Fatty acids of adipose tissue,plasma, muscle and duodenal ingesta of steers fed extruded soybeans

Effects of feeding a high-energy diet that contained extruded soybeans on fatty acid composition of lipids of adipose tissue, skeletal muscle and plasma were determined for 18 Angus steers. Steers weighing an average of 309 kg were fed either a control diet or a diet containing 14.3% extruded soybeans and 6% fat until they weighed 474 kg. A third group was fed the control diet for the first half of the experiment and the soybean-containing diet for the rest of the experiment. Samples of blood, muscle (M. trapezius) and subcutaneous adipose tissue were obtained at 309, 368 and 427 kg of body weight; steers were slaughtered at 474 kg body weight, and samples of subcutaneous and perirenal adipose tissues,M. longissimus and blood were obtained. The lipids of subcutaneous adipose tissue taken at slaughter of all steers fed full-fat, extruded soybeans contained 24% more 18:2 and 18:3 than did those of steers fed the control diet. Extruded soybeans also caused an increase in 18:3 but only a slight increase in 18:2 in perirenal adipose tissue. The proportion of unsaturated fatty acids of lipids inM. trapezius increased slightly with dietary soybeans, whereas that ofM. longissimus was not affected. Lipids of blood plasma of soybean-fed steers contained a greater proportion of 18:2 and 18:3 and concomitantly less 14:0, 15:0, 16:1 and 17:0. Results indicate that feeding steers enough extruded soybeans to raise the fat content of the diet to 6% increases the proportion of polyunsaturated fatty acids of tissue lipids of cattle, and that this altered composition results from an increased amount of these fatty acids being available for absorption by the small intestine.     

Effects of age,sex, and diet upon carcass and liver fatty acid composition of pitman-moore miniature pigs

Fatty acid composition of carcass and liver and proximate analysis of liver were studied in 14–28 day old Pitman-Moore miniature pigs, 26 sow-reared and 30 fed a semisynthetic diet in which the fat was lard. With increasing age, fat of carcass, but not of liver, became significantly more unsaturated. The percentage of palmitic acid (16∶0) and total saturated fatty acids was significantly greater and the percentage of linoleic acid (18∶2) and total unsaturated fatty acids significantly less in carcasses of male than of female pigs. No sex-related differences in proximate or fatty acid composition of the liver were noted. Carcasses of sow-reared pigs contained significantly greater percentages of myristic (14∶0), palmitoleic (16∶1), and linoleic acids and significantly lesser percentages of stearic (18∶0) and oleic (18∶1) acids than did those of pigs fed the semisynthetic diet. Diet-related differences in fatty acid composition of liver closely paralleled those of carcass, although liver contained markedly greater percentages of stearic and arachidonic (20∶4) acids and lesser percentages of palmitoleic and oleic acids than did carcass. Diet-related differences in fatty acid composition of carcass and liver are discussed in relation to the fatty acid composition of dietary fat (sow milk and lard).     

Dietary C18:1 trans fatty acids increase conjugated linoleic acid in adipose tissue of pigs

The effect of dietary C18:1 trans fatty acids on back fat composition in pigs was investigated with special emphasis on conjugated linoleic acids (CLA). A total of 12 × 4 siblings of Large White and Swiss Landrace breed were housed in groups and fattened from 22 to 103 kg live weight. Pigs were fed a control diet (barley, wheat, soybean meal) or experimental diets which consisted of the control diet with a 5% replacement of olein or stearin fractions of pork fat, or partially hydrogenated fat. The hydrogenated fat was rich in C18:1 trans fatty acids but contained only negligible amounts of CLA. In contrast olein and stearin fractions contained far less C18:1 trans fatty acids but some CLA. In the control diet no C18:1 trans fatty acids and only traces of CLA were detected. The partially hydrogenated fat led to the highest CLA content in back fat (0.44%). Intermediate amounts of CLA were measured in pigs fed the fractionated pork fat (0.22/0.23%). In pigs fed the control diet, also small amounts of CLA were detected. The results indicate that CLA may be produced by endogenous Δ9‐desaturation out of dietary trans vaccenic acid in pigs.     

Betaine supplementation affects the cholesterol but not the lipid profile of pigs

This study was undertaken to investigate the effects of long term betaine intake on the cholesterol and lipid profile of Alentejano (AL) pigs. At ?36 kg body weight (BW), castrated male and female pigs fed a commercial (C) diet, were divided into two groups: i) Group C, consuming the C diet; and ii) Group CB, consuming the C diet supplemented with 1 g/kg betaine. Pigs were slaughtered at ?100 kg BW. Fasting plasma concentrations of protein, urea, glucose, TAG, phospholipids, homocysteine, total and LDL‐ and HDL‐cholesterol were determined. Liver TAG, phospholipids, and total and free cholesterol were analyzed, as well as total lipids, cholesterol contents, and fatty acid (FA) composition of M. semimembranosus and dorsal subcutaneous fat. Betaine supplemented pigs presented significantly higher plasma concentrations of TAG, phospholipids, cholesterol, and lipoprotein cholesterol. Dorsal subcutaneous fat cholesterol concentration was also significantly higher in CB than in C pigs. No differences were detected in the most abundant FA profile (including the unsaturated to saturated FA ratio) of muscle and subcutaneous fat tissues among treatments. These data suggest that betaine induces dyslipidemia, and increases cholesterol concentration in dorsal subcutaneous fat, without affecting the FA profile of M. semimembranosus and dorsal subcutaneous fat.     

Zur Wirkung verschiedener Futterrestriktionen auf den Gehalt an intramuskulärem Fett sowie das Fettsäurenmuster der Gesamt- und Phospholipide im Muskelgewebe schwerer Mastschweine (< 160 kg LM)

Effect of Different Feeding Restrictions on the Content of Intramuscular Fat as well as on the Fatty Acid Pattern of Total Lipids and Phospholipids in the Muscle of Heavy Pigs (> 160 kg LW) The intramuscular fat content, its fatty acid composition and the fatty acid pattern of the phospholipids were analyzed in meat samples of the musculus longissimus dorsi of heavy pigs (> 160 kg LW). The pigs were fattened at different energy levels: group I intensively (13 MJ ME/kg feed), group IV extensively (11.5 MJ ME/kg feed), group II and III at first extensively and at the beginning of the middle period (54 kg LW) and the final period (103 kg LW) resp. intensively. Less intramuscular fat contents were found in the animals of group IV. A few minor fatty acids in the intramuscular fat increased significantly in the extensively fed pigs; in addition, the contents of the saturated as well as of the monoen and polyen fatty acids were not influenced. The contents of monoen fatty acids and that of polyen fatty acids decreased significantly in the fatty acid pattern of the phospholipids.     

N‐3 enrichment of pork with fishmeal: Effects on production and consumer acceptability

This study aimed to develop pork products of acceptable organoleptic quality enriched with long‐chain n‐3 polyunsaturated fatty acids (LC n‐3 PUFA). Female pigs were fed a finisher diet containing 15% PorcOmega? tuna fishmeal or a commercial diet. Pigs and rations were weighed weekly. The feed conversion ratio was significantly lower in pigs fed fishmeal than in controls (2.61 ± 0.01 versus 2.96 ± 0.06, p <0.05). After 6 weeks, the pigs were butchered and the fatty acid contents of selected pork products were analyzed by gas chromatography. Shelf life was tested by thiobarbituric acid‐reactive substances (TBARS), initially and after 5 days of cold storage, and sensory qualities were evaluated after cooking. LC n‐3 PUFA contents of pork products from pigs fed fishmeal were higher than in controls (steak 300%, stir‐fry 250%, diced 520%, mince 480%, sausage 360%; p <0.05 in all cases). There were no differences between n‐3‐enriched and regular pork in either TBARS content of stored raw products or sensory characteristics after cooking. Incorporating fishmeal in the finisher diet resulted in greater feed efficiency and production of nutritionally enhanced pork products with organoleptic profiles and stability comparable to those of regular pork.     

Effect of PUFA at sn‐2 position in dietary triacylglycerols on the fatty acid composition of adipose tissues in non‐ruminant farm animals

The influence of the distribution of polyunsaturated fatty acids on the glycerol backbone of dietary triacylglycerols on the fatty acid profile of adipose tissue and muscle phospholipids was investigated in growing‐finishing pigs (48) and broiler chicken (84). The animals were fattened on barley/soybean meal diets supplemented with a blend of soybean oil and beef tallow, either in the ratio 3:1 w/w (high‐PUFA) or 1:3 w/w (low‐ PUFA). Part of the high‐ and low‐PUFA blends was chemically interesterified to randomly distribute all fatty acids over the three positions of the glycerol. Thus, two sets of diets of identical overall fatty acid composition, but differing in the distribution of fatty acids in the triacylglycerols, were fed. Growth performance and carcass composition were neither affected by fatty acid composition nor by randomisation of dietary fats in either animal species. Apparent digestibility of energy was slightly lower in pigs fed the low‐PUFA blends. Fatty acid profile of subcutaneous fat of pigs and broilers as well as of internal body fat (lamina subserosa) and muscle phospholipids of pigs varied according to the dietary fatty acid composition but was not affected by randomisation of dietary fats. These findings are explained in terms of the hydrolysis of TAG during transport of lipids from enterocytes to adipose tissue cells and the continuous lipolysis and re‐esterification of fatty acids that take place in adipose tissue cells.     

Composition and thermal properties of cattle fats

The physical‐chemical properties, fatty acid composition and thermal properties of cattle subcutaneous, tallow and intestinal fats were determined. Subcutaneous fat differed from the other fat types with respect to its lower melting point (29.0 °C) and higher saponification (211.4 mg KOH/g) and iodine (50.55) values. The cattle fat types contained palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1n‐9) and linoleic acid (18:2n‐6) as the major components of fatty acid composition (24.58–25.90%, 10.21–33.33%, 28.18–46.05%, 1.54–1.73%, respectively). A differential scanning calorimetry (DSC) study revealed that two characteristic peaks were detected in both crystallization and melting curves. Major peaks (T_peak) of tallow and intestinal fats were similar and determined as 24.10–27.71 °C and 2.16–4.75 °C, respectively, for crystallization peaks and 7.09–9.39 °C and 43.28–46.49 °C, respectively, for melting peaks in DSC curves; however, those of subcutaneous fat (12.48 °C and –6.79 °C for crystallization peaks and 3.56 °C and 23.55 °C for melting peaks) differed remarkably from those of the other fat types.     

A diet containing myristoleic plus palmitoleic acids elevates plasma cholesterol in young growing swine

The objective of this study was to test the effect of a novel fatty acid mixture, enriched with myristoleic and palmitoleic acids, on plasma lipoprotein cholesterol concentrations. Weanling pigs were assigned to one of six groups and each group received a diet differing in fatty acid composition. Diets were fed for 35 days and contained 10 g added cornstarch/100 g (to provide baseline data) or 10 g added fatty acids/100 g. For those diets containing added fatty acids, extracted lipids contained 36% myristoleic plus palmitoleic acid combined (14∶1/16∶1 diet), 52% palmitic acid (16∶0 diet), 51% stearic acid (18∶0 diet), 47% oleic acid (18∶1 diet), or 38% linoleic acid (18∶2 diet). Witht the exception of the cornstarch diet, all diets contained approximately 30% myristic acid. There were no significant differences in weight gain across treatment groups (P=0.22). All diets caused a significant increase in triglycerides and in total, low density lipoprotein, high density lipoprotein, and very low density lipoprotein cholesterol. The increase in total plasma cholesterol from pretreatment values was greatest in pigs fed the 14∶1/16∶1 and 18∶1 diets. However, the increase in low density lipoprotein cholesterol from the pretreatment concentration was greatest in the 14∶1/16∶1-fed pigs. Increases in very low density lipoprotein cholesterol above pretreatment concentrations were lowest in 16∶0-fed pigs and greatest in 18∶1-fed pigs. Dietary fatty acids elicited changes in plasma fatty acids which generally were reflective of the diets, although the 18∶0 diet did not alter plasma fatty acid concentrations and the 16∶0 diet increased plasma 16∶0 only at the end of the study. These results demonstrated that the combination of myristoleic plus palmitoleic acids increased plasma cholesterol in young pigs, suggesting that fatty acid chain length, rather than degree of unsaturation, is primarily responsible for the effects of fatty acids on circulating lipoprotein cholesterol concentrations.     

Effect of grass vs. concentrate feeding on the fatty acid profile of different fat depots in lambs

The aim of this study was to produce high‐quality meat from lambs under different feeding conditions, as measured by the accumulation of n‐3 fatty acids and conjugated linoleic acids (CLA) in muscle and subcutaneous fat. In total, 13 male crossbred lambs (Black Head×Gotland), each at 24 kg live weight, were divided into two feeding groups. Lambs were kept either on pasture (pasture grazing, n = 6) or in the stable (concentrate feeding, n = 7). The linolenic acid (C18:3n‐3) contained in the grass was absorbed and deposited into the different lipid classes of muscle and subcutaneous fat. The proportion of total n‐3 fatty acids in the different lipids of grazing lambs was significantly (p = 0.05) higher compared to that in concentrate‐fed lambs. The n‐6/n‐3 ratio (mean ± SEM) in muscle of grazing lambs was 1.2 ± 0.09 in contrast to 2.3 ± 0.09 (p = 0.05) of the animals kept in the stable. In subcutaneous fat, this ratio was 0.9 ± 0.2 in lambs kept on pasture versus 3.5 ± 0.2 (p = 0.05) after indoor keeping. The relative concentration of C18:1trans‐11 in total muscle lipids, phospholipids, triacylglycerols and subcutaneous fat was significantly increased by grass feeding compared to concentrate feeding. Significant influences of feeding were shown for saturated fatty acids. In concentrate‐fed lambs, a lower content of saturated fatty acids was detected. The proportion of CLAcis‐9,trans‐11 (1.9 ± 0.2% vs. 1.1 ± 0.1% in muscle, 2.5 ± 0.2% vs. 1.4 ± 0.2% in subcutaneous fat, 0.7 ± 0.04% vs. 0.4 ± 0.04% in phospholipids) in lambs was significantly (p = 0.05) higher after grazing than after concentrate feeding, respectively.     

Microflora and volatile fatty acids present in inguinal pouches of the wild rabbit,Oryctolagus cuniculus,in Australia

Contents of inguinal pouches of the wild rabbit,Oryctolagus cuniculus, have been examined for the presence of microorganisms and volatile fatty acids. A total of 245 isolates were made from 167 samples taken from 75 rabbits, and microorganisms were obtained from 93% of individuals. The most common microorganism encountered wasStaphylococcus aureus, followed by the yeastCandida kruzei. Other organisms isolated wereBacillus subtilis,Escherichia coli, andStreptococcus faecalis. Quantitative analysis of volatile fatty acids in scrapings from pouches showed considerable variation between individuals. Of the acids identified, acetic acid and isovaleric acid were the most abundant. In a liquid medium containing one of these acids, the growth of microorganisms was only slightly affected. However, growth became inhibited when these fatty acids were used in combination.     

Effect of storage and grilling on fatty acids in muscle of pigs fed plant oils

The purpose of the study was to assess changes in the fatty acid composition of raw and grilled pig muscles after different storage periods. A total of 13 female and 12 castrated Pietrain×German Landrace pigs were fed a basal concentrate diet supplemented with 5% olive oil or 5% linseed oil during the growing‐finishing period. An entire cut of the pork loin with bone (15^th rib to 5^th lumbar vertebra) was stored at 5 °C for 48, 96 or 144 h. Simultaneous analyses of intramuscular fat and lipid composition were carried out on raw and grilled longissimus muscles following different storage intervals. Dietary inclusion of linolenic acid by linseed oil feeding effectively increased the long‐chain n‐3 fatty acids, whereas in the olive oil group the oleic acid in pork was higher. Mean total lipid ranged from 1.8 to 2.3% for raw and from 2.6 to 3.5% for grilled pork chops. The relative proportions of lauric acid, stearic acid and oleic acid significantly increased with storage time, while the percentages of linoleic, arachidonic, eicosapentaenoic acid and the sum of polyunsaturated fatty acids, especially n‐6 fatty acids, were decreased. Compared with raw muscle, grilling affected the relative fatty acid profile only slightly. Related to the original weight, storage and grilling increased the total fatty acid contents and the sum of saturated, monounsaturated, n‐6 and n‐3 fatty acids of loin chops, as a result of water losses.     

Influence of dietary n-3 fatty acids on the membrane properties of skeletal muscle in pigs

The aim of the experiment was the in vivo modification of long-chain fatty acids in phospholipids and to investigate the impact on Ca²⁺ transport of sarcoplasmic reticulum (SR). Ten pigs were fed daily a diet containing 1.3 g n-3 fatty acids/kg diet (control), and ten pigs were fed a diet containing 14 g n-3 fatty acids/kg diet (n-3 diet) during the growing-finishing period. The intake of dietary n-3 fatty acids increased the percentages of these fatty acids in the phospholipids of skeletal muscle sarcoplasmic reticulum (21.6% n-3 fatty acids) and in the polar fraction of total muscle homogenates (30.7% n-3 fatty acids) significantly, compared with control (3.0% and 3.9% n-3 fatty acids, respectively), while the n-6 fatty acid concentration was reduced. In phosphatidylethanolamine of skeletal muscle polar lipids eico-sapentaenoic (EPA) and docosahexaenoic acids (DPA) were increased seven times compared with control. There were no differences in the maximal rate of Ca²⁺ uptake in skeletal muscle SR between the groups. However, the activity of Ca²⁺-ATPase of skeletal muscle SR was elevated in the n-3 diet group. It is suggested, that n-3 fatty acid enriched diet can change the complex membrane composition dependent on experimental conditions and animal species leading to different effects on membrane protein activities.     

The influence of dietary fat on the lipogenic activity and fatty acid composition of rat white adipose tissue

The in vivo fatty acid synthesis rate, selected enzyme activities and fatty acid composition of rat white adipose tissue from animals fed semisynthetic diets of differing fat type and content were studied. All animals were starved for 48 hr and then refed a fat-free (FF) diet for 48 hr. They were then divided into three groups. One group was continued on the FF diet for 48 hr. Another group was fed a diet containing 44% of calories from corn oil (CO). The final group was fed a diet containing 44% of calories from completely hydrogenated soybean oil (HSO). The animals on the FF diet had a marked increase in adipose tissue fatty acid synthesis during the 96-hr feeding peroid (as measured by³H incorporation into adipose fatty acids). Addition of either CO or HSO to the diets did not significantly inhibit fatty acid synthesis in dorsal or epididymal adipose tissue. The activities of the enzymes' fatty acid synthetase, ATP-citrate lyase and glucose-6-phosphate dehydrogenase increased on the FF diet and generally were not inhibited significantly by the addition of either fat to the diets. Linoleic acid was the major polyunsaturated fatty acid (ca. 22%) in adipose tissue. Monounsaturated fatty acids (palmitoleic, oleic,cis-vaccenic) made up ca 38% of the total adipose fatty acids, while saturated fatty acids accounted for about 32% (myristic, palmitic and stearic). White adipose tissue in mature male rats was a major depot for n−3 fatty acids. There were differences in the fatty acid composition of epididymal and dorsal adipose tissue, particularly in their content of long chain, polyunsaturated fatty acids with epididymal tissue containing more of these compounds than dorsal fat. The fatty acid composition of the white adipose tissue did not change significantly during fasting or 96 hr of refeeding the FF diets. The addition of HSO to the diet for 48 hr had little influence on the adipose tissue fatty acid composition, but the addition of CO to the diet caused a 7% increase in the dorsal adipose tissue linoleate content (as percentage of total dorsal adipose tissue fatty acids) within 48 hr compared to animals fed the stock diet and those starved for 48 hr. The fatty acid synthesis data indicated that adipose tissue in the rat can continue to be a source of de novo fatty acid synthesis in animals consuming high-fat diets.     

White adipose tissue fatty acids of alpine marmots during their yearly cycle

Alpine marmots (Marmota marmota) were maintained on a laboratory diet, and the fatty acid composition of gonadal and subcutaneous whilte adipose tissues (WAT) was studied during a yearly cycle. Fatty acids (FA) released from isolated adipocytes were also identified after stimulation of in vitro lipolysis. Analysis of the FA composition of WAT depots showed that marmot WAT mainly contained monounsaturated FA(65%, mostly oleic, acid, 18:1n-9) although laboratory food contained 45% of linoleic acid (18:2n-6) and only 21% of 18:1n-9. During stimulated lipolysis, saturated FA were preferentially released from isolated adipocytes whereas unsaturated FAs were retained. Despite this selective release of FA from isolated WAT cells in vitro, and despite the FA composition of the food, marmots maintained a constant FA composition in both WAT depots throughout the year. Six months of hibernation and fasting as well as an intense feeding period did not affect this composition. The potential adaptive benefit of such regulation of WAT composition, based on a high level of monounsaturated FA, might be to maintain fat with appropriate physical properties allowing animals to accommodate to and survive the wide range of body temperatures experienced during hibernation.     

Fatty acid composition of fats of differing melting points extracted from ram subcutaneous tissue

The observation that the subcutaneous fat of pasture-fed Southdown rams consists of two distinct regions is reported. Fatty acid composition of fat from the outer and inner regions of subcutaneous tissue taken from the rib region of eight Southdown rams fed pasture were determined. Relative to the harder inner regions (mean melting point 43.1°C), the softer outer regions (mean melting point 31.8°C) were shown to contain more 9∶0-, 15∶0-, 17∶0-, 17∶1-, 18∶1-cis and total 18∶1 fatty acids; less 14∶0-, 16∶0-, 18∶0- and 18∶1-trans fatty acids; and a greater variety and a greater concentration of branched-chain components. Proportions of medium chain-length fatty acids other than 9∶0, did not differ between the layers. The fatty acid contents of serial samples taken at 1-mm intervals through these tissues were determined. Changes in concentrations of components among samples were gradual through the tissues. There was no clear connective tissue sheet, as has been reported for pigs. The inner region of the tissues contains apparently nonrandom fluctuating changes in fatty acid composition.     

Production of eicosapentaenoic acid by freshwaterVibrio

Arctic charr,Salvelinus alpinus (L.), were fed a moist pellet diet based on casein, dextrin and coconut oil in fresh water. The diet contained substantial amounts of saturated fatty acids, especially 12∶0. Polyunsaturated fatty acids in the n−3 series were not detected in the diet, but analysis of the intestinal liquor stripped from the charr showed that eicosapentaenoic acid (EPA, 20∶5n−3) accounted for 3.5% of fatty acids in total lipid. Colony forming units (CFU) of aerobic microorganisms were approximately 10⁴ per mL intestinal liquor. Seventeen bacterial strains isolated from the intestinal liquor were screened for EPA production. Four isolates contained a high proportion of EPA in their total lipid. These isolates belong to the speciesVibrio.     

Maternal Flaxseed Oil During Lactation Enhances Bone Development in Male Rat Pups

Flaxseed oil is an alpha linolenic acid source important in the growth and body development stage; furthermore, this acid acts on adipose tissue and bone health. The aim of this study was to evaluate body composition, fatty acid composition, hormone profile, retroperitoneal adipocyte area and femur structure of pups at weaning, whose mothers were fed a diet containing flaxseed oil during lactation. After birth, pups were randomly assigned: control (C, n = 12) and flaxseed oil (FO, n = 12), rats whose mothers were treated with diet containing soybean or flaxseed oil. At 21 days, the pups were weaned and body mass, length, body composition, biochemical parameter, leptin, osteoprotegerin, osteocalcin, fatty acids composition, intra‐abdominal fat mass and femur structure were analyzed. FO showed (p < 0.05): higher body mass (+12 %) and length (+9 %); body fat mass (g, +45 %); bone mineral density (+8 %), bone mineral content (+55 %) and bone area (+35 %), osteocalcin (+173 %) and osteoprotegerin (+183 %). Arachidonic acid was lower (p < 0.0001), alpha‐linolenic and eicosapentaenoic were higher (p < 0.0001). Intra‐abdominal fat mass was higher (+25 %), however, the retroperitoneal adipocytes area was lower (?44 %). Femur mass (+10 %), distance between epiphyses (+4 %) and bone mineral density (+13 %) were higher. The study demonstrates that adequate flaxseed oil content during a lactation diet plays an important role in the development of pups.     

The effect of dietary arachidonic acid on plasma lipoprotein distributions, apoproteins, blood lipid levels, and tissue fatty acid composition in humans

Normal healthy male volunteers (n=10) were fed diets (high-AA) containing 1.7 g/d of arachidonic acid (AA) for 50 d. The control (low-AA) diet contained 210 mg/d of AA. Dietary AA had no statistically significant effect on the blood cholesterol levels, lipoprotein distribution, or apoprotein levels. Adipose tissue fatty acid composition was not influenced by AA feeding. The plasma total fatty acid composition was markedly enriched in AA after 50 d (P<0.005). The fatty acid composition of plasma lipid fractions, cholesterol esters, triglycerides, free fatty acids, and phospholipid (PL) showed marked differences in the degree of enrichment in AA. The PL plasma fraction from the subjects consuming the low-AA diet contained 10.3% AA while the subjects who consumed the high-AA diet had plasma PL fractions containing 19.0% AA. The level of 22:4n-6 also was different (0.67 to 1.06%) in the plasma PL fraction after 50 d of AA feeding. After consuming the high-AA diet, the total red blood cell fatty acid composition was significantly enriched in AA which mainly replaced linoleic acid. These results indicate that dietary AA is incorporated into tissue lipids, but selectively into different tissues and lipid classes. Perhaps more importantly, the results demonstrate that dietary AA does not alter blood lipids or lipoprotein levels or have obvious adverse health effects at this level and duration of feeding.     

Characteristics of carcass composition,fat metabolism and meat quality of genetically different pigs

The aim of the study was to quantify the differences in meat and fat quality and lipid metabolism of pigs with either high or medium capacity for lipid accretion. A total of 58 castrated males of the breeds German Saddle Back (SB) and German Landrace (DL) were included in the experiment. Animals were housed individually and fed twice daily semi ad libitum. Saddle Back pigs indicated a lower lean meat content (41.4% vs 52.6%) and a higher fat percentage (40.9% vs 28.2%) in comparison to DL as a result of high lipid accumulation. The larger fat content of SB was related to an increased intramuscular fat concentration of longissimus muscle. A significant correlation between intramuscular fat content and fatty acid composition was estimated in both breeds. The relative concentration of saturated fatty acids was significantly increased in SB pigs. The percentage of polyunsaturated fatty acids (8.3%) in SB muscle fat was significantly lower than in DL muscle fat (10.7%). The de novo biosynthesis of fatty acids resulted in mostly saturated fatty acids and oleic acid. The higher activities of lipogenetic enzymes in backfat of SB proved a higher lipogenetic capacity. There were no significant differences in meat quality traits of longissimus muscle between the two breeds.