Forms of n-3 (ALA, C18:3n-3 or DHA, C22:6n-3) Fatty Acids Affect Carcass Yield, Blood Lipids, Muscle n-3 Fatty Acids and Liver Gene Expression in Lambs

The effect of different processing methods of linseed on growth performance, nutrient digestibility, blood parameters and ruminate behaviour of lambs

BACKGROUND

Oilseeds such as linseed, canola and sunflower contain unsaturated fatty acids that play important functions in the body. The aim of this study was to assess the effects of different levels of processing linseed on growth performance, nutrient digestibility, blood parameters and ruminate behaviour of lambs.

METHODS

Fifty-six Moghani male lambs (3 months of age, initial average body weight = 28 ± 1.2 kg) were allocated to seven experimental diets in randomized design (eight lambs per each treatment). The experimental diets were as follows: (1) control diet (without linseed), (2) 5% raw linseed, (3) 10% raw linseed, (4) 5% micronized linseed, (5) 10% micronized linseed, (6) 5% extruded linseed and (7) 10% extruded linseed. Lambs were fed ad libitum a basal diet as total mixed ration consisting of 25% concentrate and 75% hay.

RESULTS

The results showed that linseed level and processing method had no significant effect on dry matter intake. Average daily gain, final body weight and feed conversion ratio (FCR) in lambs were affected by experimental diets. The use of 10% micronized linseed and 10% of extruded linseed in the lambs' diet improved dry matter and crude protein digestibility significantly (p < 0.001). Blood glucose concentration observed for lambs fed 10% of micronized or extruded linseed (LS) was not different from that observed in other groups, only from the values shown by lambs fed diets 1 (control) and 2 (5% raw LS). The lowest cholesterol and the highest blood urea nitrogen concentrations were related to lambs fed the control diet (p < 0.001). Feeding processed linseed relative to control diet had no effect on feeding behaviour in lambs.

CONCLUSION

Results of this research showed that the use of extruded and micronized linseed at the level of 10% can improve FCR, nutrient digestibility, and blood parameters.

Muscle fibre type composition influences the formation of odour-active volatiles in beef

Flavour is a key driver of consumer liking, and odour-active volatiles formed in cooking are important contributors to the flavour of cooked beef. We hypothesised that the formation of odour-active volatiles in beef are influenced by the contents of type I oxidative and type II glycolytic muscle fibres. To test our hypothesis, we combined ground masseter (type I) and cutaneous trunci (type II) into beef patties, cooked them, then their volatile profiles were analysed using gas chromatography-mass spectrometry. Antioxidant capacity, pH, total heme protein, free iron, and fatty acid composition of these patties were also measured to investigate their relationship to volatile formation. Our study showed that beef composed of more type I fibres had higher 3-methylbutanal and 3-hydroxy-2-butanone, but less lipid-derived volatiles, and this could be partially attributed to the higher antioxidant capacity, pH, and total heme protein content in type I fibres. The results of our study indicate that fibre-type composition plays an important role in volatile formation and hence flavour of beef.

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.

Consumer Characterization of Wet- and Dry-Aged Mutton Flavor Profile Using Check-All-That-Apply

The aim of this study was to assess if consumers could characterize wet- and dry-aged mutton flavor profiles using CATA (check-all-that-apply). A flavor lexicon was developed for mutton, and consumers assessed wet- and dry-aged mutton patties against this lexicon using CATA methodology. Results indicate that consumers most often associated caramel and roasted flavors with dry-aged patties, and “sheepy” and metallic flavors with wet-aged patties. Volatile analysis supported the consumer characterization as there were more Maillard reaction products, including pyrazines, which are associated with roasted and cooked flavors, found in the dry-aged patty volatile profile. More 1-octen-3-one, which is associated with metallic flavors, was found in the wet-aged patty volatile profile. These results provide validation that the lexicon utilized in this study (i) is suitable for the characterization of mutton flavor and (ii) will have applications for future investigations into the flavor components driving consumer liking for mutton.

The Impact of Plant Phytochemicals on the Gut Microbiota of Humans for a Balanced Life

The gastrointestinal tract of humans is a complex microbial ecosystem known as gut microbiota. The microbiota is involved in several critical physiological processes such as digestion, absorption, and related physiological functions and plays a crucial role in determining the host’s health. The habitual consumption of specific dietary components can impact beyond their nutritional benefits, altering gut microbiota diversity and function and could manipulate health. Phytochemicals are non-nutrient biologically active plant components that can modify the composition of gut microflora through selective stimulation of proliferation or inhibition of certain microbial communities in the intestine. Plants secrete these components, and they accumulate in the cell wall and cell sap compartments (body) for their development and survival. These compounds have low bioavailability and long time-retention in the intestine due to their poor absorption, resulting in beneficial impacts on gut microbiota population. Feeding diets containing phytochemicals to humans and animals may offer a path to improve the gut microbiome resulting in improved performance and/or health and wellbeing. This review discusses the effects of phytochemicals on the modulation of the gut microbiota environment and the resultant benefits to humans; however, the effect of phytochemicals on the gut microbiota of animals is also covered, in brief.

Enrichment of Ewe’s Milk with Dietary n-3 Fatty Acids from Palm, Linseed and Algae Oils in Isoenergetic Rations

Increasing the levels of n-3 fatty acids (FA) in dairy products is an important goal in terms of enhancing the nutritional value of these foods for the consumer. The purpose of this research was to evaluate the effects of linseed and algae oil supplements in ovine isoenergetic diets on healthy milk fatty acid composition, mainly n-3. Seventy-two Churra dairy ewes were divided and randomly assigned to four experimental treatments for 6 weeks. The treatments consisted of a TMR (40:60 forage:concentrate ratio) that varied according to the inclusion of different types of fat (23 g/100 g TMR): hydrogenated palm oil (control), linseed oil (LO), calcium soap of linseed oil (CaS-LO) and marine algae oil (AO). The most effective lipid supplement to increase n-3 FA in milk was AO. 22:6 n-3 and total n-3 PUFA content increased from 0.02 and 0.60% (control) to 2.63 and 3.53% (AO), respectively. All diets supplemented with n-3 FA diminished the content of saturated FA in milk and its atherogenic index, while the levels of trans-11 18:1 and cis-9 trans-11 18:2 significantly increased. Overall, the enhancement of n-3 FA in ewe’s milk would be advantageous for the manufacture of nutritionally improved cheeses.

Changes in the liver transcriptome and physiological parameters of Japanese Black steers during the fattening period

We investigated the physiological changes during the fattening period and production characteristics in Japanese Black steers bred and raised using the typical feeding system in Japan. Here, 21 Japanese Black steers aged 12 months were used, with experimental period divided into early (12–14 months of age), middle (15–22 months), and late fattening phases (23–30 months). The liver transcriptome, blood metabolites, hormones, and rumen fermentation characteristics were analyzed. Blood triglyceride and non-esterified fatty acid concentrations increased, whereas blood ketone levels decreased, with fattening phases. Blood insulin increased with fattening phases and was positively correlated with carcass weight and marbling in late fattening phases. Rumen fermentation characteristics showed high propionate levels and low butyrate levels in late fattening phases, likely due to increased energy intake. Genes related to glucose metabolism, such as SESN3, INSR, LEPR, and FOXO3, were down-regulated in late fattening phases. Genes related to lipid metabolism, such as FABP4, were up-regulated, whereas FADS1 and FADS2 were down-regulated. These findings suggest that the physiological changes resulted from changes in the energy content and composition of diets. Liver metabolism changed with changes in fat metabolism. Insulin was strongly associated with physiological changes and productivity in Japanese Black cattle.

Effects of different feeding regimes on muscle metabolism and its association with meat quality of Tibetan sheep

This study aimed to explore the effects of different feeding regimes on muscle metabolism and its association with meat quality of Tibetan sheep through correlation analysis of meat quality and differential metabolites using untargeted and targeted metabolomics. The untargeted metabolome was detected by UHPLC-QTOF-MS, and the targeted metabolome was detected by UHPLC-QQQ-MS (amino acids) and GC-MS (fatty acids). Based on the researched results, the nutritional quality of meat, including the content of protein and fat and the edible quality of meat, including tenderness, water holding capacity (WHC), texture, and flavor of Tibetan sheep were superior in the stall-feeding group (GBZ) than in the traditional grazing group (CBZ). In the GBZ group, the key upregulated metabolites and metabolic pathways were dominated by essential amino acids (EAAs) and amino acid metabolism as well as the key downregulated metabolites and metabolic pathways were dominated by polyunsaturated fatty acids (PUFA) and lipid metabolism. Correlation analysis showed that there was a significant correlation between the results of untargeted metabolomics and some phenotypic data, including shear force, cooking loss, drip loss, chewiness, elasticity, flavor, and the content of protein and fat. Taken together, stall-feeding would be appropriate for the production of Tibetan mutton, offering better mouthfeel and higher nutrition by altering the muscle metabolism and increasing the beneficial compound deposition in the muscle.

The Sources, Synthesis and Biological Actions of Omega-3 and Omega-6 Fatty Acids in Red Meat: An Overview

The maximisation of available resources for animal production, food security and maintenance of human-animal wellbeing is important for an economically viable, resilient and sustainable future. Pasture and forage diets are common sources of short chain omega-3 (n-3) polyunsaturated fatty acids (PUFA), while grain-based and feedlot diets are common sources of short chain omega-6 (n-6) PUFA. Animals deposit n-3 and n-6 PUFA as a result of their direct consumption, as feeds or by synthesis of longer chain PUFA from short chain FA precursors in the body via desaturation and elongation processes. Research conducted over the last three decades has determined that the consumption of n-3 PUFA can improve the health and wellbeing of humans through its biological, biochemical, pathological and pharmacological effects. n-6 PUFA also play an important role in human health, but when consumed at high levels, are potentially harmful. Research shows that current consumption of n-6 PUFA by the human population is high due to their meal choices and the supplied food types. If consumption of n-3 PUFA from land- and marine-based foods improves human health, it is likely that these same food types can improve the health and wellbeing of livestock (farm animals) by likewise enhancing the levels of the n-3 PUFA in their circulatory and tissue systems. Modern agricultural systems and advanced technologies have fostered large scale animal and crop production systems. These allow for the utilisation of plant concentrate-based diets to increase the rate of animal growth, often based on economics, and these diets are believed to contribute to unfavourable FA intakes. Knowledge of the risks associated with consuming foods that have greater concentration of n-6 PUFA may lead to health-conscious consumers avoiding or minimising their intake of animal- and plant-based foods. For this reason, there is scope to produce food from plant and animal origins that contain lesser amounts of n-6 PUFA and greater amounts of n-3 PUFA, the outcome of which could improve both animal and human health, wellbeing and resilience to disease.

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

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

Partitioning of fatty acids into tissues and fluids from reproductive organs of ewes as affected by dietary phenolic extracts

Evaluation of dietary interventions with regard to fertility problems often observed in ruminant livestock is of global interest. Though the effects of polyphenol supplementation in ruminants on digestion and food quality are well described, the impact on reproductive tissues and fluids remains scarcely investigated. These compounds protect dietary unsaturated fatty acids (FA) from oxidation and biohydrogenation and thus saturation. In addition, modification of the expression of genes associated with FA metabolism may occur. Therefore, we characterized for the first time the FA profiles of reproductive tissues and fluids and investigated their potential modification by dietary polyphenols in 22 cyclic ewes. The animals were randomly divided into four groups and fed a basal diet of meadow hay and one of four concentrate types either non-supplemented (control) or supplemented with grape seed extract, Acacia mearnsii bark extract (13 g/kg dry matter (DM) each) or a combination of both (26 g/kg DM). After 10 weeks of feeding, the animals were slaughtered. Samples of reproductive (oviduct, uterus) and metabolically differently active tissues (liver, muscle, adipose) as well as of plasma and fluids from oviduct and uterus were analysed for their FA composition. In addition, the expression of lipid metabolic and antioxidant genes was analysed in all tissues except the adipose tissue. Fatty acid profiles in tissues and fluids as well as gene expression in tissues significantly differed between the different fluids and tissues. In contrast, only a few diet and matrix (fluid or tissue) × diet interactions were observed. Still, the FA profile of the uterus was the only one not at all affected by the diet. The mRNA expression was not affected by the diet for most of the genes investigated, which might in part be explained by the similar plasma polyphenol concentrations found at slaughter. Overall, our findings contribute to an improved understanding of the characteristic FA composition of reproductive tissues and fluids in sheep. In addition, the effect of polyphenols on different tissues, fluids and tissue gene expression has been confirmed as described in other animal species.

Flaxseed Oil or n-7 Fatty Acid-Enhanced Fish Oil Supplementation Alters Fatty Acid Composition, Plasma Insulin and Serum Ceramide Concentrations, and Gene Expression in Lambs

The objective of this study was to examine the effects of flaxseed (FLAX) oil or 16-carbon n-7 fatty acid -enhanced fish oil (Provinal; POA) supplementation on serum, liver and skeletal muscle fatty acid concentrations, serum ceramide and plasma insulin concentrations, and gene expression. Lambs [n = 18; 42 ± 5.6 kg body weight (BW); 7 months] were individually fed one of the three treatments: (1) control (CON), no oil supplement, (2) FLAX; at 0.1% of BW, or (3) POA at 0.1% of BW for 60 days. Daily feed intake and weight gain were decreased by 21% and 34%, respectively, for POA than FLAX. Liver and skeletal muscle concentrations of palmitoleic acid were greater by 396% and 87%, respectively, for POA than FLAX; whereas, liver and skeletal muscle α-linolenic acid concentrations were greater by 199% and 118%, respectively, for FLAX. Supplementation with POA also had greater serum and tissue concentrations of eicosapentaenoic and docosahexaenoic acids. Serum glucose and plasma insulin concentrations were elevated with FLAX supplementation at the end of the study. Supplementation with POA altered serum ceramide concentrations compared to CON or FLAX. Oil supplementation, both FLAX and POA, downregulated expression of unesterified fatty acid receptors (FFAR) 1 and FFAR4 in the liver; however, oil supplementation upregulated expression of FFAR1 in muscle. Interleukin-6 (IL6) and tumor necrosis factor-α (TNFA) expression were downregulated with oil supplementation in the liver; however, FLAX upregulated TNFA in muscle. These results show that oil supplementation can enhance uptake and deposition of unique fatty acids that alter ceramide concentrations and gene expression in tissues.

Muscle Antioxidant Enzymes Activity and Gene Expression Are Altered by Diet-Induced Increase in Muscle Essential Fatty Acid (α-linolenic acid) Concentration in Sheep Used as a Model

This study investigated the effect of dietary manipulations on muscle fatty acid composition, the activities and relative mRNA expressions of antioxidant enzymes and the relationship between muscle enzyme activity or mRNA expression and alpha linolenic acid (ALA) concentration in sheep. Eighty-four lambs blocked on liveweight were randomly allocated to four dietary treatments, lucerne pasture (Lucerne), annual ryegrass pasture (Ryegrass), feedlot pellets (Feedlot) or annual ryegrass plus feedlot pellets (RyeFeedlot). After six weeks of feeding, lambs were slaughtered and within 30 min post-mortem, samples collected from the longissimus lumborum (LL) muscle for RNA isolation and measurement of antioxidant enzyme activities. At 24 h post-mortem, LL samples were collected for determination of fatty acid concentrations. Feedlot treatment decreased ALA, eicosapentaenoic (EPA), docosapentaenoic (DPA) and docosahexaenoic (DHA) concentrations compared with other treatments and increased linoleic acid (LA) and arachidonic acid (AA) compared with Lucerne and Ryegrass (p < 0.001). The activity of Glutathione peroxidase (GPX1, p < 0.001) and Superoxide dismutase (SOD2, p < 0.001) enzymes in the muscle increased with Lucerne compared to other treatments. Lucerne increased muscle gpx1 mRNA expression by 1.74-fold (p = 0.01) and 1.68-fold (p = 0.05) compared with Feedlot and other diets, respectively. The GPX1 (r² = 0.319, p = 0.002) and SOD2 (r² = 0.244, p = 0.009) enzyme activities were positively related to ALA. There was a positive linear relationship between muscle gpx1 (r² = 0.102, p = 0.017) or sod2 (r² = 0.049, p = 0.09) mRNA expressions and ALA concentration. This study demonstrates that diet can affect concentrations of ALA and other fatty acids as well as change activities and gene expression of antioxidant enzymes in muscle. Increased antioxidant activity may, in turn, have beneficial effects on the performance, health and wellbeing of animals and humans.

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.

Effect of supplementation with linseed or a blend of aromatic spices and time on feed on fatty acid composition, meat quality and consumer liking of meat from lambs fed dehydrated alfalfa or corn

Cross-bred lambs (n=72) were fed finishing diets using a factorial arrangement of treatments: BASAL DIET (alfalfa pellets or corn), SUPPLEMENT (none, linseed or aromatic spices), TIME ON FEED (41 or 83days). Carcass and meat quality traits, fatty acid composition, color stability and consumer liking were determined. Feeding alfalfa improved sensory ratings and fatty acid composition of lamb. However, corn or longer alfalfa feeding would be recommended if heavier and fatter carcasses are sought. Consumer liking and fatty acid composition of lamb were improved with addition of spices and linseed, respectively. But additional antioxidant strategies should be considered to delay meat color deterioration during storage if lambs are fed corn-linseed for 83days. Although alfalfa basal diet and linseed supplementation improved fatty acid composition, feeding the basal diets for at least 41days resulted in low n-3 fatty acid concentrations in muscle.

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

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

Influence of Maternal and Postweaning Linseed Dietary Supplementation on Growth Rate, Lipid Profile, and Meat Quality Traits of Light Sarda Lambs

The effects of dietary extruded linseed (EL) on growth performance, meat quality, and lipid profile of Semimembranosus and Longissimus lumborum muscles of 81 Sarda lambs were studied in a 3 × 3 design: EL content (0%, 10%, and 20%) of maternal dietary concentrate fed from 20 d to parturition to 60 d of lactation and EL content (0%, 10%, 20%) of lamb concentrate fed after weaning for 30 d. The basal diet was composed of alfalfa and meadow hay during pregnancy and alfalfa hay during lactation. At slaughter, carcass and meat quality were evaluated. Sensory quality of Semimembranosus from 0% and 20% EL lambs was assessed. Both maternal and postweaning diets affected growth performance, with higher body weights recorded with the 10% EL concentrate. Carcass and meat quality were not affected by diet. Saturated and monounsaturated FA decreased and n-3 polyunsaturated FA increased with increasing EL content in lamb diet. An increase in vaccenic and rumenic acid was associated with the EL content of the maternal diet. Both diets increased the n-6/n-3 FA ratio. No differences in acceptability were detected by consumers among groups. It is concluded that EL supplementation and early life nutrition can influence performance and FA metabolism in growing lambs.