Conjugated linolenic acid (CLnA), conjugated linoleic acid (CLA) and other biohydrogenation intermediates in plasma and milk fat of cows fed raw or extruded linseed

Thirty lactating dairy cows were used in a 333 Latin-square design to investigate the effects of a raw or extruded blend of linseed and wheat bran (70:30) on plasma and milk fatty-acids (FA). Linseed diets, containing 16.6% linseed blend on a dry-matter basis, decreased milk yield and protein percentage. They decreased the proportions of FA with less than 18 carbons in plasma and milk and resulted in cis-9, cis-12, cis-15 18:3 proportions that were more than three and four times higher in plasma and milk, respectively, whereas cis-9, cis-12 18:2 proportions were decreased by 10–15%. The cis-9, trans-11, cis-15 18:3 isomer of conjugated linolenic acid was not detected in the milk of control cows, but was over 0.15% of total FA in the milk fat of linseed-supplemented cows. Similarly, linseed increased plasma and milk proportions of all biohydrogenation (BH) intermediates in plasma and milk, including the main isomer of conjugated linoleic acid cis-9, trans-11 18:2, except trans-4 18:1 and cis-11, trans-15 18:2 in plasma lipids. In milk fat, compared with raw linseed, extruded linseed further reduced 6:0–16:0 even-chain FA, did not significantly affect the proportions of 18:0, cis-9 18:1 and cis-9, cis-12 18:2, tended to increase cis-9, cis-12, cis-15 18:3, and resulted in an additional increase in the proportions of most BH intermediates. It was concluded that linseed addition can improve the proportion of conjugated linoleic and linolenic acids, and that extrusion further increases the proportions of intermediates of ruminal BH in milk fat

Effects of preconditioning and extrusion of linseed on the ruminal biohydrogenation of fatty acids 1. In vivo studies

The extent and intermediates of ruminal biohydrogenation (BH) of fatty acids (FA) from a blend of linseed and wheat bran (70:30) were investigated in the rumen fluid, rumen particle phase and duodenal flow. The blend was ground through a 3 mm screen and used raw or extruded, or was ground through a 6 mm screen and preconditioned. Three dry Holstein cows fitted with ruminal and duodenal cannulas were used in a 3 × 3 Latin square design, with 18 days adaptation. The diet contained 20% (DM basis) of the linseed based blend. Twelve samples taken over 3 days were composited for analysis of rumen fluid, rumen particle phase and duodenal flow. The BH of FA from linseed resulted in the appearance of a great number of C18:1 intermediates, among which trans-10+11 to trans-16C18:1 were the most abundant. The proportion of cis-9,trans-11C18:2 was low. Preconditioning coarsely ground linseed resulted in a lower extent of C18:2 and C18:3 BH, and lower proportions of trans-12 to trans-16C18:1 intermediates than extrusion or a lack of processing of finely ground linseed. On the contrary, extrusion did not affect the extent of BH and had no significant effect on the proportions of trans-C18:1 intermediates, but increased the proportion of cis-9,trans-11C18:2 in both rumen phases. Different digesta types resulted in different estimates of BH. The extent of BH and the proportions of trans-C18:1 intermediates were lower in the rumen particle phase and higher in the rumen fluid than in the duodenum. Moreover, interactions between digesta type and treatment of linseed were observed

Effects of preconditioning and extrusion of linseed on the ruminal biohydrogenation of fatty acids. 2. In vitro and in situ studies

The extent and/or intermediates of ruminal biohydrogenation (BH) of fatty acids (FA) were investigated in vitro and in situ using a raw, pre-conditioned or extruded blend of linseed and wheat bran (70:30). The duration of in vitro incubations were 2, 4, 8, 16 and 24 h, with 5 replicates. In situ studies used 3 dry ruminally fistulated Holstein cows in a 3 × 3 Latin square design, with 3 weeks adaptation to the linseed form. The diet contained 20% (DM basis) of the linseed based blend. The duration of in situ incubations were 2, 4, 8, 16, 24 and 48 h. BH was much slower in situ than in vitro, resulting in a much lower effective disappearance of C18:2 and C18:3. Moreover, the in situ technique suggested that the technological pre-treatment of linseed did not affect C18:2 and C18:3 rate of BH, whereas reduced rates were observed in vitro. After 8 h of in vitro incubation and onwards, proportions of cis-9,trans-11C18:2 were the highest with extruded linseed. The BH of FA from linseed resulted in the appearance of great proportions of trans-10+11 to trans-16C18:1 intermediates. Extrusion increased the proportions of trans-10+11C18:1 both in vitro and in situ and proportions or trans-C18:1 were higher in situ than in vitro. Compared to previous in vivo results with the same material, the in situ method provided poor estimates of BH rates and intermediates

Cis-15 intermediates of biohydrogenation in the duodenal flow of cows receiving linseed

Duodenal samples from a previous experiment (Akraim et al., 2006) were reanalysed for determination of cis-15 intermediates of ruminal biohydrogenation (BH). Three dry Holstein cows fitted with a duodenal cannula received a diet with 14% (dry matter basis) raw linseed. C18 fatty acids (C18FA) represented 6.3% of dietary dry matter, and contained 57.8% of C18:3. After 18 days adaptation, on each cow, twelve samples of duodenal flow were taken over 3 days, composited, and analysed for FA composition. Cis-9,trans-11,cis-15C18:3 and trans-11,cis-15C18:2 (CLnA) were identified by GC-MS. The proportion of CLnA was low, in spite of the high C18:3 intake. The first step of C18:3 BH, isomerisation to CLnA, was extensive because the C18:3 proportion was 13.5 times lower in the duodenum than in the diet (Akraim et al., 2006). The extensive C18:3 BH and the low proportion of CLnA suggest a rapid ruminal reduction of this FA. The proportion of the product of this first reduction, trans-11,cis-15C18:2, was much higher than that of CLnA, but quite variable among cows. This suggests that the reduction of this FA was slower than that of CLnA, although this reduction is supposed to be due to a broad range of bacteria. According to responsible bacteria, this reduction can lead to trans-11C18:1, or cis-15C18:1 and trans-15C18:1. Cis-15C18:1 represented only half the proportion of trans-15C18:1, suggesting either a direct BH of trans-11,cis-15C18:2 to trans-15C18:1, or a rapid isomerisation of cis-15C18:1 to trans-15C18:1

Effet du traitement thermique des graines de lin sur la biohydrogénation ruminale des acides gras polyinsaturés et la qualité de la matière grasse du lait de vache

La biohydrogénation (BH) des acides gras de graines de lin crues, conditionnées ou extrudées a été étudiée in vitro, in situ et dans les contenus ruminal et duodénal. La BH des acides gras polyinsaturés a surtout produit comme intermédiaires 9,11,15C18:3, trans-11, cis-15C18:1, et trans-11 à trans-16C18:1. Le conditionnement a ralenti la BH de C18:3 et l'extrusion a augmenté les proportions d'intermédiaires. Les résultats in vitro étaient proches de ceux obtenus sur le flux duodénal mais la BH était lente in situ avec une accumulation importante d'intermédiaires. La BH était faible dans la phase solide du contenu ruminal et élevée dans la phase liquide. L'ingestion de 2,8 kg de graines de lin crues ou extrudées par des vaches a diminué la production de lait sans modifier les taux butyreux et protéique, a diminué la teneur du lait en C6:0-C16:0 et le rapport oméga-6/oméga-3, et a augmenté les proportions de trans-C18:1, cis-9, trans-11C18:2, trans-11, cis-15C18:2, 9,11,15C18:3 et C18:3. ABSTRACT : Biohydrogenation (BH) of raw, conditioned or extruded linseed fatty acids was investigated in vitro, in situ, and in ruminal and duodenal contents. The BH of polyunsaturated fatty acids mainly resulted in the following intermediates : 9,11,15C18:3, trans-11, cis-15C18:1, and trans-11 to trans-16C18:1. Conditioning slowed down the BH of C18:3 and extrusion increased proportions of BH intermediates. In vitro results were close to that from duodenal flow but the BH rate was lower in situ with an important accumulation of intermediates. The BH was low in the rumen solid phase and high in the rumen fluid. Intake of 2,8 kg of raw or extruded linseed decreased cow milk production without modifying fat or protein percents, decreased milk content of C:0-C16:0 and omega -6/omega-3 ratio, and increased the proportions of trans-C18:1, cis-9, trans-11C18:2, trans-11, cis-15C18:2, 9,11,15C18:3 et C18:3

IN VITRO PROBAVLJIVOST SUHE TVARI LIŠĆA RETAMA RAETAM I DJELOVANJE DODAVANJA NEKIH AROMATIČNIH BILJAKA NA SUPSTRAT INKUBACIJE

This study was conducted to investigate the digestibility of Retama raetam leaves and the effect of the addition of Rosmarinus officinalis or Salvia officinalis to the incubation media. R. raetam samples (0.5 g control) or (0.4 g of R. raetam + 0.1 g of R. officinalis or S. officinalis dried leaves) were incubated with sheep rumen liquid for 12 hours and 24 hours. In vitro dry matter digestibility of R. raetam leaves was 39.10% and 42.39% after 12h and 24h of incubation with rumen fluid respec¬tively. The addition of aromatic plants did not affect the in Vitro dry matter digest¬ibility of R. raetam leaves (p<0.05).Cilj ovog rada bio je istražiti probavljivost lišća Retama raetam i djelovanje dodavanja Rosmarinus officinalis i Salvia officinalis u supstrat inkubacije. Uzorci R. raetam (0,5 g kontrola) ili (0,4 g R. raetam + 0,1 g suhog lišća R. officinalis ili S. officinalis) inkubirani su s tekućinom iz buraga ovce 12 sati i 24 sata. In vitro probavljivost suhe tvari lišća R. raetam bila je 38,10% i 42,39% nakon 12 i 24 sata inkubacije s tekućinom iz buraga ovce. Dodavanje aromatičnog bilja nije djelovalo na in vitro probavljivost suhe tvari lišća R.raetam (p< 0,05)

DJELOVANJE DODAVANJA ATRIPLEX HALIMUSA SA SALVIOM OFFICINALIS ILI ROSMARINUSOM OFFICINALIS NA IN VITRO PROBAVLJIVOST SUHE TVARI

A study was conducted to investigate the effect of supplementation of Atriplex halimus with dried powders of aromatic plants on its in vitro dry matter digestibility. 400± 5 mg of dried Atriplex samples were incubated for 12 or 24 hours with buffered rumen liquor from sheep and supplemented with 100 mg of either Salvia officinalis or Rosmarinus officinalis. The result of this study demonstrated that the in vitro dry matter digestibility of A. halimus was 48.4% and 58.9% after the incubation for 12 or 24 hr respectively. Supplementation of this stuff with S. officinalis resulted in a significant reduc¬tion (P < 0.05) in vitro DMD (44.7 and 51.6%). The same trend was observed with the addition of R. officinalis to the A. halimus samples (44.8 and 532%). It would therefore appear that, the supplements used in the current study may have a negative effect on the in vitro dry matter digestibility of A. halimus.Istraživanje je provedeno radi proučavanja djelovanja dodavanja Atriplex halimusa sa suhim prahom aromatičnog bilja na in vitro probavljivost suhe tvari. 400+- 5 mg uzoraka suhog Atriplexa inkubirano je 12 ili 24 sata s puferiranom tekućinom iz buraga ovce i nadopunjeno sa 100 mg Salvie officinalis ili Rosmarinusa officinalis. Rezultati ovog istraživanja pokazali su da je in vitro probavljivost suhe tvari A. halimus bila 48,4% odnosno 58,9% nakon inkubiranja 12 odnosno 24 sata. Rezultat dodavanja S. officinalis bilo je znatno smanjenje (P<0.05) in vitro DMD-a (44,7 i 51,6%) Isti je trend primijećen dodavanjem R. officinalis uzorcima A. halimusa (44,8 i 53,2 %). Prema tome, izgleda da dodaci upotrijebljeni u ovom istraživanju mogu negativno djelovati na in vitro probavljivost suhe tvari A. halimusa

Starch and oil in the donor cow diet and starch in substrate differently affect the in vitro ruminal biohydrogenation of linoleic and linolenic acids

Trans isomers of fatty acids exhibit different health properties. Among them, trans-10,cis-12 conjugated linoleic acid has negative effects on milk fat production and can affect human health. A shift from the trans-11 to the trans-10 pathway of biohydrogenation (BH) can occur in the rumen of dairy cows receiving high-concentrate diets, especially when the diet is supplemented with highly unsaturated fat sources. The differences of BH patterns between linoleic acid (LeA) and linolenic acid (LnA) in such ruminal conditions remain unknown; thus, the aim of this work was to investigate in vitro the effects of starch and sunflower oil in the diet of the donor cows and starch level in the incubates on the BH patterns and efficiencies of LeA and LnA. The design was a 4 × 4 Latin square design with 4 cows, 4 periods, and 4 diets with combinations of 21 or 34% starch and 0 or 5% sunflower oil. The rumen content of each cow during each period was incubated with 4 substrates, combining 2 starch levels and either LeA or LnA addition. Capillary electrophoresis single-strand conformation polymorphism of incubates showed that dietary starch decreased the diversity of the bacterial community and the high-starch plus oil diet modified its structure. High-starch diets poorly affected isomerization and first reduction of LeA and LnA, but decreased the efficiencies of trans-11,cis-15-C18:2 and trans C18:1 reduction. Dietary sunflower oil increased the efficiency of LeA isomerization but decreased the efficiency of trans C18:1 reduction. An interaction between dietary starch and dietary oil resulted in the highest trans-10 isomers production in incubates when the donor cow received the high-starch plus oil diet. The partition between trans-10 and trans-11 isomers was also affected by an interaction between starch level and the fatty acid added to the incubates, showing that the trans-10 shift only occurred with LeA, whereas LnA was mainly hydrogenated via the more usual trans-11 pathway, whatever the starch level in the substrate, although the bacterial communities were not different between LeA and LnA incubates. In LeA incubates, trans-10 isomer production was significantly related to the structure of the bacterial community

DJELOVANJE SUHIH LISTOVA ROSMARINUS OFFICINALIS I SALVIA OFFICINALIS NA IN VITRO PROBAVLJIVOST SUHE TVARI SLAME JEČMA

The study was conducted to evaluate the effect of the addition of Rosmarinus officinalis or Salvia officinalis dried leaves on the in vitro dry matter digestibility of barley straw. Barley straw samples (0.5 g control) or (0.4 g of barley straw + 0.1 g of R. officinalis or S. officinalis dried leaves) were incubated with sheep rumen liquid for 12 hours and 24 hours. Dry matter digestibility of barley straw was 21.7% after 12 hours and 43.62% after 24 hours of incubation without additives. The addition of the aromatic plants did not affect the dry matter digestibility of barley straw after 12 hours of incubation (P>0.05). Dry matter digestibility of barley straw was reduced with the addition of the aromatic plants after 24 hours of incubation; the inhibition was significant with R. officinalis (P>0.05). The addition of R. officinalis or S. officinalis dried leaves inhibits the dry matter digestibility of barley straw in vitro.Istraživanje je provedeno radi procjene djelovanja dodatka suhih listova biljaka Rusmarinus officinalis ili Salvia officinalis na in vitro probavljivost suhe tvari slame ječma. Uzorci slame ječma (0,5 g kontrola) ili (0,4 g slame ječma + 0,1 g suhih listova R. officinalis ili S. officinalis) inkubirani su s tekućinom iz buraga ovce 12 i 24 sata. Probavljivost suhe tvari slame ječma bila je 21,7% nakon 12 sati i 43,62% nakon 24 sata inkubacije bez dodataka. Dodatak aromatičnih biljaka nije djelovao na probavljivost suhe tvari slame ječma nakon 12 sati inkubacije (p>0,05). Probavljivost suhe tvari slame ječma smanjena je dodatkom aromatičnog bilja nakon 24 sata inkubacije; smanjenje je bilo značajno s R.officinalis (0,005). Dodatak suhih listova R.officinalis ili S.officinalis koči in vitro probavljivost suhe tvari slame ječma