Utilization of extruded linseed to modify fatty composition of intensively-reared lamb meat: effect of associated cereals (wheat vs. corn) and linoleic acid content of the diet

Dietary combination of linseed and hazelnut skin as a sustainable strategy to enrich lamb with health promoting fatty acids

This study investigated the effect of the inclusion of extruded linseed and hazelnut skin on fatty acid (FA) metabolism in finishing lambs. Forty lambs were divided into 4 groups and fed for 60 d with: a conventional cereal-based diet, or the same diet with 8% of extruded linseed, or 15% of hazelnut skin, or 4% of linseed plus 7.5% of hazelnut skin as partial replacement of maize. Dietary treatments did not affect growth performances, carcass traits, and ruminal fermentation. The combined effect of linseed and hazelnut skin enriched the intramuscular fat with health promoting FA. Particularly, increases in α-linolenic acid (3.75-fold), and very long-chain n-3 poly-unsaturated FA (+ 40%) were attributed to the supplementation with linseed, rich in α-linolenic acid. In addition, increases in rumenic (+ 33%), and vaccenic (+ 59%) acids were attributed to hazelnut skin tannins modulating ruminal biohydrogenation and accumulating intermediate metabolites. The simultaneous inclusion of linseed and hazelnut skin can be a profitable strategy for enriching the intramuscular fat of lambs with health promoting FA, without adverse effects on ruminal fermentation and animal performance.

Trans-10 18:1 in ruminant meats: A review

Trans (t) fatty acids (TFA) from partially hydrogenated vegetable oils (i.e., industrial trans) have been phased out of foods in many countries due to their promotion of cardiovascular disease. This leaves ruminant-derived foods as the main source of TFA. Unlike industrial TFA where catalytic hydrogenation yields a broad distribution of isomers, ruminant TFA are enzymatically derived and can result in enrichment of specific isomers. Comparisons between industrial and ruminant TFA have often exonerated ruminant TFA due to their lack or at times positive effects on health. At extremes, however, ruminant-sourced foods can have either high levels of t10- or t11-18:1, and when considering enriched sources, t10-18:1 has properties similar to industrial TFA, whereas t11-18:1 can be converted to an isomer of conjugated linoleic acid (cis(c)9,t11-conjugated linoleic acid), both of which have potential positive health effects. Increased t10-18:1 in meat-producing ruminants has not been associated with negative effects on live animal production or meat quality. As such, reducing t10-18:1 has not been of immediate concern to ruminant meat producers, as there have been no economic consequences for its enrichment; nevertheless at high levels, it can compromise the nutritional quality of beef and lamb. In anticipation that regulations regarding TFA may focus more on t10-18:1 in beef and lamb, the present review will cover its production, analysis, biological effects, strategies for manipulation, and regulatory policy.

Effects of algae supplementation in high-energy dietary on fatty acid composition and the expression of genes involved in lipid metabolism in Hu sheep managed under intensive finishing system

This study aims to investigate the effect of algae supplementation in high-energy diet (HE diet) on lipid metabolism of intensive feeding sheep. The lambs were assigned to two groups and received a standard diet (ST diet, 8.40 MJ/kg) or a HE diet (9.70 MJ/kg) based on corn, wheat bran, soybean meal. Each group was divided into two subgroups: control and algae supplement (3%, DM basis). The body fat, serum cholesterol, and oleic acid in the liver and muscle increased in lambs receiving the HE diet. However, after supplementing the microalgae (Schizochytrium sp.) in the HE diet, these parameters were all reduced. In addition, EPA, DHA and CLA cis-9, trans-11 in muscle and liver increased. Algae supplementation also altered the expression of lipid metabolism-related genes, including up-regulated FADS2, ELOVL2, SCD, CPT1α and SREBF-1, and down-regulated PPARα and PPARγ. In conclusion, algae supplementation in ST and HE diets increased n-3PUFA and improved metabolic disorder caused by the HE diet.

Effect of Flax-Seed Enriched Concentrate Supplementation in Grazing Pramenka Breed Lamb’s Diet on Omental Fat Fatty Acids

This research is aimed at determining the impact of supplementing extensively reared lambs with a limited amount of flax seed enriched-concentrate on the fatty acid profile of the lamb meat (omental fat depot). A total of 96 60-day old Pramenka breed lambs (23.85±3.98 kg live body weight; 60±10 days of age; 42 males and 54 females) raised on pasture with their dams were randomly divided in three experimental groups: control (CON) or extensive rearing group, which did not receive any supplementary feed; concentrate (CC) group, receiving 300 g of a conventional commercial concentrate feed per animal daily, and concentrate-flax seed (CC-FS) group, receiving 300 g/day of the concentrate supplemented with 5% of flax seed. After 60 days of experimental period, 10 lambs were selected (5 males and 5 females) from each group and slaughtered. Omental fat samples were taken and analyzed to determine their fatty acid profile. Significant (P>0.05) differences in the fatty acid profile between CON and CC groups were small. However, enrichment of the concentrate with 5% flax seed increased the percentages of PUFA and n-3 PUFA when compared to both CON and CC groups and thus slightly improved the nutritional characteristics of the omental fat. The effect of sex on the fatty acid profile was only observed for C20:4 n-6 and C20:5 n-3 (P < 0.05).

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.

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

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

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.

Effect of dietary starch level and its rumen degradability on lamb meat fatty acid composition

Forty lambs were fed one of four diets supplemented with a linseed and sunflower oil blend but differing in starch level (mid, ≈35 vs. high, ≈50%) and starch rumen degradability (mid, ≈70 vs. high, ≈80%). The effects of diet on growth, carcass traits and meat fatty acid (FA) composition, with emphasis on biohydrogenation intermediates were evaluated. Lambs stayed on trial for 5weeks until slaughter. Treatment had no effect on animal performance and carcass traits. High-degradability diets decreased (P=0.04) meat shear force compared with mid-degradability diets. Lipid content of meat was unaffected by the diet. Mid-starch diets increased (P<0.05) the saturated FA and cis-MUFA but decreased (P<0.05) the trans-MUFA, particularly the t10-18:1, when compared with high-starch diets. The t11-18:1 (0.7% of total FA) and c9,t11-18:2 (<0.3%) remained low and the 18:3n-3 remained high (1.74%) and unaffected by diet.

Effects of Addition of Linseed and Marine Algae to the Diet on Adipose Tissue Development, Fatty Acid Profile, Lipogenic Gene Expression, and Meat Quality in Lambs

This study examined the effect of linseed and algae on growth and carcass parameters, adipocyte cellularity, fatty acid profile and meat quality and gene expression in subcutaneous and intramuscular adipose tissues (AT) in lambs. After weaning, 33 lambs were fed three diets up to 26.7 ± 0.3 kg: Control diet (barley and soybean); L diet (barley, soybean and 10% linseed) and L-A diet (barley, soybean, 5% linseed and 3.89% algae). Lambs fed L-A diet showed lower average daily gain and greater slaughter age compared to Control and L (P < 0.001). Carcass traits were not affected by L and L-A diets, but a trend towards greater adipocyte diameter was observed in L and L-A in the subcutaneous AT (P = 0.057). Adding either linseed or linseed and algae increased α-linolenic acid and eicosapentaenoic acid contents in both AT (P < 0.001); however, docosahexaenoic acid was increased by L-A (P < 0.001). The n-6/n-3 ratio decreased in L and L-A (P < 0.001). Algae had adverse effects on meat quality, with greater lipid oxidation and reduced ratings for odor and flavor. The expression of lipogenic genes was downregulated in the subcutaneous AT (P < 0.05): acetyl-CoA carboxylase 1 (ACACA) in L and L-A and lipoprotein lipase (LPL) and stearoyl-CoA desaturase (SCD) in L-A. Fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2) and fatty acid elongase 5 (ELOVL5) were unaffected. In the subcutaneous AT, supplementing either L or L-A increased peroxisome proliferator-activated receptor gamma (PPARG) and CAAT-enhancer binding protein alpha (CEBPA) (P < 0.05), although it had no effect on sterol regulatory element-binding factor 1 (SREBF1). In the intramuscular AT, expression of ACACA, SCD, FADS1 and FADS2 decreased in L and L-A (P < 0.001) and LPL in L (P < 0.01), but PPARG, CEBPA and SREBF1 were unaffected.

The use of stoned olive cake and rolled linseed in the diet of intensively reared lambs: effect on the intramuscular fatty-acid composition

The aim of the present study was to evaluate the effect of the inclusion of stoned olive cake and rolled linseed in a concentrate-based diet for lambs on the fatty-acid composition of polar and non-polar intramuscular lipids of the longissimus dorsi muscle. To achieve this objective, 32 Appenninica lambs were randomly distributed into four groups of eight lambs each and were fed conventional cereal-based concentrates (diet C); concentrates containing 20% on a dry matter (DM) basis of rolled linseed (diet L); concentrates containing 35% DM of stoned olive cake (diet OC); and concentrates containing both rolled linseed (10% DM) and stoned olive cake (17% DM; diet OCL). The concentrates were administered together with grass hay at a 20:80 forage:concentrate ratio. Growing performances and carcass traits were evaluated. The fatty-acid composition was analysed in the total intramuscular lipids, as well as in the polar and neutral lipids. The average feed intake and the growth performance of lambs were not affected by the dietary treatments, as a consequence of similar nutritional characteristics of the diets. The inclusion of rolled linseed in the L and OCL diets increased the content of C18:3 n-3 in intramuscular total lipids, which was threefold higher in meat from the L lambs and more than twofold higher in meat from the OCL lambs compared with the C and OC treatments. The n-6:n-3 ratio significantly decreased in the meat from lambs in the L and OCL groups, reaching values below 3. The L treatment resulted in the highest level of trans-18:1 fatty acids in the muscle. Regardless of the dietary treatment, the t10-18:1 was the major isomer, representing 55%, 45%, 49% and 45% of total trans-18:1 for C, L, OC and OCL treatments, respectively. Neutral lipids from the OC-fed lambs contained the highest amount of c9-18:1 (more than 36% of total fatty acids); however, the content of c9-18:1 did not differ between the OC and C lambs, suggesting an intensive biohydrogenation of dietary c9-18:1 in the case of OC treatment. The highest content of c9,t11-18:2 was detected in the intramuscular fat from the L-fed lambs, followed by the OCL treatment. A similar trend was observed in the neutral lipid fraction and, to a lower extent, in the polar lipids.

Effects of dietary fish oil and corn oil on rat mammary tissue

The effects, on the maternal mammary gland, of diets containing similar lipid percentages but differing in composition of polyunsaturated fatty acids (PUFA) have been assessed in rats during pregnancy and lactation. For this purpose, tuna fish oil (an n-3-PUFA-enriched oil) and corn oil (an n-6-PUFA-enriched oil) were included in diets at ratios such that the caloric inputs were the same as that of the control diet. As expected, the maternal diet affected the tissue composition of dams. Unexpectedly, only the tuna fish oil diet had an effect on pup growth, being associated with the pups being underweight between the ages of 11 and 21 days. The maternal mammary gland of rats fed the tuna fish oil diet displayed two main modifications: the size of cytoplasmic lipid droplets was increased when compared with those in control rats and the mammary epithelium showed an unusual formation of multilayers of cells. These results show that the tuna fish oil diet, during pregnancy and lactation, exerts specific effects on mammary cells and on the formation of lipid droplets. They suggest that this maternal diet affects the functioning of the mammary tissue.

The effect of maternal linseed supplementation and/or lamb linseed supplementation on muscle and subcutaneous adipose tissue fatty acid composition of indoor lambs

Eighty eight lambs were used in a 2×2 factorial arrangement 1) to investigate the effect of maternal dietary linseed supplementation and/or lamb linseed supplemented concentrate on growth performance, carcass fat quality and fatty acid (FA) composition of muscle and dorsal adipose tissue of indoor lambs 2) to study the relationships between subcutaneous fat quality and FA composition. Feeding linseed to ewes increased C18:3 n-3 (ALA) proportion in milk and therefore the ALA supply to suckling lambs. However, ALA and n-3 polyunsaturated FA (n-3 PUFA) proportions in lamb tissues were not affected. Feeding linseed to lambs during the post-weaning period significantly increased the proportions of ALA and n-3 PUFA in tissues. Softer and more colored fat was associated with a decrease in even medium-chain saturated FA and increases in odd and methyl FA proportions but not with ALA proportion in subcutaneous adipose tissue.