The restriction of grazing duration does not compromise lamb meat colour and oxidative stability

Feeding pigs with hazelnut skin and addition of a concentrated phenolic extract from olive-milling wastewaters during pork processing: Effects on salami quality traits and acceptance by the consumers

Two groups of ten barrows received a conventional- (CTRL) or an experimental- (HZL) finishing diet containing 11% of hazelnut skin. From each barrow, two types of salami (namely, NITR, and PHEN) were obtained. NITR salami was added with E250 and E252. The latter were replaced by a phenolic concentrated extract from olive-milling wastewaters in PHEN salami. Salami fatty acids (FA), antioxidant capacity, lipid and color stability during refrigerated storage were assessed. A consumer test was also performed. Feeding strategy minimally affected the investigated parameters. PHEN salami had lower TBARS than NITR salami (P-value <0.001) during refrigerated storage despite comparable antioxidant capacity and similar PUFA content. Moreover, within CTRL group, lipid oxidation was lower in PHEN than NITR salami (P-value = 0.040). At the blind taste, dietary treatment did not affect salami sensorial properties nor consumer acceptance, whereas NITR salami showed better color (P-value = 0.036). Interestingly, HZL and PHEN salami showed improved sensorial properties and consumer acceptance after that consumers received information on salami origin.

Red Meat Heating Processes, Toxic Compounds Production and Nutritional Parameters Changes: What about Risk-Benefit?

The heating process is a crucial step that can lead to the formation of several harmful chemical compounds in red meat such as heterocyclic aromatic amines, N-Nitrosamines, polycyclic aromatic hydrocarbons and acrylamide. Meat has high nutritional value, providing essential amino acids, bioactive compounds and several important micronutrients which can also be affected by heating processes. This review aims to provide an updated overview of the effects of different heating processes on both the safety and nutritional parameters of cooked red meat. The most-used heating processes practices were taken into consideration in order to develop a risk-benefit scenario for each type of heating process and red meat.

Different nutritional systems influence the tenderness and lipid oxidation of ewe lamb meat without altering gene expression

Feeding is a determining factor in the various characteristics of sheep meat and animal performance, the objectives were to evaluate the effect of supplementation of ewe lambs finished in different nutritional planes on the gene expression of CASP3, CAPN1, CAPN2 and CAST and its possible association with meat quality. Samples of the Longissimus lumborum muscle of 24 ewe lambs were used, distributed in 3 groups (n=8): P (pasture), PS (pasture and supplement) and F (feedlot). Physicochemical analyses were performed for centesimal analysis, pH, lipid oxidation, Warner-Bratzler shear force and RT-qPCR for the analysis of relative gene expression of the following genes: CASP3, CAPN1, CAPN2 and CAST. There is an increase in daily weight gain and ethereal extract values in the meat of confined animals, due to the greater energy intake in the nutrition of these animals. Animals kept only on pasture have lower lipid oxidation in meat than other treatments because of the lower percentage of lipids. The Warner-Bratzler shear force is considerably higher in the meat of animals kept only on pasture but is still considered tender. The different nutritional systems do not interfere with the gene expression of CASP3, CAPN1, CAPN2 and CAST in ewe lambs.

Effects of Feeding Regimes and Postmortem Aging on Meat Quality, Fatty Acid Composition, and Volatile Flavor of Longissimus Thoracis Muscle in Sunit Sheep

The effects of different feeding regimes on antioxidant activity, meat quality, fatty acid composition, lipid oxidation, and volatile matter production in the longissimus thoracis (LT) of Sunit sheep at 0, 24, 48, 72, and 96 h postmortem were investigated. The results showed that the activity of antioxidant enzymes, tenderness, water retention, and percentage of unsaturated fatty acids were significantly higher in the pasture-fed sheep (PF) than in the concentrate-fed sheep (CF) (p < 0.05). During postmortem aging, antioxidant activity, water retention, and the proportion of unsaturated fatty acids decreased in the PF and CF (p < 0.05), while malondialdehyde (MDA) content, the proportion of saturated fatty acids, and the content of flavor substances resulting from fat oxidation increased. After 24 h of LT muscle aging, the pH and shear force of the meat started to increase and the color stabilized. The differences between shear force values and lipid volatile flavor substance content of sheep meat under different feeding regimes disappeared with increasing aging time. PF had better oxidative stability and fatty acid composition. Postmortem aging changed the oxidative stability of sheep meat, thus affecting meat quality and fatty acid composition and consequently meat flavor composition, while aging also eliminated to some extent the differences caused by feeding regimes.

Characterization of the Flavor Precursors and Flavor Fingerprints in Grazing Lambs by Foodomics

Tan sheep are greatly preferred by consumers in China because of their nutritional value and unique flavor. However, the meat quality of Tan sheep has decreased due to the change in feeding systems from grazing to indoor. Studies investigating the mechanisms for the decrease in meat quality are limited. A total of 28 Tan sheep were randomly allocated to two treatments, receiving a concentrated diet, or pasture. Flavor precursors and volatile compounds were analyzed with foodomics. E-nose and E-tongue analyses suggested that the aroma and taste profiles differed between the feeding systems. The grazing lambs had higher levels of linoleic acid and n-3 polyunsaturated fatty acids (p < 0.01). Metabolomics indicated that 25 hydrophilic metabolites active in glycolipid and amino acid metabolisms were changed by the feeding system. Among the 57 volatile compounds identified, methional, γ-butyrolactone, benzaldehyde, and ethyl acetate were at concentrations significantly higher in the grazing lambs than the indoor-fed lambs (p < 0.01). These results reveal key changes in flavor precursors and flavor profiles affected by the feeding system, which may provide an initial view of the reason for consumer preference for the grazing Tan sheep.

A quantitative review of on-farm feeding practices to enhance the quality of grassland-based ruminant dairy and meat products

In the last decades, a large body of evidence has highlighted the major role of feeding management practices in improving specific nutritional, technological and sensory quality traits of ruminant products. However, results have been mostly obtained under controlled conditions, and have been rarely validated on-farm. Therefore, a quantitative review was conducted to quantify the effects of on-farm feeding management practices on carotenoids, fat-soluble vitamins, colour, fatty acids (FAs), terpenes and sensory properties in the main animal product categories (PCs): dairy products from cattle (DC), sheep (DS) and goat (DG), and meat from cattle (MC) and sheep (MS). Four feeding scenarios were selected according to the consistency of on-farm studies in the literature: (a) feeding "Fresh herbage" instead of conserved forages; (b) ban any form of silage ("Silage-free"); (c) ban maize silage ("Maize silage-free"); (d) feeding forages from permanent grasslands rich in species or plant secondary metabolites (PSMs) ("PSM-rich permanent grassland"). Feeding fresh herbage increased the concentration of carotenoids, fat-soluble vitamin, n-3 FA, rumenic acid, and branched chain FA (BCFA), and reduced the concentration of saturated FA, for all PC, with overall stronger effect for dairy products than for meat. The texture of meat and dairy products was marginally affected, whereas feeding fresh herbage decreased lactic and increased vegetal notes in DC. The "Silage-free" feeding scenario resulted in increased vaccenic acid, rumenic acid, BCFA, and C18:3n-3 in DC. The "Maize silage-free" feeding scenario lowered n-6 FA whereas increased n-3, rumenic acid and BCFA concentrations in DC. Feeding ruminants with forages from "PSM-rich permanent grasslands" increased monounsaturated FA, n-3 FA and rumenic acid and decreased n-6 FA in dairy products, and only marginally affected meat FA composition. The DC from "PSM-rich permanent grasslands" showed higher intense, spicy and animal notes. Overall, the differences between feeding management practices observed on farm were smaller than those observed under controlled trials. Several confounding factors, not controlled when operating under on-farm conditions, could be at the origin of these divergences (i.e. mixed diets, forage characteristics, animal-related factors). This review confirmed that farming practices may differently affect several quality traits of ruminant products. It also highlighted the uneven knowledge on the effect of feeding management depending on the PC: larger for milk than for meat and decreasing when moving from cattle to sheep and from sheep to goat.

'Rotatinuous' stocking as a climate-smart grazing management strategy for sheep production

We aimed to evaluate the effect of different grazing management strategies on carcass characteristics traits, meat quality and CH₄ intensity and yield of lambs grazing Italian ryegrass pastures in Southern Brazil. A grazing trial was performed (2014 and 2015) in a randomized complete block design with two grazing management targets and four replicates. Treatments were traditional rotational stocking (RT), with pre- and post-grazing sward heights of 25 and 5 cm, respectively, and 'Rotatinuous' stocking (RN), with pre- and post-grazing sward heights of 18 and 11 cm, respectively. Castrated crossbred Texel and Polwarth lambs were used. Results indicated that diet cost per kg of dry matter (p = 0.001) and per hectare (p < 0.001) were lower for RN than for RT treatment. Final live weight (p = 0.022) and hot and cold carcass weight (p = 0.006) were greater for the RN treatment. All commercial cuts were greater for RN than for RT treatment. The RN treatment presented greater (p < 0.001) production of carcass, edible food and crude protein. Feed efficiency and feed cost conversion were better for RN than for RT treatment. CH₄ intensity per kg of carcass, edible food and crude protein gain were 2.6, 2.7 and 2.1 times lower (p < 0.001) for RN. Moreover, CH₄ yield was lower (p = 0.014) for RN than for RT treatment, with an average of 7.6 and 8.3% of the gross energy intake, respectively. We conclude that the 'Rotatinuous' stocking results in a greater carcass production, carcass quality and lower diet cost, and CH₄ intensity and yield of grazing lambs. Adopting this grazing management strategy could enhance both lamb production and mitigation of CH₄ intensity and yield in grazing ecosystems, which could be considered a good example of climate-smart livestock production.

Lamb Fattening Under Intensive Pasture-Based Systems: A Review

The benefits of pasture-based systems on the fatty acid composition of sheep meat appear to be achievable despite variability in the quality of the pastures. Lambs fed high levels of temperate pastures have an excess of N-ammonia derived from protein degradation. Furthermore, animal performance is highly variable depending on the quality of the pasture at the time of grazing, and high animal performance in these systems appears to be linked to the use of high-quality pastures with high availability, and is possibly added to by the inclusion of concentrates that allow increasing energy intake and a better use of the N in the pasture. The combination of high-quality pastures and total mixed ration offers a good alternative to the inclusion of concentrates in the diet, improving the use of N, and avoiding acidosis problems. However, information to determine the effect of a number of nutritional strategies on meat quality, and the minimum level of pasture intake necessary to achieve the benefits of pastoral systems is still lacking.

The effect of aging and muscle type on the quality characteristics and lipid oxidation of lamb meat

The research carried out on meat from 45 ram lambs of the Polish merino breed allowed to determine the effect of meat aging and muscle type on physicochemical characteristics and oxidative stability of lipids. Analysis of physicochemical traits (pH, meat color, expressed juice, cooking loss, shear force, moisture, protein, fat and total collagen content) was performed on fresh and meat aged for 14 d in the longissimus lumborum (LL) and gluteus medius (GM) muscles. The meat aging determined all physicochemical characteristics except protein and fat content. More changes in pH and meat color parameters were defined in the GM muscle compared to the LL muscle. The increase in the tenderness of meat expressed as a reduction ( P < 0.05 ) of shear force values was observed in both muscles aged for 14 d. A lower value ( P < 0.05 ) of the shear force, despite the higher content of collagen, was determined in the GM muscle compared to LL. The investigated muscles differed in the degree of lipid peroxidation expressed as thiobarbituric acid-reactive substances (TBARS) in both fresh and aged meat. The TBARS value was lower ( P < 0.05 ) in the LL muscle than in GM. In the longissimus lumborum muscle, the significantly lower content of polyunsaturated fatty acids (PUFAs) and PUFA n-6 has been recorded. The oxidation stability was not influenced by the meat aging.

Meat quality of light lambs is more affected by the dam's feeding system during lactation than by the inclusion of quebracho in the fattening concentrate

The inclusion of natural antioxidants in the diet, through fresh forages or condensed tannins, might prolong meat shelf life and modify the meat quality. The aim of this study was to evaluate the effect of the dam's feeding system during lactation and the inclusion of quebracho in the fattening concentrate of male lambs on meat color, chemical composition, and lipid oxidation. Dams and their suckling lambs were fed indoors or allowed to graze on alfalfa or sainfoin until lambs reached 42 d old. Thereafter, the weaned lambs were fed concentrates with 5% quebracho or without quebracho until reaching 22 to 24 kg BW. Meat of suckling lambs from dam's fed indoors (Indoor lambs) presented greater intramuscular fat content and lower α-tocopherol content than meat of suckling lambs from dam's fed Alfalfa (Alfalfa lambs) and Sainfoin (Sainfoin lambs; < 0.01), independent of the fattening diet. Regarding meat color of longissimus thoracis et lumborum muscle, on average, Indoor lambs' meat presented greater lightness, yellowness, and hue angle values than Alfalfa and Sainfoin lambs' meat ( < 0.05). The redness was affected by the interaction between the feeding system during lactation and the time of storage, but, on average, Alfalfa and Sainfoin lambs had greater redness than Indoor lambs ( < 0.05). The lipid oxidation from 5 to 14 d of meat display time observed for Sainfoin lambs was lower than that for Indoor lambs ( < 0.05). The intramuscular fatty acid profile of meat from the Sainfoin and Alfalfa lambs met particularly well the Food and Agriculture Organization of the United Nations recommendation for human health, compared that of meat from the Indoor lambs. The dietary inclusion of quebracho during fattening modified meat α-tocopherol content, oxymyoglobin levels after 8 d of storage, and fatty acid profiles. In conclusion, the results indicate higher importance of the diet during suckling than during the subsequent fattening period on meat quality parameters such as color, lipid oxidation, and fatty acid profile. Dams grazing Sainfoin provide a more stable lamb meat, and it would be cheaper to feed the dams with fresh forages with a high α-tocopherol content than supplementing the concentrate of the lambs with synthetic α-tocopherol.

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.

Effects of feeding legume-grass pasture and different concentrate levels on fatty acid profile, volatile compounds, and off-flavor of the M. longissimus thoracis

Pasture-finished beef is becoming more popular among consumers due to concerns related to fatty acid content and sustainable practices. The effects of finishing crossbred steers on legume-grass pasture comprised of oats, ryegrass, and clover (PAST), legume-grass pasture plus whole corn grain (WCG) supplementation (SUPP), and only with WCG (GRAIN) on fatty acids profile, volatile compounds, sensory, and texture attributes were studied. Pasture diets (PAST and SUPP) led to lower n-6/n-3 ratio (P < 0.001), and highest deposition of C18:2 cis-9 trans-11 (P < 0.001) in the lean. Beef from steers fed GRAIN had the highest values of volatile compounds associated with lipid oxidation. Off-flavor intensity was significantly greater on beef from steers fed GRAIN when compared to PAST. Overall, muscles from steers finished on PAST and SUPP showed similar attributes but differ when compared to GRAIN. The presence of forage is essential to improve fatty acid profile, decrease volatile compounds associated with lipid oxidation, and minimize off-flavor.

Exogenous and Endogenous Factors Influencing Color of Fresh Meat from Ungulates

Biochemistry of post-mortem muscle tissue is complex, and several factors affect the fresh meat color and color stability, both of which influence consumer acceptance. Therefore, improving meat color and meat color stability is of significant value to the meat industry and consumers. While extensive literature is available on the color and color stability of domestic ungulates, literature on wild ungulates is notably lacking. With an increasing global demand for meats from wild ungulates, it is critical to identify the knowledge gaps regarding their color and color stability. The objective of this paper is to overview the exogenous and endogenous factors influencing the color and color stability of fresh meats from domestic and wild ungulates. The literature highlighted that the pre- and post-harvest factors influencing meat color and meat color stability are interrelated and not mutually exclusive. Current research indicates that the effects of several of these factors are specific to species, breed, and muscle source. Novel ways to manipulate these factors using a biosystems approach should be explored to improve color attributes of fresh ungulate meats.

The effect of forage-types on the fatty acid profile, lipid and protein oxidation, and retail colour stability of muscles from White Dorper lambs

The aim of this study was to evaluate the effect of different forage-types on lamb meat quality parameters. White Dorper lambs that had grazed five forage-types, were slaughtered commercially. At 24h post-mortem, the m. longissimus lumborum (LL) was removed from one side, sliced into three equal sub-samples, vacuum packaged and assigned to ageing periods (5, 12 or 40days); the other side of LL was aged for 5days. The m. adductor femoris was used for fatty acid analysis. Lambs fed chicory+arrowleaf clover had the highest concentration of health claimable omega-3 fatty acids and the lowest omega-6:omega-3 fatty acid ratio. Forage-types with higher vitamin E content showed lower lipid oxidation levels independent of ageing period. Forage-type and ageing period did not influence the redness, yellowness, chroma or reflectance ratio (630nm÷580nm) of displayed meat. Chicory+arrowleaf clover gave the best results to improve the fatty acid content of lamb meat.

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.

Effect of vitamin E supplementation or alfalfa grazing on fatty acid composition and expression of genes related to lipid metabolism in lambs

The aim of this study was to investigate the effects of vitamin E (VE) supplementation and alfalfa grazing during fattening on fatty acid composition and mRNA expression of genes related to lipid metabolism in the LM of Rasa Aragonesa light lambs. After weaning, 48 lambs were kept indoors and fed a commercial concentrate and a VE supplemented concentrate (480 mg DL-α-tocopheryl acetate/kg DM) for 0 (control [CON]), 10 (VE10d), 20 (VE20d), and 30 d (VE30d) before slaughtering at 22 to 24 kg. Simultaneously, 8 unweaned lambs grazed in alfalfa (154 mg α-tocopherol/kg DM) paddocks with their dams and supplemented with the commercial concentrate (ALF). Immediately after slaughter, LM was sampled to determine gene expression. After 24 h of cooling at 4°C, LM was extracted to determine intramuscular fat (IMF) content and fatty acid composition. The IMF content did not differ with the dietary treatment ( = 0.212). Unweaned grazing alfalfa lambs had greater concentration of rumenic acid (C18:2 c9,t11; P < 0.001) and lower oleic acid (C18:1 c9; = 0.001) content and PUFA n-6:n-3 ratio (P < 0.001) but similar expression of genes implicated in lipid metabolism compared to the concentrate-fed lambs. Vitamin E supplementation did not modify muscle fatty acid composition; however, it increased the expression of FADS2 and ELOVL6, which are involved in desaturation of long-chain fatty acid and the elongation of SFA and MUFA. The results showed that a short period of VE supplementation, especially 10 (VE10d) and 20 d (VE20d), modified gene expression. Overall, the results showed that VE may be acting as a regulatory factor for transcriptional control of genes related to lipid metabolism in the muscle of Rasa Aragonesa light lambs (22-24 kg live weight and younger than 90 d old).

Color stability and antioxidant capacity of yak meat as affected by feeding with pasture or grain

Chen, C., Han, L., Yu, Q.-L. and Li, R.-R. 2015. Color stability and antioxidant capacity of yak meat as affected by feeding with pasture or grain. Can. J. Anim. Sci. 95: 189–195. The objective of the present study was to analyze the effect of pasture or grain on color stability and antioxidant capacity of M. longissimus lumborum (LL) from pasture-fed (PF) or grain-fed (GF) yaks. The color stability and metmyoglobin percentage (MetMb%) were determined during 9 d of aerobic refrigerated storage. The antioxidant capacity was estimated by the total phenolics content, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP). Compared with the GF group, the LL from the PF group showed significantly (P<0.05) higher redness (a* values), with lower decline rate in a* values (P<0.05) over 1 to 7 d of refrigerated storage. The LL from the PF group had a significantly (P<0.05) lower metmyoglobin accumulation rate. At the end of storage, the muscle's MetMb% of the PF and GF group were 46.33 and 56.66%, respectively. The PF group showed significantly higher total phenolics content (+23.94%; P<0.05) in muscles, resulting in greater TEAC and FRAP, which were 24.81 and 3.99% higher than the GF group (P<0.05), respectively. In conclusion, the pasture enhanced antioxidant capacity of yak meat and contributed to improve the meat color stability.

The effect of the change from a herbage- to a concentrate-based diet on the oxidative stability of raw and cooked lamb meat

Over 89 days, 10 lambs (S) were fed concentrates and hay in stall, while 9 lambs (P) grazed at pasture. Two groups of 9 animals grazed at pasture until switching to a concentrate-based diet for 14 or 37 days before slaughter (P-S14 and P-S37). The fat content of longissimus dorsi muscle (LM) increased with increasing duration of concentrate feeding (P=0.05). As a consequence, the concentration of polyunsaturated fatty acids (PUFA) and of the highly peroxidisable (HP) PUFA in the polar lipids was similar between treatments. Lipid oxidation in fresh LM over 8 days of storage was affected by the diet (P<0.0005) with the P-S37 and P treatments producing, respectively, the highest and the lowest TBARS values. The P treatment reduced TBARS in cooked minced LM over 2 days of storage and no difference was found between the P-S14, P-S37 and S treatments. Colour stability of fresh LM was not noticeably affected by the dietary treatment.

Dietary olive cake reduces the oxidation of lipids, including cholesterol, in lamb meat enriched in polyunsaturated fatty acids

Over 40 days, lambs were fed: concentrate (C), concentrate containing 20% linseed (L), concentrate containing 35% olive cake (OC), or concentrate containing 10% linseed and 17% olive cake (OCL). The polyunsaturated fatty acids (PUFA) and peroxidation index (PI) in phospholipids were increased by the L and OCL treatments (P=0.007 and P=0.003, respectively). The OC and OCL diets increased the concentration of tocopherol in muscle (P<0.001). Compared to the OC and OCL diet, the L diet increased fatty acid oxidation, measured as conjugated dienes (CD; P=0.003), peroxides (PV; P<0.001) and TBARS (P=0.002) in minced muscle over 11 days of storage in high-oxygen atmosphere. Also, the L diet increased (P<0.001) the levels cholesterol oxidation products (COPs). In conclusion, feeding olive cake improved the oxidative stability of lamb meat and the combination of olive cake and linseed improved the fatty acid composition of meat without compromising its oxidative stability.