Conjugated Linoleic Acid In Milk Research Articles

Lithium Chloride Promotes Endogenous Synthesis of CLA in Bovine Mammary Epithelial Cells.

Although conjugated linoleic acid (CLA) can promote human health, its content in milk is insufficient to have a significant impact. The majority of the CLA in milk is produced endogenously by the mammary gland. However, research on improving its content through nutrient-induced endogenous synthesis is relatively scarce. Previous research found that the key enzyme, stearoyl-CoA desaturase (SCD) for the synthesis of CLA, can be expressed more actively in bovine mammary epithelial cells (MAC-T) when lithium chloride (LiCl) is present. This study investigated whether LiCl can encourage CLA synthesis in MAC-T cells. The results showed that LiCl effectively increased SCD and proteasome α5 subunit (PSMA5) protein expression in MAC-T cells as well as the content of CLA and its endogenous synthesis index. LiCl enhanced the expression of proliferator-activated receptor-γ (PPARγ), sterol regulatory element-binding protein 1 (SREBP1), and its downstream enzymes acetyl CoA carboxylase (ACC), fatty acid synthase (FASN), lipoprotein lipase (LPL), and Perilipin 2 (PLIN2). The addition of LiCl significantly enhanced p-GSK-3β, β-catenin, p-β-catenin protein expression, hypoxia-inducible factor-1α (HIF-1α), and downregulation factor genes for mRNA expression (P < 0.05). These findings highlight that LiCl can increase the expression of SCD and PSMA5 by activating the transcription of HIF-1α, Wnt/β-catenin, and the SREBP1 signaling pathways to promote the conversion of trans-vaccenic acid (TVA) to the endogenous synthesis of CLA. This data suggests that the exogenous addition of nutrients can increase CLA content in milk through pertinent signaling pathways.

Production of conjugated fatty acids in probiotic-fermented walnut milk with the addition of lipase

Walnut milk is rich in linoleic acid (LA) and linolenic acid (LNA) in the form of triglycerides. Four LAB strains capable of converting LA and LNA could grow to 9.0 lg CFU/mL in walnut milk. However, no conjugated fatty acids were detected. Lipase was added to release LA and LNA and then LAB was inoculated to ferment walnut milk. However, conjugated linoleic acid (CLA) and conjugated linolenic acid (CLNA) were only detected in walnut milk inoculated with Bifidobacterium breve CCFM683. When 60 U/mL lipase was added, the total amount of conjugated fatty acids reached 1.33 ± 0.01 mg/mL with conversion rates of 5.0% and 11.3% for CLA and CLNA, respectively. By monitoring the fermentation progress, the amount of conjugated fatty acids could reach a maximum of 2.30 ± 0.01 mg/mL at 20 h (p < 0.05). When 20 U/mL lipase was added, the amount of conjugated fatty acids in fermented walnut milk reached 1.58 mg/mL and conversion rates increased to 7.2% and 21.6% for CLA and CLNA, respectively. Thus, adding lipase can realize the conversion of CLA and CLNA in walnut milk and reducing the amount of lipase and hydrolysis time is beneficial to improve the conversion rates, but total amount is reduced.

Producing natural functional and low-carbon milk by regulating the diet of the cattle-The fatty acid associated rumen fermentation, biohydrogenation, and microorganism response.

Conjugated linoleic acid (CLA) has drawn significant attention in the last two decades for its various potent beneficial effects on human health, such as anticarcinogenic and antidiabetic properties. CLA could be generally found in ruminant products, such as milk. The amount of CLA in ruminant products mainly depends on the diet of the animals. In general, the fat content in the ruminant diet is low, and dietary fat supplementation can be provided to improve rumen activity and the fatty acid (FA) profile of meat and milk. Especially, dietary 18-carbon polyunsaturated FA (C18 PUFA), the dominant fat source for ruminants, can modify the milk FA profile and other components by regulating the ruminal microbial ecosystem. In particular, it can improve the CLA in milk, intensify the competition for metabolic hydrogen for propionate producing pathways and decrease methane formation in the rumen. Therefore, lipid supplementation appears to be a promising strategy to naturally increase the additional nutritional value of milk and contribute to lower methane emissions. Meanwhile, it is equally important to reveal the effects of dietary fat supplementation on rumen fermentation, biohydrogenation (BH) process, feed digestion, and microorganisms. Moreover, several bacterial species and strains have been considered to be affected by C18 PUFA or being involved in the process of lipolysis, BH, CLA, or methane emissions. However, no review so far has thoroughly summarized the effects of C18 PUFA supplementation on milk CLA concentration and methane emission from dairy cows and meanwhile taken into consideration the processes such as the microorganisms, digestibility, rumen fermentation, and BH of dairy cattle. Therefore, this review aims to provide an overview of existing knowledge of how dietary fat affects rumen microbiota and several metabolic processes, such as fermentation and BH, and therefore contributes to functional and low-carbon milk production.

Relationship between the Composition of Lipids in Forages and the Concentration of Conjugated Linoleic Acid in Cow's Milk: A Review.

Simple SummaryConjugated linoleic acid (CLA) has been shown to have protective effects against various common diseases, such as obesity and cancer, improving human health. For several years, efforts have been made to increase CLA levels in milk by including sources of fats and oilseeds in the diets of lactating cows, causing a decrease in the amount of fat in the milk itself and a decrease in the yield of the products derived from it. A “safe” and economical way to increase CLA content without affecting fat content, is through grazing feeding since the content of CLA precursors (linoleic and α-linolenic acids) are present in greater quantity in pastures compared to feeding only balanced diets. The content of these precursors will depend on factors, such as age and nitrogen fertilization, since the high availability of nitrogen stimulates the synthesis of metabolic components, such as leaf protein. The bibliographic review shows how the inclusion of different forages and the agronomic management of pastures promote the improvement of CLA levels in milk, giving “an added value”.Conjugated linoleic acid (CLA), has been shown to have protective effects against various diseases, such as obesity, arteriosclerosis, diabetes, chronic inflammatory diseases, and cancer. This fatty acid in ruminants results from two processes, biohydrogenation, which takes place in the rumen, and de novo synthesis, carried out in the mammary gland, and it has linoleic and α-linolenic acids as its precursors. The amounts of precursors in the diets of animals are related to the amounts of CLA in milk. In the literature review, it was found that the milk of cows fed fresh forage has a higher amount of CLA because they have a higher amount of linoleic acid and α-linolenic acid compared to other foods used in the diets of cows. The amount of CLA precursors in pastures can be increased through agronomic practices, such as nitrogen fertilization, and regrowth age. It is also a technique used to increase the amount of CLA in milk to obtain a greater benefit regarding its nutritional value.

Identification of feeding pattern and their impact on milk fatty acid profiles from traditional dairy cows in Pangalengan Sub-district

Fatty acids (FA) profiles especially conjugated linoleic acid (CLA) are commonly used to distinguish milk quality. However, its content is very sensitive and tends to change with a different type of feed. The study aims to identify the relationship between the feeding system and milk FA profile in the Pangalengan sub-district. The feeding system and milk FA profiles were studied using two-step post observatory research. Step one, milk was collected from 27 traditional-dairy farms using purposive random sampling and compare with a large-scale farm. The result shows that FA profiles vary greatly among traditional-farms especially for long-chain FA (LCFA) which was found in small concentrations. CLA content was also found higher in traditional-farms. Step two, five traditional-farms with the highest CLA milk content were observed for their feeding systems. Parameter observed including cow’s specification, feed type used, and feed intake. The best ration produced high milk CLA and production was the ration consisted of 38 % high-quality forages and 62 % commercial concentrate. Thus, it can be concluded that milk from traditional farms was better than milk from large-scale farms. The best milk CLA was produced with a combination of 38 % high-quality forages and 62 % commercial concentrate.

The use of bacterial cultures to increase the content of conjugated linoleic acid in milk and dairy products

The bioactive properties of conjugated linoleic acid (CLA) are associated with human health promotion processes, including anticarcinogenic, antiatherogenic, antiinflammatory and antidiabetic activity, and the ability to reduce body fat. The functional properties of the bioactive component of the fat phase of cow’s milk, called conjugated linoleic acid (CLA), are described in this article. The content of conjugated linoleic acid in raw milk was studied using the capillary gas chromatography (GC) method. The content of CLA in raw milk was evaluated, taking into account the influence of the diet of feeding cows. Many samples of raw milk were studied in summer and winter for this purpose. It was determined that the concentration of conjugated linoleic acid in the fat phase of milk in winter is lower than in summer, when the diet of cows is dominated by green feed. The content of conjugated linoleic acid in the summer period ranged from 122.3 to 372.2 mg/dm 3 , and in winter it ranged from 54.7 to 136.47 mg/dm 3 . Experimental data of the possibility of increasing the content of conjugated linoleic acid in the fat phase of milk by inserting bacterial cultures is also presented. Re sults of the parameters of production conjugated linoleic acid under the influence of Lactobacillus acidophilus and Lactobacillus delbrueckii subsp . bulgaricus were obtained. The use of these bacterial cultures allowed to increase the content of conjugated linoleic acid by 23–36% in the studied samples.

Draft genome sequence of Lactobacillus delbrueckii subsp. bulgaricus LBP UFSC 2230: a tool for preliminary identification of enzymes involved in CLA metabolism.

Several Lactobacillus ssp. are recognized as potential conjugated linoleic acid (CLA) producers. We have previously reported the ability of a range of Lactobacillus delbrueckii subsp. bulgaricus strains to produce CLA in fermented milk, being a potential candidate for the fermented dairy food chain. This study reports the draft genome sequence of L. bulgaricus strain LBP UFSC 2230, isolated from Italian Grana Padano cheese. Draft genome sequence originated in a total of 4,310,842 paired-end reads that were quality trimmed and assembled into 135 contigs with a total length of 604,745,873 bp, including 2086 protein coding genes and an average GC content of 49.7%. Draft genome sequence represents an important tool to identify the enzymes involved in this strain's CLA metabolism. We identified a gene encoding an enzyme involved in biohydrogenation of linoleic acid pathway, oleate hydratase.

The effect of cereal type and α-tocopherol supplementation on selective quality and processability parameters of milk from late lactation grazing dairy cows.

This research communication addressed the hypothesis that late lactation cows offered an oat-grain-based supplement or a high level of α-TOC supplementation at pasture would have improved milk composition and processability. Over a grazing period of 49 d, 48 Holstein Friesian dairy cows were randomly assigned to one of four dietary treatments. The dietary treatments were: control, pasture only (CTRL), pasture + 2.65 kg DM barley-based concentrate + 350 IU α-TOC/kg (BARLO), pasture + 2.65 kg DM oat-based concentrate + 350 IU α-TOC/kg (OATLO) and pasture + 2.65 kg DM oat-based concentrate + 1050 IU α-TOC/kg (OATHI). Within this randomised complete block design experiment cows were blocked on days in milk (DIM) and balanced for parity, milk yield and composition. Rennet coagulation time (RCT) was reduced in milk from cows offered OATHI compared to CTRL cows and OATLO. Concentration of conjugated linoleic acid (CLA) was increased by OATHI compared to OATLO and in OATLO compared to CTRL. Supplementation with OATHI reduced individual saturated fatty acids (SFAs) in milk compared to OATLO. In conclusion, supplementing grazing dairy cows with an oat-based supplement improved total milk CLA concentration compared to pasture only. Offering a high level of α-TOC (2931 IU/d) to dairy cows reduced RCT, individual SFA and increased total CLA concentration of milk compared to a lower α-TOC level (738 IU α-TOC/d).

Effects of abomasal infusion of essential fatty acids and conjugated linoleic acid on performance and fatty acid, antioxidative, and inflammatory status in dairy cows

The objective of this study was to test the effects of essential fatty acids (EFA), particularly α-linolenic acid, and conjugated linoleic acid (CLA) supplementation on fatty acid (FA) composition, performance, and systemic and hepatic antioxidative and inflammatory responses in dairy cows. Four cows (126 ± 4 d in milk) were investigated in a 4 × 4 Latin square and were abomasally infused with 1 of the following for 6 wk: (1) coconut oil (control treatment, CTRL; 38.3 g/d; providing saturated FA), (2) linseed and safflower oil (EFA treatment; 39.1 and 1.6 g/d, respectively; providing mainly α-linolenic acid), (3) Lutalin (BASF, Ludwigshafen, Germany; CLA treatment; cis-9,trans-11 and trans-10,cis-12 CLA, 4.6 g/d each), (4) or EFA+CLA. The initial dosage was doubled every 2 wk, resulting in 3 dosages (dosage 1, 2, and 3). Cows were fed a corn silage-based total mixed ration with a high n-6/n-3 FA ratio. Dry matter intake and milk yield were recorded daily, and milk composition was measured weekly. The FA compositions of milk fat and blood plasma were analyzed at wk 0, 2, 4, and 6. The plasma concentration and hepatic mRNA abundance of parameters linked to the antioxidative and inflammatory response were analyzed at wk 0 and 6 of each treatment period. Infused FA increased in blood plasma and milk of the respective treatment groups in a dose-dependent manner. The n-6/n-3 FA ratio in milk fat was higher in CTRL and CLA than in EFA and EFA+CLA. The sum of FA <C16 in milk fat decreased in CLA and EFA+CLA in a dosage-dependent manner. Energy-corrected milk and milk fat decreased in CLA and EFA+CLA in a dosage-dependent manner and were higher in EFA and CTRL than in CLA at dosages 2 and 3. Energy balance tended to be highest in CLA cows. Milk protein content was lower in CLA and EFA+CLA than in CTRL. Milk urea concentration decreased in CLA and EFA+CLA in a dosage-dependent manner and was lower in CLA and EFA+CLA than in EFA and CTRL at dosages 2 and 3. Milk citrate concentration increased in CLA in a dosage-dependent manner and was higher in CLA and EFA+CLA than in EFA and CTRL. Glutathione peroxidase activity in blood plasma was lower in CTRL than in EFA, and plasma concentration of β-carotene increased in EFA and EFA+CLA with dosage. Increased milk citrate pointed at reduced de novo FA synthesis and a better antioxidative status in milk due to CLA treatment. Supplementation with CLA may also affect milk protein synthesis, but EFA and CLA treatment did not influence the inflammatory status in a consistent manner in mid-lactating cows.

Effect of Conjugated Linoleic Acid on Memory and Reflex Maturation in Rats Treated During Early Life.

In the critical period of neurodevelopment (gestation and lactation), maternal consumption of essential fatty acids (FAs) can alter the offspring cognitive function permanently causing damage. Lipids can regulate neurotrophin and compose brain tissue. However, the effects of maternal consumption of a mixture of conjugated linoleic acid (CLA) on an offspring nervous system are not completely clear. We aimed to investigate the impacts of different CLA concentrations mixed into the maternal diet during early life on neonatal reflex maturation and cognitive functions of the offspring. Three groups were formed: control (CG): receiving a standard diet; CLA1: receiving a diet containing 1% of CLA, and CLA3: receiving a diet containing 3% of CLA, offered during gestation and lactation. After birth, the reflex responses of the offspring were observed from the 1st to the 21st day. After weaning, the animals’ anxiety and memory were assessed using open field (OF) and novel object recognition tests. Fatty acids in the breast milk and the offspring’s brain were also quantified. The data were analyzed using one-way ANOVA and the Kruskal–Wallis test. CLA1 presented accelerated palmar grasp disappearance versus CLA3 and negative-geotaxis versus CG; and the CLA3 presented increases for most reflexes (cliff-avoidance, vibrissa-placing, negative-geotaxis, and auditory-startle response), and decrease in reflexes palmar grasp and free-fall righting versus CG (p < 0.05). CLA3 group explored less of the OF in the second exposure. CLA1 and CLA3 presented an increased exploration ratio for new objects, which indicates memory improvement. The milk tested from CLA3 demonstrated an increase in polyunsaturated fatty acids (PUFAs), and a decrease in monounsaturated fatty acids. The amount of CLA in milk was greater in CLA1 and CLA3 and in the brain offspring both presented moderated amounts of CLA. Maternal treatment with the CLA mixture induced anticipated reflex maturation and improved memory in the offspring. Even though CLA was detected in the brains in only trace amounts, offspring’s brain PUFA and SFA levels were increased. Further studies aimed to delineate the effect of maternal CLA supplementation on offspring’s brain lipid metabolism and long-term neurologic outcome are needed to confirm these findings.

Effects of forage species and feeding systems on rumen fermentation, microbiota and conjugated linoleic acid content in dairy goats

The objective of this experiment was to investigate the effects of forage species and feeding systems on ruminal fermentation, microbiota (Butyrivibrio fibrisolvens, Fibrobacter succinogenes and total bacteria) and conjugated linoleic acid (CLA) concentration of milk in dairy goats. Twenty female crossbred Saanen lactating goats (~35 ± 3.0 kg bodyweight) in early to mid-lactation stage were assigned to a 45-day completely randomised-design feeding experiment, with the following four forage (roughage) treatments: cut-and-carry grass (CG), grazing of grass (GG), cut-and-carry leucaena (CL) and grazing of leucaena (GL; n = 5). All animals were given concentrate equivalent to 1.5% of their bodyweight. The grass used in the study was napier Pak Chong 1 grass (Pennisetum purpureum × Pennisetum americanum hybrid). The results showed that irrespective of the type of forage, grazing goats (GG and GL) had a higher (P &amp;lt; 0.05) forage intake and, thus, total dry-matter and crude-protein intakes than did those fed indoors (CG and CL). However, the intake of C18:2n6 and particularly of C18:3n3 was generally higher for grass-fed goats than for leucaena-fed goats. Treatments did not exert significant differences on rumen fermentation characteristics. However, the populations of B. fibrisolvens, F. succinogenes and total bacteria were significantly (P &amp;lt; 0.05) higher in grazing goats (GG and GL) than in their counterparts fed with the cut-and-carry system (CG and CL). Goats in the grazing system also had a higher (P &amp;lt; 0.05) milk yield, and milk fat, c9, t11 CLA and omega-3 fatty acid concentrations than did those in the cut-and-carry system and only grazing goats produced detectable levels of t10, c12 CLA in milk. Putting the above together, it can be concluded that allowing dairy goats to outdoor grazing stimulates a higher forage intake, including that of C18:2n6 and C18:3n3, as well as enhancing population of B. fibrisolvens (involved in the synthesis of milk CLA), resulting in a higher milk yield, and enhances c9, t11 and t10, c12 CLA in goat milk.

Corrigendum to: Effects of forage species and feeding systems on rumen fermentation, microbiota and conjugated linoleic acid content in dairy goats

The objective of this experiment was to investigate the effects of forage species and feeding systems on ruminal fermentation, microbiota (Butyrivibrio fibrisolvens, Fibrobacter succinogenes and total bacteria) and conjugated linoleic acid (CLA) concentration of milk in dairy goats. Twenty female crossbred Saanen lactating goats (~35 ± 3.0 kg bodyweight) in early to mid-lactation stage were assigned to a 45-day completely randomised-design feeding experiment, with the following four forage (roughage) treatments: cut-and-carry grass (CG), grazing of grass (GG), cut-and-carry leucaena (CL) and grazing of leucaena (GL; n = 5). All animals were given concentrate equivalent to 1.5% of their bodyweight. The grass used in the study was napier Pak Chong 1 grass (Pennisetum purpureum × Pennisetum americanum hybrid). The results showed that irrespective of the type of forage, grazing goats (GG and GL) had a higher (P B. fibrisolvens, F. succinogenes and total bacteria were significantly (P P B. fibrisolvens (involved in the synthesis of milk CLA), resulting in a higher milk yield, and enhances c9, t11 and t10, c12 CLA in goat milk.

Enhanced digestive enzyme activity and anti-adipogenic of fermented soy-powder milk with probiotic Lactobacillus plantarum P1201 through an increase in conjugated linoleic acid and isoflavone aglycone content

This study aimed to produce fermented soy-powder milk (FSPM) with Lactobacillus plantarum P1201 and to evaluate its anti-obesity activity. Isoflavone and conjugated linoleic acid (CLA) of unfermented soy-powder milk (UFSPM) and FSPM and were analyzed via high-pressure liquid chromatography (HPLC) and gas chromatography (GC). Their inhibitory activities against α-glucosidase, α-amylase, and pancreatic lipase were assayed. Their anti-obesity activities were evaluated on the basis of their inhibitory effects on adipocyte differentiation in 3T3-L1 cells, and the expression of mRNAs associated with adipogenesis and lipid metabolism were analyzed via real time-polymerase chain reaction (RT-PCR) and quantitative PCR (qPCR). FSPM with L. plantarum P1201 increased the isoflavone aglycones (daidzein, glycitein, and genistein) content and produced CLA in soy-powder milk (SPM), both of which possessed bio-activity. Both UFSPM and FSPM showed dose-dependent inhibitory activity for α-glucosidase, α-amylase, and pancreatic lipase. FSPM, but not UFSPM, suppressed adipogenesis in 3T3-L1 cells and reduced their triglyceride content by 23.1% after treatment with 1,000 μg/mL of FSPM, compared with the control group. The anti-obesity effect of FSPM can be attributed to CLA and isoflavone aglycones, which targeted CCAAT/enhancer binding protein α (C/EBP-α) and down-regulated lipoprotein lipase (LPL), adiponectin, adipocyte fatty acid-binding protein (aP2), fatty acid synthase (FAS), and acetyl CoA carboxylase (ACC) mRNA. Furthermore, FSPM enhanced the inhibitory activity of glucosidase and pancreatic enzymes and anti-obesity activity. Further studies are required to investigate whether the anti-obesity effect of FSPM persists in an in vivo mouse model of diet-induced obesity.

Obtención de leche bovina reducida en grasa saturada y naturalmente enriquecida en ácido linoleico conjugado

Te aim of the work was to reduce the presence of the potentially atherogenic fatty acids (FA) of milk (C12: 0,C14: 0 and C16: 0) and increase the presence of conjugated linoleic acid (CLA) in confned dairy cows fed a total mixed ration (TMR) supplemented with polyunsaturated fatty acids (PUFA). Two batches of 70 multiparous cows in the frst third of lactation were used. Afer six experimental weeks and for fve consecutive days, milk samples (5) were obtained from the collector tank of non-supplemented cows (LE) and of CLA milk (LCLA) from the tank of PUFA supplemented cows. Fat content (g/100g) in LE (3,84) was higher (p<0,001) than LCLA (2.84) explained by a signifcant reduction (17,21%) in the concentration of the potentially atherogenic FA of milk. The milk atherogenic index was higher (p<0,001) in LE (4,07) compared to LCLA (2.58). Milk CLA content increased (p<0,001) by 122% in LCLA (0,77 g/100 g FA) compared to LE (0,34 g/100 g FA). Oleic acid concentration (g/100 g FA) resulted higher (p<0,001) in LCLA (23,37) compared to LE (18,78). Supplementation with PUFA in confned dairy cows increased the healthy value of the milk produced maintaining an adequate omega-6/omega-3 ratio (6,59) and confrmed the plasticity in milk fatty acid composition.

Change of feeding affects fatty acids profile of goat’s milk

Aim of this study was to analyse the effect of beginning of grazing on fatty acids (FA) profile of goat’s milk. In all milk samples profile of basic FA was determined. Proportion of “goaty flavour” fatty acids: C6:0, C8:0 and C10:0 in milk fat was the lowest (P<0.01) when goats were fed only indoors and was the highest when goats were 7 days on pasture. Proportion of C18:2 cis 6 in milk fat varied between sampling times from 2.54 to 2.63 g·100 g-1 FA. C18:3 n - 3 was the highest 1.25 g·100 g-1 FA when goats were fed only indoors, after 7 days of grazing decreased to 0.93 g·100 g-1 FA (P<0.01). On the other hand, conjugated linoleic acid (CLA) in milk was lowest 0.55 g·100 g-1 FA when goats were fed only indoors. After 7 days of grazing CLA in milk increased to 0.91 g·100 g-1 FA (P<0.01). During next sampling days CLA decreased to 0.65 g·100 g-1 FA. Development of SFA, MUFA and PUFA of goat’s milk after start of grazing was in this experiment different than published most of authors. However, described changes of fatty acids profile of goat milk confirm significant effect of beginning of grazing on milk fat composition.

Does Maternal Synbiotic Supplementation Affect Conjugated Linoleic Acid Level in Breast Milk? A Randomized Placebo-Controlled Clinical Trial.

As conjugated linoleic acid (CLA)is a potential growth promotor in newborns, the present pilot study aimed at measuring the effect of synbiotic supplementation on breast milk CLA level. Sixty lactating mothers were randomly allocated to take either synbiotic (n = 31) or placebo (n = 29) for 30 days. Maternal anthropometric indices were measured at the onset and end of the study by standard methods and body mass index was calculated. Information on food intake was collected by using a 24 hours 24-hour recall method for 2 days and food record questionnaire for 1 day. Breast milk lipids were extracted and CLA level was quantified by gas chromatography. No significant differences were observed in the baseline mean breast milk concentrations of Fatty acids (FAs) between the synbiotic and placebo groups (p > 0.05). The CLA content of breast milk increased significantly by 58% (from 0.19 ± 0.15 to 0.30 ± 0.22 mmol/L) in the supplemented group, whereas it decrease decreased slightly but not significantly by 14% (from 0.22 ± 0.14 to 0.19 ± 0.10 mmol/L) in the placebo group. After adjustment for covariates, the CLA content of breast milk was significantly higher in the supplemented group compared with placebo group after the intervention (p = 0.03). The ratio of total n - 6:3 increased significantly over time in both groups, but was not different among groups (p < 0.05). This pilot study showed that supplementation of lactating women with synbiotic, resulted in increased breast milk CLA composition. Further research using different species of probiotic bacteria and analysis of maternal and infant plasma FAs would be beneficial.

Temporal changes in milk fatty acid distribution due to feeding different levels of rolled safflower seeds to lactating Holstein cows

The objective of this experiment was to follow the time-course changes of the milk fatty acids (FA) and particularly conjugated linoleic acid (CLA), n-3, and n-6 FA in response to feeding whole rolled safflower seed (SS). Eighteen cows were blocked by milk production, days in milk, and parity, and randomly assigned to 1 of 3 diets by replacing whole cottonseed with SS. The control diet contained no SS (SS0), whereas the other diets contained 3% of dry matter as SS (SS3) or 6% SS (SS6). The study was conducted for 8 wk. Cows fed SS produced more milk than SS0, with SS3 producing more milk than SS6, but without a change in milk fat yield or milk fat %. Except for C8:0 FA, changes in milk FA were not observed until the third week of SS feeding. The C8:0 began decreasing during wk 1 of SS feeding and continued to decline to wk 8. Short-chain FA (C6:0 to C11:0) and medium-chain FA (C12:0 to C16:1) concentrations decreased in milk when cows were fed SS, whereas long-chain FA (C18:0 and higher) increased after wk 3. The milk long-chain FA increased from wk 3 until wk 5 and then reached a plateau with little difference between SS3 and SS6, whereas the short-chain FA decreased more in milk from cows fed SS6 than SS3. Total CLA increased slightly less than 5× in milk from cows fed SS compared with SS0. Over the same time frame, n-3 FA declined and n-6 FA increased in the milk from cows fed SS, with no difference between SS3 and SS6. This study indicated that SS fed at 3 and 6% of DM had the potential to increase milk production and the CLA in milk, but with a corresponding increase in n-6 FA.

Addition of conjugated linoleic acid in whole milk improves lipid profile in high fat diet induced hypercholesterolemia of rats

Conjugated linoleic acid (CLA) is an isomer of linoleic acid that has been shown to have many beneficial effects in prevention of atherosclerosis, hypertension, cardiovascular diseases and improve immune function. Although majority of CLA in the diet are derived from dairy product such as milk, however, the content of CLA in milk is affected by cow’s diet. The aim of this study was to investigate the beneficial effect of CLA supplementation in milk for improving lipid profile in high fat diet of rats. Twenty four male Sprague Dawley rats aged 8 weeks were given high fat diet for 3 weeks to induce hypercholesterolemia. Six rats were maintained in standard diet as control. Rats then were divided into 4 groups i.e. normal control, negative control, high fat diet+CLA 0.5%, high fat diet + CLA 0.5% supplemented skim milk, and high fat diet + CLA 0.5% supplemented whole milk. Blood sample was drawn after high fat diet induced hypercholesterolemia and after 4 weeks of treatment for total cholesterol, triglyceride, low-density lipoprotein cholesterol (LDL cholesterol), and high density lipoprotein cholesterol (HDL cholesterol) analysis. Body weight was measured each week. Results showed that body weight was significantly increase in all groups received high fat diet (p 0.05). Total cholesterol, triglyceride, and LDL cholesterol was significantly decrease in whole milk followed by significant increase in HDL cholesterol level. Skim milk supplemented with CLA had only modest effect on triglyceride and HDL cholesterol level. In conclusion, CLA supplementation in whole milk improves lipid profile in high fat diet.

CONJUGATED LINOLEIC ACID IN MILK AND FERMENTED MILKS: VARIATION AND EFFECTS OF THE TECHNOLOGICAL PROCESSES

Background: Conjugated linoleic acid (CLA) is a generic term used to describe a group of geometric and positional isomers of linoleic acid with a conjugated double bond system. CLA-isomers have been widely studied because of their important biological activity and their protective effects against several diseases, such as obesity, atherosclerosis, chronic inflammatory diseases, and cancer. Consequently, these biomolecules have attracted much attention from the dairy industry, since they are naturally found in ruminants’ milk, and because the development of CLA-enriched dairy foods can be a good economic opportunity given the growth of the functional foods market, in which the dairy industry plays an important role. Objectives: This work presents a comprehensive review of the following aspects: (i) The synthesis and concentration of the CLA-isomers in milk, and the main strategies employed to increase their content in a natural manner; (ii) The influence of the main technological treatments applied to milk on the concentration of CLA-isomers; and (iii) The effects of milk fermentation on the content of CLA-isomers, and the challenges of this technological process, which has been though as a promissory alternative to naturally increase the content of CLA in fermented dairy products. Methods: Information available in various databases was reviewed. A total of 103 articles were selected on the basis of their relevance and scientific-technical quality. Results: The CLA concentration in cows’ milk normally ranges between 2 and 37 mg/g fat, and is mainly affected by the dietary regime offered to the animals. From the total CLA-isomers, rumenic acid represents between 75 and 90%. The technological processes normally applied to milk (thermal processing, high pressure processing, and fermentation) might cause slight changes on the CLA concentration, but the mechanisms causing these changes have not been still established. The increase in CLA concentration by milk fermentation is strain-dependent, because of the different linoleate isomerase activity of the species. . Conclusions: Although several studies have reported increases in the concentration of CLA in milk and fermented milks in a natural manner, they are fairly moderate, and the obtained levels of CLA are significantly lower than those recommended to achieve therapeutic effects.

Effect of pomegranate seed oil as a source of conjugated linolenic acid on performance and milk fatty acid profile of dairy goats

The objective of this experiment was to investigate the effects of dietary pomegranate seed oil and linseed oil on lactational performance, ruminal fermentation parameters, nutrients digestibility and milk fatty acid (FA) content, particularly conjugated linoleic acid (CLA), conjugated linolenic acid (CLnA) and vaccenic acid (VA) of dairy goats. Twenty-four Mahabadi goats in mid lactation were assigned to three dietary treatments: 1- control diet, basal diet without added oil (CON), 2- diet supplemented with 25g/kg pomegranate seed oil (PSO), and 3- diet supplemented with 25g/kg linseed oil (LSO), on a dry matter (DM) basis. Feed intake, milk yield and 4% fat-corrected milk yield were similar for goats fed different diets. Milk fat concentration (P<0.01) and fat/ protein ratio (P<0.0001) of goats fed PSO and LSO diets increased, while milk protein, lactose and solid not fat concentrations were not affected by diets (P>0.05). Addition of vegetable oils to diet had no effect on apparent digestibility of nutrients and ruminal fermentation parameters (P>0.05). The proportions of VA (P<0.001) and C18:1 (trans-9+trans-10, P<0.01) acids were increased in milk fat from goats fed PSO and LSO diets compared with goats fed CON diet. The concentration of cis-9, trans-11 CLA (rumenic acid) increased with oil supplements (P<0.0001) and was greatest for goats fed PSO diet. Compared with CON and LSO diets, feeding PSO diet increased cis-9, trans-11, cis-13 C18:3 CLnA (punicic acid) in milk fat (P<0.0001). The concentrations of monounsaturated fatty acids (MUFA; P<0.05), polyunsaturated fatty acids (PUFA; P<0.0001) and n-3PUFA (P<0.0001) increased and n-6/n-3 PUFA ratio (P<0.0001) decreased with oil supplemented diets. In conclusion, feeding PSO and LSO to dairy goats was a useful way to increase milk fat, CLA, and VA content of milk and to reduce the n-6/n-3 PUFA ratio without negative effects on intake, milk yield, and nutrients digestibility.