitochondrial dysfunction have significant implications for the development of PSE-like meat.

Association of Serum Glucose, Serotonin, Aspartate Aminotransferase, and Calcium Levels with Meat Quality and Palatability Characteristics of Broiler Pectoralis Major Muscle

This study investigated the correlations between apoptosis-related blood biochemical parameters measured at exsanguination and the meat and sensory quality characteristics of broiler pectoralis major muscle. The concentration of serotonin showed a positive correlation with aspartate aminotransferase (AST) activity (p < 0.001) and a negative correlation with calcium content (p < 0.01). All serum parameters showed relationships with muscle pH at 15 min and/or 24 h postmortem (p < 0.05). Serum AST activity, which had a negative correlation with calcium content (p < 0.01), was positively related with muscle pH and negatively correlated with Warner−Bratzler shear force values (WBS, p < 0.05). Principal component analysis results revealed the associations between AST activity and meat quality traits, including pH24h, lightness, and WBS. Furthermore, cooked breast with higher AST activity and lower calcium level tended to exhibit higher scores of tenderness and overall acceptability than that with lower AST activity and higher calcium level (p < 0.05).

Molecular mechanism of protein dynamic change in Pacific oyster (Crassostrea gigas) during depuration at different salinities uncovered by mass spectrometry-based proteomics combined with bioinformatics

Salinity stress during depuration of Pacific oysters (Crassostrea gigas) leads to degradation in quality; therefore, an understanding of the molecular mechanisms regulating dynamic changes during depuration is needed. Here, C. gigas was depurated for 72 h at salinities ranging from 26 to 38 g/L, a ± 10-20% fluctuation from that in the production area, and the gill proteomes were analyzed by sequential window acquisition of all theoretical fragment ion mass spectra (SWATH-MS). Of the 1218 proteins analyzed, 241 were differentiating proteins (DPs). Salinity stress led to increased levels of DPs associated with glycolysis and the extracellular matrix-receptor interaction pathway, and decreased levels of DPs associated with the citric acid cycle, lipid metabolism, genetic information processing, and cell transformation, especially in oysters exposed to 38 g/L salinity (+20%). Controlling salinity fluctuation within ± 10% of the production area during depuration was conducive to maintaining quality in C. gigas.

Comparison of chicken breast quality characteristics and metabolites due to different rearing environments and refrigerated storage

The objective of the present study was to compare the breast meat quality and metabolomic characteristics from broilers that were raised in conventional (conventional farm reared-broilers; CB, n = 20) and legally approved animal welfare farms (welfare farm reared-broilers; WB, n = 20) in aerobic cold storage (1, 3, 5, and 7 d). Compared to CB chickens, the WB chickens had a larger floor size as well as lower stocking density, atmospheric ammonia, and nipple-shared chicken counts. The results demonstrated significantly higher pH, L^⁎- and b^⁎-value, and lower shear force in CB compared to WB during cold storage. Using ¹H NMR analysis, 25 compounds were identified in the chicken breast meat. Partial least square-discriminant analysis (PLS-DA) was performed based on the identified metabolites. The content of 15 metabolites (1 di-peptide, 9 free amino acids, 2 glycolytic potential-related products, 2 nucleotide-related products, and 1 organic acid) was significantly different due to the rearing environment (CB vs. WB). Among them, all free amino acids were higher in CB than in WB. Six free amino acids (glycine, isoleucine, leucine, phenylalanine, valine, and β-alanine) had variable importance in projection (VIP) score >1, regardless of the number of cold storage days. Therefore, these compounds in the breast meat may be used as potential markers to determine the rearing environment of broilers. Also, this result might be an indication of stress-related meat quality changes in broilers.

Prevalence of breast muscle myopathies (spaghetti meat, woody breast, white striping) and associated risk factors in broiler chickens from Ontario Canada

Spaghetti meat (SM), woody breast (WB), and white striping (WS) are myopathies that affect the pectoral muscle of fast-growing broiler chickens. The prevalence and possible risk factors of these myopathies have been reported in other countries, but not yet in Canada. Thus, the objective of this study was to assess the prevalence and risk factors associated with these myopathies in a representative population of Canadian broilers. From May 2019 to March 2020, 250 random breast fillets from each of 37 flocks (total, 9,250) were obtained from two processing plants and assessed for the presence and severity of myopathies. Demographic data (e.g., sex and average live weight), environmental conditions during the grow-out period (e.g., temperature), and husbandry parameters (e.g., vaccination) were collected for each flock. Associations between these factors and the myopathies were tested using logistic regression analyses. The prevalence of SM, severe WB, and mild or moderate WS was 36.3% (95% CI: 35.3-37.3), 11.8% (95% CI: 11.2-12.5), and 96.0% (95% CI: 95.6-96.4), respectively. Most (85.1%) of the fillets showed multiple myopathies. Regression analyses showed that the odds of SM increased with live weight (OR = 1.30, 95% CI 1.01-1.69) and higher environmental temperature during the grow-out period (OR = 1.75, 95% CI 1.31-2.34). The odds of WB increased with live weight (OR = 1.23, 95% CI 1.03-1.47) and when flocks were not vaccinated against coccidia (OR = 1.86, 95% CI 1.51-2.29). This study documents for the first time a high prevalence of myopathies in Ontario broilers, and suggests that these lesions may have a significant economic impact on the Canadian poultry industry. Our results indicate that environmental conditions and husbandry are associated with the development of breast myopathies, in agreement with the current literature. Future studies are needed to determine how risk factors can promote the occurrence of these conditions, in order to implement possible mitigating strategies.

Effect of salinity stress on respiratory metabolism, glycolysis, lipolysis, and apoptosis in Pacific oyster (Crassostrea gigas) during depuration stage

BACKGROUND

Depuration is an important process performed to ensure the safety of oyster consumption, and the effect of salinity stress on physiological and ecological characteristics of oyster remains unknow. In this study, the simulated depuration of Crassostrea gigas was performed with the salinities varying from ±10% to ±20% away from that of production area (26, 28, 32, 35, and 38 g L^-1 ), as well as respiratory metabolism, glycolysis, lipolysis, and apoptosis were analyzed.

RESULTS

(i) The oxygen consumption rate, ammonia discharge rate and enzyme activities related to respiratory metabolism were decreased significantly at salinities of 38 g L^-1 , indicating that salinity stress triggered the abnormal respiratory metabolism of C. gigas, further, glycolysis was enhanced. (ii) Glycogen decomposition, lactic acid increase, and fatty acid composition modifications were caused by adenosine monophosphate (AMP)-activated protein kinase (AMPK) -mediated during salinity stress. (iii) There was a clear decrease of the condition index and meat yield of C. gigas after 72 h of depuration, especially in salinity 38 g L^-1 . (iv) Salinity stress would lead to the increase of cytochrome c levels, then cause apoptosis of C. gigas, while heat shock protein 70 (HSP70) would interfere with this process.

CONCLUSION

Salinity stress had a significant effect on the physiological and ecological response of C. gigas during the depuration process, including respiratory metabolism, glycolysis, lipolysis, and apoptosis. In general, the low depuration salinity fluctuation (±10%) is helpful to maintain quality of C. gigas, as well as the optimal depuration time was 48 h. © 2021 Society of Chemical Industry.

Protective effects of chlorogenic acid on the meat quality of oxidatively stressed broilers revealed by integrated metabolomics and antioxidant analysis

Oxidation is a major cause of meat quality deterioration during broiler production, which leads to undesirable meat color and impaired water holding capacity (WHC), thereby impacting consumer appeal and satisfaction. Chlorogenic acid (CGA), a natural phenolic acid, is regarded as a potential, safer and healthier antioxidant to improve meat quality. To investigate the protective effects of CGA on the meat quality of oxidatively stressed broilers, 240 one-day-old male Cobb broiler chickens were allocated to four treatments: basal diet (control group), basal diet + dexamethasone (DEX) injection (DEX group), basal diet containing 500 mg kg^-1 CGA (CGA group), and basal diet containing 500 mg kg^-1 CGA + DEX injection (DEX_CGA group). Meat quality, antioxidant capacity, the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, and metabolomic profile were detected in the breast muscle of broilers. Then, correlation analysis between meat quality and antioxidant capacity, antioxidant-related genes, and metabolites was performed. The results indicated that CGA supplementation improved the growth performance and meat quality traits (pH, WHC, and meat color) and enhanced the antioxidant enzyme activity by activating the Nrf2 pathway in the breast muscle of oxidatively stressed broilers. A total of 619 metabolites were identified, among which 93 differential metabolites were found between control and DEX groups, and 65 differential metabolites were observed between DEX and DEX_CGA groups. Breast metabolic profiles were changed by DEX treatment, while CGA supplementation could normalize the metabolic changes in DEX-challenged broilers. Metabolic pathway analysis revealed that most of the differential metabolites between DEX and DEX_CGA groups were involved in pyrimidine/purine, propanoate and phenylalanine metabolism, primary bile acid biosynthesis, and lysine metabolism, which may contribute to explain the protective effects of CGA on meat quality. Moreover, according to the correlation analysis, four metabolites were identified as potential biomarkers to predict the meat quality. In conclusion, our findings demonstrate that CGA is an effective, natural and safe antioxidant to enhance the quality of meat from intensive industrial poultry production.

Thymol and carvacrol supplementation in poultry health and performance

BACKGROUND

Thymol and carvacrol as natural essential oils and phenol compounds are components derived from some medicinal plants, such as thyme and oregano species.

OBJECTIVES

The increasing demands in organic and healthy meat and egg consumption in human society have made it necessary to consider alternative natural compounds for the replacement of chemical compounds in poultry production. The chemical compounds can remain in meat and eggs and cause complications in human health. Therefore, these natural compounds can be fed with a higher safety in poultry production with specific effects. In this regard, the role of thymol and carvacrol as natural compounds in the poultry production has been discussed in the review.

METHODS

In this study, by searching for keywords related to thymol and carvacrol in poultry production in Google Scholar database, the articles related to different aspects of the biological effects of these two phytogenes in poultry production were selected and analyzed.

RESULTS

A review of previous studies has shown that thymol and carvacrol possess a wide range of biological activities, including antibacterial, antiviral, antioxidant, anti-inflammatory, modulating of immunity response and regulating of the gut microbial population. Also, in meat type chickens can promote growth and influence feed utilization. The beneficial effect of this compound was evaluated in hepatic toxicity and demonstrated as a hepatoprotective compound in chickens. Furthermore, these compounds can affect the behavior of layers and influence egg composition, eggshell thickness, and the sensory quality of eggs.

CONCLUSION

It seems that with the increasing demand for healthy protein products, these compounds can be used to improve performance as a substitute alternative for chemical compounds in healthy poultry farms.

Analysis of carcass traits and quantitative expression patterns of different meat quality governing genes during heat stress exposure in indigenous goats

A study was conducted to assess the impact of heat stress on various carcass traits, meat quality variables and gene expression patterns which governs meat quality in indigenous female Kodi Aadu breed. The study was conducted for 45 days in climate chamber with 12 animals randomly allocated into two groups of six animals each, KC (n = 6; Female; Control), KHS (n = 6; Female; heat stress). Majority of the major carcass traits and meat quality variables remained intact between KC and KHS groups. The myostatin (MSTN), calpain 1 (CAPN1) and Diacylglycerol Acyltransferase 1 (DGAT1) mRNA expression patterns were significantly (P < 0.01) lower in KHS group as compared to KC group. However, the calpain 2 (CAPN2), calpastatin (CAST) and Crytallin alpha (CRYA) mRNA expression patterns were significantly (P < 0.05) higher in KHS group. Thus, the study established that the major carcass traits and meat quality variables remained intact after heat stress exposure in female Kodi Aadu goats. Further, MSTN, HSP27, CRYA and HSP90 genes were identified as biomarkers for reflecting meat quality during heat stress exposure in female Kodi Aadu breed.

Effects of dietary plant essential oil supplementation on growth performance, nutrient digestibility and meat quality in finishing pigs

This study was aimed to explore the effects of dietary plant essential oil (PEO) supplementation on growth performance and meat quality in finishing pigs. A total of eighteen Duroc × Landrace × Yorkshire finishing barrows with an average initial body weight of 79.86 ± 1.94 kg were randomly assigned to CON group (fed with a basal diet) and PEO group (fed with the basal diet containing 200 mg/kg PEO) with 9 replicates per treatment. The trial lasted for 42 days. The results showed that dietary PEO supplementation significantly increased ADG during phase I (1-21 days) and the overall experimental period (p < 0.05), tended to increase ADFI in phase II (22-42 days) and the overall experimental period (p = 0.09), decreased F/G in phase I (p < 0.05) and tended to decrease F/G during the overall experimental period (p = 0.08). Meanwhile, compared to the CON group, the digestibility of DM, GE and EE in the PEO group was improved remarkably (p < 0.05). PEO supplementation also significantly improved T-AOC and lowered MDA content in longissimus dorsi (p < 0.05), tended to increase the activity of T-SOD (p = 0.06). A higher IMF content (p = 0.09) and a lower shear force (p = 0.08) of longissimus dorsi were found in the PEO group than that in CON group (p = 0.09). Furthermore, pigs fed the PEO diet showed higher mRNA abundances of GLUT4, LPL, CPT-1, CD36, FABP and LDL-R in the liver, and GLUT4 and FAS in the longissimus dorsi (p < 0.05). In conclusion, PEO fed to finishing pigs improved the growth performance and nutrient digestibility. Furthermore, PEO supplementation had the potential role to improve pork quality by increasing the antioxidant capacity and IMF content, and decreasing the shear force of longissimus dorsi to a certain extent.

Effects of Reduced Space Allowance and Heat Stress on Behavior and Eye Temperature in Unweaned Lambs: A Pilot Study

Simple Summary

In Europe, young lambs can be transported long distances for slaughter. While transport is regulated by E.U. law, there is a lack of research investigating the optimal transport conditions specifically for young lambs. For example, while the regulations set a minimum space allowance for lambs above 26 kg, no minimum is specified for young lambs meaning they can be transported in overcrowded conditions. Further, while the temperature within the vehicle must be maintained between 5–30 °C, this is well above the 21 °C said to be the upper end of the comfortable range for lambs. This study aimed to investigate how variation in space allowance and temperature can affect the welfare of young lambs. Three groups of lambs were created where either the density of individuals (0.27 vs. 0.20 m² per head) or the temperature range (12–18 °C vs. 19–30 °C) varied. Lambs housed in the higher density and heat stress groups showed more discomfort and higher body temperatures. In addition, lambs kept in the heat stress group lost weight over the course of the study, and showed signs of heat stress when the temperature exceeded 25 °C. These results indicate that the regulations for the transport of young lambs need to be refined.

Abstract

Current European animal transportation law contains only a few and vague indications concerning how to move lambs of less than 26 kg. Moreover, little information is available in the literature about factors affecting these lambs’ welfare. We investigated the effect of space allowance and ambient temperature on the welfare of unweaned Lacaune lambs during a simulation of long-distance transportation (19 h). Three groups of lambs (N = 130) were housed in equally sized pens for 19 h, Control (C; n = 39; 0.27 m² per head), Low Space Allowance (LSA; n = 52; 0.20 m² per head), and Heat Stress (HS; n = 39; 0.27 m² per head) groups. LSA lambs had lower space allowance than C but were tested at the same temperature, within their Thermoneutral zone (range = 12–18 °C). The HS lambs were, instead, subjected to higher temperatures (range = 19–30 °C). Scan sampling of behavior was conducted, eye temperature and body weight were also recorded. LSA and HS lambs showed more discomfort behaviors (p < 0.05) and higher eye temperatures (p < 0.001) compared to C lambs, while HS lambs additionally showed a decrease in body weight over the experimental period (p < 0.001). This study indicates that lower space allowances and higher temperatures impact negatively the welfare of lambs transported for slaughter suggesting that the regulation should be implemented taking these factors into account.

An early-postmortem metabolic comparison among three extreme acute heat stress temperature settings in chicken breast muscle

Normally, preslaughter acute heat stress could accelerate postmortem glycolysis and impair chicken breast (pectoralis major muscle) quality. However, previous studies indicated that it might be different when the acute heat stress temperature rises to an extreme range (above 35 °C). Therefore, this study's objectives were to compare the pH decline, glycolytic enzyme activity, and AMP-activated protein kinase (AMPK) phosphorylation at early postmortem among three extreme acute heat stress temperature settings: a control group (36 °C) and two experimental groups (38 °C and 40 °C). Although the temperature did not affect glycogen phosphorylase a and pyruvate kinase activity, there was a decrease in pH decline rate, phosphofructokinase-1 activity, and phospho-AMPK-α[Thr172] within 4 h postmortem when temperature increased from 36 to 40 °C. Temperature also affected hexokinase activity, with the 36 °C-group having the highest activity. The results of the current study, for the first time, indicated that postmortem metabolic rate in chicken breast muscle could be changed by acute heat stress temperature setting at extreme range.

Meta-analysis to predict the effects of temperature stress on meat quality of poultry

Temperature stress (TS) is a significant issue in poultry production, which has implications for animal health and welfare, productivity, and industry profitability. Temperature stress, including both hot (heat stress) and cold conditions (cold stress), is associated with increased incidence of meat quality defects such as pale, soft, and exudative (PSE) and dark, firm, and dry (DFD) meat costing poultry industries millions of dollars annually. A meta-analysis was conducted to determine the effect of ambient TS on meat quality parameters of poultry. Forty-eight publications which met specific criteria for inclusion were identified through a systematic literature review. Temperature stress was defined by extracting 2 descriptors for each treatment mean from the chosen studies: (1) temperature imposed for the experimental treatments (°C) and duration of temperature exposure. Treatment duration was categorized for analysis into acute (≤24 h) or chronic (>24 h) treatments. Meat quality parameters considered were color (L*-a*-b* scheme), pH (initial and ultimate), drip loss, cooking loss, and shear force. Linear mixed model analysis, including study as a random effect, was used to determine the effect of treatment temperature and duration on meat quality. Model evaluation was conducted by performing a k-fold cross-validation to estimate test error, and via assessment of the root mean square prediction error (RMSPE), and concordance correlation coefficient (CCC). Across both acute and chronic durations, treatment temperature was found to have a significant effect on all studied meat quality parameters. As treatment temperature increased, meat demonstrated characteristics of PSE meat and, as temperature decreased, meat demonstrated characteristics of DFD meat. The interaction between treatment temperature and duration was significant for most traits, however, the relative impact of treatment duration on the studied traits was inconsistent. Acute TS had a larger effect than chronic TS on ultimate pH, and chronic stress had a more considerable impact on color traits (L* and a*). This meta-analysis quantifies the effect of ambient TS on poultry meat quality. However, quantitative effects were generally small, and therefore may or may not be of practical significance from a processing perspective.

High-Condensed Tannin Diet and Transportation Stress in Goats: Effects on Physiological Responses, Gut Microbial Counts and Meat Quality

Feeding condensed tannin (CT)-containing diets such as sericea lespedeza (Lespedeza cuneata) and reducing stress have been reported to improve meat quality and food safety in goats. In a completely randomized design with split-plot, thirty-six uncastrated male Spanish goats were assigned to 3 dietary treatments (n = 12/treatment): ground 'Serala' sericea lespedeza hay (SER), bermudagrass (Cynodon dactylon) hay (BG), or bermudagrass hay-dewormed goats (BG-DW; Control) at 75% of intake, with a corn-based supplementation (25%) for 8 weeks. Prior to slaughter, goats were either transported for 90 min to impose stress or held in pens. Basophil counts were lower (p < 0.01) in the SER group compared to BG or BG-DW groups suggesting a better anti-inflammatory capacity due to polyphenols in the SER diet. Compared to BG-DW group, cortisol level was higher (p < 0.05) and norepinephrine was lower (p < 0.05) in the SER group. The SER group had the lowest aerobic plate counts (APC) in both rumen and rectum (p < 0.01). Longissimus dorsi muscle initial pH was not affected by diet or stress. Feeding sericea hay to goats may have beneficial effects, such as enhanced antioxidant and anti-inflammatory properties during stress and reduced gut microbial counts, without changing meat quality characteristics.

Disorders of the Reproductive Health of Cattle as a Response to Exposure to Toxic Metals

The aim of this review is to comprehensively present disorders of the reproductive system in cattle exposed to contact with toxic metals. Toxic metals are a common environmental pollutant and can come from mines, smelters, fossil fuel combustion, or volcanic eruptions. Metals have the ability to bioaccumulate in living organisms, thus contaminating the food chain and may pose a threat to humans. They accumulate mainly in the liver and kidneys, but also in muscles and fat tissue. Toxic metals such as lead (Pb), arsenic (As), mercury (Hg), and cadmium (Cd) have a negative impact on the fertility of animals; they can lead to abortions, premature calving, or oocyte dysfunction. Moreover, in the male reproductive system, they disrupt spermatogenesis, and cause apoptosis of sperm and oxidative damage. The main source of exposure of livestock to toxic metals is through the consumption of feed or contaminated water. It is important to monitor the level of heavy metals in animal products to prevent human poisoning. Toxic metal biomonitoring can be performed by testing urine, blood, milk, plasma, or hair. Chromium (Cr), arsenic (As), and cadmium (Cd) are excreted in the urine, while lead can be detected by examining the blood of animals, while in milk, arsenic (As), cadmium (Cd), nickel (Ni), and lead (Pb) can be detected. Moreover, toxic metals do not biodegrade in the environment. To purify soil and waters, remediation methods, e.g., biological or chemical, should be used.

Effects of stocking density and dietary vitamin C on performance, meat quality, intestinal permeability, and stress indicators in broiler chickens

The objective of the current study was to investigate the effects of stocking density (SD) and dietary supplementation of vitamin C on growth performance, meat quality, intestinal permeability, and stress indicators in broiler chickens. The study was conducted using a completely randomized design with a 2 × 2 factorial arrangement consisting of 2 different SD and 2 supplemental levels of dietary vitamin C. A total of 1,368 Ross 308 broiler chickens of 21 days of age with similar body weights (BW) were randomly allotted to 1 of 4 treatments with 6 replicates each. Different numbers of birds per identical floor pen (2.0 m × 2.4 m) were used to create 2 different SD levels of low SD (9 birds/m²) and high SD (18 birds/m²). The basal diet was formulated with no supplemental vitamin C to meet or exceed nutrient recommendations of the Ross 308 manual. The other diet was prepared by supplementing 200 mg/kg vitamin C in the basal diet. The study lasted for 14 days. At the end of the study, 3 male birds per replicate were selected to analyze meat quality, intestinal permeability, and stress indicators such as blood heterophil:lymphocyte (H:L) and feather corticosterone (CORT) concentrations. Results indicated that there were no interactions between different SD and dietary supplementation of vitamin C for all measurements. For the main effects of SD, birds raised at high SD had less (p < 0.01) BW, BW gain, and feed intake with increasing stress responses including greater blood H:L and feather CORT concentrations (p < 0.01) than those raised at low SD. Transepithelial electrical resistance in the jejunal mucosa was decreased (p < 0.05) at high SD, indicating an increase in intestinal permeability. However, the main effects of dietary supplementation of 200 mg/kg vitamin C were insignificant for all measurements. In conclusion, high SD of broiler chickens impairs growth performance and intestinal barrier function with increasing stress responses. However, dietary supplementation of vitamin C may have little beneficial effects on broiler chickens raised at the high SD condition used in the present study.

Validation of a Miniaturized Test Loop for the Assessment of Human Blood Damage by Continuous-Flow Left-Ventricular Assist Devices

Despite improved hemocompatibility of left-ventricular assist devices (LVADs), assessment of blood damage remains mandatory in preclinical testing as standardized by ASTM-F1841. The most relevant test fluid is fresh, non-pooled human blood, but the limited volume of a standard donation requires significantly smaller loops than those commonly used with animal blood. In a recent study with porcine blood, we verified a miniaturized test loop with only 160 mL for the ASTM-conform paired testing of at least two LVADs and a static reference. Here, we validated this mini test loop for standardized assessment of blood damage with one 450-mL single donation of fresh human blood. Blood damage was assessed for HeartMate 3 and BPX-80 in 9 experiments with heparinized human blood for 6 hours. We analyzed plasma free hemoglobin, von Willebrand factor (vWF) concentration and collagen-binding functionality and calculated indices of hemolysis and vWF-ratios. Overall, we observed less blood damage compared to our previous study; however, the differences in mean indices of hemolysis and in mean normalized vWF-ratio between BPX-80 and HeartMate 3 were consistent for human blood. Thus, our mini test loop proved to be valid for preclinical standardized assessment of blood damage with only 450 mL of fresh human blood.

Ultrasonication of beef improves calpain-1 autolysis and caspase-3 activity by elevating cytosolic calcium and inducing mitochondrial dysfunction

The objective of this study was to investigate if ultrasonication of bovine longissimus thoracis et lumborum (LTL) steaks increases calpain-1 and caspase-3 activities, and if so, to explore the underlying mechanisms that trigger their activation. Post-rigor bovine LTL steaks were subjected to ultrasonication at 40 kHz and 12 W/cm² for 40 min and subsequently aged for 14 d at 4 °C. Ultrasonication improved beef tenderness (P < 0.05) without negatively impacting pH, color, or cook loss (P > 0.05). Improved tenderness in the ultrasonicated steaks was associated with greater degradation of titin, desmin, troponin-T, and calpastatin and increased calpain-1 autolysis and caspase-3 activity (P < 0.05). In addition, ultrasonicated steaks had greater levels of cytosolic calcium and reactive oxygen species and lower mitochondrial oxygen consumption rate (P < 0.05). These data indicate that improved beef tenderness following ultrasonication is, in part, a function of increased calpain-1 and caspase-3 activities, potentially by elevating cytosolic calcium and inducing mitochondrial dysfunction, respectively.

Oxidative stress and postmortem meat quality in crossbred lambs

The objective of this study was to evaluate effects of different levels of lipopolysaccharide (LPS)-mediated oxidative stress on fresh meat quality. Crossbred lambs (n = 29) were blocked by weight and fed a standard finishing ration for the duration of the study. Lambs were individually housed and treatment groups were administered one of three intravenous injections every 72 h across a three-injection (9-day) cycle: saline control (control), 50 ng LPS/kg body weight (BW) (LPS50), or 100 ng LPS/kg BW (LPS100). Rectal temperatures were measured to indicate inflammatory response. Lambs were harvested at the Loeffel Meat Laboratory and 80 mg of pre-rigor Longissimus lumborum were collected in control and LPS100 treatments within 30 min postmortem for RNA analysis. Wholesale loins were split and randomly assigned 1 or 14 d of wet aging. Chops were fabricated after aging and placed under retail display (RD) for 0 or 7 d. Animal was the experimental unit. LPS-treated lambs had increased (P < 0.05) rectal temperatures at 1, 2, 4, and 24 h post-injection. Transcriptomics revealed significant (Praw < 0.05) upregulation in RNA pathways related to generation of oxidative stress in LPS100 compared with control. A trend was found for tenderness (Warner-Bratzler shear force, WBSF; P = 0.10), chops from LPS50 having lower shear force compared with control at 1 d postmortem. Muscle from LPS50 treatment lambs exhibited greater troponin T degradation (P = 0.02) compared with all treatments at 1 d. Aging decreased WBSF (P < 0.0001), increased sarcoplasmic calcium concentration (P < 0.0001), pH (P < 0.0001), and proteolysis (P < 0.0001) across treatments. Following aging, chops increased discoloration as RD increased (P < 0.0001), with control chops aged 14 d being the most discolored. Chops from lambs given LPS had higher (P < 0.05) a* values compared with control at 14 d of aging. The L* values were greater (P < 0.05) in LPS100 compared with both LPS50 and control. Aging tended (P = 0.0608) to increase lipid oxidation during RD across either aging period. No significant differences (P > 0.05) in sarcomere length, proximate composition, fatty acid composition, or isoprostane content were found. These results suggest that defined upregulation of oxidative stress has no detriment on fresh meat color, but may alter biological pathways responsible for muscle stress response, apoptosis, and enzymatic processes, resulting in changes in tenderness early postmortem.

Current Knowledge on River Buffalo Meat: A Critical Analysis

Simple Summary

Buffaloes are reared for different purposes, primarily for milk and dairy products. Meat is often a secondary product and mainly derives from old animals at the end of their productive or working life. However, in recent years buffalo meat has gained increased popularity due to its nutritional properties. Therefore, a huge economic potential might arise from the development of the meat sector in buffalo breeding. This review provides an overview of the recent advances in the knowledge on river buffalo meat, with a special focus on quality traits, and offers insights for future research aimed at improving the meat sector in this species.

Abstract

The estimated world population of water buffalo counts around 204 million head, mostly reared for milk production. However, buffaloes also largely contribute to the meat sector, with around 4.3 million tonnes produced in 2019, mainly derived from old animals at the end of their productive or working life and only to a small extent from young animals. Therefore, buffalo meat production has been generally considered unsatisfactory for both quantity and quality. In fact, the dressing percentage is generally lower than 50% and the meat is considered of poor quality mainly due to its dark colour and reduced tenderness. However, in recent years, the healthy properties highlighted by some studies have led to a renewed interest in buffalo meat, with a parallel increase in research. Therefore, this review aims at providing an updated picture on carcass and meat quality traits in river buffalo, with special attention to the intrinsic and extrinsic factors contributing to their variability. The research done so far has demonstrated that river buffaloes can efficiently contribute to the quanti-qualitative production of meat, provided that the meat supply chain is specifically organised for this purpose. The analysis of the available data also showed that further research is needed on the factors affecting meat production in order to gain greater knowledge essential for planning more targeted interventions.

Tracking structural modifications and oxidative status of myofibrillar proteins from silver carp (Hypophthalmichthys molitrix) fillets treated by different stunning methods and in vitro oxidizing conditions

In order to explain the increased susceptibility of stunning-stressed fillets to oxidative modifications, effect of stunning methods (percussion and gill cut) and in vitro metal-catalyzed oxidation on structural changes and oxidative status of myofibrillar proteins (MPs) from silver carp fillets was examined. In comparison to the percussion group, oxidized MPs (10 mM H₂O₂) from gill cut-stunned fillets exhibited higher extent of structural disintegration as well as elevated carbonyl levels. Using label-free proteomics, isoforms of myosin heavy chain and actin were major proteins underwent oxidative modifications including monooxidation of methionine, dioxidation of aromatic amino acids, adduction of lipid peroxidation products with aliphatic amino acids, and the carbonylation of lysine and arginine into semialdehydes. In addition, amino acids located at the tail portion of myosin were highly accessible to oxidation. Owing to the structural disorganization caused by stunning stress, MPs from gill cut-stunned fillets were more susceptible to oxidation in vitro.

Plasma metabolomic profiles as affected by diet and stress in Spanish goats

The effects of high-condensed tannin (CT) diet combined with preslaughter stress have not been studied at the metabolome level in goats. This study was conducted to determine the effects of feeding sericea lespedeza (SL; Lespedeza cuneata), a high-CT legume, and transportation stress on plasma metabolome in goats. Uncastrated male Spanish goats (age = 8 months; BW = 26.0 ± 0.48 kg) were either fed ground 'Serala' SL hay (SER), bermudagrass (Cynodon dactylon) hay (BG), or bermudagrass hay-dewormed goats (BG-DW; Control) at 75% of intake, with a corn-based supplementation (25%) for 8 weeks (n = 12/Diet). At the end of the trial, goats were subjected to one of two stress treatments (ST): transported for 90 min to impose stress (TS) or held in pens (NTS) before slaughtering, in two replicates. Live and carcass weights, and blood samples were collected at 0, 30, 60 and 90 min of transportation or holding time (Time). The data were analyzed using MIXED procedures in SAS and metabolomics data were analyzed using the R software. When measured after ST, SER group had the lowest body weight (P < 0.05) among the three diet groups. Carcass weights were high in the BG-DW, low in SER, and intermediate in BG group. Plasma creatine concentrations decreased over Time (P < 0.01) in the TS goats in all diet groups. Meat crude protein percentages were higher (P < 0.05) in SER (22.5 ± 0.22) and BG-DW (22.3 ± 0.22) groups compared to the BG group (21.6 ± 0.22). At the metabolome level, SER group had the lowest (P < 0.05) glycine, alanine, threonine, taurine, trans-hydroxyproline, methionine, and histidine concentrations and highest (P < 0.01) lysine and citrulline concentrations among the Diet groups. Butyric acid, concentration was higher (P < 0.05) in the SER group compared to BG group. Eight medium- and long-chained acylcarnitines were higher (P < 0.05) in the BG-DW group than SER or BG groups. In general, amino acid levels decreased and acylcarnitine increased with Time (P < 0.05) in all groups. Sericea diet can be beneficial in enhancing stress coping abilities in goats due to elevated butyrate, lysine, and citrulline levels; however, SER resulted in lower energy level in goats compared to BG or BG-DW groups. Fatty acid metabolism is the main energy pathway in all groups during prolonged stress. Inclusion of certain varieties of SL in the diet must be carefully controlled to prevent possible negative effect.

Relationship Between Meat Quality, Carcass Characteristics, and Protein Abundance of HSPβ1, HSPA, and DJ1 in Beef Longissimus thoracis Pre-Rigor or After 14 Days’ Aging

This study evaluated associations of heat shock proteins (HSP) and an oxidative stress protein, protein deglycase (DJ1), with beef quality and tenderness. Samples from the longissimus thoracis (N = 99) were collected pre-rigor (day 0) and after 14-d aging. Warner-Bratzler shear force (WBSF), myofibrillar fragmentation index (MFI), and a trained sensory panel were used to determine meat quality. Protein abundance of DJ1 and 2 HSP—HSPβ1 and HSPA—were assessed. Regression analyses demonstrated that DJ1 abundance after 14 d of aging is a predictor of WBSF (P &lt; 0.001), MFI (P = 0.02), and sensory panel tenderness (P &lt; 0.001). Abundance of HSPβ1 after 14 d of aging is also a predictor of MFI (P = 0.03). Additionally, abundance of both HSPβ1 and DJ1 pre-rigor are predictors of juiciness (P &lt; 0.05). Abundance of HSPβ1 pre-rigor was correlated with WBSF (R = 0.67), sensory panel tenderness (R = −0.44), juiciness (R = −0.30), and umami (R = −0.20). Abundance of DJ1 pre-rigor was also correlated with WBSF (R = 0.72), sensory panel tenderness (R = −0.44), juiciness (R = − 0.24), and umami (R = −0.31). After 14-d aging, HSP β 1 abundance was cor- related with WBSF (R = 0.66), sensory panel tenderness (R = −0.34), juiciness (R = −0.34), umami (R = −0.33), and brown/ roasted (R = −0.30). Abundance of DJ1 after 14-d aging was also correlated with WBSF (R = 0.68), sensory panel tenderness (R = −0.41), juiciness (R = −0.21), and umami (R = −0.28). These results demonstrate that abundance of HSPβ1 and DJ1 both pre-rigor and after 14 d of aging are correlated with meat tenderness and end-product quality as assessed by a trained sensory panel. Regression analyses further reveal that abundance of DJ1 and HSPβ1 after 14 d of aging is causative in development of beef tenderness and juiciness, respectively. Taken together, these results suggest that abundance of DJ1 is a predictor of tenderness, whereas abundance of HSPβ1 is related to meat quality but cannot be used to predict tenderness.

Slaughter Conditions and Slaughtering of Pregnant Cows in Southeast Nigeria: Implications to Meat Quality, Food Safety and Security

The increase in the slaughter of pregnant cows (SPCs) for meat (except as may be approved by veterinarians on health grounds to salvage the animal) is unethical. SPCs for meat is also counterproductive, detrimental to food security, and may enhance zoonotic disease transmission. In this context, therefore, this current study examined slaughter conditions and the slaughtering of pregnant cows, and the implications for meat quality, food safety, and food security in Southeast Nigeria. The direct observational method was employed to examine the slaughterhouse activities, from when the cattle arrived at the lairage to the post-slaughter stage. A pre-tested and validated closed-ended-questionnaire was used to elicit information on causes of the SPCs and the method of disposal of eviscerated foetuses. Pregnancy status of cows slaughtered was determined by palpation followed by visual examination of the eviscerated and longitudinal incised uteri. The study lasted for six months during which 851 cows out of 1931 slaughtered cattle were surveyed. Assessment/decision-making protocol of slaughterhouse conditions, welfare conditions of slaughter-cattle, reasons for sale or slaughter of pregnant cows, distribution of pregnant cows slaughtered, method of disposal of eviscerated foetuses, and estimated economic losses of SPCs were delineated. Of the 851 cows examined, 17.4% (148/851) were pregnant while 43.2% (64/148) of the total foetuses recovered were in their third trimester. Major reasons adduced for SPCs by proportion of involved respondents were: ignorance of the animals' pregnancy status (69.7%, 83/119), high demand for beef (61.3%, 73/119), preference for large-sized cattle (47.9%, 57/119), economic hardship (52.1%, 62/119) and diseases conditions (42.9%. 51/119). The conduct of SPCs for meat would not be profitable. This is because within six months, an estimated loss of about 44,000 kg of beef, equivalent to ₦ 70.1 million or $186,400 would be associated with SPCs and the consequential foetal wastages. If losses were to be replicated nationwide across slaughterhouses, 4.3 tons of beef estimated at ₦ 8.6 billion or $23 million would be wasted. Improving slaughter conditions and the welfare of slaughter-cattle in Nigerian slaughterhouses through advocacy, training of slaughterhouse workers, and strict implementation of laws promoting humane slaughter practices is imperative. Preventing SPCs for meat and inhumane slaughter practices at the slaughterhouse would enhance the welfare needs of slaughter cattle, grow the national herd size, and improve meat safety as well as food security.

Ca2+ as activator of pseudoperoxidase activity of pigeon, Eurasian woodcock and chicken myoglobins: New features for meat preservation studies

Myoglobin (Mb), hemeprotein that binds dioxygen in muscle, affects meat colour. Moreover, in presence of peroxides, metMb is a potent oxidant involved in oxidative rancidity in meat. Here, following pigeon Mb purification and primary structure mass spectroscopy characterization, we determined its autoxidation rate and pseudoperoxidase activity with respect to chicken and E. woodcock Mbs. The three Mbs exhibit different autoxidation rates (0.153-h^-1 pigeon, 0.194-h^-1 chicken and 0.220-h^-1 E. woodcock Mbs) and similar specificity constant (9.86x10³ M^-1s^-1 pigeon, 8.81x10³ M^-1s^-1 chicken and 9.90x10³ M^-1s^-1 E. woodcock Mbs), considering their pseudoperoxidase activity. Moreover, for the first time, we detected an increase in pseudoperoxidase activity in presence of Ca²⁺, particularly at pH 5.8. NMR and CD data indicate that the nonspecific Ca²⁺ binding induces small local structural rearrangements that in turn slightly reduce pigeon Mb thermal stability. However, considering Ca²⁺ concentration variations before and post-mortem, this finding must be considered for meat preservation.

Dietary taurine attenuates hydrogen peroxide-impaired growth performance and meat quality of broilers via modulating redox status and cell death signaling

Oxidative stress seriously affects poultry production. Nutritional manipulations have been effectively used to alleviate the negative effects caused by oxidative stress. This study investigated the attenuating effects and potential mechanisms of dietary taurine on the growth performance and meat quality of broiler chickens challenged with hydrogen peroxide (H2O2). Briefly, a total of 192 male Arbor Acres broilers (28 d old) were randomly categorized into three groups: non-injection of birds on basal diets (control), 10.0% H2O2 injection of birds on basal diets (H2O2), and 10.0% H2O2 injection of birds on basal diets supplemented with 5 g/kg taurine (H2O2 + taurine). Each group consisted of eight cages of eight birds per cage. Results indicated that H2O2 administration significantly reduced growth performance and impaired breast meat quality by decreasing ultimate pH and increasing shear force value (P < 0.05). Dietary taurine improved the body weight gain and feed intake and decreased feed/gain ratio of H2O2-challenged broilers. Meanwhile, oxidative stress induced by intraperitoneal injection of H2O2 suppressed the nuclear factor-κB (NF-κB) signaling and initiated autophagy and apoptosis. Compared with the H2O2 group, taurine supplementation restored the redox status in the breast muscle by decreasing levels of reactive oxygen species and contents of oxidative products and increasing antioxidant capacity (P < 0.05). Moreover, upregulated mRNA expression of NF-κB signaling-related genes, including NF-κB subunit 1 (p50) and B-cell CLL/lymphoma 2 (Bcl-2), and enhanced protein expression of NF-κB were observed in the H2O2 + taurine group (P < 0.05). Additionally, dietary taurine decreased the expression of caspase family, beclin1, and microtubule-associated protein 1light chain 3 beta (LC3-II; P < 0.05), thereby rescuing autophagy and apoptosis in breast muscle induced by H2O2. Collectively, dietary supplementation with taurine effectively improves growth performance and breast meat quality of broilers challenged with H2O2, possibly by protecting against oxidative injury and modulating cell death signaling.

Research Note: Comparison of histochemical characteristics, chicken meat quality, and heat shock protein expressions between PSE-like condition and white-stripping features of pectoralis major muscle

The present study compared the histochemical and meat quality characteristics of broiler pectoralis major (PM) muscle among the groups categorized according to muscle abnormalities, including pale, soft, and exudative (PSE)-like condition and white-striping (WS) feature. Additionally, this study investigated the associations between muscular abnormalities and expression levels of heat shock proteins (HSPs), including αβ-crystallin, HSP70, and HSP90, at the early postmortem period. The WS breasts with normal quality condition showed greater PM muscle weight and were more associated with fiber hypertrophy, compared to the no WS breasts with PSE-like condition (P < 0.05). The PSE-like group exhibited paler surface color and tougher meat, causing more fluid loss after cooking, compared to the normal quality group (P < 0.05). However, there were no significant differences in the quality traits between the WS groups (P > 0.05), except for lightness and cooking loss. Higher αβ-crystallin and HSP90 expression levels were observed in PSE-like breast compared to normal quality breast (P < 0.05), whereas WS pattern was not related with HSPs levels (P > 0.05). Therefore, HSP levels at the early postmortem period, especially those of αβ-crystallin and HSP90, were associated with the breast quality characteristics of PSE-like condition broilers.

Hepatic Oxidative Stress, Apoptosis, and Inflammation in Broiler Chickens With Wooden Breast Myopathy

Wooden breast (WB) syndrome has emerged as a global myopathy in modern commercial broiler chickens, mainly affecting the pectoralis major muscle. Recent evidence suggests that WB myopathy is a systemic disease, which might be accompanied by other physiological disparities and metabolic changes. This study was conducted to systemically investigate the potential physiological changes in liver tissues as well as the possible mechanisms involved to enhance the understanding of the etiology. A total of 93 market-age Arbor Acres male broiler chickens were sampled and categorized into control (CON) and WB groups based on the evaluation of myopathic lesions. Liver samples were collected (n = 10 in each group) for histopathological evaluation and biochemical analyses. Results indicated that WB birds exhibited significantly higher plasma aspartate amino transferase, alkaline phosphatase, and gamma glutamyl transpeptidase activities. Histopathological changes in hydropic/fatty degeneration, inflammatory cell infiltration, intrahepatic hemorrhages, elevated myeloperoxidase activity, and overproduction of nitric oxide were observed in WB liver compared with CON, suggesting the occurrence of liver injury in birds affected by WB myopathy. The WB group showed increased levels of reactive oxygen species, oxidative products, as well as enhanced antioxidant capacities in the liver. These changes were associated with impaired mitochondria morphology and mitochondrial dysfunction. WB myopathy also induced mitochondria-mediated hepatic apoptosis by upregulating levels of caspases 3 and 9, altering the expressions of apoptotic B-cell lymphoma-2 family regulators, as well as increasing the release of cytochrome c. The activation of nuclear factor kappa-light-chain-enhancer of activated B cell signaling enhanced the mRNA expression of downstream inflammatory mediators, contributing to the production of inflammatory cytokines in WB liver. Combined, these findings suggest that hepatic disorders may be conjoined with WB myopathy in broiler chickens and indicating systemic physiological disparities, and other metabolic changes accompanying this myopathy need further assessment.

Phenolic compounds as natural feed additives in poultry and swine diets: a review

Due to ban on using antibiotics in feed industry, awareness of using natural feed additives have led to a great demand. The interest of plants phenolic compounds as a potential natural antioxidant source has been considered in research community due to their predictable potential role as feed additives in poultry and swine production. However, the mode of action for their functional role and dosage recommendation in animal diets are still remain indistinct. Taking into account, the present review study highlights an outline about the mode of action of phenolic compound and their experimental uses in poultry and swine focusing on the growth performance, antioxidant function, immune function, antimicrobial role and overall health status, justified with the past findings till to date. Finally, the present review study concluded that supplementation of phenolic compounds as natural feed additives may have a role on the antioxidant, immunity, antimicrobial and overall production performance in poultry and swine.

Association between animal welfare indicators and microbiological quality of beef carcasses, including Salmonella spp., from a slaughterhouse in Ecuador

BACKGROUND AND AIM

Pre-slaughter management and slaughter operations are considered critical factors for animal welfare and meat quality. Previous studies have found poor animal welfare management at municipal slaughterhouses in Ecuador, and little is known about how this affects the microbiological quality of the meat. Therefore, the aim of the study was to analyze the association of the microbiological quality of beef carcasses and animal welfare indicators in a municipal slaughterhouse in Ecuador.

MATERIALS AND METHODS

Data for 6 months were collected from a municipal slaughterhouse in Ecuador. Five trained researchers were strategically located along the slaughter process. A total of 351 animals were observed with regard to welfare indicators, and their carcasses were sampled to evaluate microbiological quality. Antemortem (slipping, falling, and vocalization) and postmortem animal welfare indicators (bleed interval, pH, temperature, and bruises) were measured. To determine the total aerobic bacteria (TAB) and Escherichia coli counts and the presence of Salmonella spp., we collected samples by swabbing four different points of each carcass. The association between microbiological quality and animal welfare indicators was studied using univariate and multivariate logistic regressions.

RESULTS

The mean TAB count was 5.3 log CFU/cm2, and the mean total count of E. coli was 2.4 log CFU/cm2. Salmonella spp. were isolated in 3.1% of the carcasses. An electric goad was used in all animals, 19.1% slipped at least once, and 19.9% vocalized. The mean pH of the carcasses was 7.2, and 79.2% of carcasses had bruises. Multivariate analysis showed that Salmonella spp. and the TAB count were associated with pH and the number of bruises (p = 0.01 in both cases).

CONCLUSION

Although there was non-significant association between the majority of animal welfare indicators and microbiological quality, the poor management affecting animal welfare and carcass hygiene are worrisome.

Puerarin improved growth performance and postmortem meat quality by regulating lipid metabolism of cattle under hot environment

This study aims to evaluate the effect of puerarin on performance, meat quality, and serum indexes of beef cattle under hot environment. Thirty-two bulls were divided into four groups and fed diet supplemented with puerarin at 0, 200, 400, or 800 mg/kg. Results showed that heat stress was employed for 54 out of 60 days, 400 mg/kg group declined serum cortisol (COR) contents, all treatments increased the contents of total cholesterol, high density lipoprotein cholesterol, and total superoxide dismutase activity; in addition, glutathione peroxidase activity of 200 mg/kg group were enhanced, only 800 mg/kg group enhanced immunoglobulin (IgA, IgM, and IgG) and low density lipoprotein cholesterol contents compared with the control (p < .05). Moreover, 400-mg/kg puerarin increased serum growth hormone levels compared with 200 mg/kg group but declined COR concentrations compared with 200 mg/kg and 800 mg/kg groups (p < .05). More importantly, average daily gain and daily matter intake, and intramuscular fat contents of 400 mg/kg group were enhanced, but the shear force of beef in 400 mg/kg and 800 mg/kg groups were declined compared with the control (p < .05). These findings indicated that supplemental with puerarin enhanced immune and antioxidant, and 400 mg/kg of puerarin improved performance and meat quality by normalizing levels of stress hormones and increasing intramuscular fat deposition of beef cattle under hot environment.

Proximate Composition, Amino Acid Profile, and Mineral Content of Four Sheep Meats Reared Extensively in Morocco: A Comparative Study

This study aimed to compare the organoleptic and nutritional quality of four sheep meats produced in Morocco. This comparison was carried out by analyzing the proximate composition, amino acid profile, and mineral content of meat. The majority of the evaluated parameters were influenced by genetic and geographical factors (p < 0.05). The longissimus lumborum muscle had higher a^∗ value in Timahdite and Ouled-Djellal breeds. The highest values of macroelement were recorded in samples of Beni-Guil meat sampled in the Tendrera region (BGT; 1067.3 mg/100 g), while the highest microelement content was registered in Timahdite meat (5.7 mg/100 g). Iron and zinc were the major identified trace elements, while phosphorus and potassium were the most abundant macroelements. The abundant amino acid was glutamic, while cysteine and methionine were least abundant. The higher essential amino acids index (IEAA) was recorded in the Timahdite sheep meat (162.20, 158.71, 161.02, and 159.65, respectively, for Timahdite, BGT, Ouled-Djellal breeds, and Beni-Guil meat sampled in Ain Beni Mathar region). From a nutritional point of view, the studied meats had a good protein and mineral quality, due to their richness in essential amino acids and microelements. The present study provided new insights on the organoleptic quality and the nutritional value of three Moroccan sheep meats reared in outdoor production system.

Radix Puerarin Extract (Puerarin) Could Improve Meat Quality of Heat-Stressed Beef Cattle Through Changing Muscle Antioxidant Ability and Fiber Characteristics

The experiment was conducted to investigate the effects of dietary supplementation with Puerarin on meat quality, muscle antioxidant ability, and muscle fiber characteristics of beef cattle under a hot environment in summer. Thirty-two 15 ± 1.5-month-old Jinjiang bulls (291.65 ± 8.84 kg) were randomly divided into four groups with dietary Puerarin at 0 (control), 200 (Pue200), 400 (Pue400), and 800 (Pue800) mg/kg in the feed concentrate (n = 8). The feeding trial lasted for 60 days after a 10-day adaptation period (July 1-September 8); the average values of temperature, relative humidity and temperature, and humidity index were 30.68°C, 68.05%, and 81.81, respectively. The growth performance on day 40 of the experiment period was calculated. After 60 days' experimental period, four Jinjiang cattle per treatment from the control group, Pue400 group, and Pue800 group were slaughtered. Compared with the control group, the Pue400 and Pue800 groups improved the growth performance of beef cattle; the Pue800 group elevated the activities of superoxide dismutase, total antioxidant capacity, and glutathione peroxidase in the M. longissimus thoracis (LT) muscle. In the control group, the cell membrane was incomplete, and most of the mitochondria were elongated and in a fission state, while in the Pue400 and Pue800 groups, the cell membrane was clear and complete, and the mitochondria presented with round and oval shapes. Compared with the control group, the Pue400 and Pue800 groups reduced the shear force of the LT muscle, and the Pue400 group decreased the muscle fiber diameter and the myosin heavy-chain (MyHC)-IIb gene expression. Furthermore, the Pue400 and Pue800 groups decreased the ratio of AMP/ATP, the Pue800 group reduced the AMP-activated protein kinase α2 mRNA expression, and the Pue400 group improved the nuclear respiratory factor 1 mRNA expression. These results indicated that dietary supplementation with Puerarin might be beneficial to the meat quality of heat-stressed beef cattle by improving muscle antioxidant ability and reducing the MyHC-IIb muscle fiber composition. Based on the results of this study, we recommended 400 mg/kg Puerarin in the feed concentrate of beef cattle (~300 kg) for mitigation of heat stress.

Water holding capacity of Swamp Buffalo muscles raised with and without proper herd health

Fresh meat is composed of 70-75% water. Meanwhile, water holding capacity (WHC) affects storage quality, appearance, eating experience, and also contributes to loss of profit for meat entrepreneurs. WHC is influenced by the species, sex, breed, farming practices, as well as post-slaughter storage and handling. Swamp buffalo meat is leaner compared to cattle, goats, and sheep. Therefore, this study aims to determine the WHC of swamp buffalo muscles raised with two herd health programs at different aging periods. A total of 24 months old male swamp buffalo (n=4) was raised with a proper herd health protocol (HHP) and another (n=6) without a proper herd health protocol (NHHP). The drip loss (DL), thawing loss (TL), and cooking loss (CL) for longissimus dorsi (LD), supraspinatus (SS), and semitendinosus (ST) muscles were evaluated on day 1, 7, and 14. Based on the results, only SS and ST from NHHP showed significant differences (P≤0.05), while DL, LD, SS, and ST of the HHP and NHHP also differed significantly (P≤0.05). Furthermore, the TL and CL for all the muscles showed significant differences (P≤0.05) at day 7 of aging in the NHHP group, while on day 14, both were significantly higher in LD and ST muscles of NHHP compared to the HHP group. Therefore, the results showed that the muscles of the HHP group had a better WHC compared to NHHP.

Effect of pomegranate (Punica granatum L) peel powder meal dietary supplementation on antioxidant status and quality of breast meat in broilers

This study examined the antioxidant status and quality of breast meat in broiler birds fed diets supplemented with pomegranate peel powder meal (PPPM). During the 35-d feeding trial, broiler birds were fed six experimental diets: diet with 0% additives (negative control; NEGCON); diet with α-Tocopherol acetate at 200 g/tonne (positive control; POSCON); and four levels (2, 4, 6 and 8 g/kg) of PPPM, designated as PPPM₂, PPPM₄, PPPM₆, and PPPM₈. Breast muscle pH was determined 15mins and 24hrs postmortem. The breast muscles were then stored at 4 °C to determine shelf-life attributes (pH, colour, hue angle, and chroma) for 16 days. Meat from the 8 g/kg PPPM had the highest thawing loss, whereas cooking loss was lowest at 2 g/kg PPPM inclusion. The meat of birds fed 2 g/kg and 4 g/kg PPPM had the highest (P<0.05) ability to scavenge the ABTS [(2, 2-azinobis (3ethylbenzothiazoline-6 sulfonic acid))] radical cation (ABTS⁺), whereas, catalase activity was increased at 8 g/kg PPPM. The results obtained in this study indicate that 2 g/kg supplementation of pomegranate peel powder meal significantly improved the water-binding capacity of broiler breast meat, owing to the reduced cooking loss of the meat, and meat from the PPPM₂ (2 g/kg) group had the highest ability to scavenge ABTS.

Nutritional Properties and Oxidative Indices of Broiler Breast Meat Affected by Wooden Breast Abnormality

Wooden breast (WB) abnormality adversely impacts the quality of chicken meat and has been linked with oxidative stress. In this study, breast samples were taken from carcasses of 7-week-old Ross 308 broilers 20-min and 24-h postmortem. Five WB and seven non-WB control samples were assigned based on palpatory hardness (non-WB = no unusual characteristics and WB = focal or diffused hardness). WB exhibited lower contents of protein and the amino acids, i.e., isoleucine, leucine and valine, lighter surface color, lower shear force, greater drip loss and altered mineral profiles (p ≤ 0.05). Despite no difference in lipid oxidation, a greater degree of protein oxidation was found in the WB meat (p ≤ 0.05). Absolute transcript abundances of superoxide dismutase, hypoxia inducible factor 1 alpha and pyruvate dehydrogenase kinase 1 were greater in WB (p ≤ 0.05), whereas lactate dehydrogenase A expression was lower in WB (p ≤ 0.05). The findings support an association between oxidative stress and the altered nutritional and technological properties of chicken meat in WB.