Effects of sunflower oil infusions of Asparagopsis taxiformis on in vitro ruminal methane production and biohydrogenation of polyunsaturated fatty acids.

Asparagopsis taxiformis inhibits ruminal methane (CH4) production due to its bromoform (CHBr3) content. The immersion of A. taxiformis in edible vegetable oils allows the extraction and stabilization of the highly volatile CHBr3 in the oil phase. The objectives of this study were to explore the effects of adding sunflower oils with increasing concentrations of CHBr3 on in vitro ruminal methanogenesis and biohydrogenation. Five batches of 48-h in vitro incubations were performed in 14 fermentation bottles, using rumen inocula collected shortly after the slaughter of young crossbred bulls and 1 g of dry matter (DM) from a total diet of mixed feed without added oil (control) or with 60 µL of sunflower oil per gram of DM as the substrate. The treatments were the CHBr3 content in the oil added: 0 µg (B0), 25 µg (B25), 50 µg (B50), 75 µg (B75), 100 µg (B100), and 150 µg (B150) of CHBr3 per gram of substrate DM. Organic matter (OM) degradability, total gas, CH4, volatile fatty acids (VFA), long-chain fatty acids, and dimethyl acetals (DMA) were analyzed at the end of each incubation. Data were analyzed with a model considering the treatments as the fixed effect and the run as a random block and using orthogonal contrasts. Degradability of OM was higher in the control group and was unaffected by CHBr3 concentration. Total gas production per gram of degraded OM was unaffected by treatments and averaged 205 ± 29.8 mL/g. Methane (mL) production decreased linearly with increasing CHBr3 concentrations, with 33%, 47%, and 87% reductions for B75, B100, and B150, respectively. Total VFA concentration was unaffected by oil inclusion but was reduced by 20% in CHBr3-containing treatments, although without any dose-response pattern. The molar percentage of acetate decreased linearly, whereas propionate and butyrate increased linearly with the increasing CHBr3 dosage. Including oil in the diet decreased the branched-chain fatty acids and DMA content. Increasing CHBr3 concentrations did not affect branched-chain fatty acids, but linearly increased most of the identified DMA. Adding oil to the control diet increased the 18:2n-6, whereas increasing the concentration of CHBr3 had no effect on 18:2n-6 but decreased linearly the 18:0 and increased the trans-18:1 isomers. The results obtained provide evidence that oil immersions of A. taxiformis can successfully inhibit ruminal production of CH4 in vitro at doses of 100 and 150 µg/g DM, and simultaneously modulate biohydrogenation.

Nannochloropsis oceanica microalga feeding increases long-chain omega-3 polyunsaturated fatty acids in lamb meat.

To test the hypothesis that lambs fed freeze-dried Nannochloropsis oceanica (NO) biomass will have a higher deposition of EPA in tissues than those fed other Nannochloropsis EPA-sources, we fed 28 lambs with one of four diets: i) C, control, without EPA; ii) O, with 1.2% Nannochloropsis oil; iii) SD, with 12.3% spray-dried NO biomass; iv) FD, with 9.2% freeze-dried NO biomass. Dry matter intake, growth, tissues fatty acid composition, oxidative stability and sensory traits of the resultant meat were evaluated. The EPA was highest in tissues of lambs fed SD and FD compared with O but was similar between SD and FD. Total trans-18:1 did not differ among treatments, but the t10/t11-18:1 ratio decreased with all EPA containing diets. EPA diets were also supplemented with Vitamin E preventing the lipid oxidation in EPA-enriched meat and the meat sensory traits were not affected although occasionally some off-flavours were detected in FD meat.

Evaluation of the effects of different diets on microbiome diversity and fatty acid composition of rumen liquor in dairy goat.

Fat supplementation plays an important role in defining milk fatty acids (FA) composition of ruminant products. The use of sources rich in linoleic and α-linolenic acid favors the accumulation of conjugated linoleic acids isomers, increasing the healthy properties of milk. Ruminal microbiota plays a pivotal role in defining milk FA composition, and its profile is affected by diet composition. The aim of this study was to investigate the responses of rumen FA production and microbial structure to hemp or linseed supplementation in diets of dairy goats. Ruminal microbiota composition was determined by 16S amplicon sequencing, whereas FA composition was obtained by gas-chromatography technique. In all, 18 pluriparous Alpine goats fed the same pre-treatment diet for 40±7 days were, then, arranged to three dietary treatments consisting of control, linseed and hemp seeds supplemented diets. Independently from sampling time and diets, bacterial community of ruminal fluid was dominated by Bacteroidetes (about 61.2%) and Firmicutes (24.2%) with a high abundance of Prevotellaceae (41.0%) and Veillonellaceae (9.4%) and a low presence of Ruminococcaceae (5.0%) and Lachnospiraceae (4.3%). Linseed supplementation affected ruminal bacteria population, with a significant reduction of biodiversity; in particular, relative abundance of Prevotella was reduced (-12.0%), whereas that of Succinivibrio and Fibrobacter was increased (+50.0% and +75.0%, respectively). No statistically significant differences were found among the average relative abundance of archaeal genera between each dietary group. Moreover, the addition of linseed and hemp seed induced significant changes in FA concentration in the rumen, as a consequence of shift from C18 : 2n-6 to C18 : 3n-3 biohydrogenation pathway. Furthermore, dimethylacetal composition was affected by fat supplementation, as consequence of ruminal bacteria population modification. Finally, the association study between the rumen FA profile and the bacterial microbiome revealed that Fibrobacteriaceae is the bacterial family showing the highest and significant correlation with FA involved in the biohydrogenation pathway of C18 : 3n-3.

Effects of dietary inclusion of citrus pulp and rockrose soft stems and leaves on lamb meat quality and fatty acid composition.

Meat from lambs finished with high-starch diets often contains low concentration of vaccenic (t11-18:1) and rumenic (c9,t11-18:2) acids and high concentration of t10-18:1. We hypothesized that replacing cereals by dehydrated citrus pulp (DCP) and the inclusion of tanniferous feed sources in oil supplemented diets might reduce the accumulation of t10-18:1 and increase the t11-18:1 and c9,t11-18:2 in lamb meat, without affecting the productive performance. In total, 32 lambs were assigned to four diets which combine two factors: basal diet (BD) (cereals v. DCP) and Cistus ladanifer (CL) (0 v. 150 g/kg dry matter). Feed intake, average daily weight gain and carcass traits were not affected by treatments, except for dressing percentage that was reduced with DCP (P=0.046). Both DCP and C. ladanifer reduced tenderness and juiciness of meat, and C. ladanifer also reduced (P0.05) by diets. However, DCP increased the proportions of odd-chain FA (P=0.005) and several minor biohydrogenation (BH) intermediates in meat lipids. C. ladanifer had few effects on meat FA profile. The proportions of t11-18:1 and c9,t11-18:2 were high in all diets (5.4% and 1.5% of total FA, respectively) and were not influenced by the treatments. Basal diet and CL showed some significant interactions concerning FA composition of intramuscular fat. In diets without C. ladanifer, replacement of cereals by DCP increased the 18:0 (P<0.05) and decreased t10,c12-18:2 (P<0.05), t10-18:1 (P<0.10) and t10-/t11-18:1 ratio (P<0.10) with a large reduction of the individual variation for t10-18:1 and of t10-/t11-18:1 ratio. Combined with cereals, C. ladanifer increased 18:0 and reduced the BH intermediates in meat. Replacement of cereals by DCP seems to promote a more predictable FA profile in lamb meat, reducing the risk of t10-shifted BH pathways in the rumen.

The reduction of starch in finishing diets supplemented with oil does not prevent the accumulation of trans-10 18:1 in lamb meat.

The experiment was conducted to test the hypothesis that the replacement of cereal with low-starch feed ingredients in lambs' finishing diets supplemented with oils could prevent the accumulation of -10-18:1 in meat. Forty lambs were fed 1 of 4 diets supplemented with soybean oil (5.9%) and fish oil (1%) for 6 wk before slaughter. The control (CON) diet contained 43% barley, and in the other diets, barley was completely replaced by dehydrated citrus pulp (DCP), dehydrated sugar beet pulp (DBP), or soybean hulls (SH). Growth performance, feed intake, and carcass and meat quality traits were analyzed. At slaughter, LM samples were collected for gene expression evaluation, and 3 d after slaughter, LM and subcutaneous (s.c.) fat samples were collected for fatty acid analysis. None of the diets affected meat quality, but the DCP diet reduced ADG ( < 0.05) and the DCP and SH diets decreased the feed-to-gain ratio ( < 0.01). The DCP diet increased ( < 0.05) the risk of parakeratosis and the severity of the lesions. Moreover, the DBP treatment led to increased a* (redness) and b* (yellowness) in s.c. fat compared with the CON treatment ( < 0.05). The lipid content of LM did not differ ( > 0.05) with treatment and averaged 34.4 g/kg of meat. Diets had no effect ( > 0.05) on SFA, PUFA, and -MUFA sums and on the -6:-3 ratio in both LM and s.c. fat. A lower expression of fatty acid synthase (FASN) was found with the DCP treatment than with the other treatments ( < 0.001). All treatments showed a high accumulation of -10-18:1, averaging 91 mg/g fatty acid in LM and 147 mg/g fatty acid in s.c. fat. The concentration of -11-18:1 in the tissues was considerably lower than that of -10-18:1, and thus the -10-18:1:-11-18:1 ratio was above 3 with all treatments. Despite this, the SH diet clearly promoted a larger deposition of -11-18:1 and -9,-11-18:2 in tissues compared with the other treatments. () gene expression and SCD activity index in LM were reduced with the SH diet compared with the CON and DCP diets. Overall, these results clearly showed, for the first time, that low-starch/high-NDF diets are not able to prevent the establishment of -10 shifted rumen biohydrogenation pathways, evaluated by the deposition of biohydrogenation intermediates in lamb meat and fat.

Effect of feeding lambs with a tanniferous shrub (rockrose) and a vegetable oil blend on fatty acid composition of meat lipids.

The effects of feeding Cistus ladanifer (Cistus) and a blend of soybean and linseed oil (1 : 2 vol/vol) on fatty acid (FA) composition of lamb meat lipids and messenger RNA (mRNA) expression of desaturase enzymes was assessed. In total, 54 male lambs were randomly assigned to 18 pens and to nine diets, resulting from the combination of three inclusion levels of Cistus (50 v. 100 v. 200 g/kg of dry matter (DM)) and three inclusion levels of oil (0 v. 40 v. 80 g/kg of DM). The forage-to-concentrate ratio of the diets was 1 : 1. Longissimus muscle lipids were extracted, fractionated into neutral (NL) and polar lipid (PL) and FA methyl esters obtained and analyzed by GLC. The expression of genes encoding Δ5, Δ6 and Δ9 desaturases (fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2) and stearoyl CoA desaturase (SCD)) was determined. Intramuscular fat, NL and PL contents were not affected by oil or Cistus. Oil supplementation reduced (P<0.05) 16:0, c9-16:1, 17:0, c9-17:1 and c9-18:1 FA and increased (P<0.05) 18:2n-6, 18:3n-3 and the majority of biohydrogenation intermediates in NL. Cistus alone had few effects on FA of NL but interacted with oil (P<0.05) by increasing t10-18:1,t10,t12-18:2,t10,c12-18:2 and t7,c9-18:2. The t10-/t11-18:1 ratio increased with both Cistus and oil levels. The c9, t11-18:2 did not increase (P<0.05) with both oil and Cistus dietary inclusion. Oil reduced c9-16:1, 17:0, c9-17:1,c9-18:1, 20:4n-6, 22:4n-6 and 20:3n-9 proportions in PL, and increased 18:2n-6, 18:3n-3, 20:3n-3 and of most of the biohydrogenation intermediates. The Cistus had only minor effects on FA composition of PL. Cistus resulted in a reduction (P<0.05) of 20:5n-3 and 22:6n-3 in the meat PL. The expression level of SCD mRNA increased (P=0.015) with Cistus level, although a linear relationship with condensed tannins intake (P=0.11) could not be established. FADS1 mRNA expressed levels increased linearly (P=0.019) with condensed tannins intake. In summary, the inclusion of Cistus and oil in 1 : 1 forage-to-concentrate ratio diets resulted in a large increase in t10-18:1 and no increase in c9,t11-18:2 or n-3 long chain poor in polyunsaturated fatty acids in lamb meat.

Growth performance, carcass and meat quality of lambs supplemented with increasing levels of a tanniferous bush (Cistus ladanifer L.) and vegetable oils.

The effects of dietary inclusion of Cistus ladanifer L. (CL) and a vegetable oil blend were evaluated on growth performance,carcass and meat quality of fifty four lambs that were assigned to 9 diets, corresponding to 3 levels of CL(50, 100 and 200 g/kg DM) and 3 levels of oil inclusion (0, 40 and 80 g/kg DM). Treatments had no effects on growth rate. Oil depressed dry matter intake (P = 0.017), carcass muscle (P = 0.041) and increased (P = 0.016) kidney knob channel fat. Chemical and physical meat quality traits were not affected by treatments. Off-flavour perception was higher for 8% of oil (P b 0.001). The level of 100 g/kg DM of CL inclusion improved meat stability after 7 days of storage. Supplementation with linseed and soybean oils (2:1) was a good approach to improve meat nutritional value from feedlot lambs, increasing total n-3 PUFA.

Effect of reduced dietary protein and supplementation with a docosahexaenoic acid product on broiler performance and meat quality.

1. Chicken breast meat is a lean meat due to its low content of intramuscular fat (IMF) resulting in an overall lower acceptability by consumers due to a decrease in juiciness, flavour and increased chewiness. Recently, studies performed in pigs suggested the possibility of increasing IMF by decreasing dietary crude protein (CP) content, an effect possibly mediated through an increased lipogenesis. 2. Dietary supplementation with lipids rich in omega 3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) may modulate an increase in the content of these fatty acids in meat from monogastric animals and, thus, promote the daily intake of n-3 LC-PUFA by humans. 3. LC-PUFA are very susceptible to oxidation, resulting in off-flavours that affect meat quality and consumers' acceptability. 4. This trial was conducted to assess the effect of reducing dietary CP, from 21% to 17%, on chicken's meat IMF content and, simultaneously, to evaluate if a complementary supplementation with a proprietary n-3 LC-PUFA source (DHA Gold™) could improve meat quality. These effects were assessed by measuring productive performance and meat quality, oxidative stability, sensory traits and fatty acid profile. 5. A reduction in CP content of broiler diets, from 21% to 17%, balanced for lysine, improved performance while it was not sufficient to increase IMF content in chicken meat. In contrast, DHA Gold™ supplementation had a positive impact both in broiler productive parameters and in meat fatty acid profile. 6. In addition, incorporation of 7.4% of DHA Gold™ in the diet promoted carcass yield but negatively affected chicken meat acceptability by consumers, due to a decrease of meat oxidative stability. 7. Overall the data suggest that neither a dietary supplementation with DHA Gold™ nor a reduction in CP have a direct positive effect in the levels of IMF present in broiler meat.

Effect of corn supplementation of grass finishing of Holstein bulls on fatty acid composition of meat lipids.

Finishing Holstein young bulls exclusively on pasture generally results in very lean carcass and meat, but corn supplementation is expected to simultaneously improve carcass traits and intramuscular lipids (IML). The expected increase in IML would allow for a larger 18:2c9,t11 (CLA) deposition in meat without affecting the n-3 PUFA present in LM phospholipids (PL). Holstein bulls (n = 33) with initial BW of 423 ± 52.4 kg reared exclusively on pasture were assigned to 1 of 3 finishing period (85 d) diets: finished exclusively on pasture (P0) or finished on pasture and individually supplemented with 4 (P4) or 8 kg/d (P8) of ground corn. Final BW (546 ± 56.3 kg) was not affected (P > 0.05) by corn supplementation, but ADG increased (P < 0.01) with the increasing corn supplementation level from 1.23 kg/d for P0 to 1.44 kg/d for P4 and to 1.67 kg/d for P8. Subcutaneous fat depth in P0 bulls was 0.8 mm and increased (P < 0.001) in both P4 (2.9 mm) and P8 (2.7 mm) bulls, but no difference (P = 0.73) was observed between P4 and P8 bulls. Similarly, the IML increased with corn supplementation, from 1.84 g/100 g muscle in P0 to 2.96 in P4 and to 3.24 in P8, but no difference (P = 0.55) was found between P4 and P8 bulls. Corn supplementation decreased (P < 0.01) 18:1t11 in neutral lipids (NL) but not 18:2c9,t11 (P > 0.34). The 18:1t10 (mg/g total NL fatty acid [FA] ± SEM) were 2.5 ± 0.13 in P0, 5.5 ± 1.68 in P4, and 14.8 ± 3.18 in P8 bulls, being greater in P8 compared with P4 (P = 0.02). Total FA in muscle PL and SFA were unaffected, but increasing corn supplementation resulted (P < 0.001) in an increase of 18:2n-6 in PL by replacement of mostly the 18:1c9 and 18:3n-3. Notably, the total number of cis double bonds present in FA of PL remained constant (P = 0.74) with corn supplementation. Compared with P0, corn supplementation maintained (P > 0.05) the high n-3 PUFA content in meat (mg/100 g meat) and increased the 18:2c9,t11 (P = 0.028) and 18:1c9 (P < 0.001). However, increasing corn supplementation from 4 to 8 kg/d increased the 18:1t10 (P = 0.031) and had no effect on 18:2c9,t11. Therefore, supplementing grass-finished Holstein bulls with moderate amounts of ground corn (4 kg/d) increased carcass fat cover and IML, maintained n-3 PUFA, and increased 18:2c9,t11 content in meat, whereas greater corn supplementation (8 kg/d; P8) resulted in no further improvements.

Fatty acid composition of porcine cumulus oocyte complexes (COC) during maturation: effect of the lipid modulators trans-10, cis-12 conjugated linoleic acid (t10,c12 CLA) and forskolin.

The effect of maturation and of two lipid modulators supplementation along in vitro maturation (IVM) on fatty acid (FA) and dimethylacetal (DMA) composition of porcine cumulus oocyte complexes (COC) were studied. Abattoir-derived immature COC were analyzed for FA and DMA or submitted to IVM as follows: control group; t10,c12 CLA group, t10,c12 CLA supplementation for 44 h; Forskolin group, forskolin supplementation during the initial 2 h; t10,c12 CLA + forskolin group, t10,c12 CLA for 44 h and forskolin for just 2h. Each experimental group had five replicates. FA analysis of oocytes, cumulus cells (CC), follicular fluid, and culture media were performed by gas-liquid chromatography. Oocytes and their CC had different FA composition. Oocytes were richer in saturated FA (SFA) preferentially maintaining their FA profile during maturation. Mature CC had the highest polyunsaturated FA (PUFA) content. Five individual and total SFA, and monounsaturated FA (MUFA), notably oleic acid (c9-18:1), percentages were lower (P ≤ 0.023) in mature than in immature CC. t10,c12 CLA was accumulated by COC from t10,c12 CLA and t10,c12 CLA + forskolin groups, mostly in CC where MUFA and an eicosatrienoic isomer decreased (P ≤ 0.043). Nevertheless, PUFA or FA and DMA total content were not affected. Arachidonic acid was reduced in t10,c12 CLA + forskolin CC and hexadecanal-DMA-16:0 in t10,c12 CLA CC. Forskolin alone increased (P ≤ 0.043) c9-18:1 in oocytes. In conclusion, maturation process clearly changed porcine COC FA and DMA profiles, mostly of CC, also more susceptible to modifications induced by t10,c12 CLA. This possibility of manipulating COC lipid composition during IVM could be used to improve oocyte quality/cryopreservation efficiency.

Heterosis for meat quality and fatty acid profiles in crosses among Bos indicus and Bos taurus finished on pasture or grain.

Physicochemical properties and fatty acid profiles of meat from Bos indicus, Bos taurus and crossbred B. taurus×B. indicus bullocks (n=216), finished on pasture or grain, were used to estimate the effects of heterosis. Meat quality and fatty acid profiles generally benefited with crossbreeding, but the advantages from heterosis differed among finishing systems. The Warner-Bratzler shear-force in fresh and aged meat was reduced due to heterosis in pasture-finishing, but the effect was minor under grain-finishing. With pasture-finishing, heterosis caused an increase of 5% in CLA concentration, but few other changes in fatty acid profiles. In grain-finishing, heterosis caused a reduction in intramuscular fat and cholesterol, increased amounts of PUFA, n-6 fatty acids and PUFA/SFA ratio, and a decline in atherogenic index. The Δ(9) desaturase estimated activity in crossbreds showed a behavior close to B. indicus, suggesting the existence of few loci and a dominance genetic effect on enzymes involved in fatty acid synthesis and metabolism.

Direct supplementation of diet is the most efficient way of enriching broiler meat with n-3 long-chain polyunsaturated fatty acids.

1. Concentrations of beneficial omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) in poultry meat can be improved by increasing the concentration of n-3 PUFA in poultry diets. 2. A decrease in flavour quality is, however, usually associated with the dietary supplementation with n-3 PUFA, which is due to the susceptibility of PUFA to oxidation. 3. This experiment was conducted to study the effects of introducing two different n-3 fatty acid sources (extruded linseed and DHA Gold™, a proprietary algal product rich in docosahexaenoic acid), either separately or together, on broiler productive performance, and meat quality, oxidative stability, sensory traits and LC-PUFA profile. 4. Birds given the algal product displayed better productive performances than animals from other groups. 5. The data revealed an improvement in the fatty acid nutritional value of meat from birds receiving the algal product and an inefficient conversion of α-linolenic acid (LNA) into LC-PUFA. 6. Metabolisation of LNA in vivo is not sufficient to improve meat quality in n-3 LC-PUFA and direct supplementation of the diet with n-3 LC-PUFA is a better alternative to modulate an increase in beneficial fatty acids of broiler meat. 7. The overall acceptability of meat was negatively affected by the dietary supplementation with 7.4% of DHA, in contrast to the supplementation with 3.7% of DHA, which showed to be efficient in improving LC-PUFA meat content without affecting its sensory properties.

Identification of C18 intermediates formed during stearidonic acid biohydrogenation by rumen microorganisms in vitro.

In vitro batch incubations were used to study the rumen biohydrogenation of unsaturated fatty acids. An earlier study using increasing supplementation levels of stearidonic acid (18:4n-3), revealed that the rumen microbial population extensively biohydrogenates 18:4n-3 after 72 h of in vitro incubation, though several intermediates formed were not completely characterized. Therefore, in the present study, samples were reanalyzed in order to identify the 18:2, 18:3 and 18:4 biohydrogenation intermediates of 18:4n-3. Gas-liquid chromatography coupled to mass spectrometry was used to characterize these intermediates. The acetonitrile chemical ionization mass spectrometry of the fatty acid methyl esters derivatives enabled the discrimination of fatty acids as non-conjugated or conjugated biohydrogenation intermediates. In addition, the acetonitrile covalent adduct chemical ionization tandem mass spectrometry yielded prominent ions indicative of the double bond position of the major 18:3 isomers, i.e. Δ5,11,15 18:3. Furthermore, the 4,4-dimethyloxazoline derivatives prepared from the fatty acid methyl esters enabled the structure of novel 18:2, 18:3 and 18:4 biohydrogenation intermediates to be elucidated. The intermediates accumulated in the fermentation media after 72 h of incubation of 18:4n-3 suggest that similar to the biohydrogenation pathways of linoleic (18:2n-6) and α-linolenic (18:3n-3) acids, the pathway of the 18:4n-3 also proceeds with the formation of conjugated fatty acids followed by hydrogenation, although no conjugated dienes were found. The formation of the novel biohydrogenation intermediates of 18:4n-3 seems to follow an uncommon isomerization pattern with distinct double bond migrations.

Effect of trans-10 cis-12 conjugated linoleic acid on bovine oocyte competence and fatty acid composition.

The reproductive performance of dairy cows may be improved by feeding conjugated linoleic acid (CLA) supplements during early lactation. The mechanism of action of t10,c12 CLA is not clearly known. Our objective was to investigate the effect of t10,c12 CLA on oocyte maturation and lipid composition of cumulus oocyte complexes (COC). The developmental potential of oocytes incubated in in vitro maturation (IVM) medium supplemented with t10,c12 CLA to the blastocyst stage and embryo quality were also assessed. In experiment 1, abattoir-derived oocytes were matured in TCM199 + 10% serum supplemented with 100 µM t10,c12 CLA (t10,c12 CLA n = 672) or without it (control n = 672). Mature oocytes were either stained for chromatin configuration or inseminated and cultured for embryo development assessment. In experiment 2, COC and IVM culture media were subjected to fatty acid (FA) analysis prior and after maturation with t10,c12 CLA or without it (control). Total lipids and FA profiles in oocytes, cumulus cells and culture media were determined by gas chromatography. t10,c12 CLA supplementation to IVM medium improved (p = 0.05) embryo quality evaluated morphologically. This effect was associated with t10,c12 CLA presence (3.1 ± 0.7%, p = 0.04) and lower levels of arachidonic acid in FA profile of t10,c12 CLA mature oocytes (immature oocytes = 4.4 ± 1.9%, t10,c12 CLA mature oocytes = 1.0 ± 0.7%, p = 0.05). Differences in myristic and eicotrienoic acids, saturated and unsaturated FA concentrations between oocytes and cumulus cells were detected (p ≤ 0.05). In conclusion, the presence of t10,c12 CLA during maturation interfered on lipid metabolism improving bovine oocyte competence to develop into higher quality embryos.

Genotype x environment interactions for fatty acid profiles in Bos indicus and Bos taurus finished on pasture or grain.

A study was conducted to characterize lipid profiles in the M. longissimus thoracis of commercial Brazilian beef and to assess how those profiles are influenced by finishing system, genetic group, and their interaction. Intramuscular fat (IMF) and fatty acid (FA) profiles were determined in 160 bulls of the Bos taurus (n = 75) and Bos indicus (n = 85) genetic groups, finished on pasture (n = 46) or with grain supplementation (n = 114) and slaughtered in a commercial abattoir. Finishing system had a major impact on the deposition of IMF, as well as on the concentration of SFA, PUFA, and their ratio, but genetic groups showed important differences in the ability to convert SFA into cis-9 MUFA and to convert 16:0 into 18:0. When compared with pasture-finished animals, those finished with grain had greater content of IMF and SFA (P < 0.01), similar amounts of MUFA (P > 0.05), and about one-half the amount of PUFA (P < 0.01). Except for MUFA, differences in FA profiles among finishing systems were mostly mediated through their effect on IMF, even though the relationship of IMF with groups of FA differed among finishing systems. Under grain finishing, B. taurus had less SFA and greater MUFA than B. indicus (P < 0.01), but no differences were observed in PUFA (P > 0.05). With pasture-finishing, no differences were observed among the 2 genetic groups in SFA and MUFA (P > 0.05), but PUFA were decreased in B. taurus (P < 0.01). When genetic groups were compared in grain-finishing, B. taurus had a decreased ability for elongation and B. indicus had a decreased aptitude for desaturation of FA. On the other hand, with pasture-finishing a greater deposition of intermediate FA from ruminal biohydrogenation was observed in B. indicus than in B. taurus. Overall, FA profiles were affected more by finishing system in B. indicus than in B. taurus.

Rumen biohydrogenation-derived fatty acids in milk fat from grazing dairy cows supplemented with rapeseed, sunflower, or linseed oils.

The effects of supplementation with rapeseed, sunflower, and linseed oils (0.5 kg/d; good sources of oleic, linoleic, and linolenic acids, respectively) on milk responses and milk fat fatty acid (FA) profile, with special emphasis on rumen-derived biohydrogenation intermediates (BI), were evaluated in a replicated 4 x 4 Latin square study using 16 grazing dairy cows. The dietary treatments were 1) control diet: 20-h access to grazing pasture supplemented with 5 kg/d of corn-based concentrate mixture (96% corn; CC); 2) RO diet: 20-h access to grazing supplemented with 4.5 kg/d of CC and 0.5 kg of rapeseed oil; 3) SO diet: 20-h access to grazing supplemented with 4.5 kg/d of CC and 0.5 kg of sunflower oil; and 4) LO diet: 20-h access to grazing supplemented with 4.5 kg/d of CC and 0.5 kg of linseed oil. Milk fatty acids were converted to methyl esters and analyzed by gas-liquid chromatography and silver-ion HPLC. Dietary treatments had no effect on milk production or on milk protein content and milk protein production. Supplementation with rapeseed and sunflower oils lowered milk fat content and milk fat production, but linseed oil had no effect. Inclusion of dietary vegetable oils promoted lower concentrations of short-chain (including 4:0) and medium-chain FA (including odd- and branched-chain FA) and 18:3n-3, and higher concentrations of C(18) FA (including stearic and oleic acids). The BI concentration was higher with the dietary inclusion of vegetable oils, although the magnitude of the concentration and its pattern differed between oils. The RO treatment resulted in moderate increases in BI, including trans 18:1 isomers and 18:2 trans-7,cis-9, but failed to increase 18:1 trans-11 and 18:2 cis-9,trans-11. Sunflower oil supplementation resulted in the highest concentrations of the 18:1 trans-10, 18:1 cis-12, and 18:2 trans-10,trans-12 isomers. Concentrations of 18:1 trans-11 and 18:2 cis-9,trans-11 were higher than with the control and RO treatments but were similar to the LO treatment. Concentration of BI in milk fat was maximal with LO, having the highest concentrations of some 18:1 isomers (i.e., trans-13/14, trans-15, cis-15, cis-16), most of the nonconjugated 18:2 isomers (i.e., trans-11,trans-15, trans-11,cis-15, cis-9,cis-15, and cis-12,cis-15), and conjugated 18:2 isomers (i.e., trans-11,cis-13, cis-12,trans-14, trans-11,trans-13, trans-12,trans-14, and trans-9,trans-11), and all conjugated 18:3 isomers. The LO treatment induced the highest amount and diversity of BI without decreasing milk fat concentration, as the RO and SO treatments had, suggesting that the BI associated with 18:3n-3 intake may not be the major contributors to inhibition of mammary milk fat synthesis.

Effects of grass silage and soybean meal supplementation on milk production and milk fatty acid profiles of grazing dairy cows.

The effects of supplementation with grass silage and replacement of some corn in the concentrate with soybean meal (SBM) on milk production, and milk fatty acid (FA) profiles were evaluated in a replicated 4 x 4 Latin square study using 16 dairy cows grazing pasture composed of ryegrass, Kentucky bluegrass, and white clover. Each experimental period lasted for 3 wk. The 4 dietary treatments were PC, 20 h of access to grazing pasture, supplemented with 6 kg/d of corn-based concentrate mixture (96% corn; C); PCSB, 20 h of access to grazing pasture, supplemented with 6 kg/d of corn- and SBM-based concentrate mixture (78% corn and 18% SBM; CSB); SC, 7 h of access to grazing pasture during the day and 13 h of ad libitum access to grass silage at night, supplemented with 6 kg/d of C concentrate; and SCSB, 7 h of access to grazing pasture during the day and 13 h of ad libitum access to grass silage at night, supplemented with 6 kg/d of CSB concentrate. The concentrate mixtures were offered twice each day in the milking parlor and were consumed completely. Grass silage supplementation reduced dietary crude protein and concentration of total sugars, and dietary SBM inclusion increased dietary crude protein concentration and decreased dietary starch concentration. Milk yield and energy-corrected milk were increased by SBM supplementation of cows with access to grass silage. Milk protein concentration was lower in cows offered grass silage, regardless of whether SBM was fed. Dietary SBM inclusion tended to increase milk fat concentration. Plasma urea N was reduced by silage feeding and increased by SBM supplementation. Supplementation with grass silage overnight could represent a useful strategy for periods of lower pasture availability. Dietary inclusion of SBM in solely grazing cows had no effects on milk production and composition, exacerbated the inefficient capture of dietary N, and increased diet cost. Grass silage supplementation affected milk FA profiles, increasing both the FA derived from de novo synthesis and those derived from rumen microbial biomass, and decreasing the sum of C18 FA (mostly derived from diet or from mobilization of adipose tissue reserves). Milk fat concentrations of conjugated linoleic acid cis-9, trans-11, vaccenic acid (18:1 trans-11), and linolenic acid (18:3n-3) were unaffected by grass silage supplementation, suggesting that partial replacement of pasture by unwilted grass silage does not compromise the dietary quality of milk fat for humans.

Influence of pasture intake on the fatty acid composition, and cholesterol, tocopherols, and tocotrienols content in meat from free-range broilers.

Over the last centuries, Western diets acquired a dramatic imbalance in the ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA) with a concomitant reduction in the dietary proportion of n-3 PUFA. Pastures are a good source of n-3 fatty acids, although the effect of forage intake in the fatty acid profile of meat from free-range chicken remains to be evaluated. In addition, it is unknown if consumer interest in specialty poultry products derived from free-range or organic production systems is accompanied by a greater nutritional quality of these products. In this study, broilers of the RedBro Cou Nu x RedBro M genotype were fed on a cereal-based diet in portable floorless pens located either on subterranean clover (Trifolium subterraneum) or white clover (Trifolium repens) pastures. Control birds were maintained at the same site in identical pens but had no access to pasture. The capacity of ingested forage to modulate broiler meat fatty acid profiles and the meat content of total cholesterol, tocopherols, and tocotrienols was investigated in broiler chicks slaughtered at d 56. The results suggested that pasture intake (<5% DM) had a low impact on the fatty acid and vitamin E homologue profiles of meat from free-range broilers. However, breast meat from birds with free access to pasture presented lower levels of the n-6 and n-3 fatty acid precursors linoleic acid (18:2n-6) and alpha-linolenic acid (18:3n-3), respectively. In spring the levels of eicosapentaenoic acid (20:5n-3) in breast meat were significantly greater in birds consuming pastures, which suggests greater conversion of alpha-linolenic acid into eicosapentaenoic acid in these birds. Finally, when compared with meat from slower-growing genotypes obtained under the conventional European free-range production systems with slaughtering at d 81, meat from birds of the Ross genotype raised intensively and slaughtered at d 35 seemed to have greater nutritional quality.