Article

Factors Affecting Conjugated Linoleic Acid (CLA) Content in Milk, Meat, and Egg: A Review

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Abstract

An increasing interest in enhancing the conjugated linoleic acids (CLA) content in food products is attributed to its potential anti-carcinogenic, anti-diabetic, anti-obesity, anti-atherogenic, and immunomodulatory functions in experimental animal models. It is synthesized in the rumen from linoleic acid or from the endogenous conversion of t -11 C<SUB>18:1</SUB> in the mammary gland by delta<SUP>-9</SUP> desaturase. More than a dozen isomers of CLA have been detected in foods of ruminant origin, of which c -9, t -11 comprising 80 to 90%, and t -10, c -12 comprising 3-5% of total CLA are the isomers with known physiological importance. Although food products from ruminants are the richest source of CLA for humans, it is possible to enhance the CLA content of foods from non-ruminants by supplementing CLA in the diet. The CLA content in milk, meat, or egg varies greatly from a low 0.1% or less to a high 2% or more of the milk, tissue, or egg yolk lipids, with milk lipids from ruminants having the highest concentrations. A host of factors appear to affect the CLA content in milk, meat, and other food products from various species of animals, which could be broadly classified into diet, animal, and post-harvest related factors. Of all these factors, animal diet is the primary one and could be manipulated to a great extent for enhancing the concentration of CLA in food products, both from ruminants and non-ruminants. While animal-to-animal variation is also of great significance, post-harvest related factors appear to be of minor importance. In this context, the CLA content of milk, meat, and egg, and the factors affecting its concentration have been reviewed. Understanding the various factors affecting the CLA content in food products will have practical implications to the dairy, meat, or egg producers for its enrichment in food products so we can derive the potential health benefits associated with CLA.

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... Les produits laitiers présentent les teneurs et les amplitudes de variation en CLA les plus élevées, puisque ces teneurs varient de façon générale entre 3 et 9 mg/g de lipides ( Figure 10). Toutefois, une étude de O'Shea et al., (1998) (D'après Khanal & Olson, 2004) en CLA avec des teneurs pouvant atteindre jusqu'à 9 mg de CLA/g de lipides ( Figure 10). La variation des teneurs en CLA dans les produits laitiers s'explique principalement par les fortes variations de concentration initiale en CLA dans le lait entier [Lin et al., 1995]. ...
... Des études récentes ont montré que la teneur en CLA variait entre 0,2 et 1,1% des AG totaux de la viande [Mir et al., 2000a,b ;Ivan et al., 2001 ;Khanal & Olson, 2004 ;Raes et al., 2004b et entre 0,3 et 5% des AG totaux du lait de ruminant [Khanal & Olson, 2004 ;Dhiman et al., 2001 ;Chilliard et al., 2004]. D'autre part, de nombreux auteurs ont mis en évidence une augmentation des teneurs en CLA dans les produits de ruminants lorsque ces derniers sont conduits au pâturage, reçoivent une ration à [Dhiman, 1999 ;Jahreis et al., 2000 ;Khanal, 2003a ;, ou sont supplémentés avec des huiles végétales, ou des graines oléagineuses Lock & Granworthy, 2003 ;Madron et al., 2002 ;Khanal et al., 2002Khanal et al., , 2003b ou avec des huiles de poisson riches en AGPI n-3 très longs [Donovan et al., 2000 ;Scollan et al., 2001 ;Abu-Ghazaleh et al., 2003]. ...
... Des études récentes ont montré que la teneur en CLA variait entre 0,2 et 1,1% des AG totaux de la viande [Mir et al., 2000a,b ;Ivan et al., 2001 ;Khanal & Olson, 2004 ;Raes et al., 2004b et entre 0,3 et 5% des AG totaux du lait de ruminant [Khanal & Olson, 2004 ;Dhiman et al., 2001 ;Chilliard et al., 2004]. D'autre part, de nombreux auteurs ont mis en évidence une augmentation des teneurs en CLA dans les produits de ruminants lorsque ces derniers sont conduits au pâturage, reçoivent une ration à [Dhiman, 1999 ;Jahreis et al., 2000 ;Khanal, 2003a ;, ou sont supplémentés avec des huiles végétales, ou des graines oléagineuses Lock & Granworthy, 2003 ;Madron et al., 2002 ;Khanal et al., 2002Khanal et al., , 2003b ou avec des huiles de poisson riches en AGPI n-3 très longs [Donovan et al., 2000 ;Scollan et al., 2001 ;Abu-Ghazaleh et al., 2003]. ...
... CLA is formed as an intermediate during the biohydrogenation of LA to stearic acid by Butyrivibrio fibrisolvens and other ruminal bacteria or from the endogenous conversion of transvaccenic acid, the trans-11, C18:1 (TVA) by 9-desaturase in the mammary gland (Bauman and Griinari, 2001;Khanal and Olson, 2004). The search of higher concentrations of CLA in milk and other animal products is due to their antimutagenic properties, anticarcinogenic (Martin and Jenkins, 2002;Ohtsu et al, 2005), antiteratogenic, hypocholesterolemic, their role as trigger the immune response to Arteriosclerosis, prevention of obesity and diabetes, as well as acting to inhibit oxidation (Parodi, 1999;Kritchevsky, 2000, Kim andPark, 2003;Khanal and Olson, 2004). ...
... CLA is formed as an intermediate during the biohydrogenation of LA to stearic acid by Butyrivibrio fibrisolvens and other ruminal bacteria or from the endogenous conversion of transvaccenic acid, the trans-11, C18:1 (TVA) by 9-desaturase in the mammary gland (Bauman and Griinari, 2001;Khanal and Olson, 2004). The search of higher concentrations of CLA in milk and other animal products is due to their antimutagenic properties, anticarcinogenic (Martin and Jenkins, 2002;Ohtsu et al, 2005), antiteratogenic, hypocholesterolemic, their role as trigger the immune response to Arteriosclerosis, prevention of obesity and diabetes, as well as acting to inhibit oxidation (Parodi, 1999;Kritchevsky, 2000, Kim andPark, 2003;Khanal and Olson, 2004). Ohtsu et al (2005) suggest that CLA may be useful for chemoprevention of various types of tumors, in contrast to linoleic acid. ...
... Factors affecting the production of CLA can be divided into three main categories, according to Khanal and Olson (2004): a. Related to diet: b. Related to the animal; c. ...
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World production of goat s milk is estimated at 15.5 million tons annually, as it is considered a highly prized product it is easily produced on a small areas, also a tool to increase the sustainable profit ability of the farmer. Because of the higher digestibility and hypoallergenic properties of goat s milk, this is mainly consumed by the elderly, sick as well as infants. It is estimated that symptoms of cow milk allergy occur between 2.5% to 7% of infants, and research suggests that one third of allergic new-born Infants to cow's milk are tolerant to goat s milk, however often there is confusion between intolerance and milk allergy, mainly caused by alpha-s-1-casein, abundant in cow's milk. Goat s milk has a guaranteed space in the market, due of it is high biological value and low allergenicity, when compared to cow s milk and soya milk. However, there are obstacles to expansion the dairy goat market largely because of: instability in the product offering; cultural resistance of consumption, with the “goat being the cow of the poor people” and low acceptance due to the typical flavor or poor flock management. The milk and dairy products provide a large portion of saturated fat consumed and some fatty acids that are essential to human nutrition. In the recent past, milk and dairy products have become unpopular between nutritionists, but the bad reputation of saturated fatty acids, should not be widespread, since today it is known that stearic acid (18:0) has no the atherogenic effects. The essentiality of certain fatty acids has been established by the several researches due to the inability of animals and humans in synthesizing them, and its deficiency causes disorders of growth, changes in the skin, several behavioral disorders, immunological and neurological changes. Comparative studies used as references by medical associations and health institutes for the dietary reference intakes (DRIs), compares the western diets with Greek diet and the Paleolithic period, through simulations based on modern-day hunter-gatherer populations, suggests a ratio of omega 6:3 of 1-2:1, consumption much lower in saturated fatty acids, total fat and almost no of trans fatty acids, except the CLA, being more balanced and healthier than does today s diet. This is evidenced by lowest rates of cardiovascular disease, cancer, infant mortality and highest life expectancy in the Greek Islands, where the diet consists largely by Mediterranean plants and moderate portions of yogurt and cheese from goats and sheep reared on pasture. However, care should be taken in causal studies, since the origin of carcinogenesis and cardiovascular diseases is multifactorial. Thus, there is a challenge to improve the ratio of hypocholesterolemic and hypercholesterolemic fatty acids and decrease the atherogenic index to human health, which in the next few years can become a tool in the promotion of production systems of dairy goats based on pasture and supplementation.
... Diet x time interaction was noted for C4, C6, C8, C10, C14, Table 4. Means of fat and fatty acid content of total lipids of milk from cows that were fed the two diets (CTRL and EXP) at the three sampling times (7, 14, and 30 d). a-c Means within a row with different superscripts differ (p < 0.05). A-C Means within a row with different superscripts differ (p < 0.01). 1 CTRL, control group fed with total mixed ration (TMR) containing no additional oil; 2 EXP, experimental group fed with basal diet (TMR) containing the addition of 220 g/d (1% of DM) of isomerized poppy seed oil (IPO); 3 SEM, standard error of the mean; 4 probability of significant effects due to diet (D), time (T), and their interaction (D × T); * p < 0.05, ** p < 0.01, NS, not significant; 5 SFAs, saturated fatty acids; 6 SCFAs, short-chain fatty acids (FAs with C4-10); 7 MCFAs, medium-chain fatty acids (FAs with C12-16:0); 8 MUFAs, monounsaturated fatty acids; 9 PUFAs, polyunsaturated fatty acids; 10 Σ, CLA cis-9,trans-11; trans-10,cis-12; trans-9,cis-11; trans-11,cis-13 and trans-11,trans-13; 11 DI, desaturase index represents the ratio of product and substrate for Δ 9 -desaturase (double bonds are in the cis orientation unless otherwise indicated); 12 AI, atherogenic index calculated from (C12:0 + (4 x C14:0) + C16:0)/(MUFAs + PUFAs). a-b Means within a row with different superscripts differ (p < 0.05). ...
... a-b Means within a row with different superscripts differ (p < 0.05). A-C Means within a row with different superscripts differ (p < 0.01). 1 CTRL, control group fed with complex mixture and grass hay (42%:58% of DM) containing no additional oil; 2 EXP, experimental group fed with basal diet containing the addition of 20 g/d (1% of DM) of isomerized poppy seed oil (IPO); 3 SEM, standard error of the mean; 4 probability of significant effects due to diet (D), time (T), and their interaction (D × T); * p < 0.05; ** p < 0.01; NS, not significant; 5 SFAs, saturated fatty acids; 6 SCFAs, short-chain fatty acids (FAs with C4-10); 7 MCFAs, medium-chain fatty acids (FAs with C12-16:0); 8 MUFAs, monounsaturated fatty acids; 9 PUFAs, polyunsaturated fatty acids; 10 Σ, CLA cis-9,trans-11; trans-10,cis-12; trans-9,cis-11; trans-11,cis-13 and trans-11,trans-13; 11 DI, desaturase index represents the ratio of product and substrate for Δ 9 -desaturase (double bonds are in the cis orientation unless otherwise indicated); 12 AI, atherogenic index calculated from (C12:0 + (4 x C14:0) + C16:0)/(MUFAs + PUFAs). ...
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The aim of the study was to examine the effect of dietary supplementation of isomerized poppy seed oil (IPO) enriched with conjugated dienes of linoleic acid (CLA) on cow and sheep milk parameters (fat content, fatty acid profile, Δ9-desaturase index, and atherogenic index). The process of poppy seed oil alkaline isomerization caused the formation of CLA isomers with cis-9,trans-11, trans-10,cis-12, and cis-11,trans-13 configurations in the amounts of 31.2%, 27.6%, and 4.1% of total fatty acids (FAs), respectively. Animal experiments were conducted on 16 Polish Holstein Friesian cows (control (CTRL) and experimental (EXP), n = 8/group) and 20 East Friesian Sheep (CTRL and EXP, n = 10/group). For four weeks, animals from EXP groups received the addition of IPO in the amount of 1% of dry matter. Milk was collected three times: on days 7, 14, and 30. Diet supplementation with IPO decrease milk fat content (p < 0.01). Milk fat from EXP groups had higher levels of polyunsaturated fatty acids, including FAs with beneficial biological properties, that is, CLA and TVA (p < 0.01), and lower levels of saturated fatty acids, particularly short- (p < 0.01) and medium-chain FAs (p < 0.05). The addition of IPO led to a decrease in the atherogenic index.
... The first process is the incomplete biohydrogenation of linoleic acid and linolenic acid in the rumen; the second biosynthetic process is the endogenous conversion of transvaccenic acid, an intermediate of biohydrogenation, to CLA in tissues [34]. The main dietary source of linoleic acid for ruminant animals is concentrated feed consisting mainly of grains and seed oils, whereas the main dietary source of linolenic acid is pasture grasses [35]. ...
... The toughness of the meat may be explained by the higher proportion of SFA in CLA enriched muscle tissues and the consequent decrease in UFA, which increase the fat melting point [85]. In egg yolk lipids, CLA was not even detected when laying hens were fed a normal concentrate diet [35]. The effects of dietary CLA supplementation on eggs fat profile have been recently reviewed [86]; an interesting result showed that the egg yolk surface from hens fed CLA diets sometimes had relatively dark color with light spots. ...
Chapter
Conjugated linoleic acid (CLA) is a group of polyunsaturated fatty acids that exist as positional and stereo-isomers of octadecadienoate (18:2). Among these isomers, the most studied two isomers are cis 9, trans 11-CLA and trans 10, cis 12-CLA due to their biological effects. CLA can be naturally synthesized in the rumen of ruminant animals by bacteria Butyrivibrio fibrisolvens via the Δ-9-desaturase of trans 11 octadecanoic acid pathway. The major dietary sources of CLA are represented by meat and milk from ruminant animals. Although references to CLA can be traced back to the 1950s, current interest in the health benefits of CLA started in the late 1980s, after it was identified as the anti-carcinogenic component present in fried ground beef. Since then, an extensive literature has documented the anticarcinogenic effects of CLA. In addition, there is some evidence that CLA is also anti-atherosclerotic, has beneficial effects on type 2 diabetes, and may play a key role in helping to regulate body fat. The fact that the richest natural sources of CLA, meat and dairy products, are consumed by people worldwide has very interesting implications for public health.
... The nutritive interest of water buffalo milk products is also higher than cows' because of the higher concentrations of protein, fat, lactose, minerals and vitamins in buffalo milk [7]. In addition, buffalo milk and its derived products could be a good source of conjugated linoleic acid (CLA) for humans, like other food products from ruminants [8]. CLA refers to a group of polyunsaturated fatty acids (PUFA) that exist as positional and stereoisomers of conjugated dienoeic acid (18:2). ...
... CLA content is much higher in foods derived from ruminants than those from nonruminants, and with milk having higher content than meat, because of the ability of ruminants to biohydrogenate dietary unsaturated fatty acids with the help of bacteria present in the rumen [8]. In dairy products, the CLA concentrations typically range from 2.90 to 8.92 mg CLA/g fat, and the cis9, trans11-CLA isomer makes up between 73-93 percent of the total CLA [14]. ...
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Background: Water buffalos are the second most widely available milk source in countries around the world. While typical average milk compositions are readily available, information on seasonal variation in chemical composition of buffalo milk is limited -especially in the Northeastern region of the United States. Data collected in this study can be useful for the manufacture of a wide variety of specialty dairy products such as symbiotic buffalo milk yogurt. To analyze functionality, symbiotic low fat buffalo milk yogurt prototypes (plain and blueberry) were developed using a commercial starter containing probiotics. Methods: During a one-year cycle, physicochemical and mineral contents of buffalo milk were analyzed. Prototype yogurts were manufactured commercially and samples of the yogurt prototypes were analyzed for physicochemical and microbiological properties and for the survivability of probiotics during ten weeks of storage.Results: Average contents of total solids, fat, lactose, crude protein, ash, specific gravity, and conjugated linoleic acid in the milk ranged from 16.39-18.48%, 6.57-7.97%, 4.49-4.73%, 4.59-5.37%, 0.91-0.92%, 1.0317-1.0380%, and 4.4-7.6 mg/g fat, respectively. The average mineral contents of calcium, phosphorous, potassium, magnesium, sodium, and zinc in the milk were 1798.89, 1216.76, 843.72, 337.20 and 7.48 mg/kg, respectively, and remained steady throughout the year. The symbiotic low fat buffalo milk yogurts evaluated in this study contained higher amounts of protein, carbohydrates, and calcium than similar yogurts manufactured with cows’ milk. During refrigerated storage, the probiotic Lactobacillus acidophilus was viable (>1×106 CFU/g) for the first two weeks, while Bifidobacterium spp. and Lactobacillus casei remained viable during the entire ten weeks. Reducing the acidity and enhancing the flavor of the yogurts could improve the overall acceptability.Conclusion: The results indicated that the low fat buffalo milk yogurt are a rich source of nutrients and are nutritionally preferable to cows’ milk yogurts. The shelf life analysis indicated it to be a good vehicle for developing symbiotic yogurt.Keywords: Buffalo milk, conjugated linoleic acid, symbiotic yogurt, probiotic survivability, physicochemical properties, acceptability
... The first process is the incomplete biohydrogenation of linoleic acid and linolenic acid in the rumen; the second biosynthetic process is the endogenous conversion of transvaccenic acid, an intermediate of biohydrogenation, to CLA in tissues [34]. The main dietary source of linoleic acid for ruminant animals is concentrated feed consisting mainly of grains and seed oils, whereas the main dietary source of linolenic acid is pasture grasses [35]. ...
... In egg yolk lipids, CLA was not even detected when laying hens were fed a normal concentrate diet [35]. The effects of dietary CLA supplementation on eggs fat profile have been recently reviewed [86]; an interesting result showed that the egg yolk surface from hens fed CLA diets sometimes had relatively dark color with light spots. ...
... The first process is the incomplete biohydrogenation of linoleic acid and linolenic acid in the rumen; the second biosynthetic process is the endogenous conversion of transvaccenic acid, an intermediate of biohydrogenation, to CLA in tissues [34]. The main dietary source of linoleic acid for ruminant animals is concentrated feed consisting mainly of grains and seed oils, whereas the main dietary source of linolenic acid is pasture grasses [35]. ...
... The toughness of the meat may be explained by the higher proportion of SFA in CLA enriched muscle tissues and the consequent decrease in UFA, which increase the fat melting point [85]. In egg yolk lipids, CLA was not even detected when laying hens were fed a normal concentrate diet [35]. Dietary CLA supplementation did not influence yolk color in a study performed in 1999 [86], but an interesting result showed that the egg yolk surface from hens fed CLA diets sometimes had relatively dark color with light spots. ...
... All ruminants under normal physiological conditions produce only 0.2-2.0% CLA of total tissue or milk fat [16,17]. While the consumption of 120 g beef fat having CLA concentrations from 1.2 to 12.5 mg/g of fat accounts for total recommended daily intake of 1.5 to 3.5 g of CLA [5,6]. ...
... Pasture + extruded soybean 1.4 g/100 g fatty acid [16] Whole pasture 1.5 g/100 g fatty acid [17] Sunflower seed (11.2%) 400 (percentage increase) [23] Pasture 8. ...
... CLA is increasingly being studied due to its anticancer and atherosclerosis-reducing abilities along with the capability to improve immune system responses (Cook et al., 2003). Increased accumulation of CLA in dairy products is related to the increased availability of lipids achieved through modification of feeds (Khanal & Olson, 2004). Upon being available to rumen microbes, feeds with higher lipid content such as soybean and linseed oil increased the CLA content in milk through the biohydrogenation process (Dhiman et al., 2000). ...
Article
Background With the advent of new technologies and the emphasis on innovation, novel engineered particles are being developed that possess superior functional properties, consumer acceptance and cost effectiveness. The performance of particulate systems in animal derived foods is dependent on several factors including particle size, shape, chemical and structural properties. Scope and approach Micro- and nano-sized materials for the three major strategic applications in animal derived foods are discussed. Although this review describes a few examples of dairy products such as milk and cheese, it primarily emphasizes meat, poultry, fish and eggs. Key findings and conclusions While whole grains with large particle sizes influence gizzard growth and function, superfine powders of yeast cell wall and oolong tea have improved immune function and meat quality along with reductions in fat. As a part of a product reformulation strategy to reduce sodium, salt-loaded chitin nanofibers incorporated in seafood have resulted in enhanced saltiness. To reduce allergies associated with eggs, microparticulation of protein has been attempted but without any success. However, micro-sizing fish powder has enhanced transglutaminase (TGase) activity in surimi. In terms of storage strategy, ZnO nanoparticles loaded onto carboxymethyl cellulose film have improved color stability and water holding capacity (WHC) of pork. Other potential applications include reutilization of wastes in biodiesel production and nanoquantum dot-based lighting to improve the showcasing of meat. For the successful application of particle technologies in animal derived foods, knowledge gaps related to the toxicity of nanomaterials, commercialization challenges and negative public perception need to be addressed.
... This might be due to concentrate supplementation has improved the apparent digestibility of DM. In line with this result, Khanal and Olson (2004) reported that there was an increment in apparent DM digestibility for oil cake supplementations. ...
... Although conjugated linoleic acid (CLA) is a minor component of milk fat, dairy is one of the major sources of CLA in our diet. The CLA content in milk and dairy products varies greatly due to the cows' diet and can range from 0.1% up to 2% of milk lipids (Khanal and Olson 2004). High intake of CLA has been linked to decreased risk of several cancers and enhanced function of immune cells (Ip et al. 1994;Krichevsky 2004). ...
Chapter
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Sour cream is a relatively heavy, viscous product with a glossy sheen. It has a delicate, lactic acid taste with a balanced, pleasant, buttery-like (diacetyl) aroma (1). Various types of sour cream are found in many regions of the world. The products vary in regard to fat content and by the presence or absence of non-dairy ingredients. Furthermore, both cultured and direct acidification is utilized to lower pH. This chapter will cover sour cream as it is produced in the US and its French counterpart-crème fraîche.
... In addition, SCD plays a role in the biosynthesis of monounsaturated fatty acids introducing a cis double bond between carbons 9 and 10 in a spectrum of saturated fatty acids (SFA), mainly myristic (C14:0), palmitic (C16:0), stearic (C18:0) and TVA. Milk concentration of RU and TVA acids is mainly affected by diet, and supplementation with lipid sources containing unsaturated FA increases such acids concentration (Khanal and Olson, 2004). In recent years, numerous studies showed the possible increase of CLA content in the milk of dairy cattle by using a dietary supplement of vegetable oils rich in C18:2 (Bell et al., 2006;Huang et al., 2008). ...
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Aim of this study was to investigate the effects of supplementing dairy goat diets with hydrogenated palm oil (HPO; 50 g/day/head) on milk yield and composition, and on milk fatty acids profile and Stearoyl-CoA desaturase gene expression. Compared with the control diet (C), supplementation with HPO increased milk yield and fat percentage. By contrast, milk protein percentage was not different between groups. Supplementation with HPO increased (P< 0.01) short and medium chain fatty acids, as well as C14:0 and C16:1 cis-9 acids (P< 0.05). Milk from control group showed significantly (P< 0.01) higher concentration of C18:0 and lower (P< 0.05) of cis-9 trans-11CLA. Concerning the desaturase index, the HPO addition significantly affected C16:1/C16:0 and cis-9 trans-11CLA/C18:1 trans-11 (P< 0.01) and C18:1/C18:0 (P< 0.05) ratios. The SCD gene expression (arbitrary units) was higher, even if not significantly, in the control compared to the treated group and in both groups decreased along the trial (May: 0.55 vs 0.41; June: 0.51 vs 0.38; July: 0.50 vs 0.37 for C and T group, respectively). Concerning health properties of milk, showing beneficial (CLAs and palmitoleic acid increase) and adverse (myristic acid increase) effect, our results suggest that further studies are needed to address a risk/benefit assessment of HPO supplementation in goats.
... La calidad nutrimental de los productos de bovinos puede mejorarse con los residuos de las especies seleccionadas para la extracción de aceite para biodiesel, si se considera el ácido linoleico conjugado que se genera en el rumen a partir de alimentos ricos en este compuesto. El ácido linoleico conjugado se obtiene para la nutrición humana durante la digestión de la carne y productos lácticos, se considera como un componente dietético importante para el control del cáncer, diabetes y obesidad (Khanal y Olson, 2004). A pesar de los resultados obtenidos, es necesario evaluar la presencia y métodos de eliminación de los compuestos tóxicos y antinutrimentales contenidos en chicalote, higuerilla y calabacilla loca. ...
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In Mexico alternative plant material is needed for the biofuels industry in order to avoid the use of human food crops. The objective was to identify plant species with potential use in liquid biofuels production in the state of Durango, Mexico. Fifty six random samples were taken for tubercles, stalks, fruits, seeds, exudates and juice of wild and cultivated plants. Proximate analysis were performed to evaluate fat, nitrogen-free extract (water soluble carbohydrates) and protein content. Total reducing sugars content and °Bx were also determined in species intended for ethanol production such as mesquite (Prosopis laevigata) and sweet sorghum (Sorghum bicolor). For ethanol production water dissolved mesquite pod-flour and sweet sorghum juice were fermented using Saccharomyces cerevisiae. Highly significant (p
... The various milk fat components, such as CLA, sphingomyelin, butyric acid, ether lipids, ߚ-carotene and vitamin A and D, have anticarcinogenic potential (Jahereis et al., 1999;Parodi, 1999;Alkalin and Tokusoglu, 2003;Khanal and Olson, 2004). ...
... Many factors affect CLA content in milk, so there is a large variation in content. These factors are either diet, animal, or postharvest related (Khanal & Olson 2004). Feeding dairy cows in a pasture is very effective in increasing milk fat CLA content, as is feeding them fats, oils, and oilseeds that are rich in LA (Ward et al. 2003, Whitlock et al. 2002. ...
Article
Conjugated linoleic acid (CLA) is in ruminant-derived foods and is known to combat obesity-related diseases. However, CLA levels in a healthy diet are too low to produce a clinical effect. Therefore, CLA has been produced by linoleic isomerization through fermentation and chemical catalysis. Many of these techniques are not practical for food production, but a recent development has enabled production of CLA-rich triglyceride vegetable oils from high linoleic acid oils by a minor modification of conventional food-oil processing techniques. These oils were used to produce common lipid-based food, such as margarine, shortenings, and salad dressings, whose quality was enhanced by the presence of CLA-rich oil and provided a significant CLA source. Meat and egg CLA content and subsequent food quality can also be increased by addition of dietary CLA. However, consumer awareness of CLA benefits needs to increase prior to commercial-scale production of CLA-rich oil.
... Similarly, the essential fatty acids, which cannot be synthesized in our body, are also supplied by ghee. The various milk fat components, such as CLA, sphingomyelin, butyric acid, ether lipids having anticarcinogenic potential are also supplied by ghee (Alkalin and Tokusoglu 2003, Khanal and Olson 2004). Buffalo milk fat has been shown to contain a significantly higher amount of rumenic acid (the main conjugated linoleic acid) than cow milk. ...
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The present study was envisaged to develop a process of production of herbal ghee from buffalo milk using arjuna extract. Three different types of extracts viz. commercial aqueous arjuna extract powder, aqueous extract and alcoholic extract prepared in laboratory from arjuna bark were tried. It was observed that, amongst the three types of extracts when added at the level of 4% of the fat taken, ghee prepared using alcoholic extract was found superior. While selecting the level of alcoholic extract for maximizing the retention of phytosterol in ghee, it was found that there was no significant difference in overall acceptability scores of ghee samples prepared by adding the extract @ 5%, 6% and 7% by the weight of fat taken. Phytosterol content was found to be the highest, i.e. 0.38 and 0.47 mg/g when cream and butter were used as fat source at 7% level of addition of alcoholic extract, respectively. Based on the above results, the optimized product was the one that was prepared by addition of 7% alcoholic arjuna extract using creamery butter method. The chemical composition of the optimized product was found to be fat 99.92%, moisture 0.08%, free fatty acid 0.22% oleic acid, Butyro-Refractometer reading 41.5 at 40°C, Reichert-Meissl value 31.5 and phytosterol content 0.39 mg/g.
... Following endogenous desaturation (D 9 desaturase), t11 C18:1 is converted to c9, t11-C18:2 (Dhiman et al 2005, Bauman et al 2006. Due to anticipated health benefits of CLA, research efforts have been directed at evaluating this additional contribution of feedstuffs that are high in linoleic acid, including forages (Khanal andOlson 2004, Ortega-Pérez et al 2010) and as well as supplemental fats (Jenkins et al 2008, Wang andLee 2015). Coupling both production efficiencies and the consumption of a more healthful meat product would mean significant enhancement economically for the ruminant meat industry 1 . ...
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The effects of purging nut (Jatropha curcas, JCO) supplementation (0, 2, 4, and 6%, DM basis of diet) on carcass traits, tissue composition and conjugated linoleic acids (CLA) concentration in muscle was evaluated in twenty intact male lambs fed a finishing diet during 56-d. The linoleic acid proportion in JCO was 50%. Lambs were harvested at a final weight of 54.03±2.9 kg. There were no treatments effects on hot carcass weight (HCW), longissimus muscle (LM) area nor kidney-pelvic fat. However, as JCO supplementation increased, dressing percentage was decreased and fat thickness was increased. Increasing JCO in diet decreases the proportion of muscle and increases the proportion of fat in whole shoulder clod. Content of stearic acid (C18:0) in LM was not affected by JCO. However, JCO linearly increased total CLA, and hence, the CLA:C18:0 ratio. Empty body or visceral mass were not affected by JCO. Increasing JCO in diet increases visceral fat mainly through increased mesenteric fat. It is conclude that supplemental JCO does not negatively affect HCW and LM area, and represents a viable alternative for increasing CLA concentration in meat in finishing feedlot lambs.
... Addition of lipids to diets of grazing dairy cows may increase milk yield and change milk composition and its fatty acid (FA) profile (Khanal and Olson, 2004;Schröeder et al., 2004). Response depends on dose and fatty acid profile. ...
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The effect of supplementation with corn oil (CO) and its mixture with palm kernel oil (CO:PKO 75:25) to grazing cows on ruminal fermentation, milk yield, and its fatty acid (FA) profile was evaluated. The treatments were: one control treatment (C) without oil and two treatments with 720 g d⁻¹/cow of CO or CO:PKO (ether extract: 22.7 g kg⁻¹ for control treatment, 66 g kg⁻¹ for CO, and 65 g kg⁻¹ for CO:PKO). Six multiparous Holstein cows (6.3±1.8 yr, 597± 11.5 kg body weight (BW), 160±29 d in milk; mean ± standard deviation) were assigned to a double 3 × 3 × 3 Latin square design. Cows grazed (3 kg DM/100 kg BW) a Cenchrus clandestinus (previously Pennisetum clandestinum) pasture and were supplemented with 0.9 kg d⁻¹ DM corn silage, 4.2 kg d⁻¹ DM concentrate, and 9 g Cr2O3. The mixture of concentrate and oils was offered twice a day. The addition of oils increased milk yield (kg d⁻¹) (C: 21.4, CO: 23.6, CO:PKO: 23.9) and milk fat concentration (g kg milk⁻¹) (C: 31.5, CO: 34.0, CO:PKO: 34.0). Compared with control, conjugated linoleic acid (18:2c9t11 CLA) proportion (g 100 g⁻¹ FA) in milk fat was higher for oil treatments (C: 0.68, CO: 1.56, CO:PKO: 1.01). Voluntary intake and digestibility were not different among treatments. The molar ratio of acetate, propionate, and butyrate was not different among treatments, but the molar concentration of volatile fatty acids (VFA) was lower for CO and CO:PKO, resulting in a lower estimated methane (CH4) production (mL/100 mol VFA) for CO and CO:PKO treatments. Supplementing CO and CO:PKO to grazing dairy cows increases milk yield without affecting voluntary intake or diet digestibility. The proportion of conjugated linoleic acid increases more for CO than for CO:PKO.
... Following endogenous desaturation (D 9 desaturase), t11 C18:1 is converted to c9, t11-C18:2 (Dhiman et al 2005, Bauman et al 2006. Due to anticipated health benefits of CLA, research efforts have been directed at evaluating this additional contribution of feedstuffs that are high in linoleic acid, including forages (Khanal andOlson 2004, Ortega-Pérez et al 2010) and as well as supplemental fats (Jenkins et al 2008, Wang andLee 2015). Coupling both production efficiencies and the consumption of a more healthful meat product would mean significant enhancement economically for the ruminant meat industry 1 . ...
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The effects of purging nut (Jatropha curcas, JCO) supplementation (0, 2, 4, and 6%, DM basis of diet) on carcass traits, tissue composition and conjugated linoleic acids (CLA) concentration in muscle was evaluated in twenty intact male lambs fed a finishing diet during 56 d. The linoleic acid proportion in JCO was 50%. Lambs were harvested at a final weight of 54.03±2.9 kg. There were no treatment effects on hot carcass weight (HCW), longissimus muscle (LM) area nor kidney-pelvic fat. However, as JCO supplementation increased, dressing percentage was decreased and fat thickness was increased. Increasing JCO in diet decreases the proportion of muscle and increases the proportion of fat in whole shoulder clod. Content of stearic acid (C18:0) in LM was not affected by JCO. However, JCO linearly increased total CLA, and hence, the CLA:C18:0 ratio. Empty body or visceral mass were not affected by JCO. Increasing JCO in diet increases visceral fat mainly through increased mesenteric fat. It is concluded that supplemental JCO does not negatively affect HCW and LM area, and represents a viable alternative for increasing CLA concentration in meat of finishing feedlot lambs.
... This would suggest complementarity of SBM and SSM at ratios of 50/50 and 25/75 in terms of digestibility of DM and EE. Khanal & Olson (2004) reported that in general there was an increment in DM digestibility for oil cake supplementations. However, Shirzadegan & Jafari (2014) reported that the digestibilities of DM and OM were reduced by the inclusion of 15% SSM in diets of lactating dairy cows. ...
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Two experiments were carried out to determine ruminal degradability of sesame meal (SSM) and its effects on intake, digestibility, rumen parameters, chewing activity, and lamb performance when it replaced soybean meal (SBM). Degradability of dry matter (DM) and crude protein (CP) were determined with the nylon bag technique using three fistulated Zel ewes. The quickly and potentially degradable DM of SSM was lower, but their degradation rates of DM were similar. The quickly degradable protein in the SSM was greater, but the slowly degradable protein of SSM was lower. Potential degradable protein of SBM was greater. The degradation rate of protein was greater in the SSM. Thirty Zel lambs were assigned to five treatments, namely 1) control diet that contained SBM, and 2), 3), 4) and 5) diets that contained 25, 50, 75, and 100% DM of SSM partially or entirely replacing SBM and part of barley grain. There was no difference in the intakes of DM, CP, ether extract (EE), and non-fibre carbohydrate (NFC) among treatments, but neutral detergent fibre (NDF) intake increased when the SSM inclusion rate was increased. Digestibility of DM and EE, passage rate, and total mean retention time differed, but the digestibility of NDF, CP, and NFC, rumen liquid pH and NH3-N, passage rate, rumen retention time, eating time, rumination, total chewing activity, DM intake, daily gain, feed conversation ratio, carcass yield and characteristics were not different between treatments. Replacing the SBM with SSM in lamb, improved intake, digestibility, and rumen condition, without reduction in performance and carcass composition.
... An overview of the effect of varying herbage allowane on the ALA and RA concentrations in milk of grazing cows is shown in Table 5. Cows at pasture [2,95] grazing lush green grass [100,108] at a high herbage allowance [101] produce milk with the highest concentrations of PUFA. ...
... Although pasture-based diets yield milk with higher basal levels of CLAc9t11 (CLA, c9t11 conjugated linoleic acid), additional increases could be achieved through lipid supplementation (Chilliard and Ferlay, 2004). The results of supplementation with vegetable oils suggest that oils with higher content of linoleic and linolenic acids are best suited to increase the amount of CLAc9t11 in milk (Khanal and Olson, 2004), and this effect is linearly related to the amount of oil added to the feed (up to 30-40 g/kg of dry matter (DM)) (Chilliard et al., 2007). Furthermore, oils richer in linoleic acid (soybean and sunflower seed) have been found to be the most effective (Collomb et al., 2004;Hervás et al., 2006). ...
Article
Transvaccenic acid (TVA), c9t11 conjugated linoleic acid (CLA), and the proportion of unsaturated fatty acids (FAs) in bovine milk are associated with human health benefits. The effect of nutritional supplementation without (NSO) or with sunflower seed oil (63.3% linoleic acid and 28.3% oleic acid) at 20 g/kg (SO20) of dry matter (DM) and 40 g/kg of DM (SO40) was evaluated in milk cows foraging on Leucaena leucocephala in intensive silvopastoral systems (ISS). Two experiments were performed, the first on a specialized tropical dairy farm (STDF) and the second on a dual-purpose tropical farm (DPTF), where cattle are fed an average of 5.8 kg/d and 2.0 kg/d of concentrate, respectively, in addition to grazing on pasture. Sunflower seed oil supplementation tended to decrease forage intake but did not affect milk yield or the milk protein and lactose percentages in either experiment. The proportion of fat, total solids, and milk urea nitrogen (MUN) decreased with oil supplementation on the STDF. However, on the DPTF, these three variables did not change significantly when SO20 or SO40 were compared to NSO, but the values were higher for SO20 compared to SO40. The proportion of CLAc9t11 and TVA linearly increased with the two levels of supplementation in both experiments. Furthermore, the atherogenic FAs decreased, and the milk had greater amounts of unsaturated FAs (UFAs) and a lower atherogenic index. Supplementing cows under an ISS with sunflower seed oil increases the proportion of beneficial milk FAs. On the STDF oil supplementation produced milk with a lower fat content and a greater proportion of high-quality fatty acids, presenting an interesting possibility for fat restricted diets.
... However, several studies have shown the difference in the structure of dietary fatty acids with ruminant body tissues (milk or meat) [42][43][44]. In the study of Seifdavati et al. [17], CLA levels in lamb meat were two to three times higher than those of other researchers, as reviewed by Khanal and Olson [45] and McNiven et al. [20]. The results of Seifdavati et al. [17], also coincided with the findings of Tilak et al. [46], Valvo et al. [47] and Lanza et al. [3]. ...
... However, Meľuchová et al. (2008) described in milk fat of ewes on pasture increase of CLA between April and May, and then decrease in milk CLA between May and June, which is similar to results of this study. Khanal and Olson (2004) connected this lower milk CLA levels with the time required for adaptation of rumen microbes to a changing diet as well as physiology of milk fat synthesis based on type and quantity of fatty acids supplied with diet. Decrease of milk CLA isomers is correlated with decrease of α-linolenic acid content in grass lipids during pasture season (Meľuchová et al., 2008). ...
Article
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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. © 2018, University of Zagreb - Faculty of Agriculture. All rights reserved.
... Recent new findings of the nutritional significance of butterfat constituents associate their consumption with several health benefits (Fig. 7). The anti-carcinogenic potential of butterfat components, such as conjugated linoleic acids (CLA), sphingomyelin, butyric acid, ether lipids, β-carotene, and vitamins A and D were reported (Akalln & Tokusoglu, 2003;Jahreis et al., 1999;Khanal & Olson, 2004;Parodi, 1999). The role of CLA and sphingomyelin in preventing cardiovascular diseases and in immunomodulatory activity were also described Fig. 7 Butterfat constituent's association with health benefits. ...
Chapter
The objective of the present chapter was to demonstrate the state of the art in the recent advances in nutritional and functional components of dairy products research. In this chapter, the main mechanisms responsible and essential for a better understanding of nutritional and functional values of the components of milk and dairy products are highlighted. It also includes a discussion about the positive impacts of fermented milk, cheese, butter, ice cream, and dairy desserts components on the consumer's health.
... Among the several milk fat components, including CLA, butyric acid, ether lipids, β-carotene, and vitamins A and D, have the ability to reduce the various cancers (Khanal and Olson, 2004). The cancer preventive action of CLA has been explained in many studies, along with the ability to prevent atherosclerosis and in controlling some parts of the immune system (MacDonald, 2000). ...
... Buffalo milk proteins are complete proteins of high biological value, and they contain all the essential amino acids in the proportions required by the human body [15]. Furthermore, buffalo milk and its products could represent a good source of favorable conjugated linoleic acid (CLA) in human nutrition [18]. In recent decades, many studies have been devoted to improving milk fatty acid (FA) composition by increasing the amount of FA with beneficial effects on human health and with more appropriate technological properties [19]. ...
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Water buffalo (Bubalus bubalis) conservation in Serbia is under an in situ program, but additional efforts are needed to ensure the development of this animal's genetic resources biodiversity. This research aims to describe challenges and possible strategies for sustainable water buffalo milk production. In this study, the physicochemical characteristics of buffalo milk and buffalo dairy products (cheese, butter, and kajmak) were determined. Furthermore, amino and fatty acids composition and the related health lipid indices (atherogenic and thrombogenic) were assessed. The findings support the fact that buffalo milk is a reliable source of high-quality nutrients (dry matter: 16.10%, fat: 6.02%, protein: 4.61%). Leucine, lysine, and valine content were found to be high in buffalo milk and cheese. A substantial quantity of non-essential glutamic and aspartic amino acids was observed in milk, as well as glutamic acid and tyrosine in cheese. It was established that milk protein of buffalo cheese had a favorable proportion of essential and non-essential amino acids (61.76%/38.24%). The results revealed significant differences (p < 0.05) in fatty acid profiles among the three dairy products for saturated short-chain, n-3, and n-6 fatty acids. Conversely, no significant difference (p < 0.05) was observed in monounsaturated fatty acids content. Kajmak showed the most favorable anti-atherogenic and anti-thrombogenic properties due to lower saturated and higher polyunsaturated fatty acid content. These results confirmed that buffalo milk could be successfully used in producing high-quality traditional dairy products with added value and beneficial characteristics from the aspect of a healthy diet. Furthermore, it could actively contribute to the promotion of sustainable production of buffaloes and strengthen the agricultural production of rural areas and their heritage.
... CLA has drawn much attention due to the claims for their anticancerogenic, antiartherogenic, antidiabetic, and antiadipogenic properties reviewed extensively by Kim et al. (2016) and den Hartigh (2019). The content of CLA in the meat can vary considerably according to the diet but usually is within the range of 0.2 % -2% (Khanal and Olson, 2004), which coincides with our results. ...
Article
This study aimed to compare lamb meat composition from five Iberian breeds raised in their typical rearing systems and to reveal trends in compositional meat attributes due to breed or production system. The meat quality of 153 animals was analysed. The combined effect of breed × production system produced significant differences in lamb meat quality. Meat from the extensively-reared Bordaleira-de-Entre-Douro-e-Minho (BEDM) and Gallega breeds had elevated amounts of n-3 PUFAs, tocopherol content and favourable n-6/n-3 ratio. Meat from lambs grown under extensive and semi-extensive systems presented higher content of conjugated linoleic acid than the two breeds reared intensively. The meat of commercial breed (INRA401) was characterised by higher content of protein and MUFAs and lower atherogenic potential than the breeds reared in extensive and semi-extensive systems. Principal component analysis demonstrated that meat from extensively raised lambs was associated to higher SFA, CLA, α-tocopherol, n-3, atherogenic index and cholesterol content, but lower intramuscular fat and retinol content, MUFA and n-6/n-3.
... Value-added foods could be produced by increasing CLA content and changing the fatty acid profile in milk by dietary manipulation. Even though the CLA content in dairy products is affected by many factors, animal feeding strategies and specifically diets with seed/oil supplements rich in PUFA have positive effects on CLA content of milks from three species (Stanton et al., 2003; Khanal and Olson, 2004; Chilliard and Ferlay, 2004). Effects of these supplements on milk FA composition in dairy goats (Chilliard et al., 2005) and ewes (Luna et al. 2005) have been shown in many studies. ...
Article
Production of goat milk is of great importance not only for underdeveloped countries, where it provides basic nutrition and subsistence to rural people, but also for developed countries as a valued part of the total dairy industry, where it provides diversity to sophisticated consumer tastes, and supports people with allergies and gastro-intestinal disorders. High quality goat milk can be produced, and great progress has been made to improve the acceptability of dairy goat products by consumers. Properly produced goat milk has no objectionable flavor, is free of spoilage bacteria, and contains the legal minimum limits of all nutrients.
... Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of linoleic acid (c-9, cis-12 C 18:2 , linoleic acid) with two conjugated unsaturated double bounds at various carbon positions (Khanal & Olson, 2004). Conjugated linoleic acid has been shown to have anticarcinogenic effects in various cancer models such as chemically induced skin, stomach, colorectal cancer and mammary tumorigenesis (Aro et al., 2000). ...
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Three dietary inclusion rates of CLA (0, 2 and 4 g/kg feed) and aflatoxin B1 (0, 200 and 300 μg/kg feed) were tested in a 3 x 3 factorial experimental design on a total of 99 Ross-308 male broiler chickens from 1 to 42 days of age. The objective of this study was to determine the effect of dietary conjugated linoleic acid (CLA) on carcass characteristics, serum lipid variables and histopathological properties in broiler chickens receiving a diet containing aflatoxin B1 (AFB1). Carcass yield, abdominal fat weight and abdominal fat percentage were not significantly influenced by dietary CLA, AFB1 or CLA + AFB1. Altered serum lipid measurements induced by AFB1 treatments included increased serum cholesterol and triglyceride concentrations, and decreased serum concentration of high density lipoprotein (HDL). Serum HDL concentration was increased in birds supplemented with 2 and 4 g CLA/kg diet compared with the control group. However, CLA + AFB1 did not significantly affect these parameters compared to the groups that received AFB1 alone. Aflatoxin B 1 administration induced degenerative changes in the liver tissue, but dietary CLA supplementation offered protection to the livers against these changes. Aflatoxin B1 residues were not detected in any breast tissues collected from the broiler carcasses. Our results suggest that CLA provided protection against the negative effects of liver damage induced by AFB1 in broiler chickens. Furthermore, dietary CLA supplementation increased serum HDL levels.
... Conjugated linoleic acid (CLA) -a fatty acid found naturally in the dairy and meat products of ruminants-has been identified as a potential anti-obesogenic, anticancerogenic, and enhancer of the immune and inflammatory response (Den Hartigh, 2018;Whigham, Watras, and Schoeller, 2018). CLA is an 18-carbon PUFA formed as an intermediate, during the biohydrogenation (BH) of linoleic acid (C18:2 cis-9, cis-12, LA) and alpha-linolenic acid (C18:3 cis-9, cis-12, cis-15, ALA), and their transformation into stearic acid (C18:0, SA), or by the endogenous conversion of trans-vaccenic acid (C18:1 t-11, TVA) by the action of the 9-desaturase enzyme in the mammary gland (Khanal and Olson, 2004). LA and ALA are found in high proportions in the lipids of fodder and in some supplements, such as oils. ...
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Objective: To perform in vitro and in situ evaluation of a diet for dairy cattle at different rates of fish oil and soybean oil. Designmethodology/approach: Four treatments with different rates of fish oil (FO) and soybean oil (SO) were evaluated (Control: no added oil; diet 1: 2% FO; diet 2: 2% FO and 1.5% SO; diet 3: 2% FO and 3% SO). In vitro digestibility and in situ degradability were evaluated. Ammonia nitrogen, lactic acid, volatile fatty acids (VFAs), and microbial protein were determined. For the in situ evaluation, a protein degradability kinetic was carried out. The means were compared using a Tukey test at a 5% confidence level. Results: The proposed diets increased gas production in in vitro kinetics, as the addition of oils increased (p0.001) and the kinetic latency time decreased (p0.001). All diets decreased the production of short-chain fatty acids (p0.001). The production of ammonia nitrogen and lactic acid did not differ compared to the control (p0.05). Diet 3 had a higher production of propionic acid in comparison to diet 1 and 2. In the in situ kinetic, the "kd" rate increased as more oils were added. Study limitations/implications: Although all treatments increased the production (milliliters) of CH 4 and CO 2 , the gas production had a proportional increase, as a result of a better use of the diets. Findings/conclusions: The addition of oils produced changes in the fermentation patterns and in the degradation of the protein at the ruminal level, increasing bypass protein. This offers an opportunity to improve performance in certain production situations.
... Many studies have been carried out to produce CLA enriched meat and eggs. CLA enriched chicken can be accomplished by manipulation of diet which involves supplementation of linoleic acid, linolenic acid and synthetic CLA (Khanal and Olson, 2004) or introducing CLA-producing bacteria into chicken in diet. Although chemically synthesized CLA are available, chemical synthesis of CLA may produce different isomers of CLA which would exert different cell signaling pathway in human that leads to different effects on cell functions (Wahle et al., 2004). ...
Article
Conjugated linoleic acid (CLA) is a group of octadecadienoic acids that are naturally present in the highest concentrations in foods originating in ruminant animals, and dairy products such as milk. Especially large numbers of CLA polymers have been detected in beef, lamb and milk fat. Results from many in vitro and animal studies, though conflicting, have suggested that CLA supplementation may have beneficial effect on obesity, weight management, cancer, diabetes and atherosclerosis. This article provides a brief overview on the functionality, safety and toxicity of CLA as described in literature.
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Milk contains a range of bioactive components with potentially beneficial effects. Bioactive components of note include proteins such as lactoferrin and the immunoglobulins, peptides formed during milk protein hydrolysis, fatty acids such as conjugated linoleic acid, minerals, oligosaccharides and melatonin. Enhancement of bioactive components of milk is possible through a range of on-farm management processes, and also through processing to enrich the desired components. A range of milks with enhanced properties is commercially available, albeit with relatively slight supporting clinical evidence of effectiveness. With continuing elucidation of these beneficial effects and their mechanisms, demand will increase and, eventually, label claims are likely. There is increasing consumer awareness of the relationship between nutrition and health, with functional foods increasingly available as mainstream food lines in supermarkets. With the emergence of nutrigenomics, and awareness of personal nutritional needs, there will be increasing demand for functional milks and their products. Development of new, more sophisticated processing, including processes that are less likely to denature proteins, and processes to recover enriched streams of specific bioactives, will lead to wider availability of milk-derived functional foods and ingredients.
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p class="Resumen" xml:lang="es-ES"> El objetivo del presente trabajo fue realizar una revisión sobre el efecto de la suplementación con lípidos sobre la concentración de ácido linoleico conjugado (ALC-c9t11) o ruménico y otros ácidos grasos insaturados en la leche bovina. Se abordó el concepto y origen del ALC-c9t11 en rumiantes. Existe una tendencia internacional en mejorar la calidad de la alimentación, lo que implica el incremento de consumo de proteína animal, dentro de lo cual están los productos lácteos saludables y ricos en ALC-c9t11, que ha mostrado efectos anticancerígenos en modelos animales. En la leche bovina ALC-c9t11, resulta del consumo de ácidos grasos insaturados y de la extensión de la biohidrogenación ruminal. La suplementación con ácidos grasos insaturados de origen vegetal permite aumentar la concentración de ALC-c9t11 y disminuir la proporción de ácidos grasos saturados en la leche, pero la respuesta varía de acuerdo con la fuente de grasa empleada, su nivel y la interacción con la dieta basal. </div
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El objetivo de este trabajo fue evaluar el efecto de la adición de aceites vegetales en dietas representativas de vacas lecheras bajo pastoreo, sobre los ácidos grasos, fermentación ruminal y producción de metano in vitro. La investigación se desarrolló en el laboratorio NUTRILAB–GRICA, perteneciente a la Facultad de Ciencias Agrarias, Universidad de Antioquia, Medellín, Colombia, en agosto del 2013. Se utilizó la técnica de producción de gas in vitro. En cuatro dietas (dos de monocultivo en Cynodon plectostachyus y dos de sistema silvopastoril intensivo con Leucaena leucocephala), se evaluó la adición de tres aceites vegetales (girasol, lino y palma) a nivel del 2 y 4% de la MS, en un diseño completamente al azar con arreglo factorial de 4x3x2. En todas las dietas, la suplementación con aceite de girasol aumentó el contenido de ácido linoleico (C18:2 c9,12), ácido linoleico conjugado (ALC-c9t11) y ácido transvaccénico (ATV, C18:1 t11) después de la fermentación (p
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Black Bengal goat (BBG) is the most widely recognized legacy goat breed in Bangladesh. The breed is black in color yet likewise earthy, white, or dim colors additionally found. The breed has medium body size with grown-up weight 25–30 kg, little horns, short legs, and tight body structure. The BBG is one of the most compliant, all around adjusted, early maturing, prolific, productive, and tropical disease–resistant goat types of the world that produces incredible quality meat, milk, and skin. The breed is versatile in hot, moist, cruel, climatic conditions and flourishes well on a cacophonous dietary regimen from uncultivable decrepit grounds, residences, riversides, banks, sloping, and hilly territories where crop culture or dairy nourishing is inconceivable. In Bangladesh, the BBG is one of the main red meat–producing small ruminants which shares remarkable local interest during Eid-Ul-Adha, Eid-Ul-Fitr, wedding ceremony, birthday festival, circumcision, memorial programs, and other social celebrations with no social, cultural, and religious limitations. Being little in size, the BBG has been an amazing asset to advance supportable vocations for the negligible, little, and landless ranchers who rely upon free regular grazing lands for raising domesticated animals. Regardless of incredibly exceptional components and features, the production of BBG has not yet been popularized widely since meager consideration has been paid for improving their efficiency. Development of cutting edge hereditary, dietary, and health as well as disease control procedure and utilization of modern management frameworks may procure considerable changes in improving the overall performance of the BBG.
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Degummed, refined, winterized (at ‐60°C) and non‐winterized soybean, sunflower, cottonseed and safflower oil samples were used for the production of conjugated linoleic acid (CLA) by urea treatment. Fatty acids composition and CLA isomers of winterized and non‐winterized versions of oil were analyzed on GC‐MS. Winterization improved the concentration of linoleic acids (LAs) in all vegetable oils. Safflower oil exhibited the highest concentration of LAs as 84.19% followed by sunflower oil (68.54%), cottonseed oil (63.74%) and soybean oil (59.88%), respectively. In safflower oil derived CLAs, concentrations of ∆9c,11t‐18:2, ∆10t,12c‐18:2, ∆9c,11c‐18:2, ∆10c,12t‐18:2, ∆8,9,11,10,12c‐c18:2 and ∆8,9,11,10,12t‐t18:2 were calculated 47.68, 39.95, 5.42, 1.89, 3.06, 0.55 and 1.45% while in winterized safflower oil derived CLAs, these concentrations were 55.67, 41.92, 0.19, 0.78, 0.65, 0.47 and 0.32%, respectively with significant difference in induction period and peroxide value. Yield of CLA from winterize soybean, sunflower cottonseed and safflower oil was 22.58, 24.95 23.16 and 36.68%.
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Conjugated linoleic acids are natural micro-components of ruminant’s fat milk, which have gained an increasing interest because of their valuable potential effects on human health. Rumenic acid (CLA cis-9, trans-11 C18:2) is the most important of the CLA iso-forms because of its abundance and its effects. Our main objective was the identification and quantification of the rumenic acid content of fat in milks of the Bogotá savannah. Additionally, we looked for associations between dietary factors and rumenic acid concentration. In this study, seventeen milk samples coming from the Bogotá savannah and four commercial milk samples were used. A gas chromatography method that allowed us to separate and quantify more than thirty fatty acids, from butyric (C4:0) to araquidic (C20:0) and rumenic acid (conjugated 18:2) was standardized. The mean rumenic acid content of the samples was 13.6 mg/g of fat, and ranged from 6.38 mg to 19.54 mg/g of fat (3 fold variation). These results showed similar values to other literature reports conducted under grazing conditions and are in the expected range for the amount consumed by the cows. The correlation (r) values were significant for dry matter supplementation, conserved forages supplementation, silage intake, and cotton seed intake and had a negative correlation with the rumenic acid content of fat milk (r values of -0.62, -0.54, -0.48 and -0.7, respectively). However, the values for the determination coefficients (r2) of these variables were very low, suggesting that each variable had individual effect, although none of them explains completely the variation of the rumenic acid content in fat milk. In general, a clear tendency to a decrease in rumenic acid content was observed with an increase in supplementation under grazing conditions, especially when corn silage was included. In the same way, a tendency to decreasing the rumenic acid content was observed for cotton seed supplementation, though the reasons for this were not clear. The differences in the rumenic acid content found on this study strongly suggest that fresh forage feeding can be advantageous for the production of milk with high contents of rumenic acid (or high rumenic acid milks), and that under commercial conditions, supplementation with adequate products might offer an opportunity for increasing the PUFAs (Polyunsasturated Fatty Acids) supply, precursors for rumenic acid synthesis.
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Conjugated linoleic acids (CLA) have been shown to affect fatty acid synthesis in various tissues. The objective of the study was to compare the effect of a commercial source of CLA with a linoleic acid-enriched oil (LA), supplied to 12 multiparous sows during gestation and lactation, on adipose tissue and milk fatty acid composition. The CLA isomers detected in the CLA oil were (in order of magnitude) c9,t11; t10,c12; c9,c11; t9,t11/t10,t12 and c10,c12 and amounted to 58.9 g/100 g fat. Biopsies were taken from the backfat on d 7 and 97 of gestation and milk samples were collected on d 2, 9, 16 and 23 after farrowing. Collection of colostrum and mature milk samples took place at 1100 h for sows who farrowed in the morning or at 1500 h for those who farrowed in the afternoon. All major CLA isomers in the supplement were transferred to the tissue and milk fat and, compared with the LA group, significantly increased saturated fatty acid and decreased monounsaturated fatty acid levels in the tissue and milk. These findings suggest a distinct involvement of CLA in the de novo fatty acid synthesis and desaturation process in the adipose tissue and mammary gland. Estimated transfer efficiency of dietary CLA isomers was 41-52% for the backfat and 55-69% for the mature milk. The incorporation and uptake efficiency seemed to be selective with the highest values found for c9,t11-CLA. Overall, dietary CLA supplementation of sows during gestation and lactation markedly altered backfat and milk fatty acid composition.
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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.
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Mechanisms underlying milk fat conjugated linoleic acid (CLA) responses to supplements of fish oil were investigated using five lactating cows each fitted with a rumen cannula in a simple experiment consisting of two consecutive 14-day experimental periods. During the first period cows were offered 18 kg dry matter (DM) per day of a basal (B) diet formulated from grass silage and a cereal based-concentrate (0.6:0.4; forage:concentrate ratio, on a DM basis) followed by the same diet supplemented with 250 g fish oil per day (FO) in the second period. The flow of non-esterified fatty acids leaving the rumen was measured using the omasal sampling technique in combination with a triple indigestible marker method based on Li-Co-EDTA, Yb-acetate and Cr-mordanted straw. Fish oil decreased DM intake and milk yield, but had no effect on milk constituent content. Milk fat trans-11 C18:1, total trans-C18:1, cis-9 trans-11 CLA, total CLA, C18:2 (n-6) and total C18:2 content were increased in response to fish oil from 1.80, 4.51, 0.39, 0.56, 0.90 and 1.41 to 9.39, 14.39, 1.66, 1.85, 1.25 and 4.00 g/100 g total fatty acids, respectively. Increases in the cis-9, trans-11 isomer accounted for proportionately 0.89 of the CLA response to fish oil. Furthermore, fish oil decreased the flow of C18:0 (283 and 47 g/day for B and FO, respectively) and increased that of trans-C18:1 fatty acids entering the omasal canal (38 and 182 g/day). Omasal flows of trans-C18:1 acids with double bonds in positions from delta-4 to -15 inclusive were enhanced, but the effects were isomer dependent and primarily associated with an increase in trans-11 C18:1 leaving the rumen (17.1 and 121.1 g/day for B and FO, respectively). Fish oil had no effect on total (4.36 and 3.50 g/day) or cis-9, trans-11 CLA (2.86 and 2.08 g/day) entering the omasal canal. Flows of cis-9, trans-11 CLA were lower than the secretion of this isomer in milk. Comparison with the transfer of the trans-9, trans-11 isomer synthesized in the rumen suggested that proportionately 0.66 and 0.97 of cis-9, trans-11 CLA was derived from endogenous conversion of trans-11 C18:1 in the mammary gland for B and FO, respectively. It is concluded that fish oil enhances milk fat cis-9, trans-11 CLA content in response to increased supply of trans-11 C18:1 that arises from an inhibition of trans-C18:1 reduction in the rumen.
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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.
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During one's year period bulk milk samples were collected monthly from three different types of farms: 1. conventional farming - indoor feeding with silages the whole year, 2. conventional farming - grazing during summer season, 3. ecological farming - grazing during summer season. Conjugated linoleic acids (CLA), trans vaccenic and other trans isomers of milk fatty acids were analyzed. Variation of CLA in milk fat was substantial (0.26 to 1.14 % of total methyl esters) and was season-dependent. The lowest percentage of CLA (0.34 %) was found in the group, fed only fermented roughage and concentrates (most intensive production farm) the highest (0.80 %) in the ecologically produced milk fat. The concentration of CLA and trans vaccenic acid was positively correlated. There is a growing interest in CLA, considered to be beneficial in prevention of carcinogenesis. Its percentage in milk products can be increased through a suitable dietary regimen.
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Incubation of Butyrivibrio fibrisolvens with different geometrical isomers of linoleic acid indicated the specificity of the biohydrogenation system for linoleic acid or for a conjugated dienoic acid. cis-9-Octadecenoic acid, trans-9-octadecenoic acid, and trans-11-octadecenoic acid were not hydrogenated by this bacterium. The intermediates and products of biohydrogenation of linoleic acid were identified as a Δ9,11-cis-trans (or trans-cis, or both)-octadecadienoic acid and a mixture of trans-9-octadecenoic acid and trans-11-octadecenoic acid. When different positional isomers of cis-trans-conjugated octadecadienoic acid were incubated, various trans-octadecenoic acids were produced, reflecting the double bond positions of the conjugated diene substrates. The first reaction in the biohydrogenation of linoleic acid by B. fibrisolvens is the isomerization of linoleic acid to the cis-trans (or trans-cis, or both)-conjugated octadecadienoic acid. This intermediate is then hydrogenated to form a mixture of the two trans-monoenoic acids.
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Six cows were utilized in a 6 x 6 Latin square design with 21-d periods to determine effects of the postruminal profile of fatty acids on dry matter (DM) intake, milk yield and composition, nutrient digestibilities, and plasma metabolites. Treatments were abomasal infusions of 1) control [168 g/d of meat solubles (carrier for fatty acids) plus 10.6 g/d of Tween 80 (emulsifier)], 2) control plus 450 g/d of mostly saturated fatty acids, 3) control plus 450 g/d of palm oil fatty acids low in linoleic acid, 4) control plus 450 g/d of palm oil fatty acids, 5) control plus 450 g/d of soybean oil fatty acids, and 6) control plus 450 g/d of soybean oil fatty acids high in palmitic acid. Treatments 2, 3, 4, and 6 contained similar ratios of C16 to C18 fatty acids. Infusion of soybean oil fatty acids or soybean oil fatty acids high in palmitic acid decreased intakes of DM, organic matter, crude protein, acid detergent fiber, neutral detergent fiber, gross energy, and total fatty acids and tended to decrease yields of milk and fat-corrected milk compared with the infusion of mostly saturated fatty acids. Infusion of palm oil fatty acids low in linoleic acid or palm oil fatty acids decreased milk fat percentage compared with other treatments. Ruminal characteristics and apparent digestibilities of DM, organic matter, crude protein, acid detergent fiber, neutral detergent fiber, energy, total fatty acids, and total C18 fatty acids were not different. Infusion of fatty acids increased concentrations of cholesterol in plasma. The amount of unsaturated fatty acids passing into the small intestine may influence responses of dairy cows to supplemental fat.
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We examined the effect of intake of fresh pasture on concentrations of conjugated linoleic acid in milk fat. Sixteen Holstein cows were paired and divided into either the control group or the grazing group. The study involved initial, transition, and final periods. During the initial period, all cows consumed a total mixed diet. Cows in the control group were fed the total mixed diet throughout the study, and cows in the grazing group were gradually adjusted to a diet consisting of intensively managed pasture. Performance of cows in the grazing group was significantly reduced from that of cows in the control group during the final period (dry matter intake, 19% less; milk yield, 29.6 vs. 44.1 kg/d; and live weight, 40 kg less). During the initial period, when both groups were consuming a total mixed diet, concentrations of conjugated linoleic acid in milk fat were similar (X = 5.1 mg/g of milk fat). As the grazing group was gradually adjusted to pasture, concentrations of conjugated linoleic acid in milk gradually increased. During the final period, when cows in the grazing group were consuming a diet consisting of pasture only, conjugated linoleic acid concentrations in the milk fat were doubled (10.9 vs. 4.6 mg/g of milk fat). Furthermore, results showed the individual consistency of the milk fat content of conjugated linoleic acid over time but also demonstrated substantial variation among individual cows within treatment groups. Overall, this study indicated that the concentration of conjugated linoleic acid in milk fat is enhanced by dietary intake of fresh pasture.
Article
Unsaturated fatty acids of plant origin have typical structures: double bounds have 'cis'-configuration and two or more double bounds are separated by a CH2-group. Fatty-acids from fodder with double bounds of cis-configuration will be converted to fatty acids of trans-configuration and with conjugated double bounds. This reaction takes place in the stomach of ruminants by the influence of microorganisms. In fatty acids with conjugated double bounds there is no separating CH2-group between the double bounds, and properties of fatty acids change. This class of compounds - Conjugated Linolenic Acids (CLA) - has very positive physiological properties: they are antioxidative, anticancerogenic, they increase growth of muscles and bones and decrease deposition of fat. Most CLA in our food are from milkfat, in other fats from ruminants CLA can be found in similar concentrations. The content of CLA in beef is influenced by feeding, grass-silage led to higher contents of CLA than maize silage.
Article
Conjugated linoleic acid (CLA), a mixture of isomers of linoleic acid, has many beneficial effects, including decreased tumor growth in animal cancer models. The cis-9, trans-11 isomer of CLA (CLA9,11) can be formed in the rumen as an intermediate in biohydrogenation of linoleic acid. Recent data, however, indicate that tissue desaturation of transfatty acids is an important source of CLA9,11 in milk. Our objective was to determine whether supplementing a high-corn diet with soybean oil (SBO; a source of linoleic acid) would increase concentrations of CLA in ruminal contents and tissue lipids. Four ruminally cannulated steers were utilized in a Latin square design with 28-d periods. A control diet (80% cracked corn, 2.0% corn steep liquor, 8.0% ground corn cobs, and 10% supplement [soybean meal, ground shelled corn, minerals, and vitamins]) was supplemented with 2.5, 5.0, or 7.5% (DM basis) SBO. Supplemental SBO did not affect ruminal pH or concentrations of the major VFA. The proportion and amount (mg FA/g DM ruminal contents) of CLA9,11 were not increased by increasing dietary SBO. However, the proportion and amount of the trans-10, cis-12 CLA isomer (CLA10,12) in ruminal contents increased linearly (P < 0.006) as dietary SBO increased. Trans-18:1 isomers in ruminal contents increased linearly (P < 0.02) as dietary SBO increased. The proportion of CLA10,12 was correlated positively (P < 0.001) with proportions of trans-C 18: 1 isomers in ruminal contents. Conversely, CLA9,11 was correlated negatively (P < 0.05) with the proportions of trans-18:1 in ruminal contents. The same high-corn diet, supplemented with 0 or 5% SBO, was fed to 20 Angus-Wagyu heifers for 102 d in a randomized complete block design to determine the effect of added SBO on tissue deposition of CLA. Supplemental SBO did not affect feed intake, gain:feed, or carcass quality. Tissue samples were obtained from the hindquarter, loin, forequarter, liver, large and small intestine, and subcutaneous, mesenteric, and perirenal adipose depots. The concentration of CLA9,11 was greatest in subcutaneous adipose tissue but was not affected in any tissue by SBO. Supplementing high-corn diets with SBO does not increase CLA9,11 concentrations in tissues of fattening heifers. Research is needed to identify regulatory factors for pathways of biohydrogenation that lead to increased concentrations of CLA10,12 in ruminal contents when high-oil, high-concentrate diets are fed.
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This chapter discusses lipid metabolism in the rumen. Microbial activity in the rumen is responsible for the hydrolysis of esterified plant lipids and for the subsequent hydrogenation of the liberated unsaturated fatty acids. The microorganisms of the rumen are capable of lipid synthesis de novo, using as substrates the short-chain fatty acids produced as end products of microbial carbohydrate and amino-acid metabolism. These activities of hydrolysis, hydrogenation, and synthesis de novo of microbial lipid in the rumen contribute greatly to the characteristic composition of ruminant tissue lipids. Lipids comprise 6%–8% of the dry weight of leaf tissue, and are characterized by their high content of glycolipids and phospholipids. Although the lipid content of forage crops is quite low, the total amount of lipid ingested by the ruminant animal may be considerable because of the large amount of dietary material consumed.
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The amounts of octadeca-cis-9,trans-11-dienoic acid in the fatty acids of some foodstuffs, of human blood, and of human milk are reported. Ruminant fats are the major dietary source of this conjugated fatty acid. The distribution of this acid in the lipid classes of foods and in human blood serum are considered in relation to its source.
Article
Fatty acid composition and conjugated linoleic acid (CLA) content in pars costalis diaphragmatis (PCD) muscle from European and British crossbred (EBC; no Wagyu genetics) and Wagyu crossbred (WC; 75% Wagyu genetics) beef cattle were determined. Conjugated linoleic acid contents of PCD muscle from EBC (1.7 mg CLA g-1 lipid) and WC (1.8 mg CLA g-1 lipid) cattle were similar (P > 0.05), while WC cattle had higher (P < 0.05) CLA content 100 g-1 of beef on a DM basis because the lipid content of meat from WC cattle was greater (P < 0.05) than that from EBC cattle.
Conference Paper
The objective of this study was to investigate the incorporation of conjugated linoleic acid (CLA) into eggs and its effect on the fatty acid metabolism when layers are fed diets with different fat sources and fat levels. Layers were fed either a low fat diet (LF) or one of three high fat diets based on soybean oil (SB), animal fat (AF) or flaxseed oil (FSO). CLA was added at a concentration of 1 g/100 g feed from two different CLA premixes with a different CLA profile. For the trial, 144 laying hens were allocated to 12 treatments (4 basal fat sources x 3 CLA treatments) with 3 replicates of 4 hens each. No significant differences were observed in feed intake, egg weight, feed conversion or laying rate between chickens fed control and CLA-supplemented diets. Differences in yolk fat, cholesterol or yolk color were not clearly related to the dietary CLA. However, the supplementation of CLA to the diets had clear effects on the fatty acid composition, i.e., a decrease in monounsaturated fatty acids (MUFA) and an increase in saturated fatty acids (SFA) was observed, whereas the polyunsaturated fatty acids (PUFA) content were essentially unaffected. The results suggest that CLA may influence the activity of the desaturases to a different extent in the synthesis of (n-6) and (n-3) long-chain fatty acids. These effects of CLA depend on the level of (n-6) and (n-3) fatty acids available in the feed. The apparent deposition rate (%) is clearly higher for the c9, t11 isomer than for the t10, c12 isomer. Adding CLA to layers diets rich in (n-3) fatty acids produces eggs that could promote the health of the consumer in terms of a higher intake of (n-3) fatty acids and CLA.
Article
Food products from ruminants are the major dietary source of conjugated linoleic acids (CLA) for humans. The uniqueness of CLA in ruminant fat relates to the biohydrogenation of dietary unsaturated fatty acids by rumen bacteria. The CLA are inter- mediates in the biohydrogenation, and a portion escape the rumen and are incorporated into milk fat and body fat. In addition, the animal itself synthesizes cis-9, trans-11 CLA from trans-11 octadecenoic acid, another intermediate in ruminal biohydroge- nation that is absorbed. This involves ∆9-desaturase, which is present in mammary tissue (lactation) and adipose tissue (growth). Investigations to alter the content of CLA have typically involved lactating cows (milk fat); fewer data from growing cattle (body fat) are available. Dietary factors that alter the content of CLA because of effects on the rumen biohydrogenation processes in- clude unsaturated fatty acid substrates and altered rumen environment. The cis-9, trans-11 CLA isomer is the major isomer found in ruminant fat; this isomer typically represents 80 to 90% of the total CLA in milk fat, but its proportion in beef fat is less. Under certain dietary conditions the proportion of the trans-10, cis-12 CLA isomer increases. Thus, dietary factors also alter the direction of the biohydrogenation pathways in the rumen. The CLA possess anticarcinogenic effects, which relates to the cis-9, trans-11 CLA isomer, as evident from results with mammary tumors in a rat model. Lipid accretion and nutrient partitioning are also altered by CLA in several species. Recent work demonstrates that this relates primarily to the trans-10, cis-12 CLA isomer, as evident by effects on milk fat synthesis in lactating cows and body fat accretion in growing mice. Overall, consideration of functional foods containing CLA represents an exciting area of potential importance in producing food products derived from ruminants.
Article
Seasonal and regional variations in ethenoid acids of Canadian milk fat have been established from 327 authentic samples, representative of every month of the year and of 29 creameries across Canada. About 30% of the fatty acids in milk fat were unsaturated; 12% of these were polyunsaturated acids, with one-third being of the conjugated type. The average values and the 95% fiducial limits, in brackets, were as follows: conjugated dienes 1.13% (0.24–2.01), conjugated trienes 0.021% (0.001–0.033), conjugated tetraenes 0.002% (0.000–0.005), nonconjugated dienes 1.31% (0.78–1.84), nonconjugated trienes 0.89% (0.32–1.46), nonconjugated tetraenes 0.19% (0.07–0.31), nonconjugated pentaenes 0.12% (0.02–0.22), nonconjugated hexaenes 0.042% (0.001–0.083), total polyethenoid acids 3.71% (2.82–4.60), monoethenoid acids 26.1% (21.8–30.4), ethanoid acids 65.8% (60.5–71.1). The ethanoid acids which varied with the season were the conjugated dienes and trienes, the nonconjugated trienes and pentaenes, and the monoethenoid acids. They were all higher in summer than in winter milk fat. Triene values were higher in Ontario, and monoethenoid acids were higher in the coastal than in the other provinces. The most significant feature of the seasonal variations was the close relationship between iodine value, monoethenoid acids, conjugated dienes, and non-conjugated trienes. Of the total iodine value, 74% was contributed by monoethenoid acids, 14% by dienes, 8% by trienes, and 4% by tetraenes, pentaenes, and hexaenes. The occurrence of conjugated dienes in relatively large amounts and of hexaenes in all samples is of special interest as characteristics of milk fat.
Article
Two experiments with sheep were performed to test the efficacy of a linoleic acid-rich sunflower seed oil as a supplement to barley silage-based diet (6% of the dietary dry matter) to suppress protozoal numbers in the rumen and measure effects of the oil on the growth performance and tissue content of conjugated linoleic acid (CLA). In the first experiment, rumen contents were sampled (2h after feeding) from the two treatment groups of five rumen cannulated sheep on each day 0–14, and on days 16, 19, 21, 28, 35, 42 and 49. The pH and protozoal counts were determined in each sample, while volatile fatty acids (VFA) and ammonia nitrogen were determined in samples from days 7, 14, 21 and 49. In the second experiment, nine lambs were fed each of the two diets for 168 days. Thereafter, the lambs were harvested and samples of diaphragm muscle, leg muscle, rib muscle, heart, liver, kidney and subcutaneous fat were analyzed for lipid and fatty acid concentrations. Feeding the oil supplement decreased (P
Article
The effects of feeding protected or unprotected canola oil on intake, nutrient digestibility, duodenal fatty acid flows, milk yield, and milk composition were evaluated using four Holstein cows cannulated in the rumen and proximal duodenum. Cows were fed a control diet (CON) or the control diet supplemented at 3.3% of dry matter with canola oil (OIL), canolamide (AMD) (made by reacting canola oil with ethanolamine), or a mixture of equal amounts of canola oil and canolamide (MIX) in a 4×4 Latin square with four 21-day periods. Milk yield and dry matter intake averaged 38 and 24kg per day, when OIL or MIX were fed, but decreased to 33 and 19kg per day when cows were fed AMD as the only supplemental source of cis9–18:1. Total tract digestibility of dry matter (70%), crude protein (71%), and fiber (49%) was not affected by treatments. Oleic acid intake was higher due to feeding AMD (438g per day), OIL (530g per day), or MIX (531g per day) compared with CON (120g per day). Biohydrogenation of cis9–18:1 (40 versus 77%) increased when all forms of supplemental oleic acid were fed. Cis9, trans11–18:2, trans11–18:1, and 18:0 flows to the duodenum were greater when OIL (3, 104, and 647g per day) was fed compared with AMD (0, 29, and 372g per day). Flow of cis9–18:1 to the duodenum was greater (103g per day) in response to supplemental fat compared with CON (65g per day). Plasma total fatty acids and cis9–18:1 increased 15 and 61% in response to supplemental oleic acid. Milk fat percentage was not affected by treatments, but concentrations of saturated 8:0 to 16:0 in milk fat were lower when cows were fed supplemental cis9–18:1 (41%) compared with CON (58%). Cis9, trans11–18:2 and trans11–18:1 concentrations in milk fat were greater when OIL (1.1 and 4.5%) was fed compared with AMD (0.7 and 2.9%). Concentrations of cis9–18:1 in milk fat ranked by treatment were AMD (28%)=OIL (26%)>MIX (24%)>CON (16%). Converting canola oil to an amide provided partial protection against biohydrogenation of cis9–18:1. Whether fed as an oil or amide, however, supplemental cis9–18:1 elevated concentrations of oleic acid in plasma and milk fat.
Article
The relationships between fodder plants and the fatty acid composition of milk fat were studied in lowland (600–650m), mountain (900–1210m) and highland (1275–2120m) areas of Switzerland. Correlation coefficients have been calculated between the occurrence of plant families and species and the concentrations of groups of fatty acids in milk fats from the Mountains and Highlands regions, where the botanical composition of the pasture was more similar than in the Lowlands. Besides further contributing factors linked to the altitude in Mountains and Highlands (e.g. walking), the correlations indicate which plants could be responsible for the occurrence of the most abundant fatty acids in milk fat.
Article
Thetrans-18:1 acid content and distribution in fats from ewe and goat milk, beef meat and tallow were determined by a combination of capillary gas-liquid chromatography and argentation thin-layer chromatography of fatty acid isopropyl esters. Thetrans isomers account for 4.5 ± 1.1% of total fatty acids in ewe milk fat (seven samples) and 2.7±0.9% in goat milk fat (eight samples). In both species, as in cow, the main isomer is vaccenic (trans-11 18:1) acid. The distribution profile oftrans-18:1 acids is similar among the three species. The contribution of ewe and goat milk fat to the daily intake oftrans-18:1 acids was estimated for people from southern countries of the European Economic Community (EEC): France, Italy, Greece, Spain, and Portugal. It is practically negligible for most of these countries, but in Greece, ewe and goat milk fat contributeca. 45% of the daily consumption oftrans-18:1 acids from all dairy products (0.63 g/person/day for a total of 1.34 g/person/day). Thetrans-18:1 acid contents of beef meat fat (ten retail cuts, lean part) and tallow (two samples) are 2.0 ± 0.9% and 4.6%, respectively, of total fatty acids (animals slaughtered in winter). Here too, the main isomer is vaccenic acid. Othertrans isomers have a distribution pattern similar to that of milk fat. Beef meat fat contributes less than one-tenth of milk fat to thetrans-18:1 acid consumed. The daily per capita intake oftrans-18:1 acids from ruminant fats is 1.3–1.8 g for people from most countries of the EEC, Spain and Portugal being exceptions (ca. 0.8 g/person/day). In France, the respective contributions of ruminant fats and margarines to the daily consumption oftrans-18:1 acids are 1.7 and 1.1 g/person/day (60 and 40% of total, respectively). These proportions, based on consumption data, were confirmed by the analysis of fat from milk of French women (ten subjects). The mean content oftrans-18:1 acids in human milk is 2.0 ± 0.6%, with vaccenic acid being the major isomer. Based on the relative levels of thetrans-16 18:1 isomer, we could confirm that milk fat is responsible for the major part of the daily intake oftrans-18:1 acids by French people. The daily individual intake oftrans-18:1 isomers from both ruminant fats and margarines for the twelve EEC countries varies from 1.5 g in Spain to 5.8 g in Denmark, showing a well-marked gradient from the southwest to the northeast of the EEC.
Article
Conjugated octadecadienoic acids (18∶2’ conjugated linoleic acids) have been shown to be anticarcinogenic and may influence growth and nutrient partitioning. The Δ9c’ 11t−18∶2 isomer (rumenic acid’ RA) is most common in both food sources and human tissues. To determine if maternal diet can influence milk RA concentration’ breastfeeding women (n=16) were enrolled in a 3-wk crossover study. Women initially consumed minimal amounts of food containing RA during week 1’ then were assigned randomly to consume diets rich in high-fat dairy foods (and thus RA) during week 2 or 3. Milk was collected by complete breast expression twice during each experimental week. Current and chronic RA intakes were estimated by 3-d dietary records and food frequency question-naires’ respectively. Estimated chronic RA intakes ranged from 49 to 659 mg/d. Dietary RA intake was greater during the high compared to the low dairy period (291±75 vs. 15±24 mg/d’ respectively; P
Article
Conjugated diene isomers of linoleic acid (CLA), possess anticarcinogenic and antiatherogenic properties, but little is known about their metabolism. We have recently obtained evidence that CLA present in partially hydrogenated oil can be metabolized to conjugated linolenic and eicosatrienoic acids in rat liver. In the present study, we have investigated whether CLA are metabolized in the liver of lambs, which normally consume high levels of CLA produced in the rumen and present in their diet, consisting exclusively of milk. Conjugated linolenic, eicosatrienoic, and arachidonic acids were detected in lamb liver phospholipids showing that elongation and desaturation of CLA occur also in lamb tissues, and that all metabolites maintain the conjugated diene structure.
Article
Conjugated dienoic derivatives of linoleic acid (CLA), shown to be anticarcinogenic in several animal models, are present in many natural food sources. However, few quantitative data on CLA in food are available. An improved method for quantifying CLA was developed. The method was used to produce a data base of more than 90 food items including meat, poultry, seafood, dairy products, plant oils, and infant and processed foods. The principal dietary sources of CLA are animal products. In general, meat from ruminants contains considerably more CLA than meat from nonruminants, with veal having the lowest and lamb the highest (2.7 vs 5.6 mg CLA/g fat). Foods derived from nonruminant animals were far lower in CLA content except for turkey. Seafood contained low amounts of CLA, ranging from 0.3 to 0.6 mg CLA/g fat. By contrast dairy products (milk, butter, and yogurt) contained considerable amounts of CLA. Natural cheeses were also high in CLA. Among cheeses, those which were aged or ripened more than 10 months had the lowest CLA content. CLA concentrations in an assortment of processed cheeses did not vary much (avg 5.0 mg CLA/g fat). Plant oils contained far less CLA, ranging from 0.1 mg CLA/g fat (coconut oil) to 0.7 mg CLA/g fat (safflower oil). Processed, canned, and infant foods were comparable in CLA content to similar unprocessed foods. Values for foods that contained beef, lamb, and veal were generally high in CLA. However the c-9,t-11 CLA isomer, believed to be the biologically active form, tended to be lower in cooked meats. In animal and dairy products the c-9,t-11 CLA isomer accounted for 75 and 90%, respectively, of the total CLA; in plant oils less than 50% of the total CLA was the c-9,t-1 I CLA isomer. The results show that considerable differences occur in the CLA content of common foods and indicate the possibility of large variations in dietary intakes of CLA.
Article
Conjugated linoleic acid (CLA) is a collective term for metabolic by-products resulting from the conversion of linoleic acid to oleic acid by rumen bacteria. Consequently CLA is found in foods and fats of animal origin. There is a growing body of information regarding effects of dietary CLA in health and disease, but not yet any definitive mechanisms relating to its mode(s) of action. The review paper by Professor Kritchevsky and accompanying commentary by Professor Williams summarise the recent evidence from animal studies for anti-tumourigenic, anti-lipogenic and anti-atherogenic effects of CLA. These findings may open new avenues of research in several normal and disease states. Furthermore, if the health benefits suggested by animal studies can be shown to apply in human populations, the consequence of advice to reduce fat intakes, may prove to have important public health implications.
Article
The effects of grass dry matter (DM) allowance and dietary supplements of full fat rapeseeds on levels of cis-9,trans-11 octadecadienoic (CLA) acid in bovine milk were investigated. Grass allowance of 16 kg/(cow*day) resulted in reduced (p<0.05) milk fat CLA levels (3.91 mg CLA/g fat) compared to 20 kg/(cow*day) after 19 wk treatment. CLA levels increased in milk fat from cows on a high-rapeseed-supplemented diet (p<0.001) (1650 g/(cow*day) full fat rapeseed) compared to the control (pasture) and low rapeseed (p<0.01) (825 g/(cow*day) full fat rapeseed) supplemented diets. The variation in milk fat CLA levels among individual cows over both trials was 1.5–16 mg/g.
Article
Samples were taken at 9 stages of processing, from raw milk to cheese aged for 6 mo. Fatty acid distributions, conjugated linoleic acid (CLA), moisture, protein, lipid contents, and titratable acidity were determined. CLA contents were highest after 3 mo, with one type of Cheddar (3.76 mg/g lipid) higher than the other two (3.44 and 3.47 mg/g lipid). Multiple linear regression showed all composition parameters were directly related to CLA content (mg/100 g sample). The content of oleic acid isomer C18:1ω7 was also directly related to CLA content (mg/g lipid). Thus, content of CLA in Cheddar-type cheeses might be controlled by stage and conditions of processing. An understanding of the effects of processing on CLA formation in Cheddar-type cheeses will be beneficial in designing processing methods to enhance CLA contents.
Article
The identity of a previously unrecognized conjugated linoleic acid (CLA) isomer, 7 trans, 9 cis-octadecadienoic acid (18∶2) was confirmed in milk, cheese, beef, human milk, and human adipose tissue. The 7 trans, 9 cis-18∶2 isomer was resolved chromatographically as the methyl ester by silver ion-high-performance liquid chromatography (Ag+-HPLC); it eluted after the major 9 cis, 11 trans-18∶2 isomer (rumenic acid) in the natural products analyzed. In the biological matrices in-vestigated by Ag+-HPLC, the 7 trans, 9 cis-18∶2 peak was generally due to the most abundant minor CLA isomer, ranging in concentration from 3 to 16% of total CLA. By gas chromatography (GC) with long polar capillary columns, the methyl ester of 7 trans, 9 cis-18∶2 was shown to elute near the leading edge of the major 9 cis, 11 trans-18∶2 peak, while the 4,4-dimethyloxazoline (DMOX) derivative permitted partial resolution of these two CLA isomers. The DMOX derivative of this new CLA isomer was analyzed by gas chromatography-electron ionization mass spectrometry (GC-EIMS). The double bond positions were at Δ7 and Δ9 as indicated by the characteristic mass spectral fragment ions at m/z 168, 180, 194, and 206, and their allylic cleavages at m/z 154 and 234. The cis/trans double-bond configuration was established by GC-direct deposition-Fourier transform infrared as evidenced from the doublet at 988 and 949 cm−1 and absorptions at 3020 and 3002 cm−1. The 7 trans, 9 cis-18∶2 configuration was established by GC-EIMS for the DMOX derivative of the natural products examined, and by comparison to a similar product obtained from treatment of a mixture of methyl 8-hydroxy-and 11-hydroxyoctadec-9 cis enoates with BF3, in methanol.
Article
Six lactic cultures: Lactobacillus acidophilus (CCRC14079), L. delbrueckii subsp. bulgaricus (CCRC14009), L. delbrueckii subsp. lactis (CCRC14078), Lactococcus lactis subsp. cremoris (CCRC12586), Lc. lactis subsp. lactis (CCRC10791), and Streptococcus thermophilus (CCRC12257) were tested for the effects of additions of 60 g l−1 sucrose, lactose, fructose, and 10 g l−1 sodium chloride. The levels of c9,t11-conjugated linoleic acid (c9,t11-CLA) formed were determined by gas chromatography. A significant decrease in c9,t11-CLA level was observed in cultures with sucrose, lactose, fructose, and sodium chloride added, except for Lc. lactis subsp. cremoris. Inoculation of L. acidophilus into 60 g l−1 sweeteners and 10 g l−1 sodium chloride-treated skim milk medium under aerobic conditions for 24 h incubation was most effective in promoting c9,t11-CLA formation. Lactose and fructose are suggested for use in maintaining a high CLA level.
Article
The composition of fatty acids (approx. 70 acids) in 44 summer milk samples from three geographical sites was determined using high-resolution gas chromatography. We observed large differences between Lowlands (600–650 m), Mountains (900–1210 m) and Highlands (1275–2120 m) which are analogous to those observed between winter and summer fats. The largest relative increases as a function of the altitude of these three sites were those of the concentration of conjugated linoleic acids (0.87, 1.61 and 2.36 g 100 g−1), especially of the cis (c) 9 trans (t) 11 isomer (0.81, 1.50 and 2.18 g 100 g−1), and the fatty acids C18:1 t10+t11 (2.11, 3.66 and 5.10 g 100 g−1). There were significant differences in the concentration of fatty acids between the three geographical sites. Some fatty acids could also be interesting potential indicators for the origin of cream and also of the Protected Designated Origine “mountain” cheeses.
Article
The objective was to use fat supplements mixed with a high-grain ration to increase conjugated linoleic acid (CLA) levels in beef cattle tissue and provide beef that is desirable to the consumer. Sixteen steers and 8 heifers (12-18 mo of age) were blocked according to sex and body weight and assigned to 1 of 4 treatments. Animals were fed a total mixed ration consisting of 74.7% ground barley, 17.8% alfalfa hay, 5.4% corn silage, and 2.1% vitamin/mineral supplement on a DM basis plus 300 g⋅hd-1⋅d-1 of either Megalac (ML) as control, fish oil (FO), partially rumen-protected trans fat (TF), or linseed oil (LO) as a fat supplement mixed into the total mixed ration. Animals were fed for an average of 148 d and then slaughtered between 450 and 590 kg live body weight. At slaughter, muscle and adipose tissue samples were collected from the loin and round and analyzed for fatty acid profile. All samples were pooled and the overall treatment means were reported. Tissues from TF and LO cattle had higher average cis-9 trans-11 CLA levels than FO and ML treatments (P ≤ 0.05). Cis-9 trans-11 CLA levels for ML, FO, TF, and LO were 0.24 b , 0.26 b , 0.45 a , and 0.41a % of total fatty acids, respectively. Trans-10 cis-12 CLA levels were not different between treatments (P ≤ 0.05) and averaged 0.016% of total fatty acids. Color stability tests were performed on top loin steaks for 21 d. By day 7, FO steaks had a higher hue angle (indicating brownness), which continued until day 20 (P ≤ 0.05). Neck muscle vitamin E values for ML, FO, TF, and LO were 2.35 ab
Article
The faut of butter made from the morning and evening milk of different groups of cows in the herd at the C.N.R.Z. was studied over a period of a fortnight during which the cows were turn out to grass, in the spring of 1957, 1958 and 1959.Variations in the iodine value and saponification values and the soluble and insoluble volatile fatty acids of the butter fat were recorded in 1957, whereas in 1958 and 1959 only the variations in iodine value were studied with additional determination of the various poly-unsaturated (conjugated and non-conjugated) fatty acids in the butter fat.The increase in iodine value which occurs when fresh grass is introduced into the cow's diet may be abrupt (12 units in 48 hours) or less rapid depending on whether the change from the winter ration to pasture is sudden or gradual.There is a correlated increase in the amount of conjugated diene acids (expressed as percentage by weight of butter fat), with the increase in iodine value (from 0,5 to 1,3 in 1958 and 0,5 to 1,8 in 1959 for a corresponding increase of 14 units in the iodine value). A simultaneous increase in linolenic acid (0,3 to 0,8) is observed, There is a transitory increase in the amount of linoleic acid which returns to its initial value several days after the cows are turn out to grass (1,5 in 1958 and only 1,0 in 1959). There is no variation in the amount of arachidonic acid (0,3 to 0,4)
Article
Populations of large and small milk fat globules were isolated and analyzed to determine differences in fatty acid composition. Globule samples were obtained by centrifugation from milks of a herd and of individual animals produced under both pasture and barn feeding. Triacylglycerols of total globule lipids were prepared by thin layer chromatography and analyzed for fatty acid composition by gas chromatography. Using content of the acids in large globules as 100%, small globules contained fewer short-chain acids, -5.9%, less stearic acid, -22.7%, and more oleic acids, +4.6%, mean values for five trials. These differences are consistent with alternative use of short-chain acids or oleic acid converted from stearic acid to maintain liquidity at body temperature of milk fat globules and their precursors, intracellular lipid droplets. Stearyl-CoA desaturase (EC 1.14.99.5), which maintains fluidity of cellular endoplasmic reticulum membrane, is suggested to play a key role in regulating globule fat liquidity. Possible origins of differences between individual globules in fatty acid composition of their triacylglycerols are discussed.
Article
Recent literature on the composition of milk lipids is reviewed and discussed. Many additional exotic fatty acids, mainly branched chain, keto, hydroxy and isomers containing double bonds, have been identified, often with the aid of mass spectrometry. It is estimated that ca. 500 fatty acids have been found in milk lipids. Components of lipid classes have been isolated and their structure determined, e.g., glucosyl and lactosyl ceramide, sphingomyelin, ether lipids, etc. The fatty acid composition of “protected” milk is discussed. This milk, obtained from cows fed polyunsaturated oils encapsulate