Cholesterol content of muscle and adipose tissue from crossbred bulls and steers

Cholesterol content (mg/100g wet weight) of muscle and adipose tissue from crossbred bulls (N = 34) and steers (N = 35) was determined by spectrophotometry. Sampling site effects were highly significant, with subcutaneous adipose tissue (101·7) and perinephric adipose tissue (89·7) containing the most cholesterol, and longissimus muscle (58·3) containing the least. Semitendinosus and triceps brachii muscles were similar in cholesterol content (63·9 mg/100g and 63·7 mg/100g, respectively). Although sex condition differences within sampling sites were non-significant, steer carcasses may have more total cholesterol than bull carcasses because steers contain a higher percentage of fat than bulls raised under similar conditions.     

Conjugated linoleic acid (CLA) concentration,fatty acid composition and cholesterol content of some Turkish dairy products

Conjugated linoleic acid (CLA) concentrations, fatty acid composition and cholesterol content of some Turkish dairy products (butter, processed cheese, Kaymak and cream) were determined by capillary gas chromatography. The CLA and cholesterol content of some Turkish dairy products ranged from 1.50–5.60 mg/g fat and 148.30–369.04 mg/g fat, respectively. The most abundant saturated fatty acids in the dairy products investigated were palmitic acid (C16:0), stearic acid (C18:0) and myristic acid (C14:0). In all dairy products, C18:1 cis-9, 12 unsaturated fatty acid content (23.12–32.78 g/100 g) was considerably higher than others. In all samples studied, there was no correlation between CLA content of products and the linoleic acid content, or any other unsaturated fatty acid. A positive correlation between cholesterol and fat content of dairy products was observed.     

Conjugated linoleic acid (CLA) and polyunsaturated fatty acids in muscle lipids of lambs from the Patagonian area of Argentina

The concentrations of fatty acids were measured in total lipids, triacyglycerol and phospholipid fractions of intramuscular fat (IMF) from the Longissimus dorsi (LD) muscle of 10 lambs reared to approximately 30kg live weight on natural pasture with their dams. Fatty acid composition was also measured in 25 (five of each) Semitendinosus (ST), Semimembranosus (SM), Rectus femoris (RF), Gluteus (GLU) and Tensor fascia latea (TFL) muscles. Intramuscular fat percentages were similar for all muscles. Aspects of the fatty-acid patterns of relevance to human nutrition tended to favor the leg muscles with lower saturated fatty acids (SFA %), n-6/n-3 fatty acid ratios (p<0.01) and higher concentrations of the conjugated linoleic acid (CLA) (p<0.05). The estimated fatty acid concentrations (mg/100g of meat) showed higher contribution of arachidonic (C20:4 n-6), eicosapentanoic (C20:5 n-3), docosapentanoic (C22:5 n-3) and docosahexanoic (C22:6 n-3) acids in leg compared to LD lipids.     

Effect of breeding bull on the fatty acid composition of the carcass lipid in steers of a beef breed cattle

Samples of neutral lipid were taken from the carcasses of forty-eight Japanese Black steers, the progeny from three breeding bulls, on similar planes of nutrition and of the same age, and were analysed for fatty acid composition. The breeding bull seems to significantly affect the fatty acid composition of the lipid from the thoracic subcutaneous fatty tissue and the inter- and intra-muscular fatty tissues of the Longissimus dorsi muscle. No significant correlation between breeding bull and fatty acid composition of perinephric fatty tissue was found. There was an increase in total concentration of unsaturated fatty acids from internal to external sample locations.     

Conjugated Linoleic Acid (CLA) content of meat from three muscles of Massese suckling lambs slaughtered at different weights

Eighteen Massese male lambs, fed mainly maternal milk were slaughtered at 11, 14 and 17kg. Samples of Longissimus Dorsi (LD), Triceps Brachii (TB) and Semimembranosus (Sm) muscles were collected. Milk from the lamb's dams was sampled weekly. Fatty acid composition of milk and meat was determined. TB was the fattest muscle, Sm the leanest one and LD showed an intermediate value of total lipids, while the weight at slaughter did not influence total intramuscular fat content in any muscle. Although slaughter weight slightly affected overall fatty acid composition of muscles, rumenic acid and total CLA content in TB and Sm, but not in LD, significantly increased with slaughter weight. As regard milk fatty acid composition, the contents of total CLA, RA and others minor CLA isomers decreased during the first four weeks after lambing and then increased at the last control (five weeks). The animals slaughtered at a live weight of 14 and 17kg showed a greater SCD enzyme activity (estimated by product/substrate ratio) and a higher rumen activity (estimated by means of branched chain and odd chain fatty acid content in meat) than animals slaughtered at 11kg. Cis-7, trans-9 CLA content significantly increased with the slaughter age in TB and SM, while trans-7, trans-9 CLA, only increased in TB, and cis-8, cis-10 CLA, only increased in SM. Further studies are needed in order to verify weather the different behaviour of RA in LD muscle may be due to differences in muscle metabolism or fatty acid utilisation.     

Effect of high or low protein ration combined or not with rumen protected conjugated linoleic acid (CLA) on meat CLA content and quality traits of double-muscled Piemontese bulls

A trial was carried out on double-muscled Piemontese bulls to evaluate the effects of two rations differing in crude protein density (HP=14.5% DM and LP=10.8% DM) and top dressed or not with 80 g/d of rumen protected CLA (rpCLA) for a long period (336 d) on meat quality traits and CLA content. Forty-eight bulls were fed one of the four experimental diets based on corn silage and cereals and were slaughtered at an average age and body weight (BW) of 562 ± 18 d and 668 ± 56 kg, respectively. After slaughter the 5th rib cut was dissected into Longissimus thoracis (LT), other muscles (OM), inter-muscular fat (IF), cover fat (CF), and bones. Muscles and fatty tissues were analyzed for proximate composition and fatty acid (FA) profiles. Rib was composed by 81.1, 3.7, 1.6 and 13.6% of muscles, IF, FC and bone, respectively; LT and OM contained only 0.8 and 1.4% of lipid, respectively. The treatments did not influence these values, but rpCLA increased, compared to control, both c9,t11-CLA and t10,c12-CLA concentrations in all the tissues (P<0.01); t10,c12-CLA concentration was increased much more in muscles (+20 times) than in fatty tissues (from +0.2 to +0.9 times). This suggests that in the muscle this isomer is preferentially stored and/or less combusted with respect to other fatty acids. Low protein rations did not exert any influence on carcass and meat quality, as on growth performance, but reduced nitrogen excretion, their use for improving the environmental impact (process quality) of this meat production system is recommended.     

Influence of dietary conjugated linoleic acids and vitamin E on meat quality, and adipose tissue in rabbits

Eighty New Zealand White rabbits, age 55 days, half male and half female, were randomly assigned to one of four diets in a 2×2×2 factorial arrangement. The diets contained 0% or 0.5% CLA, and 60 or 240mg/kg α-Tocopheryl acetate. Forty-eight rabbits were slaughtered at age 92 days. Growth performances and carcass weight were higher (P<0.05) in 240mg/kg of α-tocopheryl acetate-fed rabbits. Fat and CLA isomers content of Longissimus Lumborum (LL) muscle was higher (P<0.05) in CLA-fed rabbits than control. Fatty acid composition of LL muscle was modified (P<0.05) and oxidative stability was increased (P<0.001) by both dietary treatments. CLA increased (P<0.05) triglyceride, total cholesterol and glucose levels in plasma. Adipocytes in interscapular and perirenal fat in the 240mg/kg α-tocopheryl acetate and 0.5% CLA groups were larger in size but lesser in number than in 60mg/kg α-tocopheryl acetate and no CLA rabbit (P<0.01).     

蒙古斑点马不同部位脂肪和肌肉组织中脂肪酸组成的比较研究

通过对蒙古斑点马不同部位脂肪和肌肉组织中脂肪酸组成进行分析比较,旨在明确蒙古斑点马体脂脂肪酸组成特点。选择3 匹成年蒙古斑点马,屠宰后采集肾周、肠周和皮下脂肪以及肩肌、背最长肌和臀肌样品,利用气相色谱法测定脂肪酸组成及含量。结果表明：蒙古斑点马不同脂肪组织中均检出19 种脂肪酸,其中饱和脂肪酸（saturated fatty acid,SFA）含量34.77%～37.38%,不饱和脂肪酸（unsaturated fatty acid,UFA）含量达60%以上,UFA中单不饱和脂肪酸（monounsaturated fatty acid,MUFA）含量33.04%～36.39%,多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）含量26.47%～27.51%,其中皮下脂肪C10:0、C18:0、C20:0含量显著低于肾周和肠周脂肪（P＜0.05）;MUFA在皮下脂肪的沉积程度较其他2 个部位高,但均无统计学差异;PUFA中C18:3 n-3含量最高,其在各脂肪组织间无显著差异。3 个不同部位肌肉中均检出15 种脂肪酸,其中SFA含量占总脂肪酸含量的38.32%～40.04%,MUFA含量占35.70%～40.19%,PUFA含量占15.25%～20.33%;SFA中背最长肌和臀肌C12:0含量显著高于肩肌（P＜0.05）,其余SFA在不同部位肌肉间无显著差异;MUFA中背最长肌C16:1含量显著高于肩肌和臀肌（P＜0.05）;肩肌n-6/n-3 PUFA比值显著高于背最长肌和臀肌（P＜0.05）;皮下脂肪的C18:3 n-3和总PUFA含量显著高于背最长肌（P＜0.05）。综上所述,蒙古斑点马不同部位脂肪和肌肉组织脂肪酸组成各具特点,但UFA含量均较高。     

Comparison of composition and quality traits of meat from young finishing bulls from Belgian Blue, Limousin and Aberdeen Angus breeds

Thirty-six young finishing bulls from three breeds (Belgian Blue, Limousin and Aberdeen Angus) were fattened over five months with finishing diets based either on sugar-beet pulp or on cereals. Nutritional quality traits of meat - fat content and fatty acid composition with emphasis on the n-6 and n-3 polyunsaturated fatty acids - along with some organoleptic quality traits were measured. The Belgian Blue bulls had the lowest intramuscular fat content associated with lower saturated and monounsaturated fatty acid contents. The polyunsaturated fatty acid content did not differ to a large extent between the breeds, the Aberdeen Angus bulls showing slightly higher values. Relative to energy intake, the overall contribution of meat to the n-3 fatty acid recommended intake was small, whatever the breed. By contrast, the contribution of meat to daily fat intake was of greater importance, especially for the Aberdeen Angus bulls. The quality traits of meat varied also according to the breed: compared to the Aberdeen Angus, the Belgian Blue bull meat had the stablest colour, the highest drip and the lowest cooking losses. The meat of Limousin bulls had intermediate characteristics for all the parameters.     

Beef lipids in relation to animal breed and nutrition in Argentina

Fatty acid (FA) composition of intramuscular fat (IMF) in M. Longissimus dorsi (LD) was measured in 72 steers from Angus (A), Charolais×Angus (CHA×A) and Holstein Argentine (HA) breeds. The steers were allotted to four dietary treatments of six animals each: T1, steers grazed on pasture; T2, steers supplemented with cracked corn grain (0.7% of live-weight) daily and free access to pasture; T3, steers supplemented with cracked corn grain (1% of live-weight) daily and free access to pasture; and T4, feedlot (concentrate based on corn, alfalfa hay and soybean meal without access to pasture). At slaughter weight, samples of LD at the 11th rib were used for intramuscular lipid analysis. The diet was shown to be more important than breed in determining FA composition. Pasture beef had higher percentages of saturated fatty acids (SFA), n-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA) and lower percentages of IMF, monounsaturated fatty acids (MUFA), n-6 PUFA and n-6/n-3 ratios than feedlot beef. HA beef presented lower percentages of SFA and more MUFA with a higher n-6/n-3 ratio than A and CHA×A. Comparing grass and feedlot beef the amounts of FA in muscle (mg/100g) were, respectively 18:3 n-3 (44 vs. 11mg), CLA (20 vs. 12mg), 20:5 n-3 (20 vs. 11mg), 22:5 n-5 (20 vs. 11mg), 22:6 n-3 (12 vs. 6mg) and n-3 PUFA (84 vs. 32mg). Feedlot beef has more SFA (1372 vs. 1081mg), MUFA (1574 vs. 1078mg), PUFA (350 vs. 227mg) and n-6 PUFA (318 vs.143mg).     

Effect of the feeding system on intramuscular fatty acids and conjugated linoleic acid isomers of beef cattle,with emphasis on their nutritional value and discriminatory ability

Thirty two Alentejano purebred bulls were used to investigate the effect of four feeding systems (pasture only, pasture feeding followed by 2 or 4 months of finishing on concentrate, and concentrate only) on meat fatty acid composition (GC-FID), including conjugated linoleic acid (CLA) isomeric distribution (Ag[+]–HPLC–DAD). In addition, meat fatty acids and CLA isomers were used to elucidate the impact of the different feeding regimens on the nutritional value of intramuscular fat and their usefulness as chemical discriminators of meat origin. The diet had a major impact on the fatty acid composition of beef (affected 27 of 36 fatty acids and 10 of 14 CLA isomers), which was independent of the fatty acid concentration. Beef fat from pasture-fed animals had a higher nutritional quality relative to that from concentrate-fed bulls. Finally, meat fatty acid composition was an effective parameter to discriminate between ruminant feeding systems, including different finishing periods on concentrate.     

Occurrence of conjugated linoleic acid in longissimus dorsi muscle of water buffalo (Bubalus bubalis) and zebu-type cattle raised under savannah conditions

Lipid extracts from longissimus dorsi muscles of 64 water buffaloes and 68 zebu-type cattle were used to quantify the amount (mg/g of lipids) of total conjugated linoleic acid (CLA), CLA isomers c9, t11 and t10, c12 and linoleic acid (LA), according to species (buffaloes and cattle), age (slaughter groups at 7, 17, 19 or 24 months of age) and gender (bulls and steers). The effects of gender and age were significant (P<0.05) but marginal. Comparisons of lipid extracts from buffaloes vs. cattle showed that total CLA (1.83 vs. 1.47 mg/g), CLA c9, t11 (1.27 vs. 1.01 mg/g) and CLA t10, c12 (0.56 vs. 0.47 mg/g) isomers as well as the CLA/LA ratio (0.10 vs. 0.07) were higher (P<0.05) in buffalo lipids. Considering the sparingly low lipid concentrations (<2 g/100 g of fresh muscle) none of the meat species should be considered a significant source of CLA.     

Effect of dietary lipid source on conjugated linoleic acid concentrations in milk fat

Conjugated linoleic acids (CLA) found in ruminant milk fat are a byproduct of incomplete biohydrogenation of lipids by ruminal bacteria. We examined the effect of different dietary fat supplements and processing methods on CLA. In trial 1, dietary supplements of Ca salts of fatty acids from canola oil, soybean oil, and linseed oil increased CLA content of milk fat by three- to fivefold over the control diet. Trials 2 and 3 examined the effect of processing methods for heat treatment of full fat soybeans. In trial 2, extrusion, micronizing, and roasting resulted in two- to threefold greater concentrations of CLA in milk fat than the control diet (raw ground soybeans). In trial 3, different temperatures of extrusion (120, 130, and 140 degrees C) increased the CLA content of milk fat to a similar extent; CLA averaged 19.9 mg/g of fatty acids for the extrusion treatments compared with 4.2 mg/g of fatty acids for the control diet (raw ground soybeans). Fish oil (200 and 400 ml/d) was examined in trial 4 and both levels resulted in CLA concentrations in milk fat that were about threefold greater than the control diet. In trial 5, grain and silage from a high oil corn hybrid increased the CLA content of milk fat; however, responses were modest with the CLA concentration (mg/g of fatty acids) averaging 4.6 and 2.8 for diets with high oil hybrid and normal hybrid, respectively. Similarly, dietary supplements of animal fat byproducts (tallow plus yellow grease; trial 6) resulted in modest increases in the CLA content of milk fat. Overall, several dietary manipulations involving lipid sources and processing methods were identified that allow for a marked increase in the conjugated linoleic acid content of milk fat.     

Conjugated linoleic acid content of beef differs by feeding regime and muscle

The project objective was to determine the CLA content of three muscles (Longissimus lumborum, LD; Semimembranosus, SM; Triceps brachii, TB), in both raw and cooked states, in cattle finished on pasture or with grain supplements. Cattle were randomly assigned to one of four finishing regimens; pasture (n=11), pasture with grain supplement (n=11), pasture with grain supplement containing soyoil (n=12), and feedlot (n=12). In the raw state, TB had higher (P<0.05) CLA than LD or SM on a mg/g sample basis. Total CLA was higher (P<0.05) in the soyoil diet when compared to the other three feeding regimes on a mg/g sample basis and when expressed as mg/g fat in both raw and cooked analyses. Pasture inclusion produced higher levels (P<0.05) of total CLA than the feedlot diet on a mg/g fat basis for cooked samples while maintaining acceptable eating quality.     

Chemical composition of meat and blubber of the Cape fur seal (Arctocephalus pusillus pusillus)

Although the Cape fur seal is harvested commercially in southern Africa, no data exist to indicate whether its meat composition is such that it can be consumed by humans. Presently, these animals are harvested mainly for their hides. Little is known about the chemical composition of the meat and blubber and whether it could be processed into food or animal feed. This is the first report on the chemical composition of the Pectoralis muscle and fat of seal pups and bulls. The fat content in the muscle of pups was higher (4.2 g/100 g) than recorded in bulls (2.4 g/100 g). The protein content in muscle, on the other hand, was similar (23.2 g/100 g) for animals of both age groups. The blubber of bulls had a higher protein level (26.6 g/100 g) compared to that of pups (14.6 g/100 g), but a lower fat content (67.1 g/100 g vs 77.2 g/100 g). Muscle of bulls contained 33% saturated fatty acids (SFA), 29% monounsaturated fatty acids (MUFA) and 38% polyunsaturated fatty acids (PUFA). Muscle of pups contained 39% SFA, 30% MUFA and 31% PUFA. The toxin content in Cape fur seal blubber was lower than that reported for the blubber of Canadian seals. The organochlorine content in the blubber of Cape fur seals was lower than 13.7 ng/g oil, whereas levels as high as 87.2 ng/g have been reported in Canadian seal oil. The chemical composition of the Cape fur seal is such that it could be classified as a healthy meat source.     

Determination of the Amount of trans-Octadecenoate and trans-9,trans-12-Octadecadienoate in Fresh Lean and Fatty Tissues of Pork and Beef

Longissimus muscle and subcutaneous fat from 17 pork and 6 beef carcasses were analyzed for trans-octadecenoates and trans-9,trans-12-octadecadienoate (linolelaidate) content by argentation thin layer chromatography and/or glass capillary gas liquid chromatography. No detectable amount of trans-9,trans-12-octadecadienoate was found in pork or beef. In pork the amount of trans-octadecenoates ranged from 0.0074 – 0.0077 g/100g of fresh Longissimus muscle and 0.1453 – 0.1549 of fresh subcutaneous fat. The content of trans-octadecenoates in beef ranged from 0.0782 – 0.0839 g/100g of fresh Longissimus muscle and 2.4280 – 2.7368 g/100g of fresh subcutaneous fat. The content of trans fatty acids contributed by pork and beef to the human diet is negligible relative to that derived from other dietary sources.     

Comparison of meat quality between eland (Taurotragus oryx) and cattle (Bos taurus) raised under similar conditions

Physical, chemical and sensory characteristics of meat were compared between non-domestic eland (Taurotragus oryx) bulls (n = 6) and domestic Fleckvieh (Bos taurus) bulls (n = 6) which were finished under controlled conditions of feeding and management. Musculus longissimus lumborum from eland were darker and less yellow in colour, with a higher pH₂₄ and lower contents of intramuscular fat and total collagen, compared to cattle. Contents (mg/100 g muscle tissue) and proportions (g/100 g of FA determined) of SFA and MUFA were higher (P < 0.01) in cattle. Although the proportion of total PUFA were higher (P < 0.001) in eland, contents of PUFA were similar between species. Meat from cattle was consistently scored higher (P < 0.05) for sensory texture characteristics, juiciness, flavour, and overall acceptance. We concluded that bulls of eland provided low-fat meat with a beneficial fatty acid composition from a human nutrition perspective, but with lower sensory scores, compared to bull beef.     

Effect of cooking methods on fatty acids,conjugated isomers of linoleic acid and nutritional quality of beef intramuscular fat

The effect of boiling, microwaving and grilling on the composition and nutritional quality of beef intramuscular fat from cattle fed with two diets was investigated. Longissimus lumborum muscle from 15 Alentejano young bulls fed on concentrate or pasture was analyzed. Cooking losses and, consequently, total lipids, increased directly with the cooking time and internal temperature reached by meat (microwaving > boiling > grilling). The major changes in fatty acid composition, which implicated 16 out of 34 fatty acids, resulted in higher percentages in cooked beef of SFA and MUFA and lower proportions of PUFA, relative to raw meat, while conjugated linoleic acid (CLA) isomers revealed a great stability to thermal processes. Heating decreased the PUFA/SFA ratio of meat but did not change its n−6/n−3 index. Thermal procedures induced only slight oxidative changes in meat immediately after treatment but hardly affected the true retention values of its individual fatty acids (72–168%), including CLA isomers (81–128%).     

Effect of dose of calcium salts of conjugated linoleic acid (CLA) on percentage and fatty acid content of milk fat in midlactation holstein cows

Increasing conjugated linoleic acid (CLA) content of milk fat from lactating dairy cattle has become a research interest due to the possible health benefits afforded humans consuming CLA. Dietary supplementation of CLA to lactating dairy cows is one potential method by which CLA content of milk and dairy products may be enhanced. Feeding CLA in calcium salt form could potentially deliver CLA to the lower digestive tract through prevention of biohydrogenation by rumen microbes. Milk fat depression (MFD) occurs when cows receive CLA-60, a commercially available CLA source containing numerous CLA isomers, abomasally. Our objectives were to determine the quantity of CLA as calcium salts required to elicit maximal MFD and to evaluate the effects of CLA supplementation on fatty acid composition of milk fat. Five Holstein cows at approximately 93 DIM were utilized in a 5 x 5 balanced Latin square crossover design. Periods were 14-d in length with a 5-d treatment phase and 9-d rest phase. Treatments were 5-d supplementation of 0, 12.5, 25, 50, and 100 g of CLA-60 in calcium salt form. Milk samples were collected on d 5 of CLA supplementation and analyzed for composition and fatty acid profile. Regression analysis of milk fat data suggested that MFD was not maximized over the dose levels investigated, despite delivery of 34.5 g of trans-10, cis-12 CLA in the 100-g dose of CLA. Supplementation with 50 and 100 g of CLA per day resulted in a reduction of milk fat percent of 29 and 34%, respectively. Trend analysis indicated a linear decrease in the milk fat content of caprylic, capric, and lauric acids as the dose of CLA increased. Milk fat content of cis-9, trans-11, and trans-10, cis-12 CLA increased at an increasing rate as dose increased.     

Meat quality attributes of the Longissimus lumborum muscle of the Kh'ara genotype of llama (Lama glama) reared extensively in northern Chile

Twenty male llama of the Kh'ara genotype, reared extensively in the north of Chile, were slaughtered at ages between 2 and 4 permanent teeth (2 to 3.5 years) and analyses were carried out on the Longissimus lumborum muscle, including composition (moisture, fat, protein, ash, cholesterol, amino acids, fatty acid profile and collagen content) and meat quality parameters (pH, color, water holding capacity and Warner–Bratzler shear-force). Llama meat was characterized by a low cholesterol (39.04 mg/100 g) and intramuscular fat (1.56%) content, a total collagen content of 6.28 mg/g, of which 20.28% was soluble collagen. Amino acid composition and fatty acid profile were similar to those found for beef finished on forage. Llama meat showed a low n − 6/n − 3 (4.69) and hypocholesterolemic/hypercholesterolemic (1.55) ratio and acceptable values of DFA (65.78%). Quality parameters in llama Longissimus muscle were within the ranges reported for more traditional meats such as beef and lamb.