Concentration Of Vaccenic Acid Research Articles

Growth, feed intake, carcass characteristics, and meat fatty acid profile of lambs fed soybean oil partially replaced by fish oil blend

The objective of this study was to evaluate the effects of partial replacement of soybean oil by fish oil on dry matter intake (DMI), growth, carcass characteristics, and meat fatty acid profile of feedlot lambs. Fifty Santa Ines male lambs with 17.1±2.8 of initial body weight (BW) were individually penned and used in a randomized complete block design with 10 blocks and 5 treatments. Dietary treatments, dry matter (DM) basis, consisted of: (1) control diet (CONT) with a 10:90 of forage to concentrate ratio, (2) control diet supplemented with 40g/kg of soybean oil (0FO), (3) control diet supplemented with 2.5g/kg of fish oil blend+37.5g/kg of soybean oil (25FO), (4) control diet supplemented with 5g/kg of fish oil blend+35g/kg of soybean oil (50FO), and (5) control diet supplemented with 7.5g/kg of fish oil blend+32.5g/kg of soybean oil (75FO). Diets were mixed once daily and fed ad libitum. At the end of the 84-day feeding trial, all animals were slaughtered for carcass characteristics evaluations and meat fat acid profile determination. Animals fed soybean oil had reduced DMI compared to control; however, the average daily gain (ADG), feed efficiency (FE) and final BW were not affected. The animals fed fish oil had similar DMI, ADG, FE and final BW to those receiving the control treatment. The DMI, ADG, FE and final BW were not affected by the increasing substitution of soybean oil for fish oil. Most carcass characteristics were not affected by treatments. The shrink after chilling was lower for the 50FO diet. Short, medium, and long-chain fatty acids were similar for all diets. Stearic acid concentration was higher for lambs fed the fat diets vs. control. However, stearic acid concentration decreased linearly when fish oil replaced soybean oil. Vaccenic acid concentration was higher for lambs fed fat diets vs. control. In addition, vaccenic acid increased linearly with fish oil inclusion. The conjugated linoleic acid (CLA) C18:2 cis-9, trans-11 showed higher concentration in meat of animals fed diets containing fish oil compared to control, but it was not affected by soybean oil inclusion. Feeding small amounts of fish oil blend plus soybean oil does not exert an additional effect on the concentration of CLA C18:2 cis-9, trans-11 in relation to the exclusive use of soybean oil. However, the mixture of 7.5g/kg DM of fish oil blend with 32.5g/kg DM of soybean oil is recommended, because it improves the lipid profile of the meat by increasing the concentration of vaccenic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Additionally, supplementing 7.5g/kg DM of fish oil blend mixed with 32.5g/kg DM of soybean had no negative effect on the feed intake, ADG, FE and carcass characteristics of the lambs fed high concentrate diet.

Milk fatty acids profile and arterial blood milk fat precursors concentration of dairy goats fed increasing doses of soybean oil

The provision of fatty acid sources in ruminant diets allows the manipulation of fatty acid profiles in milk and meat, permitting to increase the fatty acids of interest, such as conjugated linoleic acid. The objectives of this experiment were to evaluate the inclusion of increasing doses of soybean oil (30, 60 or 90g/d) on intake, total tract digestibility of nutrients, milk production and composition, arterial and milk fatty acid profiles, and arterial concentrations of glucose, acetate, and β-hydroxybutyrate in dairy goats. Four multiparous Saanen goats with mean initial DIM 32±6 and mean initial BW 63±7kg were assigned in a 4×4 Latin square. Does were housed in tie stalls and fed a 40% of corn silage and 60% concentrate diet. Experimental treatments consisted of: (1) basal diet without soybean oil infusion (control); (2) basal diet plus an oral infusion of 30mL soybean oil; (3) basal diet plus an oral infusion of 60mL soybean oil; and (4) basal diet plus an oral infusion of 90mL soybean oil. The DM and OM intakes decreased linearly (P<0.05) with increasing soybean oil supply. Dry matter digestibility was negatively influenced by oil (P<0.01); however, the OM digestibility was not affected by soybean oil doses. Milk production tended to decrease (P=0.07) by soybean oil supply, although when this was corrected to 3.5% fat, it decreased linearly (P<0.01) as a result of the decreasing (P<0.05) milk fat content. Vaccenic acid concentration in arterial blood increased (P<0.01) 127% with 90g/d of soybean oil addition. Appearance of C18:2 t10, c12 in milk caused a reduction (P<0.01) in milk fat and reached a 31% reduction when 90g/d of soybean oil was offered compared to the control diet, while the opposite occurred with C18:2 c9, t11, which decreased (P<0.05) with increasing doses of soybean oil. Increasing soybean oil had no effect on arterial blood concentrations of glucose, acetate and β-hydroxybutyrate. Therefore, the decrease in milk fat concentration was due to the inhibition of mammary synthesis of fatty acids, but not by a limitation of its precursors for fatty acid synthesis.

Effect of Dietary Vegetable Oil Supplementation on C18 Fatty Acids and Conjugated Linoleic Acid Production; An In vitro Fermentation Study

An in vitro rumen fermentation trial was conducted to investigate effect of dietary vegetable oil supplement on fatty acids metabolism in cattle. The incubation was carried out using rumen fluid obtained from Brahman x Native crossbred beef cattle. The diets were formulated by using basal diet with no vegetable oil (CON), basal diet with 4% of palm oil (PO), 4% of canola oil (CA), 4% of coconut oil (CO) and 4% of sunflower oil (SF). Fatty acid profiles were determined at 12, 24 and 48 h after incubation time. The results found that linoleic acid (LA) was decreased with diet CON, diet PO, diet CA and diet SF (p<0.05). Stearic acid (SA) resulted increased with diet CON, diet CA, diet CO and diet SF at 24 and 48 h. The SF diet contain high level of LA showed the highest concentration of cis9 trans11 conjugated linoleic acid (CLA) when compared with other diets. Vaccenic acid (VA) was increased with all the five diet, especially with diet SF and diet CA after 24 h. Base on this study, it suggests that supplementation of SF could improve the concentration of VA and cis9 trans11 CLA in the rumen.

Fatty acid composition of the longissimus dorsi muscle in crossbred steers fed different sources of fatty acids

The objective of this study was to evaluate the fatty acid composition of the longissimus dorsi muscle in carcasses of ¾ Bos taurus taurus ¼ Bos taurus indicus steers fed different sources of fatty acids. Thirty-six steers aged 14 months, with a mean live weight of 320 kg, were fed the following diets for 96 days: 1) control diet, containing no supplemental fat source; 2) CaSFA, diet containing 50 g calcium salts of fatty acids per kg total dry matter; 3) CS diet, containing 210 g cottonseed per kg total dry matter. The fatty acid composition of the longissimus dorsi muscle was determined by gas chromatography. No difference in slaughter weight, carcass weight, backfat thickness, or longissimus dorsi muscle area was observed between animals receiving the diets CaSFA and CS. Animals consuming the two fat-supplemented diets presented higher concentrations of oleic (C18:1), palmitic (C16:0) and stearic (C18:0) acids, corresponding to an average 80.76% of total fatty acids, and higher concentrations of vaccenic acid (C18:1 t11) in the muscle when compared with the control group. Supplementation of the diet of feedlot crossbred steers with CaSFA or cottonseed did not promote significant alterations in the lipid composition of the longissimus dorsi muscle.

Effects of feeding increasing dietary levels of high oleic or regular sunflower or linseed oil on fatty acid profile of goat milk

In this work, the effects of increasing amounts of 3 plant oils in diets on the fatty acid (FA) profile of goat milk were studied. The study consisted of 3 experiments, one per oil tested (linseed oil, LO; high oleic sunflower oil, HOSFO; and regular sunflower oil, RSFO). The 3 experiments were conducted successively on 12 Malagueña goats, which were assigned at random to 1 of 4 treatments: 0, 30, 48, and 66 (H) g of added oil/d. A basal diet made of alfalfa hay and pelleted concentrate (33:67) was used in all of the experiments. For each animal, milk samples collected after 15 d on treatments were analyzed for fat, protein, lactose, and FA composition, whereas individual milk yield was measured the last 3 d of each experiment. Oil supplementation affected neither dry matter intake nor milk production traits. Increasing the oil supplementation decreased the content of saturated FA (especially 16:0) in milk fat and increased mono- and polyunsaturated FA in a linear manner. Vaccenic acid content linearly increased with the oil supplementation by 370, 217, and 634% to 5.32, 2.66, and 5.09g/100g of total FA methyl esters with the H diet in LO, HOSFO, and RSFO experiments, respectively. Rumenic acid content linearly increased with LO and RSFO supplementation by 298 and 354% from 0.53 and 0.41g/100g of total FA methyl esters with the 0g of added oil/d diet. The content of trans-10-18:1 was not affected by LO supplementation but showed an increasing linear trend with HOSFO supplementation and linearly increased with RSFO supplementation. The ratio of n-6 to n-3 polyunsaturated FA in milk fat was decreased by about 70% with the H diet in the LO experiment and it was increased by 54 and 82% with the H diet in the HOSFO and RSFO experiments. In conclusion, LO supplementation in this work seemed to be the most favorable alternative compared with HOSFO or RSFO supplementation.

Grazing Period Variations in Cow Milk Vaccenic Acid (VA) and Conjugated Linoleic Acid (CLA)

The primary objective of this study was to examine the effect of breed, lactation and grazing period on the cis 9, trans 11-Conjugated Linoleic Acid (c9,t11-CLA) and trans 11-Vaccenic Acid (VA) levels in cow's milk. The secondary objective was to compare the properties of cheese products made from the study milk to commercially available cheeses. Milk samples from a commercial dairy farm representing 3 breeds (Fleckvieh Cross, n=19; Holstein, n=18; Jersey, n=12) were analyzed at three points in the grazing period. Daily yield, CLA yield, VA, yield and the percentage of VA in milk were greatest in June, intermediate in July and lowest in September. The percentage of c9,t11-CLA in milk was lower in September compared to June and July. The VA and c9,t11-CLA content of cheese made from the milk samples were ~2-fold higher than commercially available samples of Cheddar and ~1.5-fold higher than commercially available samples of Mozzarella. In conclusion, the c9,t11-CLA and VA contents of milk decrease over the June through September grazing period, likely due to the grazing material.

The Effect of Forage Level and Oil Supplement on Butyrivibrio fibrisolvens and Anaerovibrio lipolytica in Continuous Culture Fermenters.

The objective of this study was to evaluate the effects of forage level and oil supplement on selected strains of rumen bacteria believed to be involved in biohydrogenation (BH). A continuous culture system consisting of four fermenters was used in a 4×4 Latin square design with a factorial arrangement of treatments, with four 10 d consecutive periods. Treatment diets were: i) high forage diet (70:30 forage to concentrate (dry matter basis); HFC), ii) high forage plus oil supplement (HFO), iii) low forage diet (30:70 forage to concentrate; LFC), and iv) low forage plus oil supplement (LFO). The oil supplement was a blend of fish oil and soybean oil added at 1 and 2 g/100 g dry matter, respectively. Treatment diets were fed for 10 days and samples were collected from each fermenter on the last day of each period 3 h post morning feeding. The concentrations of vaccenic acid (t11C18:1; VA) and c9t11 conjugated linoleic acid (CLA) were greater with the high forage diet while the concentrations of t10 C18:1 and t10c12 CLA were greater with the low forage diet and addition of oil supplement increased their concentrations at both forage levels. The DNA abundance of Anaerovibrio lipolytica, and Butyrivibrio fibrisolvens vaccenic acid subgroup (Butyrivibrio VA) were lower with the low forage diets but not affected by oil supplement. The DNA abundance of Butyrivibrio fibrisolvens stearic acid producer subgroup (Butyrivibrio SA) was not affected by forage level or oil supplement. In conclusion, oil supplement had no effects on the tested rumen bacteria and forage level affected Anaerovibrio lipolytica and Butyrivibrio VA.

Effects of dietary turmeric supplementation on plasma lipoproteins, meat quality and fatty acid composition in broilers

An experiment with 200 day-old male broiler chickens was conducted to investigate the effect of the dietary supplementation of turmeric rhizome powder (TRP) on plasma lipoprotein concentrations, and the meat quality and fatty acid composition of the thigh muscle of the broilers. The four treatments were 0% (F.TRP), 0.25% (L.TRP), 0.50% (M.TRP) and 0.75% (H.TRP) TRP in the diets. The pH and the fat, protein, dry matter and ash concentrations of thigh meat did not show significant differences between treatments. There were no significant differences between treatments in the concentrations of plasma triglyceride, total cholesterol and very low-density lipoprotein-cholesterol (VLDL-c) at three weeks, and for plasma lowdensity lipoprotein (LDL-c) at three and six weeks of age. At week 6, the M.TRP- and H.TRP-fed birds showed lower plasma triglyceride and VLDL-c concentrations than the birds in the other treatments. At weeks 3 and 6 the concentration of plasma high-density lipoprotein-cholesterol (HDL-c) of the M.TRP- and H.TRP-fed birds was significantly higher than that of the F.TRP-fed birds. At week 6, the H.TRP-fed birds had significantly lower concentrations of saturated fatty acids (SFA) in the thigh and total cholesterol in the plasma than the F.TRP-fed birds and the other birds. Moreover, a significantly higher thigh vaccenic acid concentration was indicated for the H.TRP-fed birds compared with the L.TRP- and F.TRP-fed birds. In orthogonal comparisons, TRP consumption reduced the concentration of plasma triglycerides and dry matter of thigh meat, as well as triglyceride, palmitic acid and total SFA concentrations, but increased the thigh meat protein and plasma HDL-c concentrations significantly, compared with the control. In conclusion, supplementation of TRP in broiler chickens diets can decrease the concentrations of SFAs and triglycerides in thigh meat and improve the meat quality as a result.

Effects of replacing palm oil with maize oil and Curcuma longa supplementation on the performance, carcass characteristics, meat quality and fatty acid profile of the perirenal fat and muscle of growing rabbits

An experiment has been conducted to study the effects of the inclusion of plant oil in rabbit diets. This study was aimed at evaluating the beneficial effects of the inclusion of maize oil (MO), rich in unsaturated fatty acids (UFAs), compared to palm oil (PO) containing saturated fatty acids (SFAs), on the meat fatty acid (FA) profile. As UFAs are susceptible to rancidity, Curcuma longa (CL), which is known for its antioxidant properties, was also added (3 g/kg) to the diet with two plant oils. CL contains curcuminoids, volatile oils, sugars, proteins, resins and polyunsaturated fatty acids (PUFAs). We also evaluated the influence of CL inclusion in the diet on the FA profile of the meat. Furthermore, the possibility of using these oil-enriched diets and the ability to assimilate CL in rabbits was evaluated by analysing the performance, carcass characteristics and meat quality. At the end of the experiment, there were no significant differences between the groups concerning the live weight, live weight gain, feed consumption, feed efficiency, carcass yield or the percentages of edible organs. The hind legs, forelegs, loins and abdominal wall, breast and ribs, skin and limbs and head were not affected by the oil type or by the inclusion of CL. The chemical composition, pH and oxidative status of the Longissimus dorsi muscle of the rabbits fed the experimental diets were not affected by the oil source or by the CL supplementation. Conversely, it has been shown that it is possible to modify the FA profile of rabbit meat and fat by dietary means. The SFA/PUFA ratio significantly decreased from −18% to −16% in the meat and from −25% to −23% in the perirenal fat of the rabbits fed diets containing MO without or with CL supplementation, respectively, compared to same tissues of the rabbits fed diets containing PO without or with CL supplementation, respectively. Similar trends were found for the atherogenic index, which decreased from −20% to −17% in the meat and from −26% to −23% in the perirenal fat, respectively, and the thrombogenic index, which decreased from −19% to −24% in the meat and from −24% to −23% in the perirenal fat, respectively. CL increased the α-Linolenic acid and PUFA n-3 contents and reduced the vaccenic acid content and the n-6/n-3 ratio in the meat of the rabbits fed the PO or MO diets.

Increasing pasture intakes enhances polyunsaturated fatty acids and lipophilic antioxidants in plasma and milk of dairy cows fed total mix ration

Polyunsaturated fatty acids and lipo-soluble vitamins in the milk are considered as neutraceutical compounds due to their beneficial effects on human health. The aim of the present study was to evaluate the changes in fatty acid composition and fat-soluble antioxidant content in plasma and milk from cows fed with different dietary proportions from pasture. Cows from a farm in the Hyblean mountain region in Italy were randomly divided into three groups (12 animals per group): CTRL fed only a total mix ration (TMR); 30P fed a TMR supplemented with 30% dry matter (DM) from pasture and 70P fed a TMR supplemented with 70% DM of pasture. Blood and milk samples were collected, stored and analysed for their content of fatty acids and fat-soluble antioxidants. Fatty acid profiles were significantly modified by different diets. CLA, vaccenic acid (VA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) significantly (P < 0.05) increased in plasma as a function of the proportion of pasture added to the diet. In agreement with these data, a progressively significant (P < 0.05) increase in concentrations of VA, CLA and EPA was observed in the milk. Such changes in fatty acid composition were accompanied by a concomitant increase in the concentrations of α-tocopherol and β-carotene in both plasma and milk. The increase in EPA, DHA and CLA, β-carotene and α-tocopherol in plasma may not only have a beneficial impact for milk and meat quality, but may also result in an increased protection against inflammatory events.

Effect of the feeding system on the fatty acid composition, expression of the Δ9-desaturase, Peroxisome Proliferator-Activated Receptor Alpha, Gamma, and Sterol Regulatory Element Binding Protein 1 genes in the semitendinous muscle of light lambs of the Rasa Aragonesa breed

BackgroundConjugated linoleic acids (CLAs) are receiving increasing attention because of their beneficial effects on human health, with milk and meat products derived from ruminants as important sources of CLA in the human diet. SCD gene is responsible for some of the variation in CLA concentration in adipose tissues, and PPARγ, PPARα and SREBP1 genes are regulator of SCD gene. The aim of this work was to evaluate the effect of the feeding system on fatty acid composition, CLA content and relative gene expression of Δ9-desaturase (SCD), Peroxisome Proliferator-Activated Receptor Gamma (PPARγ), Peroxisome Proliferator-Activated Receptor Alpha, (PPARα) and Sterol Regulatory Element Binding Protein (SREBP1) in Rasa Aragonesa light lambs in semitendinous muscle. Forty-four single-born male lambs were used to evaluate the effect of the feeding system, varying on an intensity gradient according to the use of concentrates: 1. grazing alfalfa, 2. grazing alfalfa with a supplement for lambs, 3. indoor lambs with grazing ewes and 4. drylot.ResultsBoth grazing systems resulted in a higher concentration of vaccenic acid (VA), CLA, CLA/VA acid ratio, and a lower oleic content, oleic acid (C18:1)/stearic acid (C18:0) ratio, PUFA n-6/n-3 ratio and SCD expression compared to other diets. In addition feeding system affected the fatty acid composition and SCD expression, possibly due to CLA concentration or the PUFA n-6/n-3 ratio. Both expression of the SCD gene and the feeding system were important factors affecting CLA concentration in the animal's semitendinous muscle. PPARγ, PPARα and SREBP1 expression seemed to be unaffected by the feeding system. Although no significant results were found, PPARγ, PPARα and SREBP1 showed similar expression pattern as SCD. Moreover, the correlation results between SCD expression and PPARγ (p < 0.01), as well as SREBP1 (p < 0.01) expression, may suggest that these genes were affecting SCD expression in a different way.ConclusionsThe data indicated that the feeding system is the main factor affecting the fatty acid composition and SCD gene expression, which is also affected by CLA and possibly by n-6/n-3 PUFAs.

Season and altitude effects on milk fatty acid profile in Sarda dairy sheep flocks

Diet plays a major role in modulating the fatty acid composition of ruminant milk. It is also well known that the intake of fresh forages has a positive influence on polyunsaturated fatty acid (PUFA), particularly CLA and omega- 3, compared with diets based on dry forage and concentrates. Altitude influences, directly, grass availability and botanical composition of the pasture, and, indirectly, the amount of concentrate supplemented to the diet. Therefore, the altitude where farms are located at may give indirect information about the type of feeding system trough analysis of milk fat. The objective of this survey was to investigate variations in the milk fatty acid profile, focusing on the content of vaccenic acid (VA), conjugated linoleic acid (CLA) and n-3 fatty acid (FA), of Sarda dairy ewes flocks located at different altitudes throughout Sardinia. Bulk milk samples were collected in spring (April) and in summer (July) from 36 flocks located at different altitudes: 3 flocks in the lowlands (Low), 3 flocks in the hills (Hill) and 3 in the highlands (High) in 4 provinces (Sassari, Nuoro, Oristano and Cagliari) of Sardinia (Italy). Milk fatty acid profile was analyzed by gas-chromatography. Data were analyzed with a linear model with altitude (A), season (S), province (P) and altitude x season as fixed factors. The interaction was never significant. The season influenced significantly almost all fatty acids analyzed. The proportion of short chain FA (C4-C10) decrease (10.0 vs 7.0 mg/100 mg FA; P<0.01) and that of medium chain FA increase (43.2 vs 45.5 mg/100 mg FA; P<0.10) from spring to summer. The long chain FA did not vary between spring and summer but the concentration of oleic acid (C18:1 cis 9) increased significantly from spring to summer (22.3 vs 25.1 mg/100 mg FA; P<0.01). The proportion of n-3 FA was higher in spring than summer (1.2 vs 0.7 for n- 3 FA; P<0.01). The variation in n-3 FA in milk fat was mainly due to the variation in a-linolenic acid (ALA; 18:3n- 3) which decrease from 1.0 to 0.5 mg/100 mg FA from spring to summer. The same pattern was showed by vaccenic acid (VA; trans -11 18:1) that decrease from 1.6 vs 0.8 mg/100 mg FA. No variation in cis 9, trans 11 CLA has been observed between spring and summer (1.0 vs 0.8 mg/100 mg FA). A reduction of PUFA (5.64 vs 5.10; P<0.10), n3/n6 ratio (0.38 vs 0.21) and content of C20:5 n-3 (0.13 vs 0.07 mg/100 mg FA) from spring to summer has been observed. Unexpectedly, the milk FA profile was not affected by altitude, except for C18:1 c9, probably because of the low number of samples analyzed.

Improving the fatty acid profile of dairy cow milk by combining grazing with feeding of total mixed ration

Grazing cows could produce milk with a higher proportion of polyunsaturated fatty acids, which is beneficial to human health, compared with non-grazing cows, though grazing alone could compromise milk production. Under oceanic climate conditions, a study involving 15 dairy cows, fed total mixed ration (TMR) ad libitum in combination with different grazing times of 12 h (TMR12), 6 h (TMR06) and zero grazing time (TMR00) with the aim to evaluate different strategies on the fatty acids profile of milk and milk production. No differences were seen between the treatments with respect to milk yield (34.4+/-6.3 kg/d) or milk protein content (30.4+/-1.8 g/kg). The milk produced by the TMR12 cows had less total fat (36.2 vs. 38.2 g/kg) and saturated fatty acid (FA, 69.39 vs. 71.44 g/100 g FA) than that produced by the TMR00 cows. The concentration of vaccenic acid in the TMR06 and TMR12 milk was twice that of the TMR00 milk (4.22, 4.09 and 2.26 g/100 g FA respectively). Linear increases in conjugated linoleic (CLA) and linolenic acids were observed with increasing grazing time. Pasture was an important source of FA especially C18:3 for TMR06 and TMR12 cows. Under oceanic climatic conditions, the grazing of dairy cows as a complement to feeding with TMR can improve the FA profile of milk and increase its CLA content.

Supplementation with barley or spineless cactus ( Opuntia ficus indica f. inermis) cladodes on digestion, growth and intramuscular fatty acid composition in sheep and goats receiving oaten hay

An 84-day experiment, comprising growth and digestibility trials, was conducted to evaluate the effect of replacing barley with spineless cactus ( Opuntia ficus indica f. inermis) cladodes (cactus) on feed intake, digestion, blood metabolites, growth and meat quality of male lambs and kids consuming oaten hay. The replacement of barley by cactus decreased drinking water intake ( P = 0.002) but had no effect on feed intake, diet digestibility and N balance ( P > 0.05). Irrespective of animal species, the barley diet exhibited higher concentrations of allantoin in urine ( P = 0.005) and therefore a higher microbial N supply ( P = 0.063) than the cactus diet. Average daily gain was greater for the barley than for the cactus diet ( P < 0.05), with a tendency for a greater difference for goats (46 g/day vs. 24 g/day) than for sheep (46 g/day vs. 39 g/day). The replacement of barley with cactus did not produce major differences in meat intramuscular fatty acid composition. Vaccenic acid concentration was significantly affected by treatment, being higher in meat of animals offered the cactus diet compared with the barley diet, while the accumulation of conjugated linoleic acid was not affected by the inclusion of cactus in the diet. Total saturated fatty acids, monounsaturated fatty acids (FA) and polyunsaturated FA were not influenced by supplementation with cactus. Despite the higher level of total n-6 FA in kids’ meat, the n-6/n-3 ratio had a very low value, which is favourable for human health. It is concluded that, in terms of equivalent energy, cactus cladodes could replace barley in the diet of lambs and kids without substantial detrimental effects on digestion, growth and meat quality. Therefore, cactus could be used as a cost-effective feed supplement for sheep and goats on low quality roughages raised in dry areas.

Grazing cows are more efficient than zero-grazed and grass silage-fed cows in milk rumenic acid production

Six rumen-cannulated Holstein cows in early lactation were assigned to 3 treatments: grazing (G), zero-grazing (ZG), and grass silage (GS) harvested from the same perennial rye grass sward in a 3×3 Latin square design with three 21-d periods. The objectives of this study were to investigate the underlying mechanisms for the reported elevation in milk rumenic acid (RA) concentration associated with G compared with ZG and GS, and to identify the important variables contributing to the milk RA response. Grazing animals were offered 20kg of dry matter/cow per day; indoor animals were offered ad libitum grass or silage. A concentrate at a rate of 3kg/d was also offered to all cows. Rumen, plasma, and milk samples were collected in the third week of each period. Data were analyzed by the MIXED procedure of SAS. Dry matter intakes were less for GS with no difference between G and ZG. Milk yield was greater for G than for ZG or GS. Milk fat and protein contents were less for GS with no difference between G and ZG. The combined intake (g/d) of linoleic and linolenic (18:3n-3) acids was different across the treatments (G: 433; ZG: 327; and GS: 164). Rumen pH was less for G with no difference between ZG and GS. Concentrations of volatile fatty acids and ammonia nitrogen in rumens were not different across the treatments. Wet rumen fill was less for G with no difference between ZG and GS. Vaccenic acid concentrations were different across the treatments in rumen (G: 12.30%, ZG: 9.31%, and GS: 4.21%); plasma (G: 2.18%, ZG: 1.47%, and GS: 0.66%) and milk (G: 4.73%, ZG: 3.49%, and GS: 0.99%). Milk RA concentrations were greater for G (2.07%) than for ZG (1.38%) and GS (0.54%). Milk desaturase index based on the ratio cis-9-14:1/14:0 was not different across the treatments. Milk RA yield per 100g of linoleic acid and linolenic acid intake (efficiency) was 2.23, 1.50, and 0.62g in G, ZG, and GS, respectively, suggesting that G cows were more efficient than ZG and GS cows in milk RA production. Stepwise regression analysis of a group of variables revealed that plasma vaccenic acid accounted for 95% of the variation in milk RA production. Milk desaturase index did not enter into the model. Overall findings suggest that substrate intake influenced milk RA production but it was not the only factor involved. There were differences in efficiency of milk RA production, which appears to depend on the factors regulating ruminal vaccenic acid production and its supply to the mammary tissue.

The effect of grazing on the composition of conjugated linoleic acid isomers and other fatty acids of milk and cheese in goats

1. Conjugated linoleic acid and vaccenic acid contents in cheeses: An overview from the literature Mohamed H. Abd El-Salam, Safinaz El-Shibiny Journal of Food Composition and Analysis CrossRef

Composição química e perfil de ácidos graxos do leite e muçarela de búfalas alimentadas com diferentes fontes de lipídeos

Avaliaram-se a composição química e o perfil de ácidos na gordura do leite de búfalas alimentadas com fontes de lipídeos. Foram utilizadas nove búfalas em lactação, multíparas e com produção média diária de leite de 6,5kg. O delineamento experimental foi quadrado latino 3x3, triplo, composto por três tratamentos, três períodos de 21 dias e nove repetições. Os tratamentos foram dietas sem lipídeo adicional, com grão de soja e com óleo de soja. A proporção de silagem de milho variou entre 70 e 75%. A inclusão de óleo de soja elevou os teores de gordura no leite e no queijo tipo muçarela. As concentrações de ácidos graxos saturados (AGS) variaram de 62,8 a 69,8%. Não houve diferenças nos teores de AGS entre os tratamentos sem lipídeo adicional e com grão de soja. O tratamento com óleo de soja resultou em queda de 10% no teor de AGS. As fontes lipídicas reduziram as concentrações de AGS e aumentaram as concentrações de ácidos graxos insaturados. Ácidos graxos encontrados na muçarela, em ordem decrescente, foram: palmítico, oleico, láurico e esteárico. O óleo de soja apresentou maior capacidade de elevar as concentrações do ácido linoleico conjugado (CLA) e do ácido vaccênico no leite e no queijo muçarela.

Metabolic fate of fatty acids involved in ruminal biohydrogenation in sheep fed concentrate or herbage with or without tannins1

A 2 x 2 factorial experiment was carried out to evaluate the effect of herbage or concentrate feeding and dietary tannin supplementation on fatty acid metabolism and composition in sheep ruminal fluid, plasma, and intramuscular fat. Twenty-eight male lambs were divided into 2 equal groups at 45 d of age and kept in individual pens. One group was given exclusively fresh herbage (vetch), and the other group was fed a concentrate-based diet. Within each treatment, one-half of the lambs received supplementation of quebracho powder, providing 4.0% of dietary DM as tannins. Before slaughter, blood samples were collected. The animals were slaughtered at 105 d of age, and ruminal contents and LM were collected. Blood plasma, ruminal fluid, and LM fatty acid composition was determined by gas chromatography. Tannin supplementation reduced (P < 0.05) the concentration of stearic acid (-49%) and increased the concentration of vaccenic acid (+97%) in ruminal fluid from concentrate-fed lambs. Within concentrate- and herbage-based diets, tannin supplementation reduced the accumulation of SFA in blood (P < 0.05) compared with lambs fed the tannin-free diets. When tannins were included in the concentrate, the LM contained 2-fold greater concentrations of rumenic acid compared with the LM of the lambs fed the tannin-free concentrate (0.96 vs. 0.46% of total extracted fatty acids, respectively; P < 0.05). The concentration of PUFA was greater (P < 0.05) and SFA (P < 0.01) less in the LM from lambs fed the tannin-containing diets as compared with the animals receiving the tannin-free diets. These results confirm, in vivo, that tannins reduce ruminal biohydrogenation, as previously reported in vitro. This implies that tannin supplementation could be a useful strategy to increase the rumenic acid and PUFA content and to reduce the SFA in ruminant meats. However, the correct dietary concentration of tannins should be carefully chosen to avoid negative effects on DMI and animal performance.

Effect of weight of slaughter and feeding regimen on conjugated linoleic acid and trans fatty acid content in lamb meat: a meta-analysis approach

A meta-analysis approach was used in order to synthesize findings of six trials comparing 177 individual data of CLA, vaccenic acid (VA) and total trans fatty acids (TFA) of lamb’s meat: “slaughter weight” (0-14kg, 14-18kg, 18-24kg and <24kg), “muscle” (longissimus dorsi, and other muscles); “feeding regimen”: milk (pre-weaned animals fed maternal milk); pasture (weaned grazing animals) and “confined” (weaned animals reared indoor and fed hay and concentrate). The fixed effects included in the model. Results showed that the meat from lambs slaughtered at 14-18kg and from grazing animals maximized the content of CLA and VA and minimized the content of others TFA.

Corn oil or corn grain supplementation to steers grazing endophyte-free tall fescue. II. Effects on subcutaneous fatty acid content and lipogenic gene expression1

Twenty-eight Angus steers (289 kg) were finished on a high-concentrate diet (85% concentrate: 15% roughage; CONC), or endophyte-free tall fescue pastures with corn grain supplement (0.52% of BW; PC), corn oil plus soybean hull supplement (0.10% of BW corn oil plus 0.45% of BW soybean hulls; PO), or no supplement (pasture only; PA). Subcutaneous adipose tissues were processed for total cellular RNA extraction and fatty acid composition by GLC. Relative expression of genes involved in lipogenesis [fatty acid synthase (FASN), acetyl-CoA carboxylase, lipoprotein lipase, stearoyl-CoA desaturase (SCD)] and activators of transcription [(peroxisome proliferator-activated receptor-gamma), C/EBPalpha, sterol regulatory binding protein-1, signal transducer and activator of transcription-5, and Spot-14] was determined by real-time quantitative PCR. Housekeeping gene (glyceraldehyde 3-phosphate dehydrogenase and beta-actin) expression was used in analysis to normalize expression data. Total fatty acid content was greatest (P < 0.001) for CONC and least (P < 0.001) for PA. Supplementation of grazing cattle increased (P < 0.001) total fatty acid content compared with PA, but concentrations were less (P < 0.001) than for CONC. Myristic and palmitic acid contents were greater (P < 0.001) for CONC than for PO and PC, which were greater (P < 0.001) than for PA. Stearic acid content was greater (P < 0.01) for PO than for CONC, PC, and PA. Finishing on CONC increased (P < 0.001) total MUFA content by 68% compared with PA. Corn grain supplementation increased (P < 0.001) MUFA content compared with PA; in contrast, MUFA content did not differ (P > 0.05) between PO and PA. Corn oil supplementation increased (P < 0.001) trans-11 vaccenic acid content in subcutaneous fat by 1.2-, 1.7- and 5.6-fold relative to PA, PC, and CONC, respectively. Concentrations of the cis-9, trans-11 CLA isomer were 54, 58, and 208% greater (P < 0.01) for PO than for PA, PC, and CONC, respectively. Corn grain supplementation to grazing steers did not alter (P > 0.05) the cis-9, trans-11 CLA isomer compared with PA. Oil supplementation increased (P < 0.001) linoleic acid (C18:2) content by 56, 98 and 262% compared with CONC, PC, and PA, respectively. Relative mRNA expression of SCD was upregulated (P < 0.001) by 46-, 18- and 7-fold, respectively, for CONC, PC, and PO compared with PA. Relative FASN mRNA expression was also upregulated (P = 0.004) by 9- and 5-fold, respectively, for CONC and PC compared with PA. Grain feeding, either on CONC or supplemented on pasture, upregulated FASN and SCD mRNA to increase MUFA and de novo fatty acids in subcutaneous adipose tissue. Upregulation of SCD with grain feeding and reduced tissue CLA concentrations suggest that the decreased CLA concentrations were the result of limited substrate (trans-11 vaccenic acid) availability.