Linoleic Acid Content Of Milk Research Articles

Increasing Conjugated Linoleic Acid Content in Milk and Cheese after Supplementing a Blend of Crude Soybean Oil Sediment Combined with Fish Oil to Grazing Dairy Cows

The aim of the work was to improve the healthy value of milk and cheese fatty acids (FA) by feeding a mix of crude soybean oil sediment (CSOS) combined with fish oil (FO) to grazing dairy cows. The CSOS is a by-product commonly discarded after oil extraction containing 3.3% moisture, 6% total ash and 70.7% oil, locally available, comparatively economic and easy to mix with other feed ingredients. The experiment lasted 55 days from September 30th to November 23th 2018 and was carried out at the dairy farm “Gacef” provider of milk to the dairy industrial plant “Capilla Del Se?or” (CDS) located at the Villa María City, Córdoba Province, Argentine. A herd of 80 multiparous Holstein cows producing 24 kg-1 milk·cow-1·day-1 was used. The cows grazed an alfalfa and an oat pasture that represented about 47% of total dry matter (DM) intake supplemented at 8.5 kg DM·cow-1·day-1 with a total mixed ration (TMR) composed (DM basis) by cracked corn grain (35.18%), whole plant corn silage (31.98%), pelletized soyben meal (17.99%), the CSOS supplement (13.85%) and FO (0.99%). The TMR was supplied by halves after each milking time in groupal feeders yielding 1.4 kg·cow-1·day-1 of the CSOS and 0.1 kg·cow-1·day-1 of FO. Before the start of lipid supplementation, milk samples (5) were obtained from the farm-tank representing the standar or reference milk (Ref-Milk). After 21 days of supplementary lipid supply, additional milk samples (5) were obtained representing the modified milk (Mod-Milk). Milk samples were analyzed for chemical composition and milk FA profile. At each time, sufficient quantities of both (Ref- and Mod-Milk) were collected for manufacturing six types of cheeses. The results were analyzed through the Student-T test for independent observations. Oil supplementation did not modify (P > 0.05) the chemical composition of milk. Concentration of butyric acid (C4:0) in milk was not affected (P -1 FA and was decreased to 49.67 g 100 g-1 FA in Mod-Milk (P -1 FA in Ref-Milk to 38.13 g 100 g-1 FA in Mod-Milk (+19.07%) whereas polyunsaturated FA (PUFAs) increased (+36.1%) from 4.71 to 6.41 (P -1 FA) for the total concentration of the potentially atherogenic fraction of milk FA (C12:0 to C16:0). The atherogenic index (AI) also decreased (P trans-11 C18:1) in Mod-Milk averaged 7.77 g 100 g-1 FA which represented a 162 % increase (P -1). Concentration of conjugated linoleic acid (CLA, cis-9, trans-11 C18:2) in Ref-Milk averaged 1.47 g 100 g-1 FA and showed an important increase (P -1 FA, +163%). The omega 6/3 ratio resulted lower (P < 0.012) in the Ref-Milk (2.28) compared to the Mod-Milk (2.83). Milk and cheese FA composition were highly correlated (R2 = 0.99, P < 0.0001). The Mod-Cheeses showed similar results in AI, total concentration of SFAs, MUFAs and PUFAs compared to the milk of origin. Differences in FA composition between the cheeses made with the Ref- and Mod-Milk were equivalent to those described for milks. It is concluded that supplementation with a blend of CSOS supplement and FO was an effective way to improve the healthy value of dairy products by reducing contents of SFAs, atherogenic FAs and the atherogenicity index with a concomitant increase in VA and CLA. Modifications induced in the Mod-Milk were recovered in the Mod-Cheeses. The results obtained may help to reduce saturated fat intake and fight or prevent incidence of non-communicable, cardiovascular and chronic diseases.

Effect of ruminal administration of soy sauce oil on rumen fermentation, milk production and blood parameters in dairy cows.

ObjectiveTo evaluate soy sauce oil (a by-product of making whole soybean soy sauce) as a new dietary lipid source, a large amount of soy sauce oil was administered into the rumen of dairy cows.MethodsFour Holstein dairy cows fitted with rumen cannulae were used in a 56-day experiment. Ruminal administration of soy sauce oil (1 kg/d) was carried out for 42 days from day 8 to day 49 to monitor nutritional, physiological and production responses.ResultsDry matter intake and milk yield were not affected by soy sauce oil administration, whereas 4% fat-corrected milk yield and the percentage of milk fat decreased. Although ruminal concentration of total volatile fatty acids (VFA) and the proportion of individual VFA were partially affected by administration of soy sauce oil, values were within normal ranges, showing no apparent inhibition in rumen fermentation. Administration of soy sauce oil decreased the proportions of milk fatty acids with a carbon chain length of less than 18, and increased the proportions of stearic, oleic, vaccenic and conjugated linoleic acids. Conjugated linoleic acid content in milk became 5.9 to 8.8 times higher with soy sauce oil administration. Blood serum concentrations of non-esterified fatty acid, 3-hydroxybutyric acid, total cholesterol, free cholesterol, esterified cholesterol, triglyceride and phospholipid increased with administration of soy sauce oil, suggesting a higher energy status of the experimental cows.ConclusionThe results suggest that soy sauce oil could be a useful supplement to potentially improve milk functionality without adverse effects on ruminal fermentation and animal health. More detailed analysis is necessary to optimize the supplementation level of this new lipid source in feeding trials.

Conjugated linoleic acid content in milk of Chilean Black Friesian cows under pasture conditions and supplemented with canola seed (Brassica napus) concentrate

At present, there is limited and contradictory information about the effects of the use of canola (Brassica napus) seed as supplement on the contents of conjugated linoleic acid (CLA) in milk of grazing cows. The objective of this study was to evaluate the effect of a dietary supplement with canola seed on the production and composition of milk, and CLA concentration in Chilean Black Friesian cows under pasture conditions. Three experiments were done. Experiment 1: control group was fed 5 kg d-1 of commercial concentrate without canola (0-TC1) and treatment group that was fed 3.75 kg of commercial concentrate plus 1.16 kg of whole canola seed (1.16-TC1). Experiment 2: Control group was fed 8 kg d-1 commercial concentrate without canola (0-TC2) and treatment group that was fed 6.2 kg of commercial concentrate plus 1.2 kg of ground canola seed (1.2-TC2). Experiment 3: control group was fed 6 kg d-1 commercial concentrate without canola (0-TC3) and treatment group was fed 6 kg of commercial concentrate with 20% of whole canola seed (1.2 kg d-1, 1.2-TC3). The duration of each experiment was 60 days. No differences in milk production and quality were observed among the experimental groups in every assay. The CLA isomers trans-10, cis-12 and cis-10, cis-12 were higher than those normally found in the scientific literature. There was no effect of the inclusion of canola seed on total CLA content or the content of cis-9, trans-11, trans-10, cis-12 and cis-10, cis-12 isomers.

Effect of feeding fresh forage and marine algae on the fatty acid composition and oxidation of milk and butter

This study evaluated the effects of feeding fresh forage either as pasture plus a concentrate (PAS) or as a silage-based total mixed ration (TMR), combined with either a ruminally inert lipid supplement high in saturated fatty acids (−) or a ruminally protected microalgae containing 22g of docosahexaenoic acid (DHA)/100g of fatty acids (+) on the fatty acid (FA) composition and oxidation of milk and butter. For the 8 mid-lactation Holstein cows in this study, milk yield was not significantly affected by treatment, averaging 32.3±1.28kg/d. Milk fat content was higher for PAS−, averaging 5.05 compared with 4.10±0.17% for the mean of other treatments, and was significantly depressed with microalgae supplementation (3.97 vs. 4.69±0.17%). The saturated fatty acid level in the milk of cows fed TMR− was significantly higher than that of the other treatments (66.9 vs. 61.2g/100g of FA). The level of monounsaturated FA was lowered by feeding TMR− (27.4 vs. 32.0g/100g of FA), whereas levels of polyunsaturated FA were elevated by feeding PAS+ compared with the mean of the other treatments (6.54 vs. 5.07g/100g of FA). Feeding the rumen-protected microalgae increased the DHA content of milk more than 4-fold (0.06 to 0.26g/100g of FA) with the PAS treatment. The conjugated linoleic acid content of milk was highest for PAS+ compared with the other treatments (4.18 vs. 3.41g/100g of FA). In general, the fatty acid composition of butter followed that of milk. Overall, feeding the TMR supplemented with the rumen-protected microalgae increased the levels of volatile products of oxidation in milk and butter. No effect of forage type or microalgae supplementation was observed on the oxidative stability or antioxidant capacity of milk, although the oxidative stability of butter exposed to UV was reduced with microalgae supplementation, particularly with TMR, as assessed by using the ferric reducing ability of plasma assay.

Conjugated linoleic acid content of milk from buffaloes fed a mustard oil‐based diet

Fifteen Murrah buffaloes were distributed in groups I, II and III. The group I animals were fed with groundnut cake‐based concentrate, group II animals with mustard cake‐based concentrate and group III with 2% of mustard oil added to the group II feed. Conjugated linoleic acid (CLA) estimation in milk was done by using GC. The average total CLA contents (mg/g milk fat) in the three groups were 6.84, 12.12 and 19.50 mg/g of fat respectively. Hence it was concluded that addition of 2% mustard oil resulted in a 185% increase in milk fat total CLA content.

Effects of fat source and dietary sodium bicarbonate plus straw on the conjugated linoleic acid content of milk of dairy cows

The effects of fat source (0.7 kg of fatty acids from extruded soybeans or palmitic acid), of sodium bicarbonate (0.3 kg) plus straw (1 kg) and the interaction of these treatments on the content of conjugated linoleic acid (CLA) in the milk of dairy cows were examined. During nine weeks a group of 10 cows received a ration with palmitic acid and bicarbonate plus straw (ration PAB). During three periods of three weeks a second group of 10 cows received successively a ration with extruded soybeans and bicarbonate plus straw (ration ESB), a ration with palmitic acid without bicarbonate or straw (ration PA), and a ration with extruded soybeans without bicarbonate or straw (ration ES). Rations ES and ESB increased the content of polyunsaturated fatty acids in milk, but decreased milk fat content, compared to rations PAB and PA. Ration ESB led to the greatest milk CLA content, by a synergy between the high amount of dietary fat, and the action of bicarbonate plus straw, favouring trans11 isomers of CLA and C18:1, presumably via a ruminal pH near neutrality. Ration ES favoured trans10 isomers, not desaturated in the mammary gland, so that the milk CLA content was lower than with ration ESB, and resulted in the lowest milk fat content. In conclusion, a ration supplemented with both extruded soybeans and bicarbonate plus straw, was an efficient way to increase the CLA content in the milk of dairy cows.

Conjugated Linoleic Acid (CLA) Content of Milk from Cows Fed Different Diets

Conjugated linoleic acid (CLA) is a naturally occurring fatty acid in foods derived from ruminants. CLA is a term used for a mixture of positional and geometric isomers of linoleic acid that contain conjugated unsaturated double bonds. CLA has been shown to have many properties that are beneficial for human health. Two experiments were conducted at the same time on two groups of midlactating primiparous cows to determine the conjugated linoleic acid content of milk. Experimental diets were fed for 13 months – the first group of animals was offered a maize silage-based diet while the second group was fed a grass hay-based diet. Grass hay based diet supplied a significantly (P<0.01) larger CLA concentration in every controlled month. The CLA content in cows fed a grass hay-based diet varied between 153.85 mg/kg of milk reported in May 2004 and 419.01 mg/kg of milk reported in July 2004. The CLA content in group fed maize silage-based diet varied between 150.58 mg/kg of milk reported in May 2004 and 303.05 mg/kg of milk reported in July 2004. Increasing the CLA concentration in milk can increase the nutritive and therapeutic value of milk and dairy products.

Factors Affecting Conjugated Linoleic Acid Content in Milk and Meat

Conjugated linoleic acid (CLA) has been recently studied mainly because of its potential in protecting against cancer, atherogenesis, and diabetes. Conjugated linoleic acid (CLA) is a collective term for a series of conjugated dienoic positional and geometrical isomers of linoleic acid, which are found in relative abundance in milk and tissue fat of ruminants compared with other foods. The cis-9, trans-11 isomer is the principle dietary form of CLA found in ruminant products and is produced by partial ruminal biohydrogenation of linoleic acid or by endogenous synthesis in the tissues themselves. The CLA content in milk and meat is affected by several factors, such as animal's breed, age, diet, and management factors related to feed supplements affecting the diet. Conjugated linoleic acid in milk or meat has been shown to be a stable compound under normal cooking and storage conditions. Total CLA content in milk or dairy products ranges from 0.34 to 1.07% of total fat. Total CLA content in raw or processed beef ranges from 0.12 to 0.68% of total fat. It is currently estimated that the average adult consumes only one third to one half of the amount of CLA that has been shown to reduce cancer in animal studies. For this reason, increasing the CLA contents of milk and meat has the potential to raise the nutritive and therapeutic values of dairy products and meat.

Effects of dietary sunflower seeds on lactation performance and conjugated linoleic acid content of milk

The conjugated linoleic acid (CLA) concentration in milk and the lactation performance of cows fed either a control (CON) or a sunflower seed [SS; 7% of dietary dry matter (DM)] containing diet were compared in a 12-wk lactation trial, starting from week 3 after calving, with 17 multiparous and 8 primiparous cows. The CON and SS diets were isonitrogenous and provided 4 and 6% crude fat in the total mixed rations and were fed to 13 and 12 cows, respectively. Daily DM intake (DMI ), milk production and weekly body weights were recorded. Milk samples collected weekly at four consecutive milkings were individually analyzed for fat, protein and lactose content, and fatty acid composition. The DMI and milk production of the cows fed t he CON and SS diets were 20.5 ± 0.80 and 20.2 ± 0.80 kg d-1 (P &gt; 0.05) and 38.2 ± 1.71 and 38.2 ± 1.71 kg d-1 (P &gt; 0.05), respectively. No differences due to diet were observed for cow body weight, body condition score, or for content and yield of milk fat, protein and lactose. The CLA cis-9, trans-11 concentration in milk from cows fed the CON and SS diets was 3.9 and 7.9 mg g-1 fatty acids (P &lt; 0.01), respectively. The average CLA cis-9, trans-11 yield in milk from cows fed CON and SS diets was 5.1 ± 0.07 and 10.9 ± 0.07 g d-1, respectively, or 114% greater (P &lt; 0.05) for cows fed the SS diet. The study indicates that sunflower seed inclusion at 7% of dietary DM to dairy cows increases the CLA concentration and yield in milk, without affecting DMI, milk production or composition. Key words: Conjugated linoleic acids, cow, milk, sunflower seed

The fatty acid composition of small and large naturally occurring milk fat globules

AbstractNative milk fat globules of various mean diameters, ranging from d43 = 1.5 to 7.3 μm, were obtained using microfiltration of raw whole milk acquired in winter and spring. After total lipid extraction, fatty acid composition was characterized by methyl and butyl ester analysis using gas chromatography. The oleic and linoleic acid content of milk obtained in winter increased with fat globule size, whereas myristic and palmitic acid decreased. There was significantly more lauric, myristic and palmitoleic acid, and less stearic acid in small fat globules compared to large fat globules in milk obtained in both winter and spring. The relative content of oleic and linoleic acids were found to depend on fat globule size and season. Results are interpreted on the basis of the relative content of milk fat globule membrane depending on fat globule size, and on consequences of compositional variations on milk fat globule melting behavior.

Increase of Conjugated Linoleic Acid Content in Milk by Fermentation with Lactic Acid Bacteria

ABSTRACT: The objectives of this study were to identify the factors and procedures responsible for increasing the conjugated linoleic acid (CLA) content in fermented milk. Fourteen lactic acid bacteria were screened for CLA‐producing ability using sunflower oil (containing 70% linoleic acid) as a substrate. Among the screened strains, Lactococcus lactis I‐01 showed the highest CLA‐producing ability. The optimal concentration of sunflower oil for CLA production was 0.1 g/L in whole milk, which accounted for 0.25% of total milk fat. Our results demonstrated that CLA formation in fermented milk could be affected by numerous factors such as bacterial strain, cell number, optimal substrate concentration, and the period of incubation at neutral pH.

Changes in the conjugated linoleic acid content of milk from dairy cows throughout the year

AbstractConjugated linoleic acid (CLA) is a naturally occurring anticarcinogen found in dairy products which is produced in the rumen as an intermediate in the biohydrogenation of polyunsaturated fatty acids by the bacteria Butyrivibrio fibrivsolvens. An experiment was conducted to examine the changes in CLA concentration in bovine milk throughout the year. 338 milk samples were taken from the University of Nottingham's commercial dairy herd between December 1997 and March 1999. All animals followed the same dietary regime throughout the study. Samples were analysed for fat and CLA content. Morning and evening samples were pooled to calculate daily fat and CLA concentrations and yields. There was a small variation in milk yield (P&lt;0.05) whereas CLA content and yield varied considerably (P&lt;0.001) throughout the year (CLA = 0.91 to 2.81 mg/g of fat). The highest concentrations were found during the summer months when the cows were mainly eating fresh grass as opposed to conserved forages. Fat content and yield followed by the month were the predominant factors affecting CLA output. Results indicate that, if required, CLA in milk could be increased through suitable dietary management practices.

Conjugated linoleic acid content of milk and cheese from cows fed extruded oilseeds.

Extruded oilseeds were fed to 24 dairy cows to study the influence on the conjugated linoleic acid content of milk and cheese. Cows were fed one of three diets that contained forage and grain in a ratio of 47:53. A control diet containing 13.5% soybean meal was compared with diets containing 12% full fat extruded soybeans or 12% full fat extruded cottonseed. The control, extruded soybean, and extruded cottonseed diets contained 2.73, 4.89, and 4.56% fatty acids, respectively. Measurements were made during the last 5 wk of the 8-wk experiment. The DM intakes and 3.5% fat-corrected milk yields were higher for cows fed the extruded soybean and extruded cottonseed diets than for cows fed the control diet. A tendency for lower fat and protein contents in the milk of cows fed the extruded soybean and extruded cottonseed diets was detected. Most of the C18 fatty acids were increased in the milk and cheese when extruded soybeans and cottonseeds were fed. The conjugated linoleic acid content in milk and cheese increased a mean of 109% when full fat extruded soybeans were fed and increased 77% when cottonseeds were fed compared with the conjugated linoleic acid content when the control diet was fed. Processing the milk into cheese did not alter the conjugated linoleic acid content. The conjugated linoleic acid content of milk and cheese can be increased by the inclusion of full fat extruded soybeans and full fat extruded cottonseeds in the diets of dairy cows.

Digestion and metabolism of dietary fat in farm animals.

Fat digestion and metabolism differ widely between animal species. In ruminants, dietary fats are hydrogenated in the rumen before intestinal absorption so that absorbed fatty acids (FA) are more saturated than dietary FA. In non-ruminants, intestinal FA digestibility depends on the level of saturation of dietary FA. Fat supplementation of the diet of cows decreases milk protein and has a variable effect on milk fat, depending on the source of dietary lipids. When encapsulated lipids are used, the linoleic acid content of milk is increased, but the organoleptic quality of milk may be altered. Supplementary lipids are incorporated into non-ruminant body fat, whereas de novo lipogenesis is reduced. There is a close relationship between the nature of dietary FA and nonruminant body FA.