Pros and cons of the supplementation with oilseed enriched concentrates on milk fatty acid profile of dairy sheep grazing Mediterranean pastures (original) (raw)
Related papers
Journal of Dairy Research, 2013
An effective strategy for enhancing the bioactive fatty acids (FA) in sheep milk could be dietary supplementation with a moderate level of a combination of soybean oil with fish oil (SFO) without negative effects on milk yield and its chemical composition. Thus, the objective of this study was to determine the effects of a moderate forage diet supplementation with SFO on milk chemical composition and FA profile, as well as on plasma FA. Twelve dairy sheep were assigned to two homogenous sub-groups. Treatments involved a control diet without added oil, and a diet supplemented with 23·6 g soybean oil and 4·7 g fish oil per kg dry matter (DM) of the total ration. The results showed that SFO diet had no effect on milk yield and chemical composition. In blood plasma the concentrations of trans-11 C 18:2 (VA), C 18:2n-6 , C 20:5n-3 (EPA) and C 22:6n-3 (DHA) were significantly higher while those of C 14:0, C 16:0 and C 18:0 were lower in sheep fed with SFO diet compared with control. The SFO supplementation of sheep diet increased the concentrations of VA, cis-9, trans-11 C 18:2 CLA, trans-10, cis-12, C 18:2 CLA, EPA, DHA, monounsaturated FA (MUFA), polyusaturated fatty acids (PUFA) and n-3 FA and decreased those of short chain FA (SCFA), medium chain FA (MCFA), the saturated/unsaturated ratio and the atherogenicity index value in milk compared with the control. In conclussion, the SFO supplementation at the above levels in a sheep diet, with moderate forage to concentrate ratio, improved the milk FA profile from human health standpoint without negative effects on its chemical composition.
Revista de Chimie
This research was conducted to study fatty acids composition, especially content of n-3 FA; c9,t11-CLA (rumenic acid) and t11-C18:1 (vaccenic acid) and health lipid indices of milk according to the feeding practices in sheep. The exeperimental diets consisted of: P - pasture without any diet supplementation, PC - pasture + standard concentrate (500 g/d), PCs - pasture + fat-enriched concentrate (camelina seed-based concentrate: 500 g/d). Camelina seeds (Cs - Camelina sativa L) were used to increase the beneficial FA concentration in milk fat. PC diet as compared to P diet increases daily milk yield and the content of milk fat, but it adversely affects the quality of milk fats. Fat in the milk of PC ewes had a higher content of hypercholesterolemic FA, while the polyunsaturated FA (PUFA) concentration decreased (p [ 0.001). The use Cs in the concentrate mixture (PCs diet) increased by more than double the c9,t11-CLA, C20:5n-3 (EPA), C22:6n-3 (DHA), C18:3n-3 (ALA) and t11-C18:1 (VA) (...
Effect of part-time grazing and alfalfa hay supplementation on fatty acid content of sheep's milk
2011
Part-time grazing is a traditional flock management method in th e Basque Country region of Northern Spain which starts in late winter or early spring according to we ather conditions. Pasture feeding is supple- mented indoors with forage (alfalfa and conserved forages) and concentrate to meet milk production require- ments. The objective of this study was to evaluate the effect of actual grazing time on the amount of individual fatty acids in the milk obtained. The experiment was conducted during 4 weeks from late April until mid-May. Sheep were separated into 4 homogeneous groups of 12 sheep e ach, and randomly assigned to 3 different
The Influence of Oil Addition on the Fatty Acid Composition of Sheep's Milk During Lactation
Agriculture and Forestry, 2023
The aim of this study was to determine the impact of plant sources of fat in food for sheep on the fatty acid composition of milk samples obtained from 210 sheep (herd of pure Pramenka and a herd of crossbred sheep) in the area of the Una Sana Canton. The studies were conducted in three periods: winter, spring and summer, and the herd is divided into experimental and control groups of sheep. Extruded flax seed has been added to nutrition in experimental group of sheep in every period of research in the amount of 3.5%. The total content of saturated fatty acids was the highest during the summer with the experimental group (70.75%), which plant sources of fat were added to. The most common saturated fatty acids in the analyzed samples of milk were: palmitic, myristic, stearic and lauric, whose values varied depending on the treatment of nutrition and research period. The differences found in the content of saturated fatty acids between the period of investigation of milk sample of experimental and the control group showed statistically very highly significant effect (p<0.001). The content of unsaturated fatty acids was the highest during the summer in the control group of sheep (32.00%). Of monounsaturated fatty acids mostly consisted of oleic during the summer period (25.60%) in the milk of the control group. Of polyunsaturated fatty acids, linoleic acid (3.6%) in the milk of control and α-linolenic (1.90%) of milk experimental group of sheep were the most prevalent in the winter. The lowest ratio of omega-6/omega-3 fatty acids in sheep's milk was achieved in the period of feeding sheep with old grass (July), 1.46% in the milk of the experimental group of sheep that were fed with concentrates in which omega-3 preparations were added.
Journal of dairy …, 2010
Ruminant diet supplementation with sunflower oil (SO) and fish oil (FO) has been reported as a good strategy for enhancing some milk fat compounds such as conjugated linoleic acid (CLA) and n-3 polyunsaturated fatty acids in dairy cows, but no information is available regarding dairy sheep. In this work, ewe diet was supplemented with FO, alone or in combination with SO, with the aim of improving milk nutritional value and evaluating its effect on animal performance. Sixty-four Assaf ewes in mid lactation, fed a highconcentrate diet, were distributed in 8 lots of 8 animals each and assigned to 4 treatments (2 lots/treatment): no lipid supplementation (control) or supplementation with 20 g of SO/kg (SO), 10 g of FO/kg (FO), or 20 g of SO plus 10 g of FO/kg (SOFO). Milk production and composition, including a complete fatty acid profile, were analyzed on d 0, 3, 7, 14, 21, and 28 of treatments. Supplementation with FO tended to reduce dry matter intake compared with the control treatment (−15%), and its use in combination with SO (SOFO) resulted in a significant decrease in milk yield as well (−13%). All lipid supplements reduced milk protein content, and FO also reduced milk fat content by up to 21% alone (FO) and 27% in combination with SO (SOFO). Although the mechanisms involved in FO-induced milk fat depression are not yet well established, the observed increase in some milk trans-FA that are putative inhibitors of milk fat synthesis, such as trans-9,cis-11 CLA, and the 63% decrease in C18:0 (consistent with the theory of reduced milk fat fluidity) may be involved. When compared with the control, lipid supplementation remarkably improved the milk content of rumenic acid (cis-9,trans-11 CLA; up to 4-fold increases with SO and SOFO diets), whereas FO-containing diets also increased milk n-3 polyunsaturated fatty acids, mainly docosahexaenoic acid (with mean contents of 0.29 and 0.38% of total fatty acids for SOFO and FO, respective-ly), and reduced the n-6:n-3 FA ratio to approximately half the control value. All lipid supplements resulted in high levels of some trans-FA, mainly trans-11 C18:1 (vaccenic acid) but also trans-10 C18:1.
Journal of dairy science, 2011
The study tested the hypothesis that certain underused forages and agro-industrial byproducts available in dry areas may positively influence fatty acid (FA) composition and antioxidative properties of milk by their contents of residual oil or phenolic compounds or both. Sixty multiparous fat-tailed Awassi ewes were allocated to 6 groups in a completely randomized block design. During 50 d, the ewes were group-fed 2.5 kg of dry matter/d per ewe 1 of 6 isonitrogenous and isoenergetic diets (forage:concentrate, 0.3:0.7). The test feeds, comprising 30% of the diets, replaced either barley straw [lentil straw, olive leaves, and Atriplex (saltbush) leaves, rich in phenolic compounds or electrolytes] or conventional concentrate ingredients (olive cake and tomato pomace; ∼10% lipids) from the control diet. The diets containing olive cake and tomato pomace were rich in oleic acid (18:1 cis-9; 27% of total dietary FA) and linoleic acid (18:2 cis-9,cis-12; 37%), respectively. Profiles of FA w...
Journal of dairy science, 2010
In an attempt to develop strategies for enhancing the nutritional value of sheep milk fat, dairy ewe diet was supplemented with 3 incremental levels of marine algae (MA), in combination with sunflower oil, to evaluate the effects of these marine lipids on milk fatty acid (FA) profile and animal performance. Fifty Assaf ewes in mid lactation were distributed in 10 lots of 5 animals each and allocated to 5 treatments (2 lots per treatment): no lipid supplementation (control) or supplementation with 25 g of sunflower oil/kg of DM plus 0 (SO), 8 (SOMA(1)), 16 (SOMA(2)), or 24 (SOMA(3)) g of MA (56.7% ether extract)/kg of DM. Milk production and composition, including FA profile, were analyzed on d 0, 3, 7, 14, 21, and 28 of treatment. Neither intake nor milk yield were significantly affected by lipid addition, but all MA supplements decreased milk fat content from d 14 onward, reaching a 30% reduction after 28 d on SOMA(3). This milk fat depression might be related not only to the joint...
Animal Research, 2005
The objective of this study was to observe the effect of supplementation with vegetable oils (VO) on the fatty acid profiles and conjugated linoleic acid (CLA) content of milk fat. Twelve dairy cows in mid lactation fed on pasture were blocked by body weight, milk production and days in lactation and randomly allocated from blocks to 3 treatments repeated in a Latin square design with periods of 28 day duration. The treatments were as follows: cows on pasture supplemented with 5 kg concentrate per head per day (C), supplemented with 4.5 kg concentrate + 0.5 kg sunflower oil per head per day (SFO) and supplemented with 4.5 kg concentrate + 0.5 kg soybean oil per head per day (SBO). The animals were grazed as a group and were stocked at 2.5 heads per hectare. The treatments had no effect on milk yield or protein yield and content, but decreased milk fat yield and content (P < 0.05). Milk fat from the cows supplemented with VO had a lower concentration of short and medium chain fatty acids (P < 0.05) and a higher concentration of long chain fatty acids (P < 0.05). The addition of VO to the diet also resulted in a reduction in saturated and an increase in unsaturated fatty acids of milk fat (P < 0.05). The hypercholesterolemic fatty acids in milk fat (i.e. C12:0, C14:0 and C16:0) decreased while the concentration of oleic and linoleic acids increased with VO (P < 0.05). There was no effect on linolenic acid. Finally, the inclusion of VO in the diet increased (P < 0.05) the contents in milk fat of the various cis/trans isomers of oleic acid (including trans-vacenic, TVA) and of CLA which increased by 61%.
Journal of Dairy Science, 2011
The effect of supplementing a basal diet with 1 of 3 plant oils on productive efficiency and milk fatty acid composition was studied in dairy goats. Sixteen Malagueña goats were used in a 4 × 4 Latin square experiment with 21-d periods and 4 goats per treatment. The basal diet comprised 30% alfalfa hay and 70% pelleted concentrate. Experimental treatments were control (basal diet without added oil) and the basal diet supplemented with 48 g/d of high oleic sunflower oil (HOSFO), regular sunflower oil (RSFO), or linseed oil (LO). Dry matter intake and body weight were not affected by treatments. Milk production was higher in HOSFO treatment and milk fat content was higher in RSFO and LO treatments, although no differences in milk energy production or milk renneting properties were found. The RSFO and LO treatments increased the proportion of vaccenic acid in milk fat more so than the HOSFO diet, and rumenic acid followed the same pattern. The content of trans10-18:1 remained low in all experimental diets (<0.7% of total fatty acid methyl esters) although HOSFO and RSFO diets increased it. The variations in the fatty acid profiles observed with the 4 diets, mainly the unsaturated fatty acid isomer contents, are extensively discussed. Compared with that in the control diet, the n-6:n-3 fatty acid ratio in milk fat substantially decreased with the LO, increased with RSFO, and did not change with HOSFO. The addition of moderate amounts of LO to the diets of dairy goats has favorable effects on milk fatty acid composition from the point of view of the human consumer, without negative effects on animal performance. 1 Control = diet with no added oil; HOSFO, RSFO, and LO = diets enriched with 48 g/d of high oleic sunflower oil, regular sunflower oil, or linseed oil, respectively. 2 Basal diet supplied 4.8, 0.7, 5.5, 14.2, and 3.0 g/d of 16:0, 18:0, cis-9-18:1, 18:2n-6, and 18:3n-3, respectively, calculated according to INRA (2002). 3 Composition (g/kg, as fed): maize, 375; barley, 374.9; soybean meal, 200; vitamin and mineral premix (Maxi