Effect of diet finishing mode (pasture or mixed diet) on antioxidant status of Charolais bovine meat

Identifying biomarkers of sheep welfare using a metabolic discrepancy model

The welfare of an animal is largely determined by the transient state within them that relates to what they experience. We evaluated candidate biomarkers of mental state and experience from human biomedicine as possible welfare biomarkers for sheep using a metabolic energy discrepancy model. The metabolic status of female Merino sheep was altered over three periods to induce changes in their experience and coping capacity. The first group was fed at maintenance for all periods (n = 11); the second group was fed above maintenance in period 1, at maintenance in period 2, and below maintenance in period 3 (n = 12); and the third group was fed below maintenance in period 1, at maintenance in period 2, and above maintenance in period 3 (n = 11). An isolation box test was used at the start and end of each feed period to assess the coping capacity of each sheep. Our results indicated that two of the five candidate biomarkers, insulin-like growth factor 1 and thiol oxidation, were associated with positive and negative experiences in the sheep, respectively. Future research should validate these biomarkers in sheep with other testing paradigms and in other ruminant species.

Meat Quality of Dairy and Dairy × Beef Steers Reared in Two Production Systems Based on Forages and Semi-Natural Pastures

To safeguard an agricultural landscape with high biodiversity, livestock grazing on semi-natural pastures is crucial, and steers are well suited to such production systems. This study compared meat quality, including technological traits, sensory attributes, and fatty acid composition, of purebred dairy steers (D) and dairy × beef crossbreed steers (C), reared in two distinct production systems. Sixty-four steers (thirty-two per breed type) were included. Half were kept in a production system that had relatively high feed intensity (H), with one grazing summer on semi-natural pastures and slaughtered at 21 months of age. The other half were kept in a production system that had low feed intensity (L), with two grazing summers on semi-natural pastures and slaughtered at 28 months. Colour, water holding capacity, Warner-Bratzler shear force, sensory attributes, and fatty acid profiles were measured on the Musculus longissimus lumborum. Meat from L steers with two grazing seasons was darker (p = 0.003) and contained a higher proportion of unsaturated fatty acids (p = 0.006) than meat from more intensively reared H steers. Meat from C steers was perceived as having a coarser fibre structure (p = 0.022) with an acidic odour (p = 0.040) compared to D steers. Additionally, cooked meat from L steers was evaluated as having a pinker appearance by an analytical sensory panel (p = 0.008). In summary, breed type and production system had no major effect on technological and sensory attributes for forage and pasture-fed steers, but fatty acid composition was improved with more unsaturated lipids in meat from L steers.

Challenges and opportunities in characterisation of phytochemicals in pasture-fed meat produce

Consumers are becoming increasingly concerned with the origin, welfare, and nutritional quality of meat they consume. Existing literature suggests that pasture-fed livestock can absorb phytonutrients from their feed into their meat. Advanced analytical methods such as liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) have now made it possible to identify plant-derived non-volatile compounds in meat. These biomarkers are crucial for authenticating pasture-fed meat to underpin stringent meat quality regulations and assurance systems, thus enhancing industry reputation and competitiveness. Studies have shown that animals fed with a diet rich in phytochemicals exhibit higher total polyphenol content (TPC) in their muscle compared to those fed with a concentrate diet. However, there is limited information available on the bioavailability of phytochemicals in meat. The aim of this review is to comprehensively analyse the latest methods for extracting, purifying, and characterising non-volatile biomarkers in meat, and to evaluate their effectiveness as indicators of meat authenticity and nutrition.

Finding biomarkers of experience in animals

At a time when there is a growing public interest in animal welfare, it is critical to have objective means to assess the way that an animal experiences a situation. Objectivity is critical to ensure appropriate animal welfare outcomes. Existing behavioural, physiological, and neurobiological indicators that are used to assess animal welfare can verify the absence of extremely negative outcomes. But welfare is more than an absence of negative outcomes and an appropriate indicator should reflect the full spectrum of experience of an animal, from negative to positive. In this review, we draw from the knowledge of human biomedical science to propose a list of candidate biological markers (biomarkers) that should reflect the experiential state of non-human animals. The proposed biomarkers can be classified on their main function as endocrine, oxidative stress, non-coding molecular, and thermobiological markers. We also discuss practical challenges that must be addressed before any of these biomarkers can become useful to assess the experience of an animal in real-life.

Effect of beef long-storage under different temperatures and vacuum-packaging conditions on meat quality, oxidation processes and microbial growth

BACKGROUND

The global beef market demands the meat industry to ensure product quality and safety in markets that are often very distant. The present study aimed to evaluate the effects of chilled (CH, 120 d) and chilled-then-frozen (CHF, 28 d + 92 d) storage conditions of beef vacuum packaged (VP) and vacuum packaged with antimicrobial (VPAM) on meat quality, oxidative status and microbial loads. Treatments resulted from the combination of storage condition and packaging type: VP + CH, VP + CHF, VPAM + CH and VPAM + CHF.

RESULTS

Warner-Bratzler shear force values decreased in all treatments after 28 d of chilling. Except for VP + CH, L* values (lightness) of meat color did not differ in each treatment as the storage time increased. Meat from VP + CH had greater a* values than CHF treatments on day 120 of storage. A consumer panel did not detect differences in tenderness, flavor and overall liking between VP and VPAM beef, but they preferred CHF steaks rather than CH beef. TBARS values did not differ between VP and VPAM and between CH and CHF at any time during the storage period. At the end of storage time, all treatments except VP + CHF presented a greater concentration of thiols than at 48 h post-mortem. On day 120 of storage, VP + CH had greater catalase enzyme activity than CHF treatments while VP + CH and VP + CHF showed a greater superoxide dismutase activity than VPAM + CHF. Storage condition (CH or CHF) had a greater impact on microbial counts than the type of packaging.

CONCLUSION

Freezing meat after an ageing period represents a suitable strategy to extend beef storage life without a detrimental impact on its quality. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Strategies to improve the postharvest management of flat oyster (Ostrea edulis) from aquaculture using the short-term storage and package in an innovative closed-circuit system

This study aimed to improve postharvest management of flat oysters reared in a longline system in the mid Adriatic Sea, using short-term storage and package in an innovative closed-circuit system. For the trial, 870 oysters were employed, divided into three experimental groups (A, B, and C), N = 270 oysters each group, whereas the remaining 60 oysters were used for the 2 controls. Each group differed in relation to the time spent in the depuration tank and the time of packaging: group A was packed and immediately transferred to the cell; group B was depurated in a tank for 48 h, then packed and transferred to the cell; group C was depurated in a tank for 48 h and then packed, depurated for another 24 h and transferred to a cell. Samples of each group were sampled at different times of permanence in cell (t0) up until 12 days (t12) for biomorphometric, sensorial, nutritional, and microbiological analysis. Although the nutritional and sensorial quality of the oysters was more pronounced in group A, B and C groups also showed good results. In these two groups, thanks to the use of the modern water recirculation system the quality and safety of oysters was improved by reducing the presence of sludge and eliminating fecal contaminants completely than A treatment and seawater control. These results were also confirmed by the tank control, where a more extended depuration period positively influenced the same parameters emphasizing the importance of the adequate depuration processes in oyster production.

Performance and meat quality in pigs fed hydrolysable tannins from Tara spinosa

This study aimed to assess the effect of dietary tara (Tara spinosa (Feuillée ex Molina) Britton & Rose) hydrolysable tannins on performance and meat quality of finishing pigs. Twenty barrows (crossbred PIC × Piétrain; age: 125 ± 5 d; bodyweight: 60.8 ± 3.89 kg) were randomly assigned to two groups and fed ad libitum for 7 weeks a control diet (CON) or a diet supplemented with 10 g/kg of tara tannins (TAT), respectively. No differences (P > 0.10) on growth performance and carcass traits were observed between the two groups. Meat fatty acid profile was not affected (P > 0.10) by the diet, but the content of C22:5 n-3 tended to be lower (P = 0.079) in TAT pork. Dietary tannins tended to reduce (P = 0.095) meat cholesterol. The diet had no effect (P > 0.10) on fat-soluble antioxidant vitamins, hydrophilic antioxidant capacity, catalase activity, and glutathione peroxidase activity. Superoxide dismutase activity tended to be lower (P = 0.087) in TAT meat than in CON meat. Dietary tannins did not affect (P > 0.10) backfat and meat color development during 6 days of refrigerated storage, but TAT meat tended to be darker (P = 0.082). Meat from pigs fed tara tannins showed lower (P = 0.028) hydroperoxides content and a tendency toward lower conjugated dienes (P = 0.079) and malondialdehyde (P = 0.084) contents. Also, dietary tannins delayed lipid oxidation in meat subjected to oxidative challenges such as catalysis and cooking (P < 0.05). The positive effect of dietary tara hydrolysable tannins on lipid oxidation was likely due to their antioxidant and anti-inflammatory capacity, but it may have been mitigated by the high α-tocopherol content in meat.

Measuring the Phytochemical Richness of Meat: Effects of Grass/Grain Finishing Systems and Grapeseed Extract Supplementation on the Fatty Acid and Phytochemical Content of Beef

Grass-finished beef (GFB) can provide beneficial bioactive compounds to healthy diets, including omega-3 polyunsaturated fatty acids (n-3 PUFAs), conjugated linoleic acid (CLA), and secondary bioactive compounds, such as phytochemicals. The objective of this study was to compare fatty acids (FAs), micronutrients, and phytochemicals of beef fed a biodiverse pasture (GRASS), a total mixed ration (GRAIN), or a total mixed ration with 5% grapeseed extract (GRAPE). This was a two-year study involving fifty-four Red Angus steers (n = 54). GFB contained higher levels of n-3 PUFAs, vitamin E, iron, zinc, stachydrine, hippuric acid, citric acid, and succinic acid than beef from GRAIN and GRAPE (p < 0.001 for all). No differences were observed in quantified phytochemicals between beef from GRAIN and GRAPE (p > 0.05). Random forest analysis indicated that phytochemical and FA composition of meat can predict cattle diets with a degree of certainty, especially for GFB (5.6% class error). In conclusion, these results indicate that GFB contains higher levels of potentially beneficial bioactive compounds, such as n-3 PUFAs, micronutrients, and phytochemicals, compared to grain-finished beef. Additionally, the n-6:n-3 ratio was the most crucial factor capable of separating beef based on finishing diets.

The Oxidative and Color Stability of Beef from Steers Fed Pasture or Concentrate during Retail Display

Beef production in Uruguay is based on pasture (~85%) or concentrate (~15%), resulting in differences in meat quality. The objective of this study was to compare the oxidative stability and color of beef from these two systems during refrigerated retail display. For these purposes, the Semimembranosus muscle was removed from ten Aberdeen Angus steers raised and fed on pasture (130 days prior to slaughter) and from another ten steers fed concentrate (100 days prior to slaughter), sliced. The muscles were placed in a refrigerated showcase for 3, 6, and 9 days. The contents of β-carotene, α-tocopherol, and fatty acids were determined before the meat was placed on display. Lipid and protein oxidation, color, and heme iron content were determined before and during display. The meat from pasture-fed steers had a lower intramuscular fat content (1.78 ± 0.15 vs. 4.52 ± 0.46), lower levels of monounsaturated fatty acids, a lower n-6/n-3 ratio, less lipid and protein oxidation, lower L* and a* values, and higher levels of α-linolenic acid, DHA, total n-3, β-carotene, and α-tocopherol. In conclusion, the meat from pasture-fed steers was more stable during retail display from an oxidative point of view, which may be due to its higher levels of antioxidant compounds such as β-carotene and α-tocopherol and had a healthier fatty acid profile for consumers.

Seasonal patterns of oxidative stress markers in captive Asian elephants in Thailand and relationships to elephant endotheliotropic herpesvirus shedding

Introduction

Oxidative stress refers to an imbalance between oxidant and antioxidant activity and accumulation of reactive oxygen species, which can have detrimental effects on animal health. Annual fluctuations in oxidative stress status can occur, increasing disease susceptibility during certain time periods. However, a full understanding of factors related to oxidative stress in Asian elephants and how to mitigate the negative consequences is lacking.

Methods

This study measured six serum oxidative stress markers [reactive oxygen species (ROS), malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), albumin, glutathione peroxidase (GPx), and catalase] and two stress markers [serum cortisol and fecal glucocorticoid metabolites (fGCM)] in 23 captive Asian elephants in Thailand over a 12 months period to examine relationships with age and season.

Results

Seasonal variations were observed, with several markers exhibiting significantly higher concentrations in the summer (ROS, MDA, 8-OHdG, albumin) and lower values during the rainy/winter seasons (MDA, 8-OHdG, albumin, catalase). By contrast, GPx was the only marker to be highest during the rainy season. For the stress markers, higher fGCM concentrations were noted during the rainy season, which contrasts with earlier studies showing more activity in the winter (tourist season). Positive correlations were found between the temperature-humidity index and ROS, GPx, and fGCM, while a negative correlation was observed with serum albumin. Elephant endotheliotropic herpesvirus (EEHV) shedding events were associated with higher concentrations of ROS and MDA. A moderate negative correlation was observed between 8-OHdG and the PCR threshold cycle of EEHV shedding (Ct), indicating DNA damage may be involved in EEHV shedding in elephants.

Discussion

Results revealed significant age and seasonal effects on several oxidative stress markers, indicating those factors should be considered in study design and data interpretation. There also may be physiological adaptations in oxidative stress conditions in relation to environmental changes that could impact health outcomes.

Analysis of physicochemical properties of dry-cured beef made from Hanwoo and Holstein meat distributed in South Korea

The purpose of the study is to check the possibility of developing dry-cured meat from Hanwoo (South Korean native cattle) and Holstein cattle considering the differences between breeds and use this data for the preparation and development of dry cured ham unique to South Korea. Same-grade Semitendinosus muscle from Hanwoo and Holstein was cured using a curing agent with 4.6% salt content at 4 °C for 7 days, and then aged for 70 days. Data was analyzed through physicochemical characterization, and the manufacturing period was established through weight loss, volatile basic nitrogen (VBN), thiobarbituric acid reactive substances (TBARS). Moisture content and weight loss of both samples significantly decreased during the manufacturing process (P < 0.05). TBARS was significantly higher in Hanwoo and VBN in Holstein (P < 0.05). According to the values of VBN (less than 20 mg/100 g) and TBARS (less than 2 mg MDA/kg), dry aging for 5 weeks is appropriate for both samples. The principal component analysis of 5 weeks-aged Holstein showed a dramatically changing trend due to myofibril fragmentation as indicated by Sodium dodecyl sulfate-polyacrylamide-gel electrophoresis. In addition, 5 weeks-aged Holstein contains methanethiol (cheese), butan-2-one (butter), and 3-3-ethyl-2-methyl-1,3-hexadiene (fatty acid-derive) compounds that represent fermentation and aging flavors. Therefore, the possibility of product development was confirmed by the 5-week aging of Holstein dry-cured ham.

Role of the endoplasmic reticulum in the search for early biomarkers of meat quality

Defects in meat quality such as dark, firm and dry (DFD) beef have been related to high levels of oxidative stress that produce cellular alterations that may affect to the process of meat quality acquisition. Despite the important role of endoplasmic reticulum (ER) in the cellular response to oxidative stress, its function in the muscle-to-meat conversion process has not yet been studied. In this study, differences in muscular antioxidant defense and the unfolded protein response (UPR) of the ER in CONTROL (normal pH₂₄) and dark, firm, and dry (DFD, pH₂₄ ≥ 6.2) beef at 24 h post-mortem were analyzed to understand the changes in the muscle-to-meat conversion process related to meat quality defects. DFD meat showed poor quality, lower antioxidant activity (P < 0.05) and higher UPR activation (P < 0.05), which indicates higher oxidative stress what could partly explain the occurrence of meat quality defects. Therefore, the biomarkers of these cellular processes (IRE1α, ATF6α, and p-eIF2α) are putative biomarkers of meat quality.

Effect of different botanically-diverse diets on the fatty acid profile, tocopherol content and oxidative stability of beef

BACKGROUND

Beef from pasture-fed animals is viewed as a healthier and more welfare-friendly alternative to concentrate-fed beef. Botanically-diverse pastures consisting of numerous plant species may alter the fatty acid (FA) profile and the tocopherol content of beef, as well as the oxidative stability of the meat. In the present study, steers were assigned to one of three botanically-diverse diets: perennial ryegrass (PRG), perennial ryegrass + white clover (PRG + WC) or multi-species (MS), all with a finishing diet of the respective botanically-diverse silages plus a cereal-based concentrate, consistent with production systems in Ireland. The FA profile, tocopherol content, oxidative stability and colour of meat during storage were measured.

RESULTS

Compared to the other diets, the MS diet resulted in higher proportions of linolenic acid (C18:3n-3c), linoleic acid (C18:2n-6c) and total polyunsaturated fatty acids (PUFA), with higher PUFA:saturated fatty acid and n-6:n-3 ratios in the meat. α-Tocopherol concentrations were lowest in the meat of animals from the MS diet. In uncooked meat, lipid oxidation and colour values were affected by storage time across all diets, whereas the MS diet led to higher hue values only on day 14 of storage. When cooked, meat from animals on PRG + WC and MS diets had higher lipid oxidation on days 1 and 2 of storage than meat from animals on the PRG diet.

CONCLUSION

Feeding steers on a botanically-diverse diet consisting of six plant species can improve the n-3 FA and PUFA concentration of beef, affecting the susceptibility of cooked, but not uncooked, beef to oxidation. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Can botanically-diverse pastures positively impact the nutritional and antioxidant composition of ruminant meat? - Invited review

A desire for more sustainable pasture-based ruminant feeding systems has led to growing interest in utilising botanically-diverse pastures (BDP) over monoculture pastures. Research suggests that, from a human consumption viewpoint, grass-based ruminant feeding leads to more nutritionally desirable fatty acid (FA) and antioxidant concentrations in meat compared with concentrate feeding, which can affect meat quality. The FA, antioxidant and secondary metabolite content of plants differ, depending on species, maturity and seasonality, offering the potential through targeted feeding of BDP to produce meat with superior nutritional and antioxidant profiles. This review explores the effect, if any, that grazing ruminants on BDP has on the FA profile, fat-soluble vitamin, and antioxidant content of meat. The input-output relationship between forage and red meat constituents is complex and is likely affected by species diversity, forage consumption patterns and modulation of rumen fermentation processes. Further investigation is required to fully understand the effect that BDP may have on the composition and quality of ruminant meat.

Antioxidant Properties and Proximate Composition of Different Tissues of European Beaver

The chemical composition, content of cholesterol, retinol and α-tocopherol, and the total antioxidant capacity of different tissues from wild beavers were investigated. The total phenolic contents and free radical scavenging activity (DPPH and ABTS assays) were analysed spectrophotometrically, and fat-soluble vitamins were quantified using high-performance liquid chromatography. The type of tissue (skeletal muscle from loin and hind leg vs. adipose tissue from subcutaneous fat and tail) significantly affected content of all chemical components. The concentration of cholesterol was not related to total fat content. The retinol and α-tocopherol contents (µg/100 g) were significantly higher in the tail (13.0 and 391.2) and subcutaneous fat (12.2 and 371.3) compared to skeletal muscles (as an average 9.1 and 361.4). Among all tissues the tail showed significantly the highest values of DPPH (3.07 mM TE/100 g), ABTS (3.33 mM TE/100 g), and total phenolics (TPC, 543.7 mg GAE/100 g). The concentration of retinol was positively correlated with α-tocopherol (0.748, p < 0.001), and both vitamins were very strongly correlated with DPPH (0.858 and 0.886, p < 0.001), ABTS (0.894 and 0.851, p < 0.001), and TPC (0.666 and 0.913, p < 0.001). The principal component analysis proved that moisture, ash, and protein contents were representative for skeletal muscles, whereas, retinol, α-tocopherol, ABTS and DPPH accurately described the antioxidant capacity of tissue from the tail.

Effects of nomadic grazing system and indoor concentrate feeding systems on performance, behavior, blood parameters, and meat quality of finishing lambs

The objective of the study was to evaluate the effects of three production systems on growth performance, behavior, blood parameters, carcass characteristics, and meat quality. A total of 30 lambs (n = 10 lambs/treatment) were randomly assigned to three production systems that included rotational grazing (NG) and two different levels of concentrate (CON), one with medium (roughage/concentrate ratio 50:50% based on DM, MC) and one with high concentrate (roughage/concentrate ratio 30:70% based on DM, HC) during the 90-day fattening period. At the start of the experiment, all lambs averaged 90 ± 4 days of age (mean ± SD) and were slaughtered at an average of 180 ± 3 days (mean ± SD). CON-fed lambs had higher average daily gain and loin thickness than NG-fed lambs. The NG lambs spent more time eating, drinking, and standing, but less time resting and rumination than the CON-fed lambs. In addition, plasma lipid, β-hydroxybutyrate, and urea levels were higher, while phosphorus levels were lower in NG-fed lambs than in CON-fed lambs. CON-fed lambs had better carcass yield, but gastrointestinal tract and rumen weights were lower than NG lambs. CON-fed lambs had higher pH values 0 h post mortem than the NG lambs; however, there was no effect of treatment on pH 24 h post mortem. The post-mortem color of the LD muscle of NG lambs had a higher lightness and yellowness index and a lower redness index than that of the LD muscle of CON-fed lambs. The results of this study showed that lambs fed CON had better carcass yield than lambs fed NG, although feed intake, feed conversion ratio (FCR), growth performance, carcass yield, and meat quality of lambs fed MC and HC were similar.

Plant Antioxidants in Dry Fermented Meat Products with a Healthier Lipid Profile

Consumers' perception of meat products has changed in recent years, which has led to an increased interest in healthier meat products. In response to this demand, academia and industry have made efforts to reformulate meat products, especially dry fermented meat products, which are known for their high fat contents, mainly saturated fat. The use of plant or marine oils stabilized in emulsion gels (EGs) or oil-bulking agents (OBAs) as animal fat replacers has been one of the most advantageous strategies to reformulate dry fermented meat products with a healthier lipid content (quality and quantity), but an increase in their polyunsaturated fatty acid content can trigger a significant increase in lipid oxidation, negatively affecting sensory and nutritional quality. The use of antioxidants is the main strategy to delay this deteriorative reaction, but the controversy around the safety and toxicity of synthetic antioxidants has driven consumers and industry toward the use of plant antioxidants, such as phenolic compounds, carotenoids, and some vitamins and minerals. This review provides information about the use of plant antioxidants to control lipid oxidation of dry fermented meat products with healthier lipids.

Feeding tannins to dairy cows in different seasons improves the oxidative status of blood plasma and the antioxidant capacity of cheese

The aim of the present study was to assess the dietary supplementation of tannins to grazing dairy cows in 2 seasons characterized by a good quality pasture (spring) or a poor-quality pasture (summer). The effects of dietary tannins were assessed on plasma antioxidant status and cytokines profile and on the antioxidant properties of cheese and cheese in vitro digestates. Fourteen lactating dairy cows were divided into 2 homogeneous groups (n = 7): a control group (CON), and an experimental group (TAN) receiving 150 g/head per day of tannins supplementation. The experiment was performed twice, in spring and in summer. The animals were free to graze on spontaneous pasture (spring) or on dry stubble (summer). Blood was sampled at the beginning (d 0), at the midpoint (d 11), and at the end (d 22) of the trial. Individual cheese was produced before the beginning (d -1) and at the end (d 22) of the trial from the milk collected from each cow. On blood plasma, the reactive oxygen metabolites (ROM), biological antioxidant potential (BAP), nonesterified fatty acids quantification, and cytokines profile in terms of IL-10, IL-8, IL-1β, and IFN-γ were determined. Data on ROM demonstrated that tannins supplementation lowered oxidative stress both in spring and in summer. Accordingly, TAN diet increased BAP levels compared with the CON during summer trial. Thus, feeding tannins resulted in lower ratio between ROM and BAP (oxidative stress index) in both spring and summer. Cytokines' profile showed lower IL-1β values in TAN group at d 22 during spring season, with a concomitant higher IL-10 level, during summer season. Moreover, TAN group had a lower level of IFN-γ in plasma than CON group, both in spring and in summer. On cheese samples, the in vitro digestion was performed and on cheese and cheese digestates (gastric and intestinal digestate) the free radical scavenging antioxidant activity was evaluated. The intestinal digestate fraction registered the highest antioxidant activity compared with cheese and gastric digestate, in both spring and summer seasons. Furthermore, an improvement of the antioxidant property of cheese and cheese digestates was found. Present data demonstrated that tannins supplementation contributed to reduce the oxidative stress of lactating dairy cows and showed an increase of anti-inflammatory cytokines ratio.

Dietary α-lipoic acid supplementation improves postmortem color stability of the lamb muscles through changing muscle fiber types and antioxidative status

This study investigated the effect of dietary α-lipoic acid (600 mg/kg) supplementation on the postmortem color stability of the biceps femoris from lambs. The results showed that dietary α-lipoic acid supplementation increased a* and decreased b* and metmyoglobin (MMb) percentage of the biceps femoris with the time of storage (P < 0.05). The content of malondialdehyde (MDA) reduced with the time of storage after treatment with α-lipoic acid (P < 0.05). α-lipoic acid increased the myoglobin (Mb) content, and myosin heavy chain I (MyHC I) gene expression but decreased glycogen content, lactate dehydrogenase (LDH) activity, and MyHC IIb gene expression (P < 0.05). The T-AOC value, catalase (CAT) activity, and expression of SOD and CAT gene expression increased after α-lipoic acid treatment (P < 0.05). Therefore, dietary α-lipoic acid supplementation improved the meat color by regulating muscle fiber types and inhibited glycolysis. Moreover, α-lipoic acid maintained meat color stability by effectively inhibiting muscle oxidation via enhancing the antioxidant capacity.

Effect of dietary magnolia bark extract supplementation in finishing pigs on the oxidative stability of meat

BACKGROUND

Magnolia bark extract (MBE) is a natural supplement with antioxidant, anti-inflammatory, and antimicrobial activities. Its properties suggest that the dietary supplementation in livestock could improve the quality of products. Therefore, the aim of this study was to investigate, for the first time, the effect of dietary MBE supplementation (0.33 mg/kg) in finishing pigs on the oxidative stability of meat. Oxidative stability is of paramount importance for pork, as it affects storage, retail, and consumer acceptance. For the purpose, the fatty acid profile, cholesterol, fat-soluble vitamins, antioxidant enzymes (catalase, glutathione peroxidase, and superoxide dismutase), non-enzymatic antioxidant capacity (TEAC, FRAP, and Folin-Ciocalteu assays), color stability, and lipid stability of pork were assessed.

RESULTS

Concerning carcass characteristics, dietary MBE did not affect cold carcass yield, but reduced (P = 0.040) the chilling weight loss. The meat from pigs fed MBE had a lower (P = 0.031) lightness index than the control meat. No effect on intramuscular fat, cholesterol, and fatty acid profile was observed. Dietary MBE did not affect the content of vitamin E (α-tocopherol and γ-tocopherol) in pork, whereas it reduced (P = 0.021) the retinol content. The catalase activity was 18% higher (P = 0.008) in the meat from pigs fed MBE compared with the control group. The MBE supplementation reduced (P = 0.039) by 30% the thiobarbituric acid reactive substances (TBARS) in raw pork over 6 d of aerobic refrigerated storage. Instead, no effect on lipid oxidation was observed in cooked pork. Last, the meat from pigs fed MBE reduced Fe³⁺-ascorbate catalyzed lipid oxidation in muscle homogenates, with a lower (P = 0.034) TBARS value than the control group after 60 min of incubation.

CONCLUSIONS

Dietary MBE supplementation in finishing pigs delayed the lipid oxidation in raw meat. This effect was combined with an increased catalase concentration. These results suggest that dietary MBE could have implications for improving the shelf-life of pork.

Effect of Feeding Alfalfa and Concentrate on Meat Quality and Bioactive Compounds in Korean Native Black Goat Loin during Storage at 4°C

The primary aim of this study was to evaluate the effect of feeding alfalfa: Concentrate at different ratios (8:2 or 2:8) to Korean native black goats (KNBG) for 90 days on meat quality and bioactive compound content. Feeding KNBG alfalfa and concentrate at different ratios did not impact meat pH, color, microorganism composition, volatile basic nitrogen levels, or lipid oxidation. The low alfalfa (KLA) group exhibited increased oleic acid and monosaturated fatty acid levels, both of which impact the palatability traits of meat. The abundance of bioactive compounds increased in the loin meat of the KLA group, leading to an increase in antioxidant activities. Our results suggest that feeding alfalfa and concentrate at a 2:8 ratio to KNBG can increase taste-related fatty acids and bioactive compounds in loin meat, relative to that achieved by feeding at an 8:2 ratio. Further investigation is required to evaluate the quality and the metabolites of bioactive compounds in KNBG meat and the effect of the different dietary ratios of forage and concentrate.

Effect of different levels of organic zinc supplementation on pork quality

This study investigated the effect of two supplementation levels of zinc glycinate (ZnGly) on performance, carcass characteristics, and meat quality of growing-finishing pigs. Thirty pigs (bodyweight: 61 ± 4.0 kg) were assigned to three treatments and fed ad libitum for 56 days a diet supplemented with 0 (control), 45 (Zn45), or 100 mg/kg (Zn100) of ZnGly. The highest ZnGly supplementation lowered the average daily gain (P = 0.031); while, cold carcass weight did not differ between treatments. Both ZnGly levels reduced carcass chill loss (P < 0.001). Micromineral content, color stability, and fatty acid profile of meat were not altered by ZnGly. Superoxide dismutase activity was lowered by Zn45 compared to control (P = 0.007); while, catalase activity was enhanced by Zn100 (P = 0.003). Although ZnGly supplementation did not influence lipid oxidation in raw meat and in meat homogenates incubated with pro-oxidant catalysts, Zn45 limited lipid oxidation in cooked meat (P = 0.037). Our results demonstrated that supplementing pigs with 45 mg/kg of ZnGly could improve the oxidative stability of pork subjected to strong pro-oxidant conditions, but this effect needs to be further elucidated.

Age-specific effect on endogenous oxidative and antioxidative characteristics of longissimus thoracis muscle of yak during early postmortem period

Effects of age on postmortem redox states were investigated in yak muscles. Extended postmortem time reduced the muscle antioxidant capacity and induced oxidation in lipids, myoglobin, and proteins. Compared with older yaks, muscles of younger ones could delay this oxidation process due to lower initial myoglobin content of 30.7%, lipid peroxidation of 42.4%, H₂O₂ of 41.2%, and intramuscular fat of 65.6% (of 3.66 times higher PUFAs). They also possessed greater antioxidase content/activity, such as phospholipase A2 content of 30.7% and glutathione reductase activity of 50.6%. Muscles exhibited age-specific overall antioxidative characteristics during 72 h postmortem and gradually formed overall oxidative ones after 72 h postmortem with an initial similarity between 2- and 4-year (or 6- and 12-year) on canonical discriminant analyses. The formation of age-specific overall oxidative characteristics can be attributable to the antioxidative specificity of age on canonical correlation analyses. Age-specific redox characteristics required differentiated preference in meat processing and preservation.

Survival of Embryos and Fry of Sea Trout (Salmo trutta m. trutta) Growing from Eggs Exposed to Different Concentrations of Selenium during Egg Swelling

Adequate selenium (Se) availability enhances the health and growth of organisms, but overdose of it can be harmful and pathogenic. The study's objective was to analyse the impact of short-term exposure of sea trout fertilised eggs to inorganic selenium (SeO₂) at concentrations from 0 to 32 mg Se L^-1 to find the optimal and toxic dose of Se on early fish development. Se accumulated in the body, embryos' survival rate, and growth in the first four months of life was examined. Swelling of fertilised eggs in water supplemented with Se at a concentration from 0.5 to 8 mg Se L^-1 was associated with a slightly positive impact on the hatching rate. At higher Se concentration, a harmful effect on the survival of the embryo was observed. The survival of fry was similar in all groups, while the fry length and weight correlated positively with Se concentration in its body. Immersion of fertilised eggs in water enriched with Se during egg swelling can constitute a method to supplement the element to non-feeding stages of fish. In selenium-poor areas, this innovative method can be implemented in aquaculture to improve breeding outcomes. Se concentration should be adjusted to the chemical compound, fish species, and Se's content in the yolk.

The Activity of Chosen Antioxidant Enzymes in Ostrich Meat in Relation to the Type of Packaging and Storage Time in Refrigeration

The aim of the study was to investigate the changes in the activity of antioxidant enzymes, i.e., superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity in ostrich meat, as influenced by various packaging systems and storage time under refrigeration. Three packaging methods were used: vacuum packaging (VP) and modified atmosphere packaging (MAP) in two combinations of gases, MAP1 (40% O₂/40% CO₂/20% N₂) and MAP2 (60% O₂/30% CO₂/10% N₂). Meat samples were taken from the M. ilifibularis (IF) muscles of eight ostriches in each treatment group. The meat samples were stored in a refrigerator in 2 °C and analyzed at days 0, 4, 8, 12 and 16. The lowest level of SOD activity during storage was observed in ostrich muscles packed in vacuum, as compared to MAP1 and MAP2. In turn, the highest increase in GPx activity was recorded in VP, especially up to day 8 of storage, when this parameter reached maximum value (54.37). GR increased up to the eighth day of storage in MAP1 and VP. Between the 12th and 16th days of storage, stabilization of the GR activity level was observed only in VP, while under MAP1, it further decreased. DPPH remained relatively stable until the eighth day of storage and after this period, a decrease in this parameter was recorded, reaching the lowest value on day 12 for all types of packaging systems.

Assessment of total (anti)oxidant status in goat kids

The redox potential of goat serum was assessed by different spectrophotometric assays. Among them, three methods are commonly applied for the evaluation of the oxidative (reactive oxygen metabolites, ROMs, and total oxidant status, TOS) and nitrosative (NO ⚫ metabolites, NO x ) stress, and four methods for the evaluation of the antioxidant status: the total antioxidant capacity (TAC) based on the ferric reducing ability of plasma (FRAP), the total antioxidant activity (TAA) based on the reduction of the coloured ABTS ⚫ + radical cation, the free radical scavenging activity (FRSA) based on the reduction of the purple DPPH ⚫ , and the total thiol levels (TTLs) based on their interaction with DTNB to form a highly coloured anion. Besides, myeloperoxidase (MPO) and ceruloplasmin oxidase (CP) activities were also assessed. Except for TAA, analytical data showed a great inter-individual variation for both oxidant and antioxidant assays. ROMs were strongly correlated with CP, while TOS with MPO and TAC. Furthermore, a tendency between TOS and FRSA was shown. NO x was correlated with TAC and TAA, and a tendency with TOS was shown. No correlations appeared among the antioxidant assays, even if a tendency between TAC and TAA was evidenced, but TAC was correlated with MPO activity. The observed correlation between ROMs and CP is discussed as a possible analytical interference. The absence of correlation among the antioxidant biomarkers suggests the simultaneous use of a panel of tests to verify any changes in the redox balance, mainly in livestock in which reference values for each biomarker are lacking.

Effect of Breeding Techniques and Prolonged Post Dry Aging Maturation Process on Biomolecule Levels in Raw Buffalo Meat

Recently, several concerns have been expressed on red meat quality and consumption. The aims of this study were to evaluate the influence of different breeding techniques and a prolonged post dry aging (PDA) maturation process on biomolecules level in raw buffalo meat. In the first experiment, two groups of animals were maintained with different space availability (15 vs. 10 m²/animal) for 90 days and biomolecules content was evaluated. In experiment 2, two diets (with or without ryegrass green forage) were used to assess the concentration of these biomolecules. Finally, in experiment 3, the meat of the animals that showed the highest content of biomolecules was chosen to assess the influence of the PDA maturation process. Buffaloes reared at 15 m² showed a significantly (p < 0.05) higher content of the considered biomolecules compared with their counterparts. Similarly, buffaloes fed green forage showed higher content of biomolecules (p < 0.05) compared with the control group. The meat of the animals bred at 15 m² and fed green forage showed a significant (p < 0.01) increase of biomolecules content during the PDA maturation process up to 60 days without influence microbiological profile in terms of total aerobic bacterial counts, yeasts, and molds. In conclusion, breeding techniques and PDA maturation system could enhance biomolecules levels in terms of quality, without affect health standards.

The Effect of Grazing Level and Ageing Time on the Physicochemical and Sensory Characteristics of Beef Meat in Organic and Conventional Production

This study investigated the influence of the production system (conventional vs. organic), the grass consumption level and the ageing period (7 and 14 days) on beef quality. Three groups of samples from Limousin × Avileña calves were analysed: F100, formed by animals fed 100% on forage; F74, formed by animals fed on an average amount of forage of 74%; and F35, formed by animals fed on straw fodder (35%) and concentrate (65%). The results showed that the higher the grass content, the lower the fat oxidation and the higher the n-3 content, but also the higher the SFA level, the initial Warner-Bratzler shear force (WBSF), and the more residue it leaves on chewing. As for the effect of production system, organic samples showed higher intramuscular fat content and lower moisture and MUFA content. These samples were darker and showed lower values for flavour quality. Among the organic samples, F100 had higher n-3 and CLA content and higher values for colour, hardness, odour and flavour quality. Increased ageing time may improve the sensory characteristics of the meat, especially in the case of the F100 samples. The results pointed out that F100 samples aged at least 14 days showed the best physico-chemical, nutritional and sensory characteristics.

Health-Promoting Phytonutrients Are Higher in Grass-Fed Meat and Milk

While commission reports and nutritional guidelines raise concerns about the effects of consuming red meat on human health, the impacts of how livestock are raised and finished on consumer health are generally ignored. Meat and milk, irrespective of rearing practices, provide many essential nutrients including bioavailable protein, zinc, iron, selenium, calcium, and/or B12. Emerging data indicate that when livestock are eating a diverse array of plants on pasture, additional health-promoting phytonutrients—terpenoids, phenols, carotenoids, and anti-oxidants—become concentrated in their meat and milk. Several phytochemicals found in grass-fed meat and milk are in quantities comparable to those found in plant foods known to have anti-inflammatory, anti-carcinogenic, and cardioprotective effects. As meat and milk are often not considered as sources of phytochemicals, their presence has remained largely underappreciated in discussions of nutritional differences between feedlot-fed (grain-fed) and pasture-finished (grass-fed) meat and dairy, which have predominantly centered around the ω-3 fatty acids and conjugated linoleic acid. Grazing livestock on plant-species diverse pastures concentrates a wider variety and higher amounts of phytochemicals in meat and milk compared to grazing monoculture pastures, while phytochemicals are further reduced or absent in meat and milk of grain-fed animals. The co-evolution of plants and herbivores has led to plants/crops being more productive when grazed in accordance with agroecological principles. The increased phytochemical richness of productive vegetation has potential to improve the health of animals and upscale these nutrients to also benefit human health. Several studies have found increased anti-oxidant activity in meat and milk of grass-fed vs. grain-fed animals. Only a handful of studies have investigated the effects of grass-fed meat and dairy consumption on human health and show potential for anti-inflammatory effects and improved lipoprotein profiles. However, current knowledge does not allow for direct linking of livestock production practices to human health. Future research should systematically assess linkages between the phytochemical richness of livestock diets, the nutrient density of animal foods, and subsequent effects on human metabolic health. This is important given current societal concerns about red meat consumption and human health. Addressing this research gap will require greater collaborative efforts from the fields of agriculture and medicine.

Wójciak K. Peptides from Different Carcass Elements of Organic and Conventional Pork-Potential Source of Antioxidant Activity

The growing consumer interest in organic foods, as well as, in many cases, the inconclusiveness of the research comparing organic and conventional foods, indicates a need to study this issue further. The aim of the study was to compare the effects of meat origin (conventional vs. organic) and selected elements of the pork carcass (ham, loin, and shoulder) on the meat proteome and the antioxidant potential of its peptides. The peptidomic approach was used, while the ability of antioxidants to scavenge 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS), to chelate Fe(II) ions, and to reduce Fe(III) was determined. Most peptides were derived from myofibrillary proteins. The meat origin and the element of the pork carcass did not have a significant effect on the proteome. On the other hand, the pork origin and the carcass element significantly affected the iron ion-chelating capacity (Fe(II)) and the reducing power of peptides. In particular, pork ham from conventional rearing systems had the best antioxidant properties in relation to potential antioxidant peptides. This could be a factor for human health, as well as for stabilized meat products (e.g., toward lipid oxidation).

Volatile Organic Compounds, Oxidative and Sensory Patterns of Vacuum Aged Foal Meat

The study aimed to evaluate the effect of 14-day vacuum aging on the volatile compounds (VOC) profile, oxidative profile, antioxidant enzymes activity, and sensory evaluation in the Longissimusthoracis muscle of foal meat under vacuum aging. Longissimusthoracis (LT) was sampled in 20 mm thick slices, vacuum packed, and stored at 4 °C. Samples were randomly assigned to different aging times (1, 6, 9, 14 days after slaughtering). VOCs, thiobarbituric acid reactive substances (TBARs), hydroperoxides, carbonyl proteins, superoxide dismutase, catalase, and glutathione peroxidase were analyzed, and a sensory test was performed. A nested one-way analysis of variance (ANOVA) was performed for aging time as an independent variable. Significance was set at p < 0.05. The main VOCs originating from cooked steaks were aldehydes, (from 47.18% to 58.81% of the total volatile compounds), followed by hydrocarbons (from 9.32% and 31.99%). TBARs and hydroperoxides did not show variations due to aging (p > 0.05), instead, protein carbonyls showed higher values at the 14th day (p < 0.01). Catalase, superoxide dismutase, and glutathione peroxidase showed increasing values during aging time (p < 0.01). Vacuum aging slowed down lipid oxidation, and protein oxidation was shown to be present. However, the best vacuum aging duration is in the range of 6-9 days from slaughtering, with an improvement of sensory evaluation.

Effects of Feeding Increasing Levels of Yerba Mate on Lamb Meat Quality and Antioxidant Activity

Simple Summary

The population’s growing concern for health and the increased consumption of natural products have led to the study of the use of bioactive compounds in animal feed, especially those containing antioxidants. An example of this is yerba mate (Ilex paraguariensis), a plant highly consumed in South America due to its antioxidant properties, which benefit human health and can reduce the incidence of cardiovascular diseases. However, the effects of yerba mate on animal feed as well as the composition and preservation of meat products are unknown. Therefore, the objective of the current study was to evaluate the effects of the inclusion level of yerba mate extract in the lamb’s diet on meat quality traits, antioxidant activity, and shelf-life. Our results showed that the use of the extract in lamb feed did not negatively affect the characteristics of lamb meat nor increase lipoperoxidation during a six-day storage period. The inclusion of 4% yerba mate extract (YME) resulted in a higher value in the yellow colour of the meat.

Abstract

The present study investigated the inclusion of yerba mate extract (YME) in the lamb’s diet on meat quality traits, antioxidant activity, and shelf-life. Thirty–six lambs were distributed according to a block design with the following groups: control group without YME (0%) and three treatment groups with 1, 2, and 4% YME inclusion in the dry matter. The animals were fed these diets for 53 days. Samples were collected from the Longissimusthoracis (LT) muscle to analyze antioxidant activity and meat quality. Samples were placed on a counter display simulating a retail environment for 0, 3, and 6 days at 4 ± 2 °C. All data were analyzed using a MIXED model with orthogonal contrasts. Inclusion of 1 and 4% YME in the diet changed the yellow (b*) and the chroma (C*) of the meat (p ≤ 0.05). The pH, colour, thiobarbituric acid reactive substances, and carbonyl values were influenced by the retail display time for all the evaluated treatments (p ≤ 0.03). However, neither diet nor the retail display time influenced the oxidation of proteins or the antioxidant enzyme activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione activity (GSH) in meat. Therefore, the inclusion of 4% YME showed positive results in the yellow and colour stability parameters of the meat without increasing the lipid peroxidation values or altering the normal meat quality parameters in lambs.

The effect of parity number on the metabolism, inflammation, and oxidative status of dairy sheep during the transition period

The objective of this study was to evaluate whether dairy sheep during the transition period are affected by their parity numbers with regard to (1) body weight (BW), body condition score (BCS), and production performance (milk yield and composition) and (2) metabolic, inflammation, and stress biomarkers. For this purpose, 30 Sarda dairy ewes [15 primiparous (PRP) and 15 multiparous (MUP) ewes] were recruited on d 90 of gestation. Each group was homogeneous according to age, BW, and BCS. Sampling was carried out at -60, -30, -7, 0, +30, and +60 d from lambing. The MUP ewes showed a higher BW (46.32 vs. 38.71 kg) and larger litter size (1.45 vs. 1.06 kg) but a lower BCS (2.47 vs. 2.70) than the PRP ewes. Furthermore, the MUP ewes had lower concentrations of glucose (3.49 vs. 4.27 mol/L), cholesterol (1.63 vs. 1.81 mmol/L), free fatty acids (0.47 vs. 0.62 mmol/L), and triglycerides (0.22 vs. 0.25 mmol/L) compared with PRP ewes. With regard to inflammation and oxidative stress parameters, the PRP group had higher haptoglobin (0.48 vs. 0.18 g/L) and paraoxonase (187.90 vs. 152.11 U/L) activity than the MUP group. Overall, the MUP ewes were characterized by greater milk production performance and greater feed intake, resulting in a better energy balance, than the PRP ewes. Interestingly, these findings highlighted a different metabolic and inflammatory response over the transition period between PRP and MUP ewes, with the latter displaying lower concentrations of inflammatory-related biomarkers.

Lipid oxidation induced by heating in chicken meat and the relationship with oxidants and antioxidant enzymes activities

The aim of the current research was to examine lipid oxidation in chicken meat heated to different temperatures followed by refrigerator storage and the factors contributing to lipid oxidation. It showed that lipid oxidation was significantly promoted when meat was heated up to 70°C and stored for 2 and 4 D as measured by thiobarbituric acid reactive substance. The monounsaturated fatty acids and polyunsaturated fatty acids also decreased significantly (P < 0.05) with the increase of heating temperature. The liberation of nonheme iron and increase of hydroxyl radical were observed in heated chicken meat, and the activities of antioxidant enzymes was decreased considerably at higher temperatures. The changes of these prooxidants and antioxidants might constitute a possible mechanism for the stronger lipid oxidation in heated meat.

Lipid oxidation, pre-slaughter animal stress and meat packaging: Can dietary supplementation of vitamin E and plant extracts come to the rescue?

Normand cull-cows received a diet enriched in n-3 polyunsaturated fatty acids (PUFA), known to enhance nutritional quality, but to decrease beef lipid stability. Half of the cows received a supplementation of vitamin E and plant extracts rich in polyphenols during the finishing period. Half of each feeding group was slaughtered under limited, the others under added stress conditions. Longissimus thoracis (LT) and Semitendinosus (ST) were evaluated after storage under air, or 70% O₂/30% CO₂ or vacuum conditions. Irrespectively of diet, pre-slaughter stress i) increased post-mortem malondialdehyde (MDA) formation except in vacuum-stored meat, ii) decreased vitamin A levels in the LT, iii) decreased vitamin E levels in meat stored in 70% O₂/30% CO₂ and total anti-oxidant status in vacuum stored meat. Effects were global; dietary supplementation with vitamin E and plant extracts was associated with lower MDA levels and MetMb percentage and higher levels of vitamin A and E.

Evaluation of the adaptogenic propertries of the Quark product enriched with probiotics, polyphenols and vitamins

The aim of the study is to evaluate protective properties of the quark product manufactured with transglutaminase and enriched with probiotics, oligomerous proanthocyanidines and vitamins; the biological experiment on the growing laboratory Wistar stock rats has been carried out. The rats of two from three groups subjected within 21 days to the effect of low-frequency weak variable magnetic field received in semi-synthetic diet composition extra experimental and control samples of the quark product. The index of feed intake and the rats’ body mass growth was registered within 32 days. At the end of the experiment blood serum biochemical index was evaluated. It was revealed that the animals consuming the experimental product substantially gained the mass before the effect (gain from the 1st up to 10th days made up 12%) as well as after effect (gain from 11th up to 32nd days – 10.3%); upon completion of the experiment the gains of these animals exceeded the gains of the rats consuming the control product by more than 28%. The experiment revealed the lipolipedemic and hypoglycemic effect of the experimental quark product that has been evidenced by the significant reduction of cholesterol (by more than 20%), glucose (up to 40%) in the rats’ blood serum. On administration of the experimental dairy product in the animals’ diet subjected to the impact of low-frequency weak magnetic field the effect of the broken balance recovery in antioxidant/pro-oxidant system was observed due to reduction of pro-oxidant load at the enzymatic as well as low molecular links of the antioxidant system. The identified antioxidant and adaptogenic effect of the developed dairy product promoting to reduce the intensity of free-radical oxidation at the impact of low-frequency electromagnetic field on the body make it possible recommend it in dietotherapy for correction of antioxidant/pro-oxidant status.

Meat quality, fatty acids, volatile compounds, and antioxidant properties of lambs fed pasture versus mixed diet

The aim of the present work was to investigate the effects of feeding regimens (pasture vs. mixed diet) on meat quality, fatty acids, volatile compounds, and antioxidant properties in lamb meat. In total, 24 lambs were allotted into two feeding regimens at 10.23 kg live weight. Lambs were fed on pasture grass (PG group, n = 12) or mixed diet (M group, n = 12). Longissimus thoracis (LT) muscle samples from the M group had a higher intramuscular fat (IMF) (p < 0.05), pH45minvalue (p < 0.01), and ash (p < 0.05) than the PG group. In contrast, the shear force (p < 0.05), L*(p < 0.05), and b* (p < 0.001) in M group were lower than in PG group. Analyses indicated that PG group contained higher linolenic acid (C18:3n3) and docosatrienoic acid (C22:3n6) (p < 0.05) than the M group. Major volatile compounds in the muscles included hexanal, heptanal, nonanal, octanal, 1-pentanol, 1-hexanol, 1-octen-3-ol, and 2,3-octanedione. The levels of hexanal, nonanal, and 2,3-octanedione were significantly lower in PG lamb muscle (p < 0.01). In contrast, 1-pentanol and 1-hexanol levels were higher in M lamb muscle (p < 0.01). Muscle from PG lamb exhibited higher catalase (CAT) and glutathione peroxidase (GPx) activity (p < 0.05). PG muscle also contained a higher radical-scavenging ability (RSA; p < 0.001) and cupric-reducing antioxidant capacity (CUPRAC; p < 0.05). Overall, the improved antioxidant status in PG muscle inhibited lipid peroxidation (aldehydes and ketones), thereby improving the meat quality.

Differential hepatic oxidative status in steers with divergent residual feed intake phenotype

Oxidative stress occurs when oxidant production exceeds the antioxidant capacity to detoxify the reactive intermediates or to repair the resulting damage. Feed efficiency has been associated with mitochondrial function due to its impact on cell energy metabolism. However, mitochondria are also recognized as a major source of oxidants. The aim of this study was to determine lipid and protein oxidative stress markers, and gene and protein expression as well as activity of antioxidant enzymes in the liver of steers of divergent residual feed intake (RFI) phenotypes. Hereford steers (n = 111) were evaluated in post-weaning 70 days standard test for RFI. Eighteen steers exhibiting the greatest (n = 9; high-RFI) and the lowest (n = 9; low-RFI) RFI values were selected for this study. After the test, steers were managed together under grazing conditions until slaughter when they reached the slaughter body weight. At slaughter, hepatic samples were obtained, were snap-frozen in liquid nitrogen and stored at -80°C until analyses. Hepatic thiobarbituric acid reactive species and protein carbonyls were greater (P = 0.05) and hepatic 4-hydroxynonenal protein adducts tended (P = 0.10) to be greater for high- than low-RFI steers. Hepatic gene expression glutathione peroxidase 4, glutamate-cysteine ligase catalytic subunit and peroxiredoxin 5 mRNA was greater (P ≤ 0.05) and glutathione peroxidase 3 mRNA tended (P = 0.10) to be greater in low- than high-RFI steers. Hepatic protein expression and enzyme activity of manganese superoxide dismutase and glutathione peroxidase enzyme activity tended (P ≤ 0.10) to be greater for low- than high-RFI steers. High-efficiency steers (low-RFI) probably had better hepatic oxidative status which was strongly associated with greater antioxidant ability near to the oxidant production site and, therefore, reduced oxidative stress of the liver. Decreased hepatic oxidative stress would reduce maintenance requirements due to a lower protein and lipid turnover and better efficiency in the use of energy.

Fatty acid compositions, free radical scavenging activities, and antioxidative enzyme activities of high-preference and low-preference beef cuts of Hanwoo (Bos taurus coreanae) cows

Objective

This study compared fatty acid compositions and antioxidant activities of high-preference cuts (loin, tenderloin, and rib) and low-preference cuts (brisket, topside, and shank) of Hanwoo (Bos taurus coreanae) cows to obtain potentially useful information for promoting the consumption of various low-preference cuts.

Methods

Individual 500 g samples of fresh beef were collected from each of the six cuts from 10 Hanwoo cows (quality grade 1) and immediately freeze-dried. The dried samples were evaluated for fatty acid composition, free radical scavenging activities (hydroxyl, alkyl, and 2, 2′-diphenyl-1-picrylhydrazyl [DPPH] radical), and antioxidative enzyme activities (glutathione peroxidase [GPx], glutathione-S-transferase [GST], and superoxide dismutase [SOD]).

Results

The percentages of total polyunsaturated fatty acids were significantly higher in low-preference cuts than in high-preference cuts (p<0.05). Hydroxyl, alkyl, and DPPH radical scavenging activities were significantly higher in low-preference cuts than in high-preference cuts (p<0.05). In addition, the activities of antioxidant enzymes, such as GPx, GST, and SOD, were significantly higher in low-preference cuts compared with high-preference cuts (p<0.05).

Conclusion

These results may influence consumers to include more low-preference cuts in their selections based on the nutritional facts, which could help to balance the beef market in South Korea.

Effects of olive-cake supplementation on fatty acid composition, antioxidant status and lipid and meat-colour stability of Barbarine lambs reared on improved rangeland plus concentrates or indoors with oat hay plus concentrates

The effects of feeding system (indoor vs rangeland) and olive-cake (OC) supplementation (control vs supplemented) on fatty acid (FA) composition, lipid oxidation status and meat-colour stability were studied. Lambs were fed indoor with hay (OH) or reared on improved rangeland (RL). All lambs received concentrate at a rate of 400 g/head.day. Twenty-four 6-month-old Barbarine lambs with an average weight of 24.3 ± 1.1 kg were assigned into the following four groups: OH without OC, OH with OC, RL without OC and RL with OC. Supplemented groups received 280 g/day of OC. Lambs were reared for ~3 months and then slaughtered at 33 kg. Feeding lambs on rangeland increased proportions of polyunsaturated fatty acids (PUFA, P < 0.05), n-3 PUFA (P < 0.01) and long-chain n-3 PUFA (P < 0.01) and decreased those of C16:0 and monounsaturated fatty acids (P = 0.052). Higher PUFA : saturated FA (SFA) (P < 0.001) and lower n-6 : n-3 PUFA (P < 0.01) ratios were found for RL lambs. The peroxidisability index was higher (P = 0.024) for RL lambs. Whereas, a lower malondialdehyde concentration (P < 0.001) was found for meat of RL group after 5-day storage, because of a higher vitamin E concentration (P < 0.001) and catalase activity (P = 0.002). Moreover, colour was more stable for meat of RL lamb. OC supplementation reduced only superoxide dismutase activity (P = 0.033) and did not have any effect on lipid peroxidation and colour stability. No interactions were noted between the feeding system and olive-cake supplementation. Meat lambs produced on rangeland had a healthier fatty acid composition. Lipids were more stable to oxidation than was meat produced indoor with hay and concentrate.

Seasonal changes in serum oxidative stress biomarkers in dairy and beef cows in a daytime grazing system

This study aims to evaluate the oxidative stress during hot summer season using serum oxidative stress biomarkers and elucidate the effects of serum antioxidant vitamin levels in dairy and beef cows in a daytime grazing system. Blood samples were collected once a month from eight Holstein Friesian (HF) and 10 Japanese Black (JB) cows from November 2013 to October 2014. Serum values of derivatives of reactive oxygen metabolites (d-ROMs) tended to be higher in March in both breeds and those in HF cows were kept at higher (P<0.001) levels than those in JB cows during the study period. Serum levels of biological antioxidant potential (BAP) in both breeds were maintained at almost the same values during study period. The OSI [(d-ROMs/BAP) × 100] values in both breeds showed similar seasonal changes, i. e. increase from December to March and decrease from March to August or September. In addition, the OSI values in HF cows were kept at higher (P<0.01) levels than those in JB cows during the study period. Serum concentrations of α-tocopherol, β-carotene, blood urea nitrogen and total cholesterol showed similar seasonal changes in both breeds, low in the winter and high from spring to summer, which may be attributed to the pasture grass intake. Opposite changes in OSI values and serum concentrations of α-tocopherol and β-carotene indicated that antioxidant vitamin levels could affect oxidative stress status.

The Effect of Extensive Feeding Systems on Growth Rate, Carcass Traits, and Meat Quality of Finishing Lambs

This review aims to summarize the relevant published information about the effects of extensive feeding systems on the carcass and meat quality characteristics of lambs. Lambs finished in a feedlot or with supplementation under extensive systems exhibit faster growth rates, achieve target weights quicker, and produce heavier carcass weights when compared to grazing lambs. However, the literature also shows that finishing lambs on high-quality pasture can produce satisfactory growth rates without compromising carcass and meat quality traits. Lately, the consumer demand for products perceived as "healthy" and that are produced where animal welfare is optimal under systems which do not impact negatively on the environment, has heightened the interest in lamb production under extensive systems. Lambs raised on pasture can meet many of these specifications. Also, lambs fed higher quality green pasture can produce meat with greater amounts of health-claimable omega-3 fatty acids such as eicosapentaenoic acid plus docosahexaenoic acid than feeding systems based on feedlot pellets, grain, or dry pasture/straw. It is apparent that in some previous published research, the number of animals allocated for each treatment, and the lack of replicates, makes it difficult to formulate a correct understanding of the effect of forages on lamb carcass and meat quality. Future research should concentrate on the effect of legume, improved pasture, and specialized forage finishing systems on growth rate, carcass traits, and nutritional value of meat using well-designed experiments with an adequate number of lambs and appropriate paddock replicates per treatment.