Opportunities and Implications of Pasture-Based Lamb Fattening to Enhance the Long-Chain Fatty Acid Composition in Meat

The carcass characteristics and quality of meat from lambs grazing perennial wheat with different companion legumes (clover, serradella, lucerne) or a mineral supplement

This study compared carcasses as well as the quality and mineral concentration of meat from lambs extensively grazing perennial wheat with clover (PW + C), serradella (PW + S), lucerne (PW + L), or a mineral salt supplement (PW + Min). A split-plot design was used, wherein 3 crossbred ewe lambs (n = 72 in total) (sub-plots) grazed each of 4 forage types (plots), that were replicated across 6 locations (blocks). The feeding study concluded after 96 d, when all the lambs were slaughtered. The left longissimus lumborum muscles (LL) were collected and wet aged for either 5 or 56 d post-mortem. Lambs grazing PW + Min were found to produce carcasses with lower dressing percentage values to those grazing the other forage types (P = 0.037). The LL of lambs grazing PW + L had the lowest crude protein values (P = 0.015). Forage type by ageing period interactions did not affect meat quality. The 56 d ageing period resulted in higher purge loss (P < 0.001) and TVB-N values (P < 0.001) and a decline in shear force (P < 0.001) compared to the 5 d ageing period. The other carcass and meat quality parameters were not affected by forage type; including hot carcass weight, pH decline parameters, eye muscle area, cooking loss, intramuscular fat, sarcomere length, colour stability, and concentrations of calcium, iron, magnesium, sodium, and zinc in the LL. These findings confirm that perennial cereal production systems, that include legume forages with contrasting protein, energy, and micronutrient profiles, can deliver comparable lamb carcasses and meat quality.

Comparison of production performance and meat quality characteristics between Guizhou Black goats and F4 generation hybrids of South African Kalahari Goats

This study spanned 6 years and 4 generations, involving the progressive crossbreeding of South African Kalahari Goat (SK) and Guizhou Black Goat (GB) over three generations, followed by cross fixation F3 with F1 in the fourth generation, accompanied by the use of molecular markers technology to select a high fertility population, resulting in the creation of a hybrid goat, BKF4 (11/16 SK lineage and 5/16 GB lineage). A comparative evaluation of the BKF4 hybrid breed and its parental breeds was conducted. Reproductive and production parameters of GB, SK, and BKF4 goat groups were monitored, including lambing rate (LR), survival rate (SR), daily weight gain at 3 months of age (DWG), and adult body weight (ABW) (n = 110, 106, 112 per group). In addition, dressing percentage (DP) (n = 12 per group) and analyses of amino acids (n = 8, 6, 10 per group) and fatty acids (n = 6 per group) were conducted to evaluate meat quality indicators. Results: (1) Reproductive and production performance: The index of LR reached 199%, significantly higher than GB and SK (p ≤ 0.001), with a SR of 95.0%, markedly higher than SK (p ≤ 0.001); DWG was 276.5 g, ABW reached 56.6 kg and with a dressing percentage (DP) of 54.5%, they are significantly surpassing GB (p ≤ 0.001). (2) Regarding meat quality: pH45-value and crude protein content (CP) increased, while intramuscular fat content increased compared to GB and ash content decreased. The amino acid composition was similar to GB, but the taste was more similar to SK. However, there were some negative impacts on fatty acid composition and functionality. (3) PCA analysis revealed that: BKF4 exhibited superior meat quality compared to GB and SK, influenced by two key factors contributing 83.49% and 16.51% to the explained variance, respectively. The key factors affecting meat quality include intramuscular fat (IMF), nutrient index (NI), PUFAs/MUFAs, n-6FAs, and drip loss (DL).

Bioaccessibility of condensed tannins and their effect on the physico-chemical characteristics of lamb meat

The bioaccessibility of tannins as antioxidants in meat is essential to maximise their effectiveness in protecting the product. This property determines the amount of tannins available to interact with meat components, inhibiting lipid and protein oxidation and, consequently, prolonging shelf life and preserving the sensory quality of the product. The objective of this study was to evaluate the bioaccessibility of condensed tannins (CT) from Acacia mearnsii extract (AME) and their effect on the physico-chemical characteristics of fattened lamb meat. Thirty-six Dorset × Hampshire lambs (3 months old and 20.8 ± 3.3 kg live weight) were used. The lambs were distributed equally (n = 9) into four treatments: T1, T2, T3 and T4, which included a basal diet plus 0%, 0.25%, 0.5% and 0.75% of CT from AME, respectively. At the end of the fattening period, bioaccessibility was evaluated, the animals were slaughtered and a sample of the longissimus dorsi (LD) muscle was collected to assess colour, lipid oxidation, cooking weight loss and shear force on days 1, 4, 7 and 14 of shelf-life, in samples preserved at -20 °C. In addition, the long chain fatty acid profile was analysed. A completely randomised design was used, and the means were compared with Tukey's test (P < 0.05). The mean lightness (L*), yellowness (b*) and hue (H*) values were higher for T3 and T4. The addition of CT did not affect (P > 0.05) redness (a*), cooking weight loss (CWL) or shear force (SF). T4 decreased (P < 0.05) stearic acid and increased cis-9 trans-12 conjugated linoleic acid (CLA). Bioaccessibility was higher in the supplemented groups (T1 < T2, T3 and T4). In conclusion, supplementing CT from AME in the diet of lambs did not reduce lipid oxidation, but T3 or T4 improved some aspects of meat colour and CLA deposition.

Impact of Agro-Byproduct Supplementation on Carcass Traits and Meat Quality of Hair Sheep and Wool × Hair Crossbreds Grazing on Fescue Pasture

The effects of breed type (purebred or crossbred) and supplementation of agro-byproducts on the growth, carcass characteristics, and meat quality of landrace hair (Barbados Blackbelly; BB and St. Croix; SX) lambs was evaluated. Thirty-six 7.5-month-old purebred hair (BB and SX; body weight = 24.1 ± 4.26 kg) and terminal sire (Dorset; DO) crossbred lambs (DO × BB and DO × SX; body weight = 31.4 ± 3.50 kg) rotationally grazed predominantly on Jesup tall fescue pasture during spring with or without agro-byproduct supplementation (soyhull or corn gluten feed at 2% of BW). Following a 77d grazing period, the lambs were harvested, and their carcass characteristics and meat composition were evaluated. Both supplementation and crossbreeding significantly increased their carcass weight and primal cuts, whereas only supplementation increased (p < 0.01) the dressing percentage, and crossbreeding increased the shear force (p < 0.01). Regardless of breed type, supplementing agro-byproducts improved the lipid oxidation stability and texture properties of the fresh lamb, whereas the pasture-only lambs had healthier fatty acid profiles compared with the supplemented lambs. The results indicate that both terminal sire crossbreeding and byproduct supplementation can be used to affect the carcass characteristics and meat composition of landrace hair sheep lambs.

Review of Feeding Systems Affecting Production, Carcass Attributes, and Meat Quality of Ovine and Caprine Species

Growth rate, carcass attributes, and meat quality traits of small ruminants (i.e., sheep and goats) depend on various factors, among which the feeding system is one of the most important factors. However, how feeding systems affect these parameters differ between sheep and goats. Therefore, this review aimed to evaluate the differences in how different feeding systems affect the growth performance, carcass characteristics, and meat quality of sheep and goats. It also explored the effects of a new finishing strategy-time-limited grazing with supplements on these traits. Compared with stalled feeding, finishing lambs/kids on pasture-only feed reduced the average daily gain (ADG) and carcass yield, while supplemented-grazing lambs/kids had near-equivalent or higher ADG and carcass attributes. Pasture-grazing increased the meat flavor intensity and healthy fatty acid content (HFAC) of lamb/kid meat. Supplemental grazing lambs had comparable or superior meat sensory attributes and increased meat protein and HFAC compared to stall-fed ones. In contrast, supplemental grazing only improved the meat color of kids but had little effect on other meat qualities. Moreover, time-limited grazing with supplemental concentrates increased the carcass yield and meat quality in lamb meat. Overall, the effects of different feeding systems on growth performance and carcass traits were comparable between sheep and goats but differed in terms of the 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.

Fatty Acid Indices and the Nutritional Properties of Karakul Sheep Meat

This study aimed to evaluate the fatty acid profile and health lipid indices of sheep meat (from 52 Karakul sheep from NE Romania). The effect of age at slaughter and the influence of muscle region were studied for nutritional parameters, especially the fatty acids from lipid fractions. Based on the fatty acid profiles and lipid contents, the sanogenic indices were determined for two sheep muscle groups. Thus, two different muscle regions from lamb and adult sheep were analysed from both genders, the Longissimus dorsi and Triceps brachii, to argue the advantages of each category and the rationalization, in terms of meat consumption, regarding their impact on human health. Sheep meat has many components with beneficial effects on human health. Apart from the fact that it is an important source of nutrients due to its high content of proteins, lipids, and minerals, it is also a product that can provide fundamental bioactive compounds for maintaining metabolic functions. The qualitative indices assessment revealed that lambs have meat with high PUFA content on Longissimus dorsi muscles (approx. 25% of total fatty acids), 0.68 for PUFA/SFA, with highest values for n-3 (approx. 8%) and n-6 (approx. 14%). Appropriate values can also be observed in Triceps brachii muscles from adult sheep. The sanogenic indices also presented good values for Longissimus dorsi from lambs and Triceps brachii from adult sheep (polyunsaturation index = 7.2-10.2; atherogenic index = 0.56-0.67; thrombogenic index = 0.78-0.96; hypocholesterolemic/hypercholesterolemic index = 2.4-2.7 (for Longissimus dorsi)).

Evaluation of fatty acid and antioxidant variation in a complex pasture system as compared to standard cattle feed in the Great Lakes region

As the demand for grass-fed ruminant products keeps increasing, more data are needed to assess the nutritional value of feedstuffs, especially pastures. In addition, global climate change adds another challenge to the management of grasslands with projections of changing temperature and precipitation patterns. Consequently, the variations in bioactive compounds such as fatty acids and antioxidants in feeds will be harder to predict. Therefore, it is critical to report region and time-specific results of the nutritional value of feeds intended for ruminant nutrition. The objectives of this study were to compare the antioxidant and fatty acid content of commonly used feedstuffs including a complex pasture mixture from the Great Lakes Region and a traditional grain-based diet, and to assess the variations of these bioactive compounds in the pasture over the course of two grazing seasons. Weather parameters including temperature and rainfall were recorded for the length of the study. Feed samples were collected between June and September 2019 and 2020 and analyzed for nutrient composition, chlorophyll A and B, carotenoids, and total phenols. Fatty acids were analyzed by GC-MS. Correlations were reported to analyze the relationship between individual plant species, antioxidants, and fatty acids. We observed higher antioxidant parameters in the pasture compared to the grain diet. Total polyunsaturated fatty acids were higher in the pasture including α-linolenic acid while the grain diet was higher in n-6 polyunsaturated fatty acids including linoleic acid. The n-6:n-3 ratio was more beneficial in the pasture and was 50–90 times higher in the grain diet. Variations in the fatty acid profile of the pasture were observed and varied between 2019 and 2020. Plant growth cycles, climatic conditions, and grazing methods were hypothesized to cause these changes. Altogether, this study increased our knowledge about the nutritional value of feedstuffs and will help ranchers and researchers to better understand the variations of bioactive content based on region, season, and climatic conditions.

Tropical grass and legume pastures may alter lamb meat physical and chemical characteristics

The present study assessed the influence of the type of the tropical pastures on lamb body weight (BW) gain and meat quality. Fifty-four lambs were allocated to three grazing pastures: (1) AG - Aruana grass (Panicum maximum cv. IZ-5); (2) PP - pigeon pea legume (Cajanus cajan cv. Anão); and (3) CS - contiguous swards, half of the paddock with AG and half with PP. After 92 days of grazing, the lambs were slaughtered. Carcasses were evaluated and the longissimus muscle was collected to determine color, lipid profile, tocopherol concentrations, and lipid oxidation. Although the pastures present differences in the characteristics of nutritional quality, the animals did not show difference in BW gain. The results show that all forage presented similar concentration of alpha-tocopherol (137 ± 14.37 mg kg^-1 of fresh matter), whereas total and condensed tannin contents were greater in PP, intermediate in CS, and the lowest in AG treatment (P = 0.0001). Meat α-tocopherol content was similar among treatments (P = 0.1392), with an average concentration close to the optimal level to reduce the meat oxidation. Meat from AG treatment had 45 and 25% lower n-6/n-3 ratio than meat from PP and CS treatments, respectively. The legume increases the unsaturated fatty acids and the grass can reduce the n6/n3 ratio. The level of condensed tannin concentration did show to have important effect on meat characteristics. Both tropical pastures studied can provide a high amount of alpha-tocopherol, generating a great potential to increase the concentration of this antioxidant in lamb's meat.

Reis M, Silcock P, Johnson PL, Realini CE. Relationships among Consumer Liking, Lipid and Volatile Compounds from New Zealand Commercial Lamb Loins

Loin sections (m. Longissimus lumborum) were collected at slaughter from forty-eight lamb carcasses to evaluate consumer-liking scores of six types of typical New Zealand commercial lamb and to understand the possible underlying reasons for those ratings. A consumer panel (n = 160) evaluated tenderness, juiciness, flavor liking, and overall liking of the different types of lamb loins. Consumer scores differed among the types of lamb meat for all the evaluated attributes (p < 0.05). Further segmentation based on overall liking scores showed two consumer clusters with distinct ratings. Correlation and external preference map analyses indicated that one consumer cluster (n = 75) liked lamb types that had lower total lipid content, a lower proportion of branched-chain fatty acids, oleic and heptadecanoic acids; and a higher proportion of polyunsaturated fatty acids and volatile compounds (green and fruity descriptors). Consumer liking of the other segment (n = 85) was less influenced by fatty acids and volatiles, except hexanoic, heptanoic and octanoic acids (rancid, fatty, and sweaty descriptors). Thus, the fatty acid profile and the volatile compounds derived from their oxidation upon cooking seem to be a stronger driver of consumer liking of lamb for some consumers than others.

Characterization of growth phenotypes and gastrointestinal tract microbiota in sheep fed with caragana

AIMS

Using high-protein caragana as an unconventional feed supplement has promising application potential in livestock feeding programmes, and verifying its function is of great importance to guide efficient dietary management of livestock.

METHODS AND RESULTS

This study investigated the resulting changes in the growth, slaughter performance, serum physiological index, physical and chemical characteristics of meat, ruminal and intestine morphology and gastrointestinal tract microbiota in sheep fed with caragana (CAR), corn straw (COR) and alfalfa (ALF) diets. The CAR group showed an increased abundance of Christensenellaceae R-7 group, Marvinbryantia, Ruminococcaceae NK4A214, Lachnospiraceae UCG-002 and Desulfuromonas in the rumen compared with ALF, and CAR group mainly enhanced starch and sucrose metabolism, fructose and mannose metabolism, photosynthesis and d-alanine metabolism in the rumen compared with ALF.

CONCLUSIONS

CAR diet positively changed the fatty acid profile of longissimus dorsi muscle and significantly altered the composition and function of the microbiota in the rumen, ileum and cecum.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study systematically demonstrated the feasibility of CAR as an alternative to ALF for animal fattening in a complete formula granulated feed and provided a fundamental basis for further research and development of CAR as an unconventional feed source for ruminants.

Effect of Rearing Season on Meat and Intramuscular Fat Quality of Beni-Guil Sheep

Twenty Beni-Guil-PGI female lambs were used to study the effects of rearing season on meat quality characteristics, fatty acids profile, and lipid content. The animals were reared according to the pastoral-transhumant system in the eastern region of Morocco. The treatments consisted of 10 female lambs reared in summer-autumn (SA) and slaughtered at winter season and 10 female lambs reared in winter-spring (WS) and slaughtered at spring season. After the slaughter, the longissimus lumborum was collected for each animal for meat quality analysis. Compared to lambs reared in SA, the meat from the WS group showed higher ( $p<0.01$ ) pH, chroma, and lightness values (5.79 vs. 5.72, 23.97 vs. 18.46, and 47.03 vs. 41.04, respectively). On the other hand, the meat from WS presented higher ( $p<0.05$ ) intramuscular fat content (5.14 % vs. 3.82%, respectively). However, the intramuscular fat of the lambs reared in SA was characterized by greater ( $p<0.01$ ) PUFA percentage (16.82% vs. 12.40%, respectively), thrombogenic ( $p<0.001$ ) and atherogenic index ( $p<0.001$ ), and PUFA/SFA ratio ( $p<0.01$ ; 0.42 vs. 0.25, respectively). Nevertheless, those reared in WS season have a higher ( $p<0.001$ ) PUFA n − 3 (2.58% vs. 1.14%, respectively) content, and therefore favorable ( $p<0.001$ ) n − 6/n − 3 ratio (3.78 vs. 12.98, respectively).

Sensory Characteristics of Male Impala (Aepyceros melampus) Meat, Produced under Varying Production Systems and Nutrition

The objective of this study was to determine the influence of three production systems (intensive, semi-extensive and extensive) with differing nutrition on the descriptive sensory and fatty acid profiles of sub-adult (±15-18 months old) male impala longissimus thoracis et lumborum (LTL) muscles. The discriminant analysis plot showed that extensively produced impala had a sensory profile distinct from the intensive and semi-extensive system impala. Extensively produced impala had the highest sensory ratings for overall intensity, gamey, beef-like, herbaceous, and sweet-associated aroma and flavor of their meat. The intensive and semi-extensive system impala did not differ for most of the sensory attributes, except for higher ratings for gamey flavor, liver-like flavor, tenderness and mealiness, and lower ratings for residue found in semi-extensive system impala. The overall aroma and flavor intensities of impala meat in general had strong positive correlations with gamey, beef-like, herbaceous, and sweet-associated aromas and flavors; however, marketing should be adjusted depending on the nutrition received by the impala, to allow consumers to select their preferential sensory profile. Impala meat from all three production systems had low fat contents (<2%), and desirable fatty acid profiles.

Untargeted and Targeted Metabolomics Profiling of Muscle Reveals Enhanced Meat Quality in Artificial Pasture Grazing Tan Lambs via Rescheduling the Rumen Bacterial Community

Tan is a local fat-tail sheep that is famous for its great eating quality but with little attention to its meat metabolome. The aim of this study was to investigate Tan-lamb meat metabolome as well as the key rumen bacteria related to the beneficial compound deposition in the muscle using untargeted and targeted metabolomics under different feeding regimes: indoor feeding (F), artificial pasture grazing with indoor feeding (GF), and pure artificial pasture grazing (G). The untargeted metabolome was detected by ultraperformance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Ruminal bacterial communities were detected by 16S rRNA sequencing. Using untargeted metabolomics, the main three altered metabolic pathways in the lamb, including amino acid, lipid, and nucleotide metabolisms, were found in the G group compared to the GF and F groups. Increased N-acetyl-l-aspartic acid, N-acetylaspartylglutamate, acetylcarnitine, and l-carnitine, but decreased carnosine and creatinine, were the main newly found G group-associated metabolites, which might contribute to the improved lamb meat functional quality. Compared to the F group, the G group feeding increased the contents of sweet amino acids (e.g., glycine, alanine, serine, and threonine) and umami amino acids (e.g., glutamic acid and aspartic acid) in the muscle, and G and GF groups increased the level of meat polyunsaturated fatty acid (PUFA), especially the concentration of n3 PUFA, and reduced n6/n3 in the muscle by targeted metabolomics. The abundance of ruminal Moryella was decreased, and Schwartzia and Anaeroplasma were increased in the G group, which were both strongly correlated with the n3 PUFA and other functional compounds in the muscle of lambs. In conclusion, artificial pasture grazing modified the meat amino acid and fatty acid composition as well as the related biological pathways through rescheduling the rumen bacterial community, which would be a better selection for production of healthier lamb meat products.

Growth, Carcass and Meat Characteristics of Grass-Fed Lambs Weaned from Extensive Rangeland and Grazed on Permanent Pastures or Alfalfa

Western Patagonia lamb production systems are based on extensive rangeland. The harsh climate limits the adoption of more intensive systems. Therefore, producers must focus on developing differentiated products. The aim of this study was to evaluate growth patterns, carcasses and nutritive value of meat from 45 lambs. Lambs were divided into three groups: 15 lambs were slaughtered at weaning (W), with the remaining 30 weaned lambs being allocated to grazing either alfalfa (AG) or permanent pasture (PPG). AG lambs were significantly heavier and had higher condition scores than PPG lambs. Further, AG lambs showed higher carcass weight and larger tissue depth and commercial cuts. Moreover, W lambs had lower shear force and more tender meat than either AG or PPG lambs. The three systems showed a low shear force and acceptable sensory traits. Low levels of cholesterol, with low levels of saturated fat, classified these cuts of meat as extra lean. W lambs had higher omega-3 fatty acid content than AG or PPG lambs. Overall, results showed that meat from the three lamb production systems showed health claimable levels of omega-3 fatty acids and were low in fat and thereby, can be classified as lean meat.

Fatty Acid Composition and Volatile Profile of M. longissimus thoracis from Commercial Lambs Reared in Different Forage Systems

Animal production factors can affect the fatty acid and volatile profile of lamb meat. The fatty acid and volatile composition of the M. longissimus thoracis was evaluated from 150 lambs from 10 groups of commercial lambs that differed in age, sex, diet and breed, from three farms, which represent typical forage lamb production systems in New Zealand. The meat from 4-month-old composite lambs slaughtered at weaning had a similar polyunsaturated to saturated fatty acid ratio compared to 6- to 8-month-old composite lambs, but a greater ratio than that of 12-month-old Merino lambs (p < 0.05), with all ratios being lower than the recommended ≥0.45. All lamb production systems produced meat with an omega-6 to omega-3 ratio below 1.5, well below the recommended ratio ≤ 4.0. Meat from 4-month-old lambs had higher C12:0, C14:0 and C16:0 and lower C18:0, reflecting the composition of the milk diet, resulting in higher atherogenic index than meat from other animal groups, while meat from 12-month-old Merino lambs, with lower content of polyunsaturated fatty acids, showed higher thrombogenic index. Meat from lambs processed at weaning contained the greatest concentration of eicosapentaenoic and docosahexaenoic acids, which would qualify as a 'source' or 'good source' of these target fatty acids based on the Commission of Regulation of the European Union or the Food Standards Australia New Zealand guidelines, respectively. Volatiles were extracted from the headspace of raw lean meat and 36 volatile compounds were identified. The abundance of carbon disulphide, isododecane, heptanal, 2,5-hexanediol and 3-octanone and pentanoic, octanoic, nonanoic and heptanoic acids was similar between all groups of lambs. Meat from 12-month-old Merino lambs had low abundance of acetic, propanoic, butanoic and hexanoic acids, and hexanal, octanal and dimethyl sulphide. For 6- to 8-month-old composite lambs, hexanal, octanal and nonanal were present at higher relative abundance in meat from lambs that grazed on chicory than perennial ryegrass. The significant differences in the fatty acid and volatile profiles in meat from 12-month-old Merino lambs compared with lambs slaughtered at weaning or further grazed on red clover, chicory or mixed pasture may result in distinctive nutritional value and lamb flavour.

Fatty acids, health lipid indices, and cholesterol content of sheep meat of three breeds from Moroccan pastures

The lipid analysis of commercial lamb's meat, from two main Moroccan production areas Middle Atlas and highlands of eastern Morocco, was conducted. This study concerns the lipid quality of sheep meat from Beni Guil (BG) and Timahdite (Ti) as indigenous breeds and that of the Ouled Djellal (ODj) breed of Algerian origin. To study the effect of the geographical area, the meat samples from the Beni Guil breed were taken in the two main locations of this breed: in the region of Ain Beni Mathar (BGA) and that of Tendrara (BGT). The fatty acid profiles of the sheep meats analyzed showed the following: (i) polyunsaturated fatty acid (PUFA) richness was of 12.87 % and 20.59 % respectively for BGA and BGT breeds; (ii) polyunsaturated  /  saturated fatty acid ratios were ranged between 0.28 to 0.50 respectively for BGA and Ti breed; and (iii) PUFA- n - 3 content was 1.71 % for ODj breed and 2.13 % for BGA. Thus, the PUFA- n - 6   /  PUFA n - 3 ratios range between 4.92 and 9.6 for BGA and Ti sheep meat, respectively. The cholesterol content was 0.08 % and 0.12 % of fresh meat respectively for ODj and BGA. Finally, meats of BGA and ODj have similar thrombogenicity (1.23 and 1.27 respectively) and atherogenicity indices (0.71 and 0.68 respectively). Statistically, these values were significantly higher than those registered for Ti breed (IT: 1.04 and AI: 0.51). In conclusion, from a nutritional point of view, it can be deduced that these meats have an interesting lipid quality due to their richness in desirable fatty acid (UFA  +  C18 : 0).

Effects of Roughage Quality and Particle Size on Rumen Parameters and Fatty Acid Profiles of Longissimus Dorsi Fat of Lambs Fed Complete Feed

The fatty acid composition for the longissimus dorsi (LD) fat of carcass sheep is a crucial factor impacting meat quality. We performed a 90-day feeding trial of 25 Naemi lambs to investigate the effects of roughage sources (alfalfa or wheat straw) of two sizes (regular and 1 cm chopped) when fed with pelleted total mixed ration (TMR) on the growth performance, fermentation patterns, and fatty acid (FA) composition of longissimus dorsi (LD) fat. Lambs were randomly assigned to individual pens with five treatment diets, as follows: C, control group with TMR; T1, TMR and regular alfalfa hay; T2, TMR and alfalfa hay chopped to 1 cm; T3, TMR and regular wheat straw; and T4, TMR and wheat straw chopped to 1 cm. Four lambs were randomly selected from each treatment (20 total) and sacrificed. LD fat of the carcass was extracted and analyzed for FA using a gas chromatography-mass spectrometry. Significantly increased feed intake was found in T1 and T2. The FA composition of LD fat in T2 had higher unsaturated fatty acid (UFA), omega-6 (n6), and omega-3 (n3) FA content. Conjugated linoleic acid (CLA) and α-linoleic acid were highest in lambs fed T1 and T2. Feeding different types of roughage, especially alfalfa hay, either regular or chopped, with total pelleted mixed ration is crucial to improving feed intake and body weight gain, as it positively enhances the rumen microbial fermentation process by controlling rumen pH. The FA profiles of meat from lambs fed TMR with regular or 1 cm particle size alfalfa hay (T1 and T2) are recommended for human consumption as a source of healthy FAs.

Effects of a high-fibre and low-starch diet in growth performance, carcass and meat quality of young Alentejana breed bulls

Growth performance, carcass and meat quality of 16 Alentejana bulls fed for 90 days with a conventional cereal-based (Control) or a high-fibre and low-starch (HFLS) diet were studied. The HFLS diet included 20% alfalfa hay, 4.8% soybean oil, 6% soybean hulls, 6% dehydrated citrus and 6% sugar beet pulps in substitution of grain. Ryegrass hay was offered to a maximum of 20% of total intake in both diets. Bulls were individually housed, weighed every 14 days, and feed intake was registered daily. Average daily weight gain, dry matter intake, carcass and most meat quality traits were not affected by the diet (P > .05). Feeding an HFLS diet, therefore, can improve beef fatty acid profiles without negatively impacting animal performance or meat quality.

Milk and meat fatty acids from sheep fed a plantain-chicory mixture or a grass-based permanent sward

Plantain and chicory are interesting forage species since they present good nutritional quality and are more resistant to drought than many temperate grasses. The fatty acid (FA) profile in milk and meat is related to a growing concern for the consumption of healthy foods, that is, with a lower content of saturated FA, higher polyunsaturated FA (PUFA) and a favourable n-6 : n-3 FAs ratio. Our objective was to evaluate the FA content in ewe's milk and lamb's meat fed a plantain-chicory mixture (PCH) or a grass-based permanent sward (GBS) dominated by perennial ryegrass. Eighteen Austral ewes in mid-lactation were allocated to PCH and GBS treatments. Milk samples were obtained during September (spring). Thirty weaned lambs were finished on both treatments from November to December (7 weeks), slaughtered and their meat sampled. Fat from milk and meat samples was extracted and stored until analysed by gas chromatography. Milk fat from GBS was higher than from PCH (P < 0.05) in C18:0 (11 385 v. 5874 mg/100 g FA), 9c-18:1 (15 750 v. 8565 mg/100 g FA), 11 t-18:1 (4576 v. 2703 mg/100 g FA) and 9c,11 t-18:2 (1405 v. 921 mg/100 g FA) and lower in 18:2n-6 (827 v. 1529 mg/100 g FA) and 18:3n-3 (943 v. 1318 mg/100 g FA) FA. Total mono-unsaturated FA was higher in GBS than PCH (P < 0.05). Meat fat from PCH swards presented a higher (P < 0.05) content than GBS for 18:2n-6 (46.8 v. 28.2 mg/100 g FA), linolenic (24.6 v. 14.2 mg/100 g FA), polyunsaturated FA (119.7 v. 73.4 mg/100 g FA), n-6 (65.9 v. 40.8 mg/100 g FA) and n-3 (53.8 v. 32.5 mg/100 g FA), respectively. No effect of treatment (P > 0.05) was detected for 9c-18:1 (283.9 v. 205.8 mg/100 g FA), 11 t-18:1 (26.2 v. 19.3 mg/100 g FA) and 9c,11 t-18:2 (10.1 v. 7.6 mg/100 g FA), for PCH and GBS. These results suggest that grazing a PCH mixture results in a higher concentration of PUFA in ewes' milk and in lambs' fat, as compared to a GBS sward.

Adipose Tissue Modification through Feeding Strategies and Their Implication on Adipogenesis and Adipose Tissue Metabolism in Ruminants

Dietary recommendations by health authorities have been advising of the importance of diminishing saturated fatty acids (SFA) consumption and replacing them by polyunsaturated fatty acids (PUFA), particularly omega-3. Therefore, there have been efforts to enhance food fatty acid profiles, helping them to meet human nutritional recommendations. Ruminant meat is the major dietary conjugated linoleic acid (CLA) source, but it also contains SFA at relatively high proportions, deriving from ruminal biohydrogenation of PUFA. Additionally, lipid metabolism in ruminants may differ from other species. Recent research has aimed to modify the fatty acid profile of meat, and other animal products. This review summarizes dietary strategies based on the n-3 PUFA supplementation of ruminant diets and their effects on meat fatty acid composition. Additionally, the role of n-3 PUFA in adipose tissue (AT) development and in the expression of key genes involved in adipogenesis and lipid metabolism is discussed. It has been demonstrated that linseed supplementation leads to an increase in α-linolenic acid (ALA) and eicosapentaenoic acid (EPA), but not in docosahexaenoic acid (DHA), whilst fish oil and algae increase DHA content. Dietary PUFA can alter AT adiposity and modulate lipid metabolism genes expression, although further research is required to clarify the underlying mechanism.

Effects of dietary fat sources on the intramuscular and subcutaneous adipose tissue fatty acid composition, and consumer acceptability of lamb

BACKGROUND

Lamb diets can alter the fatty acid (FA) profile of muscle and adipose tissue, which may affect the sensory quality and consumer acceptability of the meat. In this study, lambs received one of four pre-slaughter diets: a barley / maize / soya-based concentrate (C), supplemented with a saturated fat source (Megalac®) (SAT), or supplemented with protected linseed oil (PLO); or a by-product (citrus pulp / distillers' grain / soya-based) diet (BPR). Intramuscular FAs and adipose tissue branched-chain FAs were measured and consumer evaluation (hedonic liking and attribute intensity) was undertaken with cooked lamb.

RESULTS

Compared to the other diets, the BPR diet resulted in a higher muscle concentration and a greater proportion of C18:2n-6, and greater proportions of conjugated linoleic acid (c9,t11-C18:2) and n-6 polyunsaturated FAs (PUFA), whereas the PLO diet resulted in higher muscle proportions of C18:0 and saturated FAs, higher concentrations of C18:3n-3 and n-3 PUFA, and a lower n-6 to n-3 ratio. The consumer acceptability of lamb was not affected by the pre-slaughter diets.

CONCLUSION

Changes in the FA profile of lamb muscle and adipose tissue through the inclusion of sources of saturated fat, protected linseed oil, or by-products in the pre-slaughter diet did not result in consumer detection of significant effects on the acceptability of the cooked meat. © 2020 Society of Chemical Industry.

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.

Comparison of muscle fatty acid composition and lipid stability in lambs stall-fed or pasture-fed alfalfa with or without sainfoin pellet supplementation

Currently, consumers are increasingly interested in obtaining high-quality and healthy lamb meat. Compared to grain-based diets, dietary forage legumes such as alfalfa and condensed tannin (CT)-rich sainfoin increase the levels of polyunsaturated fatty acids (PUFAs) that are beneficial for health in lamb meat thanks to their high content in PUFA and/or their impact on ruminal biohydrogenation. However, they can therefore adversely affect its oxidative stability. Thus, the impact of dietary forage legumes on lamb longissimus thoracis (LT) muscle FA composition and their stability to peroxidation was studied in 36 Romane lambs grazing alfalfa (AF; n = 12) or alfalfa plus daily supplementation with CT-rich sainfoin pellets (AS; n = 12; 15 g DM/kg BW, 42 g CT/kg DM) or stall-fed concentrate and grass hay indoors (SI; n = 12). Lambs were slaughtered at a mean age of 162 ± 8.0 days after an average experimental period of 101 ± 8.1 days. Forage legumes-grazing lambs outperformed SI lambs in LT nutritional quality, with more conjugated linoleic acids and n-3 PUFAs, especially 18:3n-3, eicosapentaenoic and docosahexaenoic acids (P < 0.001), and thus lower n-6 PUFA/n-3 PUFA and 18:2 n-6/18:3 n-3 ratios (P < 0.001). Peroxidizability index was higher (P < 0.001) in LT muscle of forage legumes-grazing lambs. Concurrently, two endogenous antioxidant enzyme activities, superoxide dismutase and glutathione peroxidase, were, respectively, similar and lower (P < 0.001) for forage legumes-grazing compared with SI lambs. A lower vitamin E level in SI lambs compared with forage legumes-grazing lambs (1.0 v. 3.8 mg/g, P < 0.001) could explain that malondialdehyde content, a marker of lipid oxidation intensity, was 0.63 µg/g in SI after 8 days in aerobic packaging conditions, whereas it remaining steady at 0.16 µg/g in forage legumes-grazing lambs. Dietary forage alfalfa thus improved FA composition of lamb LT muscle and their stability to oxidation when compared to SI lambs. However, supplementation of alfalfa-grazing lambs with CT-rich sainfoin pellets did not affect the nutritional quality of LT muscle FAs.

Dietary Supplementation of Tannin-Extracts to Lambs: Effects on Meat Fatty Acids Composition and Stability and on Microbial Characteristics

Two extracts derived from plant material rich in hydrolysable (Tara, T; Caesalpinia spinosa) or condensed (Mimosa, M; Acacia mearnsii) tannins were added to lamb's diet and their effects on meat quality and on microbial population were evaluated; a diet without tannins represented the Control (C). Meat pH, vitamin E, intramuscular fat content and muscle fatty acid composition were determined. Oxidative stability and microbiological analyses were performed on meat samples after 0, 4 and 7 days of refrigerated storage. Psychrotrophic bacteria were identified through MALDI-TOF MS analysis. Regarding meat fatty acids, Tara treatment decreased the percentage of monounsaturated fatty acids. The counts of all microbial groups were similar among dietary treatments at day 0, while a significant reduction of microbial loads was observed in T-group at day 7. Pseudomonas fluorescens group count was significantly affected by T extract supplementation. The MALDI-TOF MS identification revealed the dominance of Pseudomonas fragi species in all samples while Pseudomonas lundensis, Brochothrix thermosphacta and Candida famata were revealed only in control ones. In conclusions, the tannin extract supplementation is a promising dietary strategy to preserve lamb meat quality.

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.

Supplementation with plant-derived oils rich in omega-3 polyunsaturated fatty acids for lamb production

In this report, an overview of the health benefits of omega-3 long-chain (≥C20) polyunsaturated fatty acids (n-3 LC-PUFA) and recent progress in using alpha linolenic acid (ALA) rich sources derived from oilseeds to enhance productive performance, n-3 PUFA profiles and sensory properties of lamb for human consumption is reviewed. Omega-3 LC-PUFA can prevent mental health issues and chronic human disorders including cancer, cardiovascular and inflammatory diseases. The median amount of n-3 LC-PUFA consumption is generally lacking in Western diets. More attention is now being paid to the use of innovative nutritional strategies to improve PUFA content in ruminants, which could subsequently increase the content of health-benefitting n-3 LC-PUFA for human consumption. The richest sources of dietary n-3 LC-PUFA are derived from marine products, while forage and oilseeds such as flaxseed, canola, and their oils are abundant in ALA. Numerous studies have shown that dietary ALA increases n-3 LC-PUFA levels of edible tissues. However, other studies concluded that ALA rich supplementation led to no differences in tissue FA profiles because of extensive biohydrogenation of dietary ALA, limited conversion from ALA to n-3 LC-PUFA and low incorporation of n-3 LC-PUFA into edible tissues. Generally, the inclusion of ALA rich sources in lamb diets potentially increases ALA content in lamb. It is proposed that supplementing ruminants with ALA-rich sources at or below 6% can promote n-3 PUFA profiles in lamb and is unlikely to have negative effects on feed intake, growth, carcass and sensory properties.

Fatty acids in intramuscular fat of Ile de France lambs in two different production systems

The fatty acid (FA) composition in the intramuscular fat (IMF) of the musculus longissimus dorsi (MLD) of Ile de France purebred lambs in two different production systems in Slovakia was evaluated using gas chromatography. In the first production system, lambs and ewes were assigned to pasture without access to concentrates (P). In the second system, lambs and ewes were confined indoors with hay/silage and access to concentrates (S). An analysis of variance with the following factors was employed: production system, sex, and production system-sex interactions. The proportions of arachidonic, eicosapentaeonic, docosapentaeonic, and docosahexaenoic FAs, i.e. long-chain polyunsaturated FA (PUFA), were significantly higher in P lambs (1.83, 0.82, 0.92, 0.29 g 100 g- 1 FAME, respectively) than in S lambs (0.45, 0.14, 0.30, 0.09 g 100 g- 1 FAME, respectively). The proportions of conjugated linoleic acid (CLA), n-6 PUFA, n-3 PUFA, and essential FA (linoleic and α -linolenic) were also significantly higher in P lambs (2.10, 8.50, 4.55, and 8.80 g 100 g- 1 FAME, respectively) than in S lambs (0.65, 3.27, 1.50, and 3.64 g 100 g- 1 FAME, respectively). The proportions of palmitic acid and myristic acid as important individual saturated FAs (SFA) were significantly higher in S lambs (28.51 and 8.30 g 100 g- 1 FAME, respectively) than in P lambs (21.80 and 5.63 g 100 g- 1 FAME, respectively). The proportion of all SFAs was also significantly higher in S lambs (57.87 g 100 g- 1 FAME) than in P lambs (48.70 g 100 g- 1 FAME). From a nutrition and human health point of view (i.e. higher proportions of PUFA, CLA, and essential FAs and lower proportions of SFAs), meat from P lambs was found to be more favourable and would be more highly recommended for consumption.

Ruminant meat flavor influenced by different factors with special reference to fatty acids

Ruminant meat flavor is an important quality and sensory parameter which relays mainly on the organoleptic characteristics of meat. Meat flavor is vital factor for the palatability and acceptability of meat by the consumers. There are various intrinsic and extrinsic factors that influence eating quality of meat. Among these factors, flavor is the major contributor. Fat and low-molecular-weight water-soluble compounds are the most important precursor components in meat, responsible for the meat flavor. The present review focus on the different pre and post-harvest factors that influences the ruminant meat flavor. Raw meat has little flavor but cooking adds value in flavor due to different temperature and cooking methods. The volatile flavoring compounds which are responsible for cooked meat flavor are produced thermally by the Maillard's reaction itself or interaction with lipid oxidation products and vitamin degradation. In nutshell, this review provides perception into previous literature on flavor that affected by various factors particularly the fatty acids and cooking methods.

Effect of finishing diet and duration on the sensory quality and volatile profile of lamb meat

Animal production factors can affect the sensory quality of lamb meat. The study investigated the effect of diet composition and duration of consumption on the proximate analysis, volatile profile and sensory quality of lamb meat. Ninety-nine male Texel × Scottish Blackface lambs were raised at pasture for 10 months before being assigned in groups of 11 to one of the following treatments: 100% Silage (S) for 36 (S36), 54 (S54) or 72 (S72) days; 50% Silage - 50% Concentrate (SC) for 36 (SC36), 54 (SC54) or 72 (SC72) days; 100% Concentrate (C) for 36 (C36) or 54 (C54) or 72 (C72) days. A trained sensory panel found Intensity of Lamb Aroma, Dry Aftertaste and Astringent Aftertaste to be higher in meat from lambs on the concentrate diet. Discriminant analysis showed that the volatile profile enabled discrimination of lamb based on dietary treatment but the volatile differences were insufficient to impact highly on sensory quality. Muscle from animals in the S54 group had higher Manure/Faecal Aroma and Woolly Aroma than the SC54 and C54 groups, possibly related to higher levels of indole and skatole. Further research is required to establish if these small differences would influence consumer acceptability.

Framework for life cycle assessment of livestock production systems to account for the nutritional quality of final products

Life cycle assessment (LCA) is widely regarded as a useful tool for comparing the environmental impacts of multiple livestock production systems. While LCA results are typically communicated in the form of environmental burdens per mass unit of the end product, it is increasingly becoming recognized that the product quality also needs to be accounted for to truly understand the value of a farming system to society. To date, a number of studies have examined environmental consequences of different food consumption patterns at the diet level; however, few have addressed nutritional variations of a single commodity attributable to production systems, leaving limited insight into how on-farm practices can be improved to better balance environment and human nutrition. Using data from seven livestock production systems encompassing cattle, sheep, pigs, and poultry, this paper proposes a novel framework to incorporate nutritional value of meat products into livestock LCA. The results of quantitative case studies demonstrate that relative emissions intensities associated with different systems can be dramatically altered when the nutrient content of meat replaces the mass of meat as the functional unit, with cattle systems outperforming pig and poultry systems in some cases. This finding suggests that the performance of livestock systems should be evaluated under a whole supply chain approach, whereby end products originating from different farm management strategies are treated as competing but separate commodities.

Distribution of fatty acids and phospholipids in different table cuts and co-products from New Zealand pasture-fed Wagyu-dairy cross beef cattle

Wagyu beef products are marketed as luxury goods to discerning consumers and the lipid content and composition are important drivers of wagyu product value. Wagyu beef is an extensively marbled meat product, well characterised for its tenderness and flavour. In New Zealand, pasture-fed Wagyu-dairy beef production is increasing to meet demand for ultra-premium meat products. Important for these characteristics is the composition of lipid species and their distribution across the carcass. The aim of this study was to analyse the distribution of fatty acids and phospholipids in 26 table cuts, nine co-products and three fat deposits of carcasses from New Zealand pasture-fed Wagyu-dairy cross beef carcasses (n = 5). Phospholipid and fatty acid levels varied across different cuts of the carcass, but typically cuts with high levels of phospholipids also had high levels of omega-3 fatty acids and low levels of saturated fatty acids. This work will be used in the future to examine the potential health aspects of pasture-fed Wagyu beef.

Can we improve the nutritional quality of meat?

The nutritional value of meat is an increasingly important factor influencing consumer preferences for poultry, red meat and processed meat products. Intramuscular fat content and composition, in addition to high quality protein, trace minerals and vitamins are important determinants of nutritional value. Fat content of meat at retail has decreased substantially over the past 40 years through advances in animal genetics, nutrition and management and changes in processing techniques. Evidence of the association between diet and the incidence of human non-communicable diseases has driven an interest in developing production systems for lowering total SFA and trans fatty acid (TFA) content and enrichment of n-3 PUFA concentrations in meat and meat products. Typically, poultry and pork has a lower fat content, containing higher PUFA and lower TFA concentrations than lamb or beef. Animal genetics, nutrition and maturity, coupled with their rumen microbiome, are the main factors influencing tissue lipid content and relative proportions of SFA, MUFA and PUFA. Altering the fatty acid (FA) profile of lamb and beef is determined to a large extent by extensive plant and microbial lipolysis and subsequent microbial biohydrogenation of dietary lipid in the rumen, and one of the major reasons explaining the differences in lipid composition of meat from monogastrics and ruminants. Nutritional strategies can be used to align the fat content and FA composition of poultry, pork, lamb and beef with Public Health Guidelines for lowering the social and economic burden of chronic disease.

Omega-3 Long-Chain Fatty Acids in the Heart, Kidney, Liver and Plasma Metabolite Profiles of Australian Prime Lambs Supplemented with Pelleted Canola and Flaxseed Oils

The objective of the study was to ascertain whether human health beneficial omega-3 long-chain (≥C20) polyunsaturated fatty acid (n-3 LC-PUFA) content in heart, kidney and liver can be enhanced by supplementing prime lambs with graded levels of canola and flaxseed oil. Health status of the lambs, as a consequence of the supplementation, was also investigated by examining their plasma metabolites. Sixty purebred and first-cross lambs were allocated to one of five treatments of lucerne hay basal diet supplemented with isocaloric and isonitrogenous wheat-based pellets without oil inclusion (Control) or graded levels of canola oil at 2.5% (2.5C), 5% (5C), flaxseed oil at 2.5% (2.5F) and 5% (5F) in a completely randomised design. Pre-slaughter blood, post-slaughter kidney, liver and heart samples were analysed for plasma metabolite and fatty acid profiles. Summations of docosapentaenoic acid and docosahexaenoic acid, and total n-3 LC-PUFA were enhanced in the liver and kidney of 5F supplemented lambs with a marked decrease in n-6/n-3 ratio and significant breed differences detected. There were generally no deleterious impacts on animal health status. A combination of 5% oil supplementation and lamb genetics is an effective and strategic management tool for enhancing n-3 LC-PUFA contents of heart, kidney and liver without compromising lamb health.

Nutritional enhancement of sheep meat fatty acid profile for human health and wellbeing

Dietary fatty acids (FA) consumed by sheep, like other ruminants, can undergo biohydrogenation resulting in high proportions of saturated FA (SFA) in meat. Biohydrogenation is typically less extensive in sheep than cattle, and consequently, sheep meat can contain higher proportions of omega (n)-3 polyunsaturated FA (PUFA), and PUFA biohydrogenation intermediates (PUFA-BHI) including conjugated linoleic acid (CLA) and trans-monounsaturated FAs (t-MUFA). Sheep meat is also noted for having characteristically higher contents of branched chain FA (BCFA). From a human health and wellness perspective, some SFA and trans-MUFA have been found to negatively affect blood lipid profiles, and are associated with increased risk of cardiovascular disease (CVD). On the other hand, n-3 PUFA, BCFA and some PUFA-BHI may have many potential beneficial effects on human health and wellbeing. In particular, vaccenic acid (VA), rumenic acid (RA) and BCFA may have potential for protecting against cancer and inflammatory disorders among other human health benefits. Several innovative strategies have been evaluated for their potential to enrich sheep meat with FA which may have human health benefits. To this end, dietary manipulation has been found to be the most effective strategy of improving the FA profile of sheep meat. However, there is a missing link between the FA profile of sheep meat, human consumption patterns of sheep FA and chronic diseases. The current review provides an overview of the nutritional strategies used to enhance the FA profile of sheep meat for human consumption.

Application of Hyperspectral imaging to predict the pH, intramuscular fatty acid content and composition of lamb M. longissimus lumborum at 24h post mortem

Cost-effective, rapid and objective measurement of lamb quality on a routine basis is an important step for lamb value chains wishing to manage lamb product quality. Hyperspectral imaging (HSI) technology has shown promise as a solution for objective non-invasive prediction of meat quality. The performance of HSI applied 24h post mortem to lamb M. longissimus lumborum (LL) within a processing plant environment was assessed over two sampling years to evaluate its suitability for an objective lamb meat quality assurance tool. Calibration and validation steps were undertaken to evaluate HSI prediction performance for predicting fatty acid content and composition (n=1020 lambs) and pH (n=2406 lambs). Practical considerations of reference meat quality data quality and validation strategies are discussed. HSI can be used to predict meat quality parameters of lamb LL with varying accuracy levels, but ongoing calibration and validation across seasons is required to improve robustness of HSI for objective non-invasive assessment of lamb meat quality.

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.

Relationships between botanical and chemical composition of forages: a multivariate approach to grasslands in the Western Italian Alps

BACKGROUND

Plant composition of species-rich mountain grasslands can affect the sensorial and chemical attributes of dairy and meat products, with implications for human health. A multivariate approach was used to analyse the complex relationships between vegetation characteristics (botanical composition and plant community variables) and chemical composition (proximate constituents and fatty acid profile) in mesophilic and dry vegetation ecological groups, comprising six different semi-natural grassland types in the Western Italian Alps.

RESULTS

Mesophilic and dry grasslands were comparable in terms of phenology, biodiversity indices and proportion of botanical families. The content of total fatty acids and that of the most abundant fatty acids (alpha-linolenic, linoleic and palmitic acids) were mainly associated to nutrient-rich plant species, belonging to the mesophilic grassland ecological group. Mesophilic grasslands showed also higher values of crude protein, lower values of fibre content and they were related to higher pastoral values of vegetation compared to dry grasslands. The proximate composition and fatty acid profile appeared mainly single species dependent rather than botanical family dependent.

CONCLUSION

These findings highlight that forage from mesophilic grasslands can provide higher nutritive value for ruminants and may be associated to ruminant-derived food products with a healthier fatty acid profile. © 2016 Society of Chemical Industry.

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.