scholarly journals Relationships Between Milk and Milk Fat Composition and Trans-Lactation Changes in Mammary Gland Enzyme Activities in Grazing Cattle

1972 ◽  
Vol 25 (6) ◽  
pp. 1341 ◽  
Author(s):  
WB Currie
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Palmitic Acid ◽  
Enzyme Activities ◽  
Milk Fat ◽  
Blood Lipids ◽  
De Novo ◽  
Grazing Cattle ◽  
Fat Composition

Ohanges in milk and milk fat composition during complete lactations of four grazing cows are described. Correlations among the proportions of pairs of milk fat fatty acids were interpreted to indicate that fatty acids were of three groups-those reaching the gland preformed as blood lipids, those synthesized de novo in the gland, and a fraction, chiefly palmitic' acid, derived from both sources. The pro-portions of all groups of acids varied in an erratic manner compared with steady changes observed in other studies with cows on controlled feeding.

scholarly journals Fatty acids and composition of their important groups in milk fat of Czech Pied cattle

2011 ◽  
Vol 51 (No. 5) ◽  
pp. 181-188 ◽  
Author(s):  
M. Pešek ◽  
E. Samková ◽  
J. Špička
Keyword(s):  
Fatty Acids ◽  
Palmitic Acid ◽  
Dairy Cows ◽  
Milk Fat ◽  
Chromatographic Method ◽  
Monounsaturated Fatty Acids ◽  
Fat Composition ◽  
Total Proportion ◽  
The Individual ◽  
Gas Chromatographic Method

In 2003, 2004 and 2005 milk fat composition was determined three times in 55 dairy cows of Czech Pied cattle housed in a byre with stanchions and fed under conditions usual on Czech production farms. Fatty acids were determined by a gas chromatographic method, 26 acids out of the total 37 acids observed in chromatograms were identified. The highest proportions were observed for palmitic acid (29.25 ± 2.98%), oleic acid (24.47 ± 3.27%), myristic acid (12.14 ± 1.80%) and stearic acid (8.91 ± 2.44%). The proportions of saturated, unsaturated and monounsaturated fatty acids were 64.71 ± 4.18, 31.96 ± 4.20 and 27.45 ± 3.42% of total acids, respectively. The total proportion of nutritionally undesirable lauric, myristic and palmitic acid was 45.26 ± 4.77%, while that of the desirable group of polyunsaturated fatty acids was 4.51 ± 1.09%. The observed relatively wide ranges of the individual groups of fatty acids indicate that it is possible to improve the milk fat composition in Czech Pied cows.  

scholarly journals A Review of the Metabolic Origins of Milk Fatty Acids

2013 ◽  
Vol 5 (3) ◽  
pp. 270-274 ◽  
Author(s):  
Anamaria COZMA ◽  
Doina MIERE ◽  
Lorena FILIP ◽  
Sanda ANDREI ◽  
Roxana BANC ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Milk Fat ◽  
De Novo ◽  
Long Chain Fatty Acids ◽  
De Novo Synthesis ◽  
Ruminal Biohydrogenation ◽  
Long Chain ◽  
Chain Fatty Acids

Milk fat and its fatty acid profile are important determinants of the technological, sensorial, and nutritional properties of milk and dairy products. The two major processes contributing to the presence of fatty acids in ruminant milk are the mammary lipogenesis and the lipid metabolism in the rumen. Among fatty acids, 4:0 to 12:0, almost all 14:0 and about a half of 16:0 in milk fat derive from de novo synthesis within the mammary gland. De novo synthesis utilizes as precursors acetate and butyrate produced through carbohydrates ruminal fermentation and involves acetyl-CoA carboxylase and fatty acid synthetase as key enzymes. The rest of 16:0 and all of the long-chain fatty acids derive from mammary uptake of circulating lipoproteins and nonesterified fatty acids that originate from digestive absorption of lipids and body fat mobilization. Further, long-chain fatty acids as well as medium-chain fatty acids entering the mammary gland can be desaturated via Δ-9 desaturase, an enzyme that acts by adding a cis-9-double bond on the fatty acid chain. Moreover, ruminal biohydrogenation of dietary unsaturated fatty acids results in the formation of numerous fatty acids available for incorporation into milk fat. Ruminal biohydrogenation is performed by rumen microbial population as a means of protection against the toxic effects of polyunsaturated fatty acids. Within the rumen microorganisms, bacteria are principally responsible for ruminal biohydrogenation when compared to protozoa and anaerobic fungi.

Synthesis of milk fat and opportunities for nutritional manipulation

2000 ◽  
Vol 25 ◽  
pp. 201-223 ◽  
Author(s):  
J.J. Murphy
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Linoleic Acid ◽  
Milk Fat ◽  
Unsaturated Fatty Acids ◽  
De Novo ◽  
Bovine Milk ◽  
Dietary Factors ◽  
De Novo Synthesis ◽  
Long Chain

AbstractMilk fat consists of approximately 960-980 g of triacylglycerol, 20-25 g of 1,2-diacylglycerol, 10 g of phospholipid, 5g of cholesterol and very small quantities of free fatty acids and monoacylglycerol per kg. There are three stages in milk fat biosynthesis: the accumulation of fatty acids in the mammary cells through de-novo synthesis or absorption from the blood stream, triacylglycerol construction and fat globule assembly and secretion. Fatty acids in mammary secretory cells arise from two sources. Those having between 4 and 14 carbon atoms are synthesised de-novo in the mammary gland whereas those with 18 carbon atoms are of dietary origin and are absorbed from the blood stream. Palmitic acid (16 carbon atoms) is supplied almost equally from the diet and de-novo synthesis. In ruminants the principal sources of carbon for fatty acid synthesis are acetic acid and b-hydroxybutyrate.Alteration of milk fat concentration is achieved by changimore spreadable butter. Monounsaturated fatty acids in the diet have been shown to have beneficial effects on the plasma lipoprotein indicators of coronary heart disease risk. From a human nutrition point of view it could be beneficial to incorporate the long chain omega-3 fatty acids, eicosapentanoic (EPA, C20:5) and docosahexanoic (C22:6) acids, into milk fat. The principal source of these fatty acids is fish oil but research to date indicates that their transfer into milk fat is inefficient. Conjugated linoleic acid (CLA) is a collective term describing one or more positional and geometric isomers of linoleic acid (cis-9, cis-12 C18:2). CLA has been shown to have anticarcinogenic activity, antiatherogenic activity, an ability to reduce the catabolic effects of immune stimulation and an ability to enhance growth promotion and reduce body fat. It is present in ruminant milk and meat as a result of biohydrogenation in the rumen where it is an intermediate. Its concentration in bovine milk fat is influenced by dietary factors such as pasture feeding and supplementation with full fat oilseeds. Two other components of bovine milk fat which have been shown to have anticarcinogenic properties are butyric acid and sphingomyelin and their concentration warrants further study. It is likely that research will continue into means of manipulating both the content and composition of milk fat but ultimately the adoption of any of the strategies in practice is likely to depend on strong economic or consumer imperatives.ng either the level of de-novo synthesis in the mammary gland or the supply of long chain fatty acids in the diet. Dietary factors that affect the supply of acetic acid from the rumen for de-novo synthesis include fibre quantity and quality, forage to concentrate ratio, buffer inclusion, concentrate composition and concentrate feeding frequency. The effects of fat supplements on fat concentration are variable. In general, feeding rumen protected fat increases milk fat concentration whereas moderate amounts of unprotected unsaturated fat tend to decrease it.Most nutritional manipulation has been directed at increasing the proportion of unsaturated fatty acids in milk fat in order to enhance its appeal to the consumer and to produce a softer fat. A more spreadable butter could be produced from such fat thus overcoming a major criticism of conventional butter.If unsaturated fatty acids are fed to ruminants in an unprotected form rumen microbial digestion can be impaired and the unsaturated fatty acids are extensively saturated in the rumen. One strategy to overcome this is to include unsaturated fatty acids in a form protected from microbial digestion in the rumen. This resulted in the production of polyunsaturated milk fat from which a low melting point butter was produced. This product was predisposed to oxidative deterioration. More recently whole oilseeds have been fed to dairy cows. The unsaturated 18-carbon fatty acids in these seeds are hydrogenated in the rumen but the activity of a D-9 desaturase in the mammary gland and to a lesser extent the intestine converts the stearic acid (C18:0) to the monounsaturated fatty acid, oleic acid (C18:1). Milk fat rich in oleic acid is softer than conventional milk fat allowing the manufacture of a more spreadable butter. Monounsaturated fatty acids in the diet have been shown to have beneficial effects on the plasma lipoprotein indicators of coronary heart disease risk.From a human nutrition point of view it could be beneficial to incorporate the long chain omega-3 fatty acids, eicosapentanoic (EPA, C20:5) and docosahexanoic (C22:6) acids, into milk fat. The principal source of these fatty acids is fish oil but research to date indicates that their transfer into milk fat is inefficient. Conjugated linoleic acid (CLA) is a collective term describing one or more positional and geometric isomers of linoleic acid (cis-9, cis-12 C18:2). CLA has been shown to have anticarcinogenic activity, antiatherogenic activity, an ability to reduce the catabolic effects of immune stimulation and an ability to enhance growth promotion and reduce body fat. It is present in ruminant milk and meat as a result of biohydrogenation in the rumen where it is an intermediate. Its concentration in bovine milk fat is influenced by dietary factors such as pasture feeding and supplementation with full fat oilseeds. Two other components of bovine milk fat which have been shown to have anticarcinogenic properties are butyric acid and sphingomyelin and their concentration warrants further study.It is likely that research will continue into means of manipulating both the content and composition of milk fat but ultimately the adoption of any of the strategies in practice is likely to depend on strong economic or consumer imperative.

Persistency of milk trans-18:1 isomers and rumenic acid in Holstein cows over a full lactation

2011 ◽  
Vol 91 (1) ◽  
pp. 147-167 ◽  
Author(s):  
Riazuddin Mohammed ◽  
Reza Khorasani ◽  
Laksiri Goonewardene ◽  
John Kramer ◽  
John Kennelly
Keyword(s):  
Fatty Acids ◽  
Milk Fat ◽  
De Novo ◽  
Vaccenic Acid ◽  
Methyl Esters ◽  
Control Diet ◽  
Barley Grain ◽  
Holstein Cows ◽  
Test Diet ◽  
Barley Silage

Mohammed, R., Khorasani, R. G., Goonewardene, L. A., Kramer, J. K. G. and Kennelly, J. J. 2011. Persistency of milk trans-18:1 isomers and rumenic acid in Holstein cows over a full lactation. Can. J. Anim. Sci. 91: 147–167. A long-term lactation study was undertaken to determine whether the previously reported short-term persistency in vaccenic acid [VA; trans(t)11-18:1] and rumenic acid (RA) could be maintained. To test this hypothesis, 24 Holstein cows were allotted to two experimental diets (control and test) from 2 wk before calving until they were 270 d in milk (DIM). The test diet was similar to the control diet, but supplemented with sunflower seed (11.2% diet DM), fish oil (0.5%) and monensin (22 mg/kg DM) by replacing an equivalent amount of barley grain. The forage: concentrate ratio was 50:50 (DM basis) with 35% barley silage and 15% alfalfa hay. Milk was sampled every fortnight from the start of lactation until cows were 270 DIM. Data obtained were averaged into three equal periods of 90 d each, representing three stages of lactation (SOL): early-lactation (EL), mid-lactation (ML) and late-lactation (LL). Dry matter intakes were not different between treatments with greater intakes observed during ML than during EL or LL. Milk yield was not different between treatments and decreased with increasing DIM. Milk fat content and yield showed interaction between treatment and SOL with lower values observed for the test diet than control diet during EL and ML. De novo synthesized fatty acids (4:0–15:0), 16:0–16:1 and preformed fatty acids (17:0 and above) showed interaction between treatment and SOL with the former two being greater for control diet than test diet and the latter greater for the test diet than control diet within each SOL. Milk t10-18:1 (% fatty acid methyl esters, FAME) was greater for the test diet compared with control diet (4.38 vs. 1.32) and was greater during ML (3.79) than during EL (2.38) or LL (2.38). Milk VA and RA showed interactions between treatment and SOL with greater values observed for the test diet than the control diet within each SOL. When analyzed by treatment, milk VA was not different across SOL for both diets. Milk RA was not different across SOL for the test diet, but was different for the control diet; it was lower during EL than during ML. Step-wise regression analysis revealed that the variability in milk RA for the control diet (P<0.01; R2=0.97) was determined by VA (70%) and RA/VA (27%); and for the test diet (P<0.01; R2=0.987) by VA (88.7%), RA/VA (5%) and t10-18:1 (3.8%). Desaturase index based on RA/VA showed an interaction between treatment and SOL; it was greater for the control diet than the test diet within each SOL. Overall findings revealed that the differences in milk t10- and VA across SOL reflected possible differences in starch and PUFA intakes, respectively. Differences in milk RA across SOL for the control diet could be attributed to possible differences in mammary desaturase activity based on differences in RA/VA.

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

2002 ◽  
Vol 74 (1) ◽  
pp. 163-176 ◽  
Author(s):  
A.L. Lock ◽  
P.C. Garnsworthy
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Linolenic Acid ◽  
Milk Fat ◽  
Latin Square ◽  
Health Benefit ◽  
Low Linolenic Acid ◽  
Low Linolenic

AbstractIt 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.

scholarly journals Comparison of fatty acid composition in milk fat of Czech Pied cattle andHolsteincattle

2011 ◽  
Vol 50 (No. 3) ◽  
pp. 122-128 ◽  
Author(s):  
M. Pešek ◽  
J. Špička ◽  
E. Samková
Keyword(s):  
Fatty Acids ◽  
Milk Fat ◽  
Methyl Esters ◽  
Capric Acid ◽  
Holstein Cows ◽  
The Czech Republic ◽  
Milk Samples ◽  
Daily Diet ◽  
Fat Composition ◽  
The Individual

In May 2003 differences in milk fat composition in two main dairy breeds in the Czech Republic, Czech Pied cattle and Holstein cattle, were studied in two uniform groups, each containing eight cows. The groups were housed together and received the same daily diet. Fatty acids were determined in mean milk samples from the individual cows as their methyl esters using a gas chromatography procedure. The groups of the fatty acids, namely saturated (SAFA), monounsaturated (MUFA) and polyunsaturated (PUFA) ones, were examined together with the individual acids. The milk fat of Czech Pied cattle was found to contain significantly less SAFAs than the fat of Holstein cows (60.78 and 63.62% of total acids; P &lt; 0.05). Determined mean MUFA contents (27.64 and 25.76%) and total levels (34.31 and 32.11%) of all the unsaturated acids (MUFAs and PUFAs) were insignificantly elevated in the milk fat of Czech Pied cattle. The contents of the most of the individual fatty acids did not differ considerably between the breeds. In Holstein cows, significantly higher contents (P &lt; 0.05) of capric acid (C<sub>10:0</sub>) and stearic acid (C<sub>18:0</sub>) 3.30 and 4.45%, respectively, as compared with 2.69 and 2.61% for Czech Pied cows, were observed. The milk fat of Czech Pied cows had significantly higher contents of oleic acid (C<sub>18:1</sub>) 23.60% (P &lt; 0.05) and of an isomer of octadecatrienic acid (C<sub>18:3n4</sub>) 0.16% (P &lt; 0.001) as compared with 21.68 and 0.10%, respectively, in the fat ofHolstein cows. &nbsp;

scholarly journals Risk of diabetes associated with fatty acids in the de novo lipogenesis pathway is independent of insulin sensitivity and response: the Insulin Resistance Atherosclerosis Study (IRAS)

2019 ◽  
Vol 7 (1) ◽  
pp. e000691 ◽  
Author(s):  
Waqas Qureshi ◽  
Ingrid D Santaren ◽  
Anthony J Hanley ◽  
Steven M Watkins ◽  
Carlos Lorenzo ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Fatty Acids ◽  
Insulin Sensitivity ◽  
Palmitic Acid ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Diabetes Incidence ◽  
Incident Type ◽  
Insulin Resistance Atherosclerosis Study

ObjectiveTo examine the associations of fatty acids in the de novo lipogenesis (DNL) pathway, specifically myristic acid (14:0), palmitic acid (16:0),cis-palmitoleic acid (c16:1 n-7),cis-myristoleic acid (c14:1n5), stearic acid (18:0) andcis-oleic acid (c18:1 n-9), with 5-year risk of type 2 diabetes. We hypothesized that DNL fatty acids are associated with risk of type 2 diabetes independent of insulin sensitivity.Research design and methodsWe evaluated 719 (mean age 55.1±8.5 years, 44.2% men, 42.3% Caucasians) participants from the Insulin Resistance Atherosclerosis Study. Multivariable logistic regression models with and without adjustment of insulin sensitivity were used to assess prospective associations of DNL fatty acids with incident type 2 diabetes.ResultsType 2 diabetes incidence was 20.3% over 5 years. In multivariable regression models, palmitic, palmitoleic, myristic, myristoleic and oleic acids were associated with increased risk of type 2 diabetes (p<0.05). Palmitic acid had the strongest association (OR per standard unit of palmitic acid 1.46; 95% CI 1.23 to 1.76; p<0.001), which remained similar with addition of insulin sensitivity and acute insulin response (AIR) to the model (OR 1.36; 95% CI 1.09 to 1.70, p=0.01). Oleic and palmitoleic acids were also independently associated with incident type 2 diabetes. In multivariable models, ratios of fatty acids corresponding to stearoyl CoA desaturase-1 and Elovl6 enzymatic activity were significantly associated with risk of type 2 diabetes independent of insulin sensitivity and AIR.ConclusionsWe observed associations of DNL fatty acids with type 2 diabetes incidence independent of insulin sensitivity.

Expression and nutritional regulation of lipogenic genes in mammary gland and adipose tissues of lactating goats

2005 ◽  
Vol 72 (2) ◽  
pp. 250-255 ◽  
Author(s):  
Laurence Bernard ◽  
Christine Leroux ◽  
Muriel Bonnet ◽  
Jacques Rouel ◽  
Patrice Martin ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Milk Fat ◽  
De Novo ◽  
Lipid Synthesis ◽  
Nutritional Regulation ◽  
Lipogenic Genes ◽  
Lactating Goats ◽  
Negative Effect ◽  
Few Data ◽  
Long Chain

While the effect of long-chain fatty acids on adipose tissue (AT) lipogenic activities has been described in non-lactating ruminants (Vernon, 1977), little is known about their effects on the mammary gland and the AT in lactating animals. However, in cows in mid lactation, duodenal rapeseed oil infusion decreased the rate of fatty acid (FA) synthesis in AT and increased milk yield of long-chain FA (18[ratio ]1, 18[ratio ]2 and 18[ratio ]3) and decreased medium-chain FA (14[ratio ]0 and 16[ratio ]0), suggesting a depressive effect of fat feeding on mammary lipid synthesis de novo (Chilliard et al. 1991). On the other hand, in goat species, the addition of vegetable lipids to the diet led to an increase in the milk fat content and yield (Chilliard et al. 2003) suggesting that the possible negative effect of long-chain FA on FA synthesis in the lactating mammary gland could be more than compensated by increasing the supply of FA brought to the mammary gland for milk synthesis. Elsewhere, AT from various anatomical sites are characterized by different FA composition in goat (Bas et al. 1987) together with different patterns of lipogenic gene expression in sheep (Barber et al. 2000). These results suggest that each AT site is characterized by a specific metabolism. However, in lactating ruminants, few data are available on the extent of expression and regulation of genes coding for lipogenic enzymes in AT. Therefore, the current study was performed in three lipogenic tissues of lactating goats, namely the mammary gland, an internal AT site (perirenal AT) and an external AT site (subcutaneous AT).

scholarly journals The effects of intravenous infusions of triglycerides on the secretion of milk fat in the cow

1969 ◽  
Vol 23 (1) ◽  
pp. 157-172 ◽  
Author(s):  
J. E. Storry ◽  
B. Tuckley ◽  
A. J. Hall
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Milk Fat ◽  
Blood Lipids ◽  
Jugular Vein ◽  
Plasma Triglycerides ◽  
Lactating Cows ◽  
Successive Addition ◽  
Total Milk ◽  
Fatty Acid Compositions

1. Artificial emulsions of nine synthetic triglycerides ranging from tripropionin to triolein were given as continuous infusions into the jugular vein of lactating cows for periods of 2 days. The effects of these infusions on the composition of blood lipids and on the secretion of the component fatty acids in milk were examined.2. Tricaproin, tricaprylin, tripelargonin, tricaprin, trilaurin, trimyristin and triolein, in contrast to tripropionin and tributyrin, increased the yields in milk of the acid contained in the triglyceride. The increased yield of acid was positively correlated with chain length of the infused triglyceride, and with triglycerides above tricaprin the transfer of fatty acid to milk was sufficiently large to give consistently increased yields of total milk fat.3. The infusions increased the concentrations in blood plasma of cholesterol, phospholipid and in some experiments also of triglyceride. Concentrations of these lipids returned to normal by 2 days after the infusion. The fatty acid compositions of the plasma triglycerides were not affected by the infusion of triglycerides up to tripelargonin but with triglycerides longer than this the plasma triglycerides were altered in composition towards that of the infused triglyceride.4. Short- and intermediate-chain fatty acids of the infused triglycerides were elongated by the successive addition of two carbon units to give increased yields in milk of acids ranging up to C15 and C16 when they contained acids with an even and odd number of carbon atoms respectively. Possible interference with the conversion of stearic into oleic acid in the mammary gland owing to the infused emulsions is also discussed.

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