Relationship between muscle antioxidant status, forms of iron, polyunsaturated fatty acids and functionality (retail colour) of meat in lambs

Dietary iron or inulin supplementation alters iron status, growth performance, intramuscular fat and meat quality in finisher pigs

Forty LW × L pigs (20 boars and 20 gilts) (51.1 ± 0.41 kg) were allocated to a 2 × 2 × 2 factorial design with the respective factors being supplemental organic iron (Fe, 0 and 500 mg/kg), inulin (In, 0 and 50 g/kg) and sex (boars and gilts). After 5 weeks the animals were transported to an abattoir before slaughter and collection of samples. Serum iron was increased by supplemental Fe (28.4 v. 30.9 μmol/L, P = 0.05), although there was an interaction (P = 0.03) such that pigs fed diets with In had lower serum Fe concentrations than those without In (26.8 v. 32.3 μmol/L). Boars had lower (P < 0.01) haemoglobin (116 vs 125), haematocrit (36.7 v. 39.7%) and erythrocyte (6.6 v. 7.1 × 106/mL) concentrations than gilts. Dietary In increased liveweight gain (795 v. 869 g/d, P < 0.02) and carcass weight (62.9 v. 65.2 kg, P < 0.02). Dietary Fe or In supplementation did not improve muscle Longissimus thoracis et lumborum (LTL) total Fe concentration (P > 0.05). Muscle non-heme Fe concentration was higher in Fe-supplemented pigs (P < 0.04) and gilts (P < 0.05) than their counterparts. Muscle heme Fe concentration was greater (3.04 vs 2.51, P < 0.05) in boars than in gilts. The LTL marbling score was greater (P < 0.01) for In-supplemented pigs, and the response was more notable when Fe and In were fed together. These data show that dietary supplementation of Fe increased serum Fe and muscle non-heme Fe concentrations. Supplementation of In at 5% in the diet of finisher pigs improved liveweight gain and the marbling score of pork.

Intramuscular vitamin A injection in newborn lambs enhances antioxidant capacity and improves meat quality

Introduction

Vitamin A (VA) and its metabolite, retinoic acid (RA) possess several biological functions. This report investigated whether neonatal intramuscular VA injection affected antioxidative activity and meat quality in longissimus dorsi (LD) muscle of lambs.

Methods

Lambs were injected with 0 (control) or 7,500 IU VA palmitate into the biceps femoris muscle on day 2 after birth. At 3, 12, and 32 weeks of age, blood samples were collected in the jugular vein for serum levels of RA and muscle samples were collected in the biceps femoris for analysis of relative mRNA expression of enzyme contributors to retinoid metabolism. All animals were harvested at 32 weeks of age and muscle samples were collected to explore the role of VA on the meat quality and antioxidant capacity of lambs.

Results and discussion

Our results indicated that VA increased the redness, crude protein, and crude fat (p < 0.05), without affecting moisture, ash, and amino acid composition in LD muscle (p > 0.05). In addition, VA increased catalase (CAT) activity and decreased malondialdehyde (MDA) levels in LD muscle (p < 0.05). Meanwhile, greater levels of CAT and NRF2 mRNA and protein contents with VA treatment were observed in LD muscle (p < 0.05), partly explained by the increased level of RA (p < 0.05). Collectively, our findings indicated that VA injection at birth could improve lamb meat quality by elevating the redness, crude protein, crude fat, and antioxidative capacity in LD muscle of lambs.

Animal performance and meat quality characteristics from feedlot-finished steers fed increasing levels of wet distillers grain

One hundred forty-four steers were group-housed in 24 pens that were randomly assigned to one of four dietary treatments defined by the proportion of wet distiller grain plus solubles (WDGS; 0, 15, 30, or 45%) and fed for 84 d pre-slaughter. Animal performance was evaluated using the pen as the experimental unit. Whereas for carcass and meat quality characteristics, meat oxidative stability, and the consumer sensory quality of longissimus thoracis muscle one animal from each pen was randomly selected and used as the experimental unit. No differences (P > 0.05) were observed for subcutaneous fat thickness, rib eye area, marbling score or pH, color parameters, proximate composition, sarcomere length, Warner Bratzler shear force, and cooking loss. Feeding WDGS linearly increased total PUFA (P = 0.05), C18:2 n-6 (P = 0.004) proportions, and n-6/n-3 ratio (P < 0.01) but reduced C16:1 to C18:0 ratio (P < 0.01). Lipid oxidation was greater in beef from steers fed 30% and 45% WDGS (P = 0.05). Dietary WDGS linearly improved (P < 0.05) flavor and overall linking score in the consumer sensory panel.

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.

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.

Enrichment of Dairy-Type Lamb Diet with Microencapsulated Omega-3 Fish Oil: Effects on Growth, Carcass Quality and Meat Fatty Acids

The hypothesis that adding omega-3 oil to feedlot pellets will improve the meat's favourable n-3 PUFA composition was tested in this experiment. Therefore, we evaluated the productive traits and modification of the composition of n-3 PUFA of Longissimus lumborum (LL) muscle in growing lambs supplemented with microencapsulated omega-3 oil (MEOIL) in pelleted total mixed rations (TMR). Thirty six one month old Valle del Belice male lambs (14.04 ± 0.1 kg) were randomly distributed to one of the three dietary treatments (n = 12 lambs each) and provided the supplemented diets up to 14 weeks of age: 1. control (CON) pelleted TMR without omega-3 oil supplementation; 2. omega-3 oil fortified pelleted TMR at 1% (MEOIL1) supplementation; and 3- Omega-3 oil fortified pelleted TMR at 3% (MEOIL3) supplementation. Supplementing MEOIL at both levels in diet positively impacted (p < 0.05) body weight (BW) and feed efficiency. At the end of feeding period, most carcass quality traits did not vary significantly (p > 0.05) among groups, with the exception of carcass dressing and loin yield at both levels of MEOIL. The color and physical traits of LL muscle were affected by MEOIL supplementation (p < 0.05), with no significant change in chemical characteristics. Fatty acids composition of meat in term of linolenic, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were significantly (p < 0.05) influenced by both levels of MEOIL. It was concluded that the tested microencapsulated omega-3 oil preparation may be included at 1% in lamb diet for increasing unsaturated fatty acids in meat without any detrimental effects on lamb productivity.

Mixed oats and alfalfa improved the antioxidant activity of mutton and the performance of goats by affecting intestinal microbiota

Oat hay and alfalfa hay are important roughage resources in livestock production. However, the effect of the mixture of oat hay and alfalfa hay on the meat quality of Albas goats is unclear. This study aimed to investigate the effects of feeding different proportions of oat hay and alfalfa hay on the growth performance and meat quality of Albas goats. Therefore, 32 goats were fed for 70 days and randomly divided into four treatment groups on the principle of similar weight: whole oat group (OAT), oat alfalfa ratio 3:7 group (OA73), oat alfalfa ratio 7:3 group (OA37) and whole alfalfa group (Alfalfa), with eight goats in each group. Daily feed intake records, feces, feed samples, and rumen fluid collection were made throughout the trial. The goats were weighed on the last day of the trial, and four goats per group were randomly selected for slaughter. Cecum contents, meat samples, and hot carcass weight were collected, and data were recorded. Furthermore, the relationship between the rumen and cecal microbes on performance and meat quality was clarified by analyzing the rumen and hindgut microbiomes. The results showed that feeding alfalfa could significantly reduce the daily weight gain of fattening goats. Compared with the highest group (OA37), the daily weight gain decreased by 19.21%. Although there was no significant change in feed intake in the four treatments, the feed conversion rate of the alfalfa group significantly decreased by 30.24-36.47% compared to the other groups. However, with the increased alfalfa content, MDA decreased significantly, T-AOC was up-regulated, and the antioxidant activity of the fattened goat meat fed with the high alfalfa group was significantly higher than that of the low alfalfa group. Notably, the abundance of Bacteroidales_unclassified and Clostridium were strongly correlated with T-AOC and MDA. Therefore, increasing the proportion of alfalfa in the diet can affect the antioxidant activity of goat meat by improving the gut microbiota, while an oat-hay mixture can improve the growth performance of livestock.

Effects of Sheep Sires on Muscle Fiber Characteristics, Fatty Acid Composition and Volatile Flavor Compounds in F1 Crossbred Lambs

Crossbreeding significantly improves meat production performance in sheep; however, whether hybridization changes the meat quality characteristics of lambs is uncertain. We analyzed the effects of three different hybrid sires on muscle fiber characteristics (MFCs), fatty acid composition (FAC), and volatile flavor compounds (VFCs) in lambs under identical feeding conditions. Compared with those of purebred lambs, the muscle fiber diameter and cross-sectional areas of the crossbred lambs were significantly decreased (p < 0.05), and the collagen fiber content was significantly increased (p < 0.05). The numbers and area ratios of the fast and slow muscle fibers did not significantly differ between the purebred and crossbred lambs, but the expressions of four MyHC gene types differed significantly (p < 0.05). Twenty-three fatty acids were identified in both the purebred and crossbred lambs, of which thirteen were differentially expressed (p < 0.05). Saturated fatty acid (SFA) contents in the crossbred lambs were significantly increased (p < 0.05), whereas the monounsaturated fatty acid content was significantly decreased (p < 0.05). Polyunsaturated fatty acid/SFA and n-6/n-3 ratios were significantly lower in the crossbred lambs than in the purebred lambs (p < 0.05). Twenty-five VFCs were identified among the three hybrids, and aldehydes were the main VFCs. Eleven VFCs were differentially expressed in the crossbred lambs (p < 0.05). Hybrid sires affected the MFCs, FAC, and VFCs of the F1 lambs, thus providing a reference for high-quality mutton production.

The Importance of Dietary Antioxidants on Oxidative Stress, Meat and Milk Production, and Their Preservative Aspects in Farm Animals: Antioxidant Action, Animal Health, and Product Quality-Invited Review

The biological effects of oxidative stress and associated free radicals on farm animal performance, productivity, and product quality may be managed via dietary interventions-specifically, the provision of feeds, supplements, and forages rich in antioxidants. To optimize this approach, it is important first to understand the development of free radicals and their contributions to oxidative stress in tissue systems of farm animals or the human body. The interactions between prooxidants and antioxidants will impact redox homeostasis and, therefore, the well-being of farm animals. The impact of free radical formation on the oxidation of lipids, proteins, DNA, and biologically important macromolecules will likewise impact animal performance, meat and milk quality, nutritional value, and longevity. Dietary antioxidants, endogenous antioxidants, and metal-binding proteins contribute to the 'antioxidant defenses' that control free radical formation within the biological systems. Different bioactive compounds of varying antioxidant potential and bio-accessibility may be sourced from tailored feeding systems. Informed and successful provision of dietary antioxidants can help alleviate oxidative stress. However, knowledge pertaining to farm animals, their unique biological systems, and the applications of novel feeds, specialized forages, bioactive compounds, etc., must be established. This review summarized current research to direct future studies towards more effective controls for free radical formation/oxidative stress in farm animals so that productivity and quality of meat and milk can be optimized.

Effects of grape pomace supplementation on the diet of lactating ewes as compared to vitamin E on the meat shelf life of suckling lambs

Forty-eight Churra ewes and their suckling lambs were assigned to four dietary treatments: control (CTRL), VIT-E (500 mg kg-1 TMR vitamin E), GP-5 (5% grape pomace) and GP-10 (10% grape pomace). After slaughter (11.5 kg live weight), longissimus muscle of lambs was sliced, packaged under modified atmosphere (80,20%/O 2:CO 2) and stored in retail conditions. At each sampling point (0, 3, 7, 10, 14 days), microbiological, physicochemical and sensory characteristics were analysed. Vitamin E and GP-5 were found to be effective (p < 0.05) at preventing enterobacteria growth as of day 10. After day 10, vitamin E and grape pomace in the ewe's supplementation reduced metmyoglobin (p < 0.05) lipid oxidation (p < 0.05) and sensory spoilage throughout the storage period. An effect of the grape pomace dosage was observed, with the supplementation at 5% being more effective. Therefore, we can conclude that grape pomace was just as effective as vitamin E in preventing spoilage during retail storage.

The Relationship between Lipid Content in Ground Beef Patties with Rate of Discoloration and Lipid Oxidation during Simulated Retail Display

The relationships between the lipid content, lipid oxidation, and discoloration rate of ground beef during a simulated retail display were characterized in this study. A total of 276 batches of ground beef were manufactured with inside rounds and subcutaneous fat from 138 beef carcasses at different targeted levels of lean:fat. There was a total of four different targeted grind levels during the manufacture of the ground beef, and the lipid content for the samples used in this study ranged from 2% to 32% total lipid. Fatty acid composition was determined based on subcutaneous fat, whereas the proximate composition of moisture and total lipids, instrumental color, visual discoloration, and lipid oxidation measured as thiobarbituric acid reactive substances were evaluated on ground beef patties during 7 days of simulated retail at 4 °C display under LED lights. Analysis for the correlation and the creation of linear regression models indicated that lipid content played a more critical role in the discoloration rate compared to lipid oxidation and fatty acid composition. Lipid oxidation could be more reliably predicted by lipid content and instrumental color compared to visual discoloration. Overall, ground beef formulated with greater lipid content is expected to experience greater rates of lipid oxidation and discoloration during retail display.

Effect of Dietary Brown Seaweed (Macrocystis pyrifera) Additive on Meat Quality and Nutrient Composition of Fattening Pigs

The objective of this study was to evaluate the effects of dietary brown seaweed (Macrocystis pyrifera) additive (SWA) on meat quality and nutrient composition of commercial fattening pigs. The treatments were: Regular diet with 0% inclusion of SWA (CON); Regular diet with 2% SWA (2%-SWA); Regular diet with 4% SWA (4%-SWA). After slaughtering, five carcasses from each group were selected, and longissimus lumborum (LL) samples were taken for meat quality and chemical composition analysis. Meat quality traits (except redness intensity) were not affected (p > 0.05) by treatments. Samples from the 4%-SWA treatment showed the lowest a value than those from the 2%-SWA and CON treatments (p = 0.05). Meat samples from the 4%-SWA group contained 3.37 and 3.81 mg/100 g more of muscle cholesterol than CON and 2% SWA groups, respectively (p < 0.05). The SWA treatments affected (p ≤ 0.05) the content of ash, Mn, Fe, and Cu. The LL samples from 4%-SWA had the highest content of ash; however, they showed 0.13, 0.45, and 0.23 less mg/100 g of Mn, Fe, and Zn, respectively, compared to samples from CON (p ≤ 0.05). Fatty acids composition and macro minerals content (Na, Mg, and K) did not show variation due to the SWA treatments. Further studies are needed to understand the biological effects of these components on adipogenesis, cholesterol metabolism, and mineral deposition in muscle.

Effects of integrated rice-duck farming system on duck carcass traits, meat quality, amino acid, and fatty acid composition

Integrated rice-duck farming (RD) system, which aims to improve the welfare of ducks, has gained popularity in Asian countries. However, the effects of RD system on the carcass and quality traits of duck meat have not been evaluated. Here, a paddy field experiment was conducted to examine the effects of RD system on the carcass and quality traits of duck meat. A total of 180 Jinding ducklings (7 days old) were randomly divided into 2 rearing systems of floor pen rearing (FPR) system and RD system. After 11 weeks, 12 ducks from each rearing system (6 males and females each) were used for carcass traits, meat quality, amino acid, and fatty acid analyses. The results showed that ducks reared in the RD system had higher carcass yield and intramuscular fat content (P < 0.05) than those reared in the FPR system; however, ducks reared in the RD system had lower protein and moisture content (P < 0.05). Additionally, the concentration of essential amino acids, including Tyr, Val, Met, Phe, His, Ala, Arg, and Pro, was higher in the breast muscle of ducks reared in the RD system than those reared in the FPR system. Furthermore, higher saturated fatty acid (C12:0, C14:0, C16:0, C18:0, and C21:0), monounsaturated fatty acid (C16:1, C18:1, and C18:1T), and polyunsaturated fatty acid (C22:2, C18:2n-6, and C22:6n3) content was recorded in the breast muscle of ducks reared in the RD system than those reared in the FPR system (P < 0.05). Taken together, our results indicated that the RD system improved the carcass traits, intramuscular fat, essential amino acids, and polyunsaturated fatty acids profiles of the ducks. These findings suggest that the RD system is an effective strategy to improve the welfare and meat quality of ducks.

Lipid Oxidation and Colour Stability of Lamb and Yearling Meat (Muscle Longissimus Lumborum) from SheepSupplemented with Camelina-Based Diets after Short-,Medium-, and Long-Term Storage

This study investigated the impact of feeding pelleted diets containing camelina (Camelina sativa L. Crantz) hay (CAHP) or camelina meal (CAMP) as a supplement compared with a control pellet (CONP) diet, without vitamin E fortification. The fatty acid profile, retail colour, and lipid oxidative stability of lamb and yearling meat (m. longissimus lumborum) stored for short-, medium-, or long-periods (2 days (fresh), 45 days and 90 days) under chilled to semi-frozen conditions were determined. The CAMP diet altered key fatty acids (p < 0.05) in a nutritionally beneficial manner for human health compared to the other diets, with increased total omega-3, decreased omega-6 fatty acids and decreased omega-6/omega-3 ratio of muscle. Muscle vitamin E concentration was lower (p < 0.05) for both camelina diets (CAMP and CAHP) when compared with the CONP diet, with the average concentrations less than 1 mg/kg muscle for all three treatments. Animal type and storage length were factors that all affected (p < 0.05) colour and lipid oxidative stability of meat. These results emphasise the importance of vitamin E concentration in meat stored for extended periods under semi-frozen conditions to maintain desirable meat colour during retail display, and to avoid off-flavour development of the cooked meat.

Interactions of Gallic Acid with Porcine Hemoglobin: Effect on the Redox State and Structure of Hemoglobin

The effect of gallic acid (GA) on the redox state of hemoglobin (Hb) and the structural mechanism upon the Hb-GA interaction were investigated. Results indicated that GA exhibited antioxidant and pro-oxidant effects on Hb, which depended on its concentration and the redox state of Hb. The antioxidant capacity of GA contributed to the inhibition of free iron release from Hb. GA could bind to the central cavity of Hb and interacted with the heme moiety through direct hydrophobic contacts as indicated by docking analysis, but GA did not disrupt the heme structure. Conversely, GA increased the compactness of the Hb molecule and might narrow the crevice around the heme pocket, which contributed to the inhibition of Hb autoxidation and the free iron release. Results provided significant insights into the interaction of GA with redox-active Hb, which is beneficial to the application of GA in relative meat and blood products.

A comprehensive insight into the effects of microbial spoilage, myoglobin autoxidation, lipid oxidation, and protein oxidation on the discoloration of rabbit meat during retail display

The effects of the retail display temperature (8 °C, 3 °C and - 1 °C) on the discoloration of the Longissimus thoracis et lumborum of rabbits and the associations among such effects with microbial spoilage, myoglobin autoxidation, lipid oxidation, and protein oxidation were investigated. The total aerobic count, total volatile basic nitrogen content, metmyoglobin content, protein carbonyl content, and contents of thiobarbituric acid-reactive substances steadily increased during retail display. Moreover, the lightness and redness of the rabbit meat significantly (P < 0.05) declined over time, whereas the yellowness increased considerably (P < 0.05) with prolonged retail time. Canonical correlation analysis suggested that microbial spoilage, myoglobin autoxidation, lipid oxidation, and protein oxidation jointly affected rabbit meat color. Linear mixed models further revealed that microbial spoilage, myoglobin autoxidation, lipid oxidation and protein oxidation positively affected yellowness, and they inversely impacted lightness and redness.

Feeding Fungal-Pretreated Corn Straw Improves Health and Meat Quality of Lambs Infected with Gastrointestinal Nematodes

Simple Summary

Non-chemical strategies to control gastrointestinal nematode (GINs) infections are urgently needed to support the sustainable development of the livestock industry. The potential anti-parasitic properties in fungal-pretreated corn straw on health and meat quality of lambs infected with GINs were investigated in this study. In summary, feeding fungal-pretreated corn straw improved health and meat quality, including meat color and tenderness. Improved meat traits were attributed to fungal-pretreated corn straw providing additional dietary protein for lambs and secreting some nematicidal metabolites to repel GINs, which increased PCV and plasma iron content of lambs and reversed negative effects of GINs on meat quality.

Abstract

Infections with gastrointestinal nematodes (GIN) adversely affect meat color in lambs. Although white-rot fungi (WRF) pretreatment increases nutritional value and fiber digestion of corn straw for lambs, whether it can improve meat quality of lambs infected with GINs is unknown. The objective of this experiment was to study effects of feeding WRF-pretreated corn straw on the health and meat quality of lambs infected with GINs. Sixteen healthy Ujumqin lambs were orally drenched with 3rd-stage GINs larvae and randomly divided into two dietary treatments of control (CON) and WRF diets for 70 days of feeding. Results showed that feeding WRF-pretreated corn straw decreased L* and b* values (p < 0.05) and increased a* value (p < 0.01) of both longissimus thoracis et lumborum (LTL) and semimembranosus (SM) muscles of lambs infected with GINs. Feeding WRF-pretreatment corn straw decreased fecal egg count (p = 0.014) and increased packed cell volume (p = 0.013) of lambs from 28 d of feeding and increased plasma iron content (p = 0.008) of lambs from 56 d of the feeding. Feeding WRF-pretreatment corn straw decreased myosin heavy-chain (MyHC)-I (p = 0.032) and MyHC-IIα (p = 0.025) content in LTL muscle and MyHC-I (p = 0.022) and MyHC-IIβ (p = 0.048) in SM muscle of lambs. In conclusion, although there were no significant changes in the content of most amino acids or increased intensity of better flavor compounds, meat quality and health of lambs infected with GINs was significantly improved by feeding WRF-pretreated corn straw due to increased PCV and meat color and tenderness.

Effects of dietary mulberry leaf powder on growth performance, blood metabolites, meat quality, and antioxidant enzyme-related gene expression of fattening Hu lambs

This study was conducted to investigate the effects of the mulberry [Morus alba var. multicaulis (Perrott.) Loud.] leaf powder (MLP) supplementation in dietary concentrates on growth performance, blood metabolites, meat quality, and antioxidant enzyme (AOE) gene expression in fattening Hu lambs. Forty approximately 3-mo-old Hu lambs (16.5 ± 0.6 kg) were randomly allocated to five groups and fed with concentrates containing 0%, 15%, 30%, 45%, or 60% MLP (control, T15, T30, T45, and T60, respectively). The results showed that 15%–30% MLP supplementation maintained growth and carcass performance, and the weight of total stomach, especially of rumen in T15 and T30, were higher than those of the control. Dietary MLP supplementation decreased serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, cholesterol, and triglyceride levels, but increased the high-density lipoprotein levels. Moreover, MLP supplementation improved the longissimus lumborum muscle color (redness), tenderness, and water-holding capacity. It was further observed that 15% MLP supplementation enhanced all AOE mRNA levels apart from that of EPHX1. In summary, dietary MLP supplementation could partially improve the blood metabolites, meat quality, and AOE mRNA levels in the liver of fattening Hu lamb, and the level of 15% supplementation was the most promising.

The Impact of Antioxidant Supplementation and Heat Stress on Carcass Characteristics, Muscle Nutritional Profile and Functionality of Lamb Meat

The impact of antioxidant supplementation and short-term heat stress on lamb body weight gain, meat nutritional profile and functionality (storage stability of lipids and colour) of lamb meat was investigated. A total of 48 crossbred ((Merino × Border Leicester) × Dorset) lambs (42 ± 2 kg body weight, 7 mo age) were randomly allocated to three dietary treatments (n = 16) by liveweight (LW) that differed in dosage of vitamin E and selenium (Se) in the diet. Vitamin E and Se levels in the control (CON), moderate (MOD) and supranutritional (SUP) dietary treatments were 28, 130 and 228 mg/kg DM as α-tocopherol acetate and 0.16, 0.66 and 1.16 mg Se as SelPlex™/kg DM, respectively. After four weeks of feeding in individual pens, including one week of adaptation, lambs were exposed to two heat treatments. Animals were moved to metabolism cages for one week and subjected to heat treatments: thermoneutral (TN; 18-21 °C and 40-50% relative humidity) and heat stress (HS; 28-40 °C and 30-40% relative humidity) conditions, respectively. Final LW and hot carcass weight were influenced by dietary treatments with higher final live weight (FLW) (p = 0.05; 46.8 vs. 44.4 and 43.8 kg, respectively) and hot carcass weight (HCW) (p = 0.01; 22.5 vs. 21.3 and 21.0 kg, respectively) recorded in lambs fed the SUP as opposed to the CON and MOD diets. Vitamin E concentration in the longissimus lumborum (LL) muscle tended to be higher in lambs fed MOD or SUP diets than the CON group. Lipid oxidation of aged meat at 72 h of simulated retail display was reduced by antioxidant supplementation. Short-term (one week) heat stress treatment significantly increased muscle linoleic acid and total omega-6 concentrations compared with the CON group. The results demonstrate that four-week antioxidant supplementation at the SUP level improved animal productivity by increasing LW and carcass weight and the functionality of meat exhibited by reduced lipid oxidation. An increase in muscle omega-6 fatty acid concentration from short-term heat stress may induce oxidative stress via proinflammatory action.

Understanding the impact of sire lean meat yield breeding value on carcass composition, meat quality, nutrient and mineral content of Australian lamb

Advances in genomics and technology measuring body composition are now allowing sheep producers to select directly for increased lean meat yield (LMY) using Australian Sheep Breeding Values (ASBV). This experiment evaluated the impact of sire LMY ASBV on carcass composition, meat quality, nutrient and mineral content for lambs reared at pasture and finished in a feedlot. A 1% unit increase in sire LMY ASBV resulted in progeny that were leaner (0.8%) and had less fat (1.0%) on carcass. There was also a 0.2% reduction in the intramuscular fat content, a 3.2 N increase in meat toughness determined by shear force at day 5 ageing, a reduction in the redness of the fresh meat and a lower iron content. It is concluded that Australian sheep producers will need to incorporate ASBVs for other aspects of meat quality when selecting sires with increased LMY to avoid deterioration in meat quality, nutritional content of lamb and fresh meat colour.

Use of lucerne hay in ruminant feeds to improve animal productivity, meat nutritional value and meat preservation under a more variable climate

This study investigated the effect of low energy (LE) and high energy (HE) diets fed to Crossbred and Merino sheep on carcass weight, meat nutritional value (essential fatty acids) and preservative (shelf life) aspects. Animals were slaughtered after seven weeks of feeding and the longissimus lumborum (LL) and rectus femoris (RF) muscles collected for measurement of fatty acid concentration and retail colour. Liveweight and carcass weight at slaughter were not affected by dietary treatments. Adding lucerne hay as an ingredient to LE diet increased (P < .001) omega-3 fatty acids concentrations and lowered (P < .001) the omega-6: omega-3 ratio in meat. The redness of meat for LL and RF muscles at simulated retail display was higher (P < .05) for lambs fed LE than lambs fed HE diet. Results indicate that adding lucerne hay as an ingredient in ruminant diets has potential for maintaining liveweight (wellbeing) of animals as well as nutritional value and preservative aspects of meat.

Understanding the action of muscle iron concentration on dark cutting: An important aspect affecting consumer confidence of purchasing meat

We investigated the association of muscle iron concentration, in addition to ultimate pH (pHU), on dark meat formation in sheep of different breeds fed forage-based diets. At 1 h simulated display, redness of meat (a*-value) increased (P < .0001) by about 3 units as the iron concentration increased from 10 to 22 mg/kg of meat, whereas the a*-value decreased by 2 units as pHU increased from 5.5 to 6.2 in fresh meat (P < .0001). After 90 days storage the corresponding responses were about 2 units increase for iron concentration and about 1 unit decrease for pHU, respectively. The results clearly show that increased muscle iron concentration was strongly associated with reduced dark cutting in fresh and stored meat evaluated at 1 h simulated display. We conclude that it may be desirable to measure iron concentration, along with pHU, for evaluation of the potential for carcasses to produce dark cutting meat, and for the meat to turn brown during display.

Raw meat quality and salt levels affect the bacterial species diversity and community dynamics during the fermentation of pork mince

Acidification level and temperature modulate the beneficial consortia of lactic acid bacteria (LAB) and coagulase-negative staphylococci (CNS) during meat fermentation. Less is known about the impact of other factors, such as raw meat quality and salting. These could for instance affect the growth of the pathogen Staphylococcus aureus or of Enterobacterales species, potentially indicative of poor fermentation practice. Therefore, pork batters from either normal or borderline quality (dark-firm-dry, DFD) were compared at various salt concentrations (0-4%) in meat fermentation models. Microbial ecology of the samples was investigated with culture-dependent techniques and (GTG)₅-PCR fingerprinting of genomic DNA. Whilst Lactobacillus sakei governed the fermentation of normal meat, Lactobacillus curvatus was more prominent in the fermentation of the DFD meat variant. CNS were favoured during fermentation at rising salt concentrations without much effects on species diversity, consisting mostly of Staphylococcus equorum, Staphylococcus saprophyticus, and Staphylococcus xylosus. During fermentation of DFD meat, S. saprophyticus was less manifest than during that of normal meat. Enterobacterales mainly emerged in DFD meat during fermentation at low salt concentrations. The salt hurdle was insufficient to prevent Enterobacterales when acidification and initial pH were favourable for their growth.

Feeding lambs with silage mixtures of grass, sainfoin and red clover improves meat oxidative stability under high oxidative challenge

This study investigated the oxidative stability of meat from lambs fed silages in which timothy grass was totally or partially replaced by sainfoin and/or red clover. Five groups of 8 lambs were fed the following silages: timothy grass (T), mixture (50:50) of timothy with either sainfoin (T-SF) or red clover (T-RC), mixture of timothy, sainfoin and red clover (50:25:25; T-SF-RC), or mixture (50:50) of sainfoin and red clover (SF-RC). Feeding the silages containing red clover (T-RC, T-SF-RC and SF-RC) decreased the deposition of vitamin E in muscle relative to the highly unsaturated fatty acids (P < .001), did not affect the oxidative stability of fresh meat, but reduced oxidative deterioration in cooked meat and in meat homogenates incubated with pro-oxidant catalysts (P < .001). The results of this study demonstrated that feeding lambs with silages containing sainfoin and red clover improve the oxidative stability of meat subjected to strong pro-oxidant conditions and suggest that these effects should be further clarified.

Breed and Nutrition Effects on Meat Quality and Retail Color after Lamb Pre-Slaughter Stress

The main objective of this research was to investigate the interactions between breed, nutrition and pre-slaughter stress, and the potential impacts on the meat quality and retail color/shelf life of lamb meat. Forty-eight Merino and second cross (Merino × Border Leicester) × Poll Dorset lambs were allocated to 2 dietary treatments: low energy diet (LE; 7.8 MJ ME/kg and 12% CP) vs. high energy (HE; 11.8 MJ ME/kg and 12% CP). Samples of longissimus lumborum (LL), and rectus femoris (RF) were taken 15 min post-slaughter for glycogen and lactate determination. pH and temperature of muscle samples were recorded at 0.5, 1.5, 3, 4.5, 6, and 24 h post-mortem. Muscle LL samples from the same side were collected at 24 h post slaughter for tenderness, cooking loss and retail color assessment. For retail color stability, the selected portion of muscle LL was sliced to create a fresh surface, placed on a tray and over wrapped. Color measurements were made fresh (after a 30 min bloom at 4°C, d 1) and then on d 3 and 6 of display, using a Hunter lab spectrophotometer XE Plus. Second-cross lambs on HE had the highest muscle glycogen at slaughter for both LL and RF. For the RF, the pHu values were elevated in Merinos on both LE and HE diets and 2X on the LE diet. Only for 2X lamb was the HE diet sufficient to reduce the pHu. HE diet reduced blood lactate in 2X lambs and elevated in Merinos. Merinos produced tougher meat at 6 d post-slaughter, which was also reflected by higher cooking losses. Both breeds of lambs on the LE diet had longer color shelf-life (higher R630/580) than the lambs on the HE diets.

Dietary lycopene powder improves meat oxidative stability in Hu lambs

BACKGROUND

The aim of this study was to evaluate the effect of dietary lycopene powder on meat quality and the oxidative stability of lipid and protein of longissimus thoracis (LT) in lamb. A total of 30 male lambs were randomly sampled from three feeding groups (control without lycopene supplement, 200 and 400 mg kg^-1 lycopene powder respectively) after 3 months of feeding. The muscle samples were taken after slaughter and stored at 4 °C for 7 days.

RESULTS

Compared with the control, the results showed that supplementation with lycopene powder gave a higher a^* value (redness), and increased the levels of vitamin A and vitamin E. Increasing dietary lycopene powder resulted in a lower degree of lipid and protein oxidation, as evidenced by lower contents of thiobarbituric acid-reactive substance and carbonyl compounds, and higher levels of sulfhydryl groups.

CONCLUSION

Dietary lycopene powder is an effective antioxidant that blocks the oxidation of meat proteins and lipids, and has a positive effect on increasing lamb meat quality during storage. © 2018 Society of Chemical Industry.

Comparison of a grain-based diet supplemented with synthetic vitamin E versus a lucerne (alfalfa) hay-based diet fed to lambs in terms of carcass traits, muscle vitamin E, fatty acid content, lipid oxidation, and retail colour of meat

Dietary supplementation of vitamin E (VitE) in a synthetic or natural form was examined. Forty-eight lambs were assigned (n = 16) to either a grain-based diet at moderate (MOD, 42 mg∙kg^-1 VitE as all-rac α-tocopheryl acetate) or supranutritional (SUP, 285 mg∙kg^-1 of vitE) levels of synthetic VitE or a lucerne hay-based diet (LUC; 37 mg∙kg^-1 VitE) for 8 weeks. Meat from the LUC group had lower muscle n-6 and PUFA levels compared to meat from the MOD and SUP groups. Despite a similar VitE intake, muscle VitE was higher for LUC compared to MOD, while SUP lambs showed the highest VitE. Lipid oxidation did not differ between groups. For fresh meat, redness tended to be higher in LUC fed lambs than the other two groups, but brownness formation was only lower than the SUP group. For aged meat colour stability, redness tended to be higher in lambs fed SUP and LUC, whereas highest browning occurred in the MOD group.

Oxidative stability of beef from steers finished exclusively with concentrate, supplemented, or on legume-grass pasture

The objective of this study was to evaluate the effects of three finishing systems based on concentrate and legume-grass pasture on beef. Steers were finished for 91 days with an exclusively whole corn grain-based (GRAIN) diet, grazed on legume-grass pasture plus 1.4% of body weight of whole corn grain supplementation (SUPP), or grazed on legume-grass pasture (PAST) only. Lipid and myoglobin oxidation, pH, objective color, and α-tocopherol concentrations were evaluated on M. longissimus thoracis steaks. Dietary treatments did not affect pH and minimally affected protein carbonylation. Steaks from steers fed GRAIN were less red, showed higher lipid oxidation during retail display, and higher metmyoglobin formation from day 7 to 13 when compared to PAST. Levels of α-tocopherol were higher in steaks from steers fed diets containing legume and grass. Inclusion of roughage in finishing diets is essential to maintain retail color and prevent lipid and myoglobin oxidation.

Meat packaging solutions to current industry challenges: A review

Many advances have occurred in the field of smart meat packaging, and the potential for these to be used as tools that respond to challenges faced by industry is exciting. Here, we review packaging solutions to several immediate concerns, encompassing dark cutting, purge and yield losses, product traceability and provenance, packaging durability, microbial spoilage and safety, colour stability, environmental impacts, and the preservation of eating quality. Different active and intelligent packaging approaches to each of these were identified and are discussed in terms of their usefulness - to processors, retailers and/or consumers. From this, it became apparent that prior to selecting a packaging solution, industry should first define their criteria for success (e.g. How much purge is too much? What is a reasonable shelf-life to facilitate product turnover? Is the customer willing to pay for this?), and understand that packaging is not the sole solution, but acts as part of a holistic response to these issues.

The influence of the level of ewe gestation nutrition and lamb finishing diet on long-chain polyunsaturated fat concentration, antioxidant and mineral status, and colour stability of meat

The influence of ewe gestation nutrition (EGN) and lamb finishing diet (LFD) on muscle essential fatty acid, antioxidant and mineral status and retail colour of meat in F1 progeny lambs were investigated. First-cross Border Leicester × Merino and Maternal–Coopworth Composite ewes (n = 938) were artificially inseminated to nine terminal sires. From this flock, 648 pregnant ewes were selected between Day 41 and Day 49 of pregnancy, producing 72 pregnant ewes from each sire for distribution across six condition-score (CS) groups. Each CS group was balanced for three sires of high, medium and low lean meat yield and ewe breed. Variation in EGN was achieved through pasture allocations and supplementation, to meet three CS (2.5, 3.0 and 3.5) targets at lambing. At lambing, management of EGN ceased and ewes and lambs were given access to similar pasture allocations. Lambs were weaned at 12 weeks of age and backgrounded on pasture before the random allocation from within each block of sire by CS treatment combination, to the following three different finishing diets: high energy–high protein (HEHP); high energy–moderate protein (HEMP) and moderate energy–high protein (MEHP). Moderate EGN (CS 3.0) increased (P < 0.02) muscle C22:6n-3 and decreased (P < 0.04) C20:4n-6 concentrations compared with CS 2.5 and CS 3.5 EGN groups respectively. Redness of meat over the display period was greater (P = 0.005) for CS 3.0 and CS 3.5 EGN regimes than for the CS 2.5 regime. The MEHP diet reduced (P < 0.01) muscle C18:2n-6, C20:4n-6 and total n-6 fatty acid and increased antioxidant (vitamin E, P < 0.01) concentrations compared with HEHP and HEMP diets, but iron concentration was not affected. Differences in dietary vitamin E concentration between MEHP diet and HEHP or HEMP diets are likely to have contributed to increases in muscle antioxidant status. The energy and protein concentration of LFD had no effect on the health claimable n-3 fatty acid concentration in meat.

The use of oxidative stress biomarkers in live animals (in vivo) to predict meat quality deterioration postmortem (in vitro) caused by changes in muscle biochemical components

This study was conducted to determine whether circulating concentrations of blood isoprostanes can be used as an effective biomarker in lambs to predict degradation of color and/or lipid stability in meat. Lambs ( = 84) were fed diets of either lucerne pasture, annual ryegrass pasture, a commercial feedlot pellet, or a combination of annual ryegrass and feedlot pellet for 8 wk, including a 2-wk adaptation period. Blood isoprostane concentration at wk 0, 4, 6 or 8 of feeding was determined. Blood isoprostane concentration for each animal was then correlated with muscle biochemical components that impact color and/or lipid oxidative status during retail display. This included lipid oxidation levels in muscle assessed by thiobarbituric acid reactive substances and meat redness determined by a HunterLab colorimetric spectrometer. Lambs that consumed the commercial feedlot pellet had a lower muscle vitamin E level (< 0.01) and a greater level of -6 PUFA ( < 0.001) compared with lambs finished on annual ryegrass or lucerne. Lipid oxidation levels were greatest for lambs finished on the feedlot ration, lowest in lambs finished on the ryegrass diet, and intermediate for lambs finished on lucerne and ryegrass-feedlot combination ( < 0.01). After 8 wk of feeding, blood isoprostane concentration was positively correlated with lipid oxidation of meat displayed for 72 h in simulated retail conditions ( < 0.01). There was a negative linear relationship between isoprostane concentration and muscle vitamin E concentration ( = 0.07), lipid oxidation and muscle vitamin E concentration ( < 0.01) but a positive linear relationship between isoprostane concentration and muscle -6 PUFA ( < 0.001) or lipid oxidation and muscle -6 PUFA concentration ( < 0.001). Blood isoprostane concentration and lipid oxidation in meat were influenced by muscle vitamin E and -6 PUFA but not by -3 PUFA. There was no significant relationship observed between blood isoprostane concentration at 0, 4, 6 or 8 wk feeding vs. overall meat color (redness of meat) at 0 and 72 h of display, stored under simulated retail conditions. The results indicate that circulating blood isoprostane concentration can be a useful tool to predict the oxidative status of postmortem meat. Future work will examine the impact of this relationship on meat flavor/aroma deterioration post farm.

Protein profile and physicochemical characteristics of meat of lambs fed diets supplemented with rapeseed oil, fish oil, carnosic acid, and different chemical forms of selenium

Abstract. The objective of this study was to evaluate the physicochemical characteristics of the longissimus muscle of lambs fed a control diet containing 3 % rapeseed oil (RO) (group I); an experimental diet with 2 % RO and 1 % fish oil (FO) (group II); or experimental diets with coupled addition of 2 % RO, 1 % FO, and 0.1 % carnosic acid (CA) (group III) without/with 0.35 ppm Se as selenized yeast (SeY) (group IV) or selenate (SeVI as sodium selenate, Na2SeO4) (group V). The results showed that dietary FO or SeVI affected the ultimate pH and meat color in comparison to lambs fed the control diet. The differences noted between diets in the case of muscle tissue were as follows: myosin HC (heavy chain) and LC1 (light chain), 150 kDa, α-actinin, 60 kDa, and TnT (troponin T), 30 kDa protein. The addition of FO to lamb diets resulted in a lower content of 30 kDa proteins, which are indicators of proteolysis. Considering the protein profile of drip loss, results showed effects of dietary administration of FO, CA, and Se (as SeY and SeVI) on the abundance of the following sarcoplasmic proteins: AMPDA (AMP deaminase), PGM (phosphoglucomutase), PK/PGI (pyruvate kinase/phosphoglucose isomerase), CK/PGAK (creatine kinase/phosphoglycerate kinase), ALD (aldolase), LDH (lactate dehydrogenase), PGAM (phosphoglycerate mutase), and TPI (triosephosphate isomerase). The lower content of TPI (in group II with comparison to groups III–V) and PGAM (in group II with comparison to group I and III) could be due to a higher ultimate pH in the group with FO addition, whereas lower contents of CK/PGAK, ALD, and LDH were attributed to Se addition. In comparison to the control diet, all experimental diets without SeVI decreased the content of the sum of all assayed amino acids ( ∑ AAs), indispensable amino acids ( ∑ IAAs), and dispensable amino acids ( ∑ DAAs) in the muscle. The highest ratios of  ∑ IAAs to  ∑ DAAs and  ∑ IAAs to  ∑ AAs were found in the muscle of lambs fed the diet containing RO, FO, and CA. The FO-supplemented diet with CA and SeVI increased the abundance of methionine in the muscle in comparison to the control diet and the FO-supplemented diet without/with CA.

Interaction of diet and long ageing period on lipid oxidation and colour stability of lamb meat

Eighty-four crossbred wether and ewe lambs were allocated to four finishing diets. The diets were: Lucerne pasture (n=24), Annual ryegrass with sub clover pasture (n=18), Standard commercial feedlot pellets (n=24) and Annual ryegrass based pasture and commercial feedlot pellets (500g/day/head) (n=18). After 8weeks of feeding the lambs were slaughtered and the m. longissimus (LL) and m. semimembranosus (SM) were vacuum packaged and held chilled for 5 (fresh) or 60 (long aged) days, after which samples of each were displayed for 4days under simulated retail conditions. Irrespective of muscle type the long aged samples exhibited a rapid reduction in redness (a*-values) and R630/580nm ratio values such that consumer acceptable thresholds for both traits were quickly exceeded providing limited shelf life. Long ageing also lead to high TBARS levels measured as MDA mg/kg muscle suggestive of a product likely to exhibit rancidity and off flavours from lipid oxidation.

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.

Influence of dietary canola oil and palm oil blend and refrigerated storage on fatty acids, myofibrillar proteins, chemical composition, antioxidant profile and quality attributes of semimembranosus muscle in goats

BACKGROUND

Improving the unsaturated fatty acid content of ruminant meat is essential due to the generally saturated nature of fatty acids in ruminant meat and the negative effects this can have on human health. Nonetheless, enhancing the unsaturated fatty acid content of ruminant meat can have adverse effects on the shelf life and quality attributes of the meat. This study assessed the effects of dietary 80 % canola oil and 20 % palm oil blend (CPOB) on fatty acid composition, antioxidants, oxidative spoilage, cholesterol and physicochemical properties of semimembranosus (SM) muscle from goats. Twenty four Boer bucks were randomly assigned to diets containing on dry matter basis 0, 4 and 8 % CPOB, fed for 100 d and slaughtered. The carcasses were subjected to a 7 d postmortem refrigerated storage. All analyses were conducted on the SM muscle.

RESULTS

Diet had no effect (P > 0.05) on the concentration of free thiol and carbonyl and the band intensity of myosin heavy chain, actin and troponin T. The muscle glycogen, pH, water holding capacity, tenderness, glutathione peroxidase (GPX) activity, total carotenoid, δ-tocopherol, cholesterol and proximate composition did not differ (P > 0.05) between diets. The SM muscle from goats fed 4 and 8 % CPOB had lower (P < 0.05) concentration of C14:0 and C16:0 and higher (P < 0.05) concentration of C18:1 trans-11, C18:1ω-9, C18:3ω-3, C20:5ω-3 and C22:5ω-3 than the SM muscle from the control goats. Dietary CPOB increased (P < 0.05) the concentration of α and γ tocopherol and meat redness (a*) on d 1 and 4 postmortem. Regardless of diet, antioxidant vitamins, and shear force decreased (P < 0.05) while drip loss, lipid and protein oxidation increased (P < 0.05) as postmortem storage progressed.

CONCLUSION

Results evince that dietary CPOB can be used as a management tool to enhance the beneficial fatty acids and antioxidant contents of chevon without deleterious effects on its physicochemical properties and shelf life.