Dietary fatty acid sources affect conjugated linoleic acid concentrations in milk from lactating dairy cows

Effects of increasing dietary inclusion of high oleic acid soybeans on milk production of high-producing dairy cows

Recent research has highlighted the importance of dietary fatty acid profile of fatty acid supplements on production responses of high-producing dairy cows. Conventional soybeans contain ∼15% oleic acid and ∼50% linoleic acid whereas high oleic acid soybeans (HOSB) contain ∼70% oleic acid and ∼7% linoleic acid. We determined the effect of increasing dietary inclusion of roasted and ground HOSB on production responses of high-producing dairy cows. Twenty-four multiparous Holstein cows (50.7 ± 4.45 kg/d of milk; 122 ± 57 DIM) were randomly assigned to treatment sequences in a replicated 4 × 4 Latin square design with 21-d periods. Treatments were increasing doses of HOSB at 0, 8, 16, and 24% DM. The HOSB replaced conventional soybean meal and hulls to maintain similar diet nutrient composition (% DM) of 27.4 - 29.4% (NDF), 20.6% forage NDF, 27.5% starch, and 15.9 - 16.5% CP. Total fatty acid content of treatments was 1.65, 3.11, 4.52, and 5.97% DM, respectively. Pre-planned polynomial orthogonal contrasts included the linear, quadratic, and cubic effects of increasing HOSB. Increasing dietary inclusion of HOSB linearly decreased DMI and milk urea nitrogen and increased yields of milk, 3.5% fat corrected milk, energy corrected milk, and milk fat, and quadratically increased milk protein. The increased response to milk fat was due to an increase in preformed milk fatty acids. Due to the increase in milk component yields and decrease in DMI, there was an increase in feed efficiency. Increasing HOSB inclusion linearly decreased plasma BUN concentration and tended to decrease plasma insulin. Increasing HOSB had no effect on BW change or BCS change. In summary, increasing dietary inclusion of HOSB up to 24% DM increased production responses of high-producing dairy cows and did not affect body reserves.

Role of functional fatty acids in modulation of reproductive potential in livestock

Fatty acids are not only widely known as energy sources, but also play important roles in many metabolic pathways. The significance of fatty acids in modulating the reproductive potential of livestock has received greater recognition in recent years. Functional fatty acids and their metabolites improve follicular development, oocyte maturation and embryo development, as well as endometrial receptivity and placental vascular development, through enhancing energy supply and precursors for the synthesis of their productive hormones, such as steroid hormones and prostaglandins. However, many studies are focused on the impacts of individual functional fatty acids in the reproductive cycle, lacking studies involved in deeper mechanisms and optimal fatty acid requirements for specific physiological stages. Therefore, an overall consideration of the combination and synergy of functional fatty acids and the establishment of optimal fatty acid requirement for specific stages is needed to improve reproductive potential in livestock.

An investigation on conjugated linoleic acid content, fatty acid composition, and physicochemical characteristics of Iranian Kurdish butter oil

In this study, physicochemical and quality properties, fatty acid composition, and triglyceride composition of Iranian Kurdish butter oil (IKBO) obtained from yogurt drink (doogh) butter were investigated. Local doogh butter, prepared from cow's (CIKBO) and ewe's milk (EIKBO), was utilized as the raw material for this purpose. The free fatty acids (FFA) and peroxide values of IKBOs of the cow (CIKBO) and ewe (EIKBO) were obtained at 0.41 ± 0.01 and 0.39 ± 0.01 (g Oleic acid 100/g oil), and 1.32 ± 0.00 and 1.35 ± 0.00 (meq O2 kg/oil), respectively. The amounts of saturated fatty acids (SFAs): 70.27 ± 0.62 and 72.13 ± 0.84 (g/100 g), monounsaturated fatty acids (MUFAs): 19.37 ± 0.74 and 20.56 ± 0.97 (g/100 g), and polyunsaturated fatty acids (PUFAs): 1.22 ± 0.12 and 2.75 ± 0.38 (g/100 g) were obtained in CIKBO and EIKBO, respectively. The significant majority of the fatty acids (FAs) in the examined CIKBO and EIKBO were myristic (CIKBO: 13.76 ± 0.02 (g/100 g) and EIKBO: 14.83 ± 0.07 (g/100 g)), palmitic (CIKBO: 33.14 ± 0.28 (g 100/g) and EIKBO: 31.86 ± 0.02 (g/100 g)), stearic (CIKBO: 8.27 ± 0.06 (g/100 g) and EIKBO: 7.95 ± 0.06 (g/100 g)), capric (CIKBO: 4.83 ± 0.03 (g/100 g) and EIKBO: 6.75 ± 0.01 (g/100 g)), and oleic acids (CIKBO: 15.37 ± 0.12 (g/100 g) and EIKBO: 17.83 ± 0.02 (g/100 g)). The average of conjugated linoleic acid (CLA) content in EIKBO (2.20 ± 0.22 (g/100 g)) was higher than that in CIKBO (0.92 ± 0.25 (g/100 g)) (p < .05). Therefore, EKIBO is considered the superior natural supply of CLA.

Cheese and Butter as a Source of Health-Promoting Fatty Acids in the Human Diet

The assessment of fatty acid composition, including the content of conjugated linoleic acid cis9trans11 C18:2 (CLA) and trans C18:1 and C18:2 isomers in fat extracted from selected high-fat dairy products commonly available to consumers in retail sale on the Polish market, and a comparison of their indicators as to the quality of lipids was the aim of the study. The experimental materials were hard cheeses, white-mold cheeses, blue-veined cheeses, and butters. The conducted study demonstrated that various contents of groups of fatty acids and the values of lipid quality indices were found in the tested products. Butters turned out to be richer sources of short-chain, branched-chain, and odd-chain fatty acids. The fat extracted from butters and white-mold cheeses had a significantly higher (p < 0.05) content of n-3 fatty acids. Lower values of the n-6/n-3 ratio were determined in the fat extracted from butters and white-mold cheeses. The highest values of the thrombogenicity index (TI) were found in fat extracted from hard cheeses. Significantly lower values (p < 0.05) of the atherogenicity index (AI) and values of the H/H ratio were found in fat from mold cheeses. Fat from butters and white-mold cheeses had a significantly higher (p < 0.05) content of CLA and total content of trans C18:1.

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.

Fatty Acid Content, Lipid Quality Indices, and Mineral Composition of Cow Milk and Yogurts Produced with Different Starter Cultures Enriched with Bifidobacterium bifidum

This study aimed to analyze the composition of fatty acids, with particular emphasis on the content of cis9trans11 C18:2 (CLA) acid, the content of minerals, and lipid quality indices in raw milk, pasteurized milk, and in yogurts produced with selected starter cultures enriched with Bifidobacterium bifidum. The GC-FID method was used to determine the fatty acid composition of those dairy products. To analyze the contents of microelements (copper, manganese, iron, and zinc) and macroelements (magnesium, calcium) flame atomic absorption spectrometry was used. The content of phosphorus was determined with the usage of the colorimetric method and the contents of sodium and potassium with emission method. Data analysis showed that such technologies as milk pasteurization and milk fermentation had a significant impact on the fatty acid profile and contents of micro- and macroelements. The lipid quality indices: atherogenicity index (AI), index thrombogenicity (TI), hypocholesterolemic/hypercholesterolemic index (H/H), and (n − 6)/(n − 3) ratio, were at similar levels in raw and pasteurized milk and yogurts produced. Starter culture type affected the content of cis-9, trans-11 CLA C18:2 acid in yogurts. Out of the starter cultures applied in the study, only the FD-DVS YC-X16 Yo-Flex starter culture with BB-12 caused a significant (p < 0.05) increase in CLA content. The CLA content of the yogurts produced using this starter culture was 2.67 mg/g fat. In raw milk, pasteurized milk, and the second batch of yogurts, the content of cis-9, trans-11 C18:2 acid was significantly lower and reached 2.26 mg/g fat, 2.17 mg/g fat, and 2.30 mg/g fat, respectively. The study indicated that, when it comes to being a source of minerals, yogurts were better than milk. Yogurts were also characterized by significantly (p < 0.05) higher contents of all micro- and macroelements taken into account in this study than the raw milk used to produce them.

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

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.

Expression of lncRNAs in response to bacterial infections of goat mammary epithelial cells reveals insights into mammary gland diseases

Mastitis or inflammation of the mammary gland is a highly economic and deadly alarming disease for the dairy sector as well as policymakers caused by microbial infection. Transcriptomic and proteomic approaches have been widely employed to identify the underlying molecular mechanisms of bacterial infections in the mammary gland. Numerous differentially expressed mRNAs, miRNAs, and proteins together with their associated signaling pathways have been identified during bacterial infection, paving the way for analysis of their biological functions. Long noncoding RNAs (lncRNAs) are important regulators of multiple biological processes. However, little is known regarding their role in bacterial infection in mammary epithelial cells. Hence, RNA-sequencing was performed by infecting primary mammary epithelial cells (pMECs) with both gram-negative (E. coli) and gram-positive bacteria (S. aureus). Using stringent pipeline, a set of 1957 known and 1175 novel lncRNAs were identified, among which, 112 lncRNAs were found differentially expressed in bacteria challenged PMECs compared with the control. Additionally, potential targets of the lncRNAs were predicted in cis- and trans-configuration. KEGG analysis revealed that DE lncRNAs were associated with at least 15 immune-related pathways. Therefore, our study revealed that bacterial challenge triggers the expression of lncRNAs associated with immune response and defense mechanisms in goat mammary epithelial cells.

Alteration of fatty acid profile of milk in Holstein cows fed Bacillus coagulans as probiotic: a field study

BACKGROUND

Probiotics may improve milk quality and the general health status of animals.

AIMS

The effects of dietary Bacillus coagulans PRM101 on milk components, milk fatty acids (FA), and some health indicators of dairy cows were investigated.

METHODS

The probiotic was added to the feed of 12 Holstein cows (2 g/cow: 2 × 1011 CFU/cow) for 63 days compared to a control group fed on the basal ration (n=11). Milk and blood samples were taken on days 0, 21, 42, and 63.

RESULTS

The yields of milk and energy corrected milk (ECM; computed from milk weight and its fat and protein content) decreased linearly and similarly (P=0.60) in both groups. The treatment cows, however, showed quadratic increases in the weights of milk (P=0.03) and ECM (P=0.04) at d42 of the study. Energy corrected milk (d42, P<0.05) and crude protein content of milk (d42, P<0.05; d63, P<0.1) were higher in the cows receiving the probiotic. The proportions of heptadecanoic (C17:0; P=0.002) and linoleic (C18:2; P=0.077) acids in milk fat (g/100 g fat) were higher in the treatment cows on d63. Milk total antioxidant capacity (TAC), malondialdehyde (MDA), and similarly, amyloid A (AA) and haptoglobin (Hp) of milk and blood were not affected. Total antioxidant capacity and MDA were negatively correlated in the control group (r=-0.669, P=0.005). Heptadecanoic acid correlated negatively with milk MDA (r=-0.611, P=0.035) and positively (r=0.591, P=0.043) with serum Hp in the treatment cows.

CONCLUSION

Dietary B. coagulans PRM101 may improve the proportions of C17:0 and C18:2 FA in milk. Some improvements in milk protein and the health status of the cows may also be anticipated.

Feeding unsaleable carrots to lambs increased performance and carcass characteristics while maintaining meat quality

This study investigated the effect of feeding unsaleable carrots to lambs within a total-mixed ration (TMR) on performance, carcass characteristics, meat quality and sensory parameters. Thirty-six Australian Merino wether lambs were fed a control (barley-based) or carrot-based TMR for 11-weeks. Carrot-fed lambs had 2.7% higher cold dressing percentage (P = 0.03) while consuming less than control lambs. Subcutaneous fat of carrot-fed lambs contained less branch-chained, and more cis- and trans-monounsaturated fatty acids (FA; P ≤ 0.01) compared to control-fed lambs, which tended (P = 0.08) to have higher concentrations of polyunsaturated FA, despite the Longissimus lumborum (LL) muscle being unchanged by diet. Under retail display conditions, L* and hue values were lower (P ≤ 0.04) for 5 d aged LL samples from carrot-fed lambs. No differences were observed in other meat quality and sensory parameters between diets. Therefore, feeding unsaleable carrots at 45% DM in a TMR can improve lamb performance and carcass characteristics, while maintaining meat quality and FA composition.

Current Evidence to Propose Different Food Supplements for Weight Loss: A Comprehensive Review

The use of food supplements for weight loss purposes has rapidly gained popularity as the prevalence of obesity increases. Navigating through the vast, often low quality, literature available is challenging, as is providing informed advice to those asking for it. Herein, we provide a comprehensive literature revision focusing on most currently marketed dietary supplements claimed to favor weight loss, classifying them by their purported mechanism of action. We conclude by proposing a combination of supplements most supported by current evidence, that leverages all mechanisms of action possibly leading to a synergistic effect and greater weight loss in the foreseen absence of adverse events. Further studies will be needed to confirm the weight loss and metabolic improvement that may be obtained through the use of the proposed combination.

Cis-9, Trans-11 Conjugated Linoleic Acid Reduces Phosphoenolpyruvate Carboxykinase Expression and Hepatic Glucose Production in HepG2 Cells

Dysregulated hepatic gluconeogenesis is a hallmark of insulin resistance and type 2 diabetes mellitus (T2DM). Although existing drugs have been proven to improve gluconeogenesis, achieving this objective with functional food is of interest, especially using conjugated linoleic acid (CLA) found in dairy products. Both cis-9, trans-11 (c9,t11) and trans-10, cis-12 (t10,c12) isomers of CLA were tested in human (HepG2) and rat (H4IIE) hepatocytes for their potential effects on gluconeogenesis. The hepatocytes exposed for 24 h with 20 μM of c9,t11-CLA had attenuated the gluconeogenesis in both HepG2 and H4IIE by 62.5% and 80.1%, respectively. In contrast, t10,c12-CLA had no effect. Of note, in HepG2 cells, the exposure of c9,t11-CLA decreased the transcription of gluconeogenic enzymes, cytosolic phosphoenolpyruvate carboxykinase (PCK1) by 87.7%, and glucose-6-phosphatase catalytic subunit (G6PC) by 38.0%, while t10,c12-CLA increased the expression of G6PC, suggesting the isomer-specific effects of CLA on hepatic glucose production. In HepG2, the peroxisome proliferator-activated receptor (PPAR) agonist, rosiglitazone, reduced the glucose production by 72.9%. However, co-administration of c9,t11-CLA and rosiglitazone neither exacerbated nor attenuated the efficacy of rosiglitazone to inhibit glucose production; meanwhile, t10,c12-CLA abrogated the efficacy of rosiglitazone. Paradoxically, PPARγ antagonist GW 9662 also led to 70.2% reduction of glucose production and near undetectable PCK1 expression by abrogating CLA actions. Together, while the precise mechanisms by which CLA isomers modulate hepatic gluconeogenesis directly or via PPAR warrant further investigation, our findings establish that c9,t11-CLA suppresses gluconeogenesis by decreasing PEPCK on hepatocytes.

Conjugated Linoleic Acid Effects on Cancer, Obesity, and Atherosclerosis: A Review of Pre-Clinical and Human Trials with Current Perspectives

Obesity and its comorbidities, including type 2 diabetes and cardiovascular disease, are straining our healthcare system, necessitating the development of novel strategies for weight loss. Lifestyle modifications, such as exercise and caloric restriction, have proven effective against obesity in the short term, yet obesity persists because of the high predilection for weight regain. Therefore, alternative approaches to achieve long term sustainable weight loss are urgently needed. Conjugated linoleic acid (CLA), a fatty acid found naturally in ruminant animal food products, has been identified as a potential anti-obesogenic agent, with substantial efficacy in mice, and modest efficacy in obese human populations. Originally described as an anti-carcinogenic fatty acid, in addition to its anti-obesogenic effects, CLA has now been shown to possess anti-atherosclerotic properties. This review summarizes the pre-clinical and human studies conducted using CLA to date, which collectively suggest that CLA has efficacy against cancer, obesity, and atherosclerosis. In addition, the potential mechanisms for the many integrative physiological effects of CLA supplementation will be discussed in detail, including an introduction to the gut microbiota as a potential mediator of CLA effects on obesity and atherosclerosis.

Transcriptome Analysis of Long Non-Coding RNA in the Bovine Mammary Gland Following Dietary Supplementation with Linseed Oil and Safflower Oil

This study aimed to characterize the long non-coding RNA (lncRNA) expression in the bovine mammary gland and to infer their functions in dietary response to 5% linseed oil (LSO) or 5% safflower oil (SFO). Twelve cows (six per treatment) in mid lactation were fed a control diet for 28 days followed by a treatment period (control diet supplemented with 5% LSO or 5% SFO) of 28 days. Mammary gland biopsies were collected from each animal on day-14 (D-14, control period), D+7 (early treatment period) and D+28 (late treatment period) and were subjected to RNA-Sequencing and subsequent bioinformatics analyses. Functional enrichment of lncRNA was performed via potential cis regulated target genes located within 50 kb flanking regions of lncRNAs and having expression correlation of >0.7 with mRNAs. A total of 4955 lncRNAs (325 known and 4630 novel) were identified which potentially cis targeted 59 and 494 genes in LSO and SFO treatments, respectively. Enrichments of cis target genes of lncRNAs indicated potential roles of lncRNAs in immune function, nucleic acid metabolism and cell membrane organization processes as well as involvement in Notch, cAMP and TGF-β signaling pathways. Thirty-two and 21 lncRNAs were differentially expressed (DE) in LSO and SFO treatments, respectively. Six genes (KCNF1, STARD13, BCL6, NXPE2, HHIPL2 and MMD) were identified as potential cis target genes of six DE lncRNAs. In conclusion, this study has identified lncRNAs with potential roles in mammary gland functions and potential candidate genes and pathways via which lncRNAs might function in response to LSO and SFA.

Feeding high oleic acid soybeans in place of conventional soybeans increases milk fat concentration

It is well established in the literature that feeding free vegetable oils rich in oleic acid results in greater milk fat secretion than does feeding linoleic-rich oils. The objectives of these experiments were to analyze the effects of oleic and linoleic acid when fed in the form of full-fat soybeans and the interaction between soybean particle size and fatty acid (FA) profile. Soybeans were included in diets on an iso-ether extract basis and diets were balanced for crude protein using soybean meal. Experiment 1 used 63 cows (28 primiparous, PP; 35 multiparous, MP) housed in a freestall barn with Insentec roughage intake control gates (Marknesse, the Netherlands). Cows were divided into 4 mixed parity groups within the same pen. Two groups were assigned to each of the 2 diets: whole raw Plenish (WP, high oleic; Dupont-Pioneer, Johnston, IA) soybeans or whole raw conventional (WC, high linoleic) soybeans. The MP cows exhibited significantly increased milk fat yield on the WP diet compared with the WC diet. A significantly greater C18 milk FA yield by the MP cows fed WP was observed compared with those fed WC, but no difference was present in the C16 or short-chain FA yield. No effects were seen in the PP cows. Experiment 2 used 20 cows (10 PP, 10 MP) in 2 balanced 5 × 5 Latin squares within parity. Cows received 5 diets: raw WP and WC diets, raw ground Plenish and conventional soybean diets (GP and GC, respectively), and a low fat control. A significant benefit was found for the GP diet compared with the GC diet for milk fat concentration and yield. In experiment 2, no difference was observed between cows fed the WP compared with the WC diet. In experiment 2, cows consuming the Plenish diets produced less milk than when consuming the conventional soybean diets. The soybean diets resulted in significantly more C18 and less Collapse

Key Words

• bioactive fatty acid
• linoleic acid
• milk fat depression
• milk fatty acid
• oleic acid

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MESH Headings

• Animal Feed/analysis
• Animals
• Cattle/physiology
• Diet/veterinary
• Dietary Fiber
• Female
• Lactation/drug effects
• Linoleic Acids/pharmacology
• Linoleic Acids, Conjugated/pharmacology
• Milk/chemistry
• Milk/metabolism
• Oleic Acid/pharmacology
• Particle Size
• Plant Oils/pharmacology
• Random Allocation
• Glycine max/chemistry

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Grants Collapse

Affiliation(s)

K A Weld Department of Dairy Science, University of Wisconsin, Madison 53706
L E Armentano Department of Dairy Science, University of Wisconsin, Madison 53706.

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Invited review: Bioactive compounds produced during cheese ripening and health effects associated with aged cheese consumption

Traditionally, cheese is manufactured by converting fluid milk to a semisolid mass through the use of a coagulating agent, such as rennet, acid, heat plus acid, or a combination thereof. Cheese can vary widely in its characteristics, including color, aroma, texture, flavor, and firmness, which can generally be attributed to the production technology, source of the milk, moisture content, and length of aging, in addition to the presence of specific molds, yeast, and bacteria. Among the most important bacteria, lactic acid bacteria (LAB) play a critical role during the cheese-making process. In general, LAB contain cell-envelope proteinases that contribute to the proteolysis of cheese proteins, breaking them down into oligopeptides that can be subsequently taken up by cells via specific peptide transport systems or further degraded into shorter peptides and amino acids through the collaborative action of various intracellular peptidases. Such peptides, amino acids, and their derivatives contribute to the development of texture and flavor in the final cheese. In vitro and in vivo assays have demonstrated that specific sequences of released peptides exhibit biological properties including antioxidant, antimicrobial, anti-inflammatory, immunomodulatory, and analgesic/opioid activity, in addition to angiotensin-converting enzyme inhibition and antiproliferative activity. Some LAB also produce functional lipids (e.g., conjugated linoleic acid) with anti-inflammatory and anticarcinogenic activity, synthesize vitamins and antimicrobial peptides (bacteriocins), or release γ-aminobutyric acid, a nonprotein amino acid that participates in physiological functions, such as neurotransmission and hypotension induction, with diuretic effects. This review provides an overview of the main bioactive components present or released during the ripening process of different types of cheese.

The use of energy-protein supplement increases performance of high-yielding dairy cows and improves health-promoting properties of milk

Lipid additives are of particular importance in the diet of high-yielding dairy cows. The aim of this study was to determine the effects of a specially designed energy-protein supplement on dairy cows’ performance and milk composition. The experiment was conducted on 24 Polish Holstein-Friesian cows fed total mixed ration. Two kilograms of energy-protein supplement/cow.day were added to the ration for one group of cows whereas the other was fed solely the total mixed ration. The supplement consisted of whole flax seeds, wheat bran, flaxseed and fish oils, and rapeseed cake and its composition is protected by a patent. Feed intake and daily milk yield were recorded automatically for each cow. Gross milk composition and fatty acid profile of milk were determined. An ANOVA was performed to determine the influence of the supplement on performance traits and milk composition. Energy-protein supplement had a positive impact on dry matter intake and milk yield of cows. It had a little effect on the gross milk composition and somatic cell count. The effect of the additive on fatty acids in milk was beneficial, therefore its use in high-yielding dairy cows nutrition is recommended to improve health-promoting properties of milk.

Effect of high-oleic-acid soybeans on production performance, milk fatty acid composition, and enteric methane emission in dairy cows

The objective of this study was to investigate the effect of 3 soybean sources differing in fatty acid profile and processing method on productivity, milk composition, digestibility, rumen fermentation, and enteric methane emission in lactating dairy cows. The soybean sources were conventional, high-linoleic-acid variety extruded soybean meal (ESBM; 8.7% ether extract with 15% oleic and 54% linoleic acids); extruded Plenish (DuPont Pioneer, Johnston, IA), high-oleic-acid variety soybean meal (EPSBM; 8.4% ether extract with 73% oleic and 8% linoleic acids); and whole, heated Plenish soybeans (WPSB; 20.2% ether extract). The study involved 15 Holstein cows in a replicated 3 × 3 Latin square design experiment with three 28-d periods. The inclusion rate of the soybean sources in the diet was (dry matter basis) 17.1, 17.1, and 7.4% for ESBM, EPSBM, and WPSB, respectively, which resulted in ether extract concentration of the diets of 3.99, 3.94, and 4.18%, respectively. Compared with ESBM, the Plenish diets tended to increase dry matter intake and decreased feed efficiency (but had no effect on energy-corrected milk feed efficiency). The Plenish diets increased milk fat concentration on average by 5.6% and tended to increase milk fat yield, compared with ESBM. The WPSB diet tended to increased milk true protein compared with the extruded soybean meal diets. Treatments had no effect on rumen fermentation and enteric methane or carbon dioxide emissions, except pH was higher for WPSB versus EPSBM. The Plenish diets decreased the prevalence of Ruminococcus and increased that of Eubacterium and Treponema in whole ruminal contents. Total-tract apparent digestibility of organic matter and crude protein were decreased by WPSB compared with ESBM and EPSBM. Compared with the other treatments, urinary N excretion was increased by EPSBM and fecal N excretion was greater for WPSB. Treatments had marked effects on milk fatty acid profile. Generally, the Plenish diets increased mono-unsaturated (mostly cis-9 18:1) and decreased polyunsaturated, total trans-, and conjugated linoleic fatty acids concentrations in milk fat. In this study, compared with conventional, high-linoleic-acid variety extruded soybean meal, the Plenish soybean diets increased milk fat concentration and tended to increase fat yield, decreased feed efficiency, and modified milk fatty acid profile in a manner expected from the greater concentration of oleic acid in Plenish soybean oil.

Effect of increased feeding of dietary α-linolenic acid by grazing on formation of the cis9,trans11-18:2 isoform of conjugated linoleic acid in bovine milk

Feeding systems such as grazing affect the fatty acid profile of bovine milk fat. In addition, milk fat is formed as the product of fatty acid metabolism in cow bodies before being secreted into milk. However, how grazing influences milk fatty acid profile through the metabolism has not been completely characterized. When fatty acid concentrations in Holstein milk were compared between grazing and non-grazing periods, α-linolenic acid was significantly higher in the grazing period than in the non-grazing period. This could be explained with an increase in α-linolenic acid feeding with grazing. α-linolenic acid had a linear positive correlation with conjugated linoleic acid (9c,11t-18:2) (CLA) and vaccenic acid (VA) during the grazing period, whereas CLA had higher correlation with linoleic acid rather than with α-linolenic acid during the non-grazing period. These data indicate that the high content of dietary α-linolenic acid affects CLA and VA formation in milk of grazing periods via α-linolenic acid metabolism into VA.

Independent effects of dietary linoleic and linolenic fatty acids on the conjugated linoleic acid content of cows’ milk

It may be desirable to increase the level of conjugated linoleic acid (CLA) in milk as a health benefit in human nutrition. The purpose of this work was to separate the effects of linoleic and linolenic acids on CLA production in dairy cows and to determine to what extent endogenous synthesis contributes to cis-9, trans-11 CLA concentration in milk fat. Eight lactating cows and four non-lactating duodenal fistulated cows were used in a 4 ✕ 4 Latin-square design. All cows received a basal diet of grass silage that was supplemented with one of four concentrates, which were designed to differ in their linoleic and linolenic acid contents. The oil components of the concentrates were produced from mixtures of olive, linseed, rape, soya and sunflower oils to produce the four treatments: low linoleic/ low linolenic acid (LL), low linoleic/high linolenic acid (LH), high linoleic/low linolenic acid (HL) and high linoleic/ high linolenic acid (HH). Milk cis-9, trans-11 CLA contents were 0·8, 0·9, 0·9 and 1·1 g/100 g fatty acid methyl esters (P < 0·05) and yields were 5, 7, 7 and 8 g/day (P < 0·05) for the LL, LH, HL and HH treatments, respectively. The yields of trans-C18:1 fatty acids in milk were 19, 22, 21 and 23 g/day (P < 0·05), respectively. Taking the data for the cis-9, trans-11 CLA content and flow of duodenal fluid from the fistulated cows and representing this in terms of dietary intake by the lactating animals, the amounts of cis-9, trans-11 CLA produced in the rumen were calculated to be 0·8, 0·9, 1·2 and 1·1 g/day (P < 0·05) and for trans-C18:1 fatty acids 58, 58, 66 and 69 g/day (P < 0·05). Increasing linoleic and/or linolenic acids in the diet can increase the cis-9, trans-11 CLA content of cows’ milk. Only diets high in linoleic acid increased cis-9, trans-11 CLA production in the rumen. On all four diets, more than 80% of cis-9, trans-11 CLA in milk was produced endogenously by Δ9-desaturase from trans-11 C18:1 in the mammary gland. Cows on the same diet have different milk fat cis-9, trans-11 CLA concentrations that may be partially explained by differences in Δ9-desaturase activity between cows. Increasing the activity of Δ9-desaturase in the mammary gland may offer greater potential for enhancing the cis-9, trans-11 CLA content of milk fat than increasing cis-9, trans-11 CLA production in the rumen.

Effect of finishing system (feedlot or pasture), high-oil maize, and copper on conjugated linoleic acid and other fatty acids in muscle of finishing steers

Sixty Angus steers (413 ± 8.0 kg) were used to determine the effects of copper (Cu), maize type, and finishing system (confinement v. pasture) on performance, carcass characteristics, and fatty acid composition of longissimus muscle in steers. Steers in confinement were given individually high concentrate diets containing either typical or high-oil maize, using Calan gate feeders. Steers grazing pasture (tall fescue) were maintained in four pastures with each pasture containing five steers. Salt was used to limit concentrate intake in pasture steers to approximately 0.6 of that observed in confinement steers. One half of the steers in each treatment received a CuO needle bolus at the initiation of the study while the remaining steers received no supplemental Cu. Equal numbers of steers per treatment were harvested after 91, 112 or 133 days on food. Rate of gain was lower (P < 0.01; 1.2 v. 1.6 kg/day) for pasture-fed steers compared with steers receiving typical maize. Cu supplementation increased (P < 0.05) ADG in steers given typical maize (1.8 v. 1.5 kg/day) and those on pasture (1.3 v. 1.1 kg/day) but not in steers given high-oil maize diets (1.5 v. 1.5 kg/day). Gain, dry-matter intake and gain/food did not differ between steers given typical or high-oil maize. Plasma cholesterol concentrations were lower (P < 0.01) in steers given typical maize relative to steers given high-oil maize. Steers receiving a Cu bolus had higher plasma (P < 0.05) and liver (P < 0.01) Cu concentrations than steers not receiving a Cu bolus. Steers receiving typical maize had lower (P < 0.05) liver Cu concentrations than steers receiving high-oil maize. Steers finished on pasture with limited concentrate had conjugated linoleic acid (CLA) concentrations in longissimus muscle that were approximately three times higher (P < 0.01) than steers given typical maize. Cu supplementation tended (P < 0.10) to increase muscle CLA. Longissimus muscle from pasture-fed steers was lower (P < 0.01) in C16: 0 and higher (P < 0.05) in C10: 0, C17: 0, C18: 3, C20: 3 and total polyunsaturated fatty acids than steers given typical maize. Muscle C18: 1 trans and C17: 0 tended to be reduced (P < 0.10) by Cu supplementation. These results indicate that finishing cattle on pasture with limited grain increases CLA in longissimus muscle and that Cu supplementation also alters the fatty acid composition of muscle.

Effect of dietary lipid on the content of conjugated linoleic acid (CLA) in beef muscle

We have examined the effect of dietary fats containing n-3 polyunsaturated fatty acids on the conjugated linoleic acid (CLA) content of beef m. longissimus lumborum. Four groups of eight Charolais steers were given, for 120 days, grass silage plus a barley/sugar-beet feed concentrate containing one of four fat supplements: Megalac (saturated), linseed (high 18: 3),fish oil (high 20: 5 n-3, eicosapentenoic acid and 22: 6 n-3, docosahexaenoic acid) or linseed plus fish oil. The concentrates supplied 400 g/kg dry-matter (DM) intake and were designed to supply 45 g/kg of the total dietary fat calculated to be 60 g/kg of DM and to contain similar amounts of linoleic acid. Muscle from steers given the Megalac supplement contained 11·3 mg CLA per 100 g muscle and this was increased two- to three-fold in animals given the more unsaturated fat supplements. The increased deposition of CLA was similar for both linseed and fish oil supplements although the concentrations of total n-3 polyunsaturated fatty acids in the fish oil diet were much less than in the linseed diet. This suggests potent inhibition of conversion of CLA to trans vaccenic acid by fish oil fatty acids or their rumen metabolites.

High density genome wide genotyping-by-sequencing and association identifies common and low frequency SNPs, and novel candidate genes influencing cow milk traits

High-throughput sequencing technologies have increased the ability to detect sequence variations for complex trait improvement. A high throughput genome wide genotyping-by-sequencing (GBS) method was used to generate 515,787 single nucleotide polymorphisms (SNPs), from which 76,355 SNPs with call rates >85% and minor allele frequency ≥1.5% were used in genome wide association study (GWAS) of 44 milk traits in 1,246 Canadian Holstein cows. GWAS was accomplished with a mixed linear model procedure implementing the additive and dominant models. A strong signal within the centromeric region of bovine chromosome 14 was associated with test day fat percentage. Several SNPs were associated with eicosapentaenoic acid, docosapentaenoic acid, arachidonic acid, CLA:9c11t and gamma linolenic acid. Most of the significant SNPs for 44 traits studied are novel and located in intergenic regions or introns of genes. Novel potential candidate genes for milk traits or mammary gland functions include ERCC6, TONSL, NPAS2, ACER3, ITGB4, GGT6, ACOX3, MECR, ADAM12, ACHE, LRRC14, FUK, NPRL3, EVL, SLCO3A1, PSMA4, FTO, ADCK5, PP1R16A and TEP1. Our study further demonstrates the utility of the GBS approach for identifying population-specific SNPs for use in improvement of complex dairy traits.

Atheroprotective effects of conjugated linoleic acid

Atherosclerosis, the underlying cause of heart attack and strokes, is a progressive dyslipidaemic and inflammatory disease where monocyte-derived macrophage cells play a pivotal role. Although most of the mechanisms that contribute to the progression of atherosclerosis have been identified, there is limited information on those governing regression. Conjugated linoleic acid (CLA) is a generic term denoting a group of naturally occurring isomers of linoleic acid (18:2, n6) that differ in the position or geometry (i.e. cis or trans) of their double bonds. The most predominant isomers in ruminant fats are cis-9, trans-11 CLA (c9,t11-CLA), which accounts for more than 80% of CLA isomers in dairy products and trans-10, cis-12 CLA (t10,c12-CLA). Dietary administration of a blend of the two most abundant isomers of CLA has been shown to inhibit the progression and induce the regression of pre-established atherosclerosis. Studies investigating the mechanisms involved in CLA-induced atheroprotective effects are continually emerging. The purpose of this review is to discuss comprehensively the effects of CLA on monocyte/macrophage function in atherosclerosis and to identify possible mechanisms through which CLA mediates its atheroprotective effects.

Advances in research on cis-9, trans-11 conjugated linoleic acid: a major functional conjugated linoleic acid isomer

Conjugated linoleic acid (CLA) consists of a group of positional and geometric conjugated isomers of linoleic acid. Since the identification of CLA as a factor that can inhibit mutagenesis and carcinogenesis, thousands of studies have been conducted in the last several decades. Among the many isomers discovered, cis-9, trans-11 CLA is the most intensively studied because of its multiple, isomer-specific effects in humans and animals. This paper provides an overview of the available data on cis-9, trans-11 CLA, including its isomer-specific effects, biosynthesis, in vivo/in vitro research models, quantification, and the factors influencing its content in ruminant products.

Effect of supplementation of fish and canola oil in the diet on milk Fatty Acid composition in early lactating holstein cows

This study examined the effects of supplementation of fish oil and canola oil in the diet on milk yield, milk components and fatty acid composition of Holstein dairy cows in early lactation. Eight multiparous early lactation Holstein cows (42±12 DIM, 40±6 kg daily milk yield) were fed a total mixed ration supplemented with either 0% oil (Control), 2% fish oil (FO), 1% canola oil +1% fish oil (FOCO), or 2% canola oil (CO) according to a double 4×4 Latin square design. Each period lasted 3 wk; experimental analyses were restricted to the last week of each period. Supplemental oils were added to a basal diet which was formulated according to NRC (2001) and consisted of 20% alfalfa, 20% corn silage and 60% concentrate. Milk yield was similar between diets (p>0.05), but dry matter intake (DMI) was lower (p<0.05) in cows fed FO diet compared to other diets. Milk fat percentage and daily yield decreased (p<0.01) with the supplementation of fish and canola oil. The daily yield and percentage of milk protein, lactose and solids-not-fat (SNF) were not affected by diets (p>0.05). The proportion (g/100 g fatty acids) of short chain fatty acids (SCFA) decreased and polyunsaturated fatty acids (PUFA) increased (p<0.05) in milk of all cows fed diets supplemented with oil. The proportions of 6:0, 8:0, 10:0 12:0 and 14:0 fatty acids in milk fat decreased (p<0.01) for all diets supplemented with oil, but the proportions of 14:1, 16:0 and 16:1 fatty acids were not affected by diets (p>0.05). The proportion of trans(t)-18:1 increased (p<0.01) in milk fat of cows fed FO and FOCO diets, but CO diet had the highest proportion of cis(c)-11 18:1 (p<0.01). The concentration of t-10, c-12 18:2, c-9 t-11 18:2, 18:3, eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6) increased (p<0.05) in FO and FOCO diets in comparison with the other two diets. These data indicate that including fish oil in combination with canola oil significantly modifies the fatty acid composition of milk.

Estabilidade oxidativa e perfil de ácidos graxos do leite de vacas suplementadas com óleo de linhaça na dieta associado ou não ao selenito de sódio injetável

Avaliou-se o efeito da suplementação com óleo de linhaça na dieta, com ou sem injeção de selenito de sódio, sobre o perfil de ácidos graxos e sobre a estabilidade oxidativa do leite de vacas leiteiras. Catorze vacas foram distribuídas em três tratamentos: as do grupo 1, que receberam diariamente 400mL de óleo de linhaça (LIN); as do grupo 2, 400mL de óleo de linhaça + 0,2mg/kg de selenito de sódio IM (LINSe); e as do grupo 3 (controle), que não foram tratadas (C). O óleo foi fornecido diariamente após 15 dias da aplicação única de selenito de sódio, e o experimento teve duração de quatro semanas. Os animais suplementados com o óleo de linhaça produziram leite com altas porcentagens de ácido linoleico conjugado (CLA) e de ômega 3, contudo mais suscetível à oxidação. A aplicação injetável de selenito de sódio mostrou-se eficaz ao impedir a oxidação prematura do leite. Concluiu-se que a inclusão do óleo de linhaça na dieta de vacas leiteiras resulta em aumento do CLA, do ômega 3 e, consequentemente, da oxidação do leite, necessitando, assim do uso de substâncias antioxidantes ou promotores antioxidantes, como o selenito de sódio injetável.

Evaluation of FT-NIR and ATR-FTIR spectroscopy techniques for determination of minor odd- and branched-chain saturated and trans unsaturated milk fatty acids

Determination of nutritionally important trans MUFA, CLA, and OBCFA milk fatty acids (often present in amounts lower than 1.0 g/100 g of total fat) using fast and nondestructive analytical methods would enhance their use as diagnostic tools in dairy herd and human health management. Here, PLS regression using ATR/FTIR spectra indicated potential for determination of trans-11 C18:1 and trans-12 C18:1 (Rcv² ≥ 0.80), and trans-9 C18:1 in very minor concentration (Rcv² > 0.82), as well as anteiso C15:0 (Rcv² = 0.57) and iso C17:0 (Rcv² = 0.61). Furthermore, the main cis-9,trans-11 CLA isomer was predicted well despite the high trans MUFA concentration. Differentiation between the CLA and the trans MUFA signals was evident (based on specific cis/trans bands), and branched-chain saturated fatty acid methyl esters revealed specific iso and anteiso ATR/FTIR absorbance bands. None of the minor FA PLS results with FT-NIR showed interesting potential, except satisfactory predictions for trans-9 C18:1 and cis-9,trans-11 CLA. Overall, ATR/FTIR resulted in better calibrations and provided more specific information for determination of minor milk fatty acids.

Effects of increasing supplementation levels of rice bran on milk production and fatty acid composition of milk in Saanen dairy goats

In this study, the effects of four dietary supplementation levels of rice bran (RB) on milk yield and composition were examined in Saanen dairy goats. Four goats (initial bodyweight, 55.0 ± 7.1 kg) and four 21-day periods were used in a 4 × 4 Latin-square design. The diets contained 0, 5, 10, and 20% DM of RB, but were otherwise formulated to be 10.7 MJ metabolisable energy/kg and 18.8% crude protein/kg DM. Goats consumed the greatest amount of DM feed concentrate when fed the 5% RB diet (P < 0.01); however, DM forage intake was not significantly different between diets. Total DM intake of the 5% RB diet was significantly higher than that of the control diet (P < 0.05). Milk yield was the lowest from goats fed the 20% RB (P < 0.01). The protein concentration of milk was significantly lower in goats fed the control and 5% RB diets than in those fed the 10 and 20% RB diets (P < 0.01). However, milk protein production was not significantly different between diets. The concentration of fat in milk increased as the supplementation level of RB increased, although fat production did not differ between diets. The addition of RB increased the concentration of long-chain fatty acids (C16 and C18) in goat milk. No significant difference was found in milk lactose concentration between diets. Overall, the results indicate that RB supplements of up to 10% have no adverse effects on DM intake and milk production in dairy goats.

Enhanced anticancer activity of gemcitabine coupling with conjugated linoleic acid against human breast cancer in vitro and in vivo

Gemcitabine (GEM) is a nucleoside analog agent against a wide variety of tumors. To overcome its limitation of rapid metabolism in vivo that results in short circulation time and poor antitumor efficacy, a novel prodrug (CLA-GEM conjugate) has been developed through the covalent coupling of conjugated linoleic acid (CLA) to N(4)-amino group of GEM. The chemical structure of CLA-GEM conjugate was identified by NMR, FTIR and other methods. From in vitro tests, it was demonstrated that the linkage with CLA increased the plasma stability of GEM as well as the antitumor activity against human breast tumor cells (MCF-7). Importantly, it also altered the transport pattern of GEM across cell membrane (MCF-7 and MDA-MB-231), evidenced by the little effect of nucleoside transporter inhibitors (NBMPR and dipyridamole) on the IC(50) values of CLA-GEM, instead of the great effect on that of unmodified GEM. In vivo pharmacokinetic study showed that the CLA-GEM conjugate had a longer plasma half-life and a higher bioavailability compared to that of unmodified GEM. Significant stronger antitumor activity was observed in the nude mice xenografted MCF-7 breast tumor after treated with CLA-GEM than that of unmodified GEM, while no significant body weight loss was found in all treatments. In conclusion, the novel CLA-GEM conjugate prepared in this study would be a promising prodrug of gemcitabine for future clinical use.