Fatty acids in muscles and liver of Tunisian wild and farmed gilthead sea bream, Sparus aurata

The total fat content and the fatty acids profile were analysed in the dorsal and ventral muscles and in the liver from wild and farmed gilthead sea bream (Sparus aurata). The amount of fish lipid was higher in farmed than in wild fish in all studied samples and the highest level of all was observed in liver. It was noted that, among all the samples studied for saturated fatty acids (SFA) and Monounsaturated fatty acids (MUFA), whether farmed or wild, palmitic (C16:0) and oleic (C18:1 n − 9) acids were the principal saturated and monounsaturated fatty acids. The results showed that farmed fish contained a higher level of n − 3 polyunsaturated fatty acids (PUFA), particularly docosahexaenoic acids (DHA) and eicosapentaenoic acids (EPA), whereas wild fish contained a higher level of n − 6 PUFA. Arachidonic acid (C20:4 n − 6) was the primary n − 6 PUFA in wild fish whereas in farmed fish, linoleic acid (C18:2 n − 6) was the major n − 6 PUFA. Farmed fish were characterized by higher n − 3/n − 6 ratio for all samples studied, due to the abundance of n − 3 PUFA, particularly DHA.     

Fat deposition, fatty acid composition and meat quality: A review

This paper reviews the factors affecting the fatty acid composition of adipose tissue and muscle in pigs, sheep and cattle and shows that a major factor is the total amount of fat. The effects of fatty acid composition on meat quality are also reviewed. Pigs have high levels of polyunsaturated fatty acids (PUFA), including the long chain (C20-22) PUFA in adipose tissue and muscle. The full range of PUFA are also found in sheep adipose tissue and muscle whereas cattle ‘conserve’ long chain PUFA in muscle phospholipid. Linoleic acid (18:2n − 6) is a major ingredient of feeds for all species. Its incorporation into adipose tissue and muscle in relation to the amount in the diet is greater than for other fatty acids. It is deposited in muscle phospholipid at a high level where it and its long chain products eg aracidonic acid (20:4n − 6) compete well for insertion into phospholipid molecules. Its proportion in pig adipose tissue declines as fat deposition proceeds and is an index of fatness. The same inverse relationships are not seen in ruminant adipose tissue but in all species the proportion of 18:2n − 6 declines in muscle as fat deposition increases. The main reason is that phospholipid, where 18:2n − 6 is located, declines as a proportion of muscle lipid and the proportion of neutral lipid, with its higher content of saturated and monounsaturated fatty acids, increases. Oleic acid (18:1cis − 9), formed from stearic acid (18:0) by the enzyme stearoyl Co-A desaturase, is a major component of neutral lipid and in ruminants the same enzyme forms conjugated linoleic acid (CLA), an important nutrient in human nutrition. Like 18:2n − 6, -linolenic acid (18:3n − 3) is an essential fatty acid and is important to ruminants since it is the major fatty acid in grass. However it does not compete well for insertion into phospholipid compared with 18:2n − 6 and its incorporation into adipose tissue and muscle is less efficient. Greater biohydrogenation of 18:3n − 3 and a long rumen transit time for forage diets also limits the amount available for tissue uptake compared with 18:2n − 6 from concentrate diets. A positive feature of grass feeding is that levels of the nutritionally important long chain n − 3 PUFA are increased ie EPA (20:5n − 3) and DHA (22:6n − 3). Future research should focus on increasing n − 3 PUFA proportions in lean carcasses and the use of biodiverse pastures and conservation processes which retain the benefits of fresh leafy grass offer opportunities to achieve this. The varying fatty acid compositions of adipose tissue and muscle have profound effects on meat quality. Fatty acid composition determines the firmness/oiliness of adipose tissue and the oxidative stability of muscle, which in turn affects flavour and muscle colour. Vitamin E is an essential nutrient, which stabilises PUFA and has a central role in meat quality, particularly in ruminants.     

Fatty acids and tocopherol levels in M. Longissimus dorsi of beef cattle in Sweden - A comparison between seasonal diets

This study investigated the influence of Swedish outdoor feeding systems on the fatty acid composition and tocopherol content of M. Longissimus dorsi from beef. Dietary effects of pasture (PA), silage, and silage supplemented with grain (SIG) were compared. Each dietary group consisted of six animals. Higher levels (P < 0.05) of polyunsaturated fatty acids (PUFA) were found in the PA treatment. The n − 6/n − 3 fatty acid ratio of total lipids in the muscle tissue was in the range 1.2–1.5. The SIG treatment increased the n − 6/n − 3 ratio and decreased the total PUFA content of muscle tissue. The lipid class composition and the content of -tocopherol in the meat showed no differences among treatments.     

Characterisation of intramuscular, intermuscular and subcutaneous adipose tissues in yearling bulls of different genetic groups

Fatty acid (FA) composition of intramuscular (IM, Longissimus thoracis muscle), intermuscular (IT) and subcutaneous (SC) fat of one hundred intensively fed yearling bulls with different propensities to fatten were studied. Meat samples were collected from Asturiana de los Valles bulls with different genotypes with respect to the myostatin gene (mh/mh n = 24, mh/+ n = 26 and +/+ n = 25) and from Asturiana de la Montaña (n = 25) bulls lacking the mutation responsible for double muscling and characterised by small to medium-frame size adapted to less favoured mountain areas. FA profiles were expressed as percentages of total FA (g/100 g of total FA) and organised into groups (saturated (SFA), branched (BFA), monounsaturated (MUFA), C18:1trans, polyunsaturated (PUFA), n − 6, n − 3, conjugated linoleic acids (CLA), unsaturated (UFA)) and ratios (MUFA/SFA (M/S), PUFA/SFA (P/S), UFA/SFA (U/S), n − 6/n − 3).

The IT depot was the most saturated and SC depot contained the most monounsaturated FAs, while IM fat had the most polyunsaturated FAs. IM fat showed the highest P/S ratio and for the n − 6/n − 3 ratio there were no significant differences between adipose tissue depots.

In general, genotype effects were more pronounced in IM and SC fat profiles compared to the IT depot, for which no significant differences between genotypes were found in SFA, PUFA (including n − 6 and n − 3), UFA and most of the ratios. IM fat of mh/mh animals had the highest content of PUFA and thus the highest P/S ratio. Accordingly, the presence of the gene causing double muscling influenced the tendency to deposit carcass fat and its FA composition, mainly in IM fat. In general, when carcass fat decreased, SFA content decreased while PUFA and UFA contents increased due to the changes in their percentages.     

Nutritional profile of restructured beef steak with added walnuts

Amino acid, fatty acid profile, cholesterol, vitamin E and mineral contents were assessed in restructured beef steak with 20% added walnut (20W). Compared with control restructured beef steak (0% added walnut), the product with added walnut presented a lower (P < 0.05) lysine/arginine ratio, larger (P < 0.05) quantities (mg/100 g product) of monounsaturated (MUFA) and n3 polyunsaturated (PUFA) fatty acids (mainly -linolenic acid), a lower (P < 0.05) n6/n3 PUFA ratio and a higher (P < 0.05) polyunsaturated/saturated fatty acid ratio. The replacement of raw meat material by walnut reduced (P < 0.05) the cholesterol content and increased (more than 400 times) the amount of γ-tocopherol. Iron, calcium, magnesium and manganese contents of 20W sample were greater (P < 0.05) than in the control. Some changes induced by added walnut in the nutritional quality of the restructured product may present health benefits.     

Chemical, physical and sensory properties of meat from pure and crossbred Podolian bulls at different ageing times

The present study aimed to investigate the effect of crossbreeding with Limousine sires on fatty acid profile, physical and sensory properties of meat produced by Podolian young bulls. Polyunsaturated fatty acid content was influenced by crossbreeding (P < 0.01) with Podolian bulls (P) producing beef characterised by a higher level of unsaturation in comparison with crossbred animals (LP). As a consequence, P/S ratio was significantly higher in meat produced by P animals than LP (P < 0.01). P animals had higher linoleic (P < 0.05), linolenic (P < 0.05), EPA (P < 0.05) and DHA acids (P < 0.001) levels than LP subjects. No breed effect was observed for the ratio n − 6/n − 3 (P > 0.05). WBS force of LD was significantly lower in meat from crossbred subjects (P < 0.05). Both crossbreeding with Limousine and extension of ageing from 2 to 7 days improved LD tenderness as assessed by panel taste (P < 0.001).     

Irradiation effect on fatty acid composition and conjugated linoleic acid isomers in frozen lamb meat

The effect of gamma radiation processing on the lipid content, fatty acid composition and conjugated linoleic acid (CLA) profile in frozen lamb meat was investigated. Samples of longissimus thoracis muscle from lambs fed lucerne basal diets either unsupplemented or supplemented with polyunsaturated vegetable oils were irradiated (7 kGy) and analysed. CLA contents in lamb meat did not affect (P > 0.05) the levels of lipid oxidation induced by the irradiation. No significant differences (P > 0.05) were observed for fatty acid composition, related nutritional indexes (n − 6/n − 3 and PUFA/SFA), as well as for total lipid and CLA contents, between non-irradiated (control) and irradiated meat samples. In contrast, meat irradiation affected the relative proportions of total trans, trans and cis/trans CLA isomers (P < 0.001), in addition to the percentage of some minor individual CLA isomers (t11, t13 and t9, t11, with P < 0.05 and P < 0.001, respectively). The percentage of total cis/trans CLA isomers slightly decreased in irradiated samples, while the relative proportion of total trans, trans isomers slightly increased. This observation may be explained by the higher susceptibility to autoxidation of the cis double bond relative to the trans configuration.     

Meat quality characteristics of springbok (Antidorcas marsupialis). 2: Chemical composition of springbok meat as influenced by age, gender and production region

The effects of age, gender and production region on the chemical, mineral and amino acid composition of the M. longissimus dorsi (LD) muscle of springbok were investigated. There was a significant gender^*region interaction for protein content – for the four production regions it varied between 18.80 and 21.16 g/100 g. The intramuscular fat (IMF) content of the LD muscle varied between 1.32 and 3.46 g/100 g. Females (3.13 ± 0.28 g/100 g) had a higher (P < 0.05) fat content than males (1.35 ± 0.08 g/100 g). The IMF content of the adult (2.45 ± 0.26 g/100 g) and sub-adult (2.50 ± 0.28 g/100 g) categories was higher (P < 0.05) in comparison to that of the lambs (1.32 ± 0.11 g/100 g). An inverse correlation was noted between the IMF and moisture content (r = −0.49, P < 0.001) of the meat. The two main amino acids were glutamic and aspartic acid, which contributed 2.47–2.74 and 2.31–2.54 g/100 g of dry matter, respectively. Phosphorous was the predominant mineral in the LD muscle (122.92–159.78 mg/100 g of dry matter), followed by potassium (119.44–131.25 mg/100 g of dry matter) and calcium (6.57–145.18 mg/100 g of dry matter). Production region had a significant effect on the mineral and amino acid composition of the meat, while the effects of age and gender were found to be insignificant.     

Fatty acid composition and tocopherol concentrations in muscle of entire male, castrated male and female pigs, reared in an indoor or outdoor housing system

The objective of this study was to investigate the effect of outdoor rearing on the fatty acid (FA) composition and contents of tocopherols of M. longissimus dorsi polar (PL) and neutral lipids (NL) in entire males, castrated males and female pigs. Fat content did not differ between genders or rearing conditions. In PL of the indoor pig muscle the level of n − 6 highly unsaturated fatty acids (HUFA) was higher in females and entire males compared with castrated males. The outdoor environment resulted in a slightly higher level of n − 3 polyunsaturated FA (PUFA) in muscle PL and NL of entire males compared with females and castrated males. We also found an increased level of 18:2 n − 6 in the muscle PL of outdoor reared females compared with the indoor females. The higher levels of PUFA in the entire male muscle, in both PL and NL, were not accompanied by a higher level of vitamin E.     

Influence of slaughter season and muscle type on fatty acid composition, conjugated linoleic acid isomeric distribution and nutritional quality of intramuscular fat in Arouquesa-PDO veal

The effects of the slaughter season and muscle type on lipid and conjugated linoleic acid (CLA) contents, fatty acid composition and isomeric profile of CLA in Arouquesa veal, from calves reared according to the specifications of the protected designation of origin (PDO), were assessed. Arouquesa purebred calves (n = 31) were raised in a traditional production system, slaughtered in early autumn (October) or late spring (June), and the longissimus dorsi and semitendinosus muscles were sampled for analysis. Arouquesa-PDO veal only showed seasonal differences in the levels of some minor fatty acids (16:1c9, 17:1c9, 18:1t, 18:3n − 3, 20:0 and 22:4n − 6) and CLA isomers (t12,t14, t9,t11 and c11,t13). Furthermore, significant interactions between the slaughter season and muscle type were obtained for several fatty acids and CLA isomers, total lipids and CLA, and the PUFA/SFA ratio. In both seasons, veal-PDO depicts values of pasture-fed cattle. From a human nutritional perspective, veal-PDO in both slaughter seasons has relatively high CLA contents and percentages of the c9,t11 CLA isomer, which is favourable, while the n − 6/n − 3 ratios are within the recommended values for the human diet. In conclusion, the results suggest that intramuscular fat in Arouquesa-PDO veal has high nutritional value throughout the year.     

Effect of level of linseed on fatty acid composition of muscles and adipose tissues of lambs with emphasis on trans fatty acids

The effects of linseed content in concentrates on the fatty acid (FA) composition of adipose tissues and muscles of lambs were studied in a 2 × 4 design: males (M) vs. females (F) and linseed content (0%, L0, 3%, L3, 6%, L6, 9%, L9). FA proportions were determined both on a DB-wax and on a CP-Sil column in perirenal (PR), dorsal subcutaneous (SC) adipose tissue and in longissusmus dorsi muscle (IM). No effects of linseed contents in the diet on growth performances either in male or female lambs were observed. Linseed supplementation tended to decrease the fatness score. The proportion of linolenic acid increased linearly with the linseed content in the diet, from: 0.6, 0.5, and 0.5% for L0 to 1.9, 1.6, and 1.3% for L9, in PR, SC and IM, respectively. The increase in n − 3 PUFA and in total PUFA was similar to that of linolenic acid. The n − 6:n − 3 ratio decreased from 5.7, 5.3 and 5.8 for L0 to 1.8, 1.7 and 2.7 for L9, in PR, SC and IM, respectively. There was no change in the proportion of docosahexaenoic acid with linseed supplementation. The proportions of C18:1trans-10 and C18:1trans-11 did not vary in PR, SC and IM with linseed supplementation. The total proportion of trans-octadecenoic acid was high in each tissue type and group of lambs. C18:1trans-10 represented about half of the total trans-octadecenoic isomers. With an increase in linolenic acid, most cis- and trans-octadecenoic isomers also increased, but trans-10 and trans-11 isomers did not and cis-9 and cis-11 isomers decreased. With linseed supplementation there was a decrease in the Δ9 desaturase indices in SC.     

The effect of production system and age on concentrations of fatty acids in intramuscular fat of the longissimus and triceps brachii muscles of Angus-cross heifers

The concentrations of fatty acids were measured in intramuscular fat from the longissimus lumborum (LL) and triceps brachii (TB) muscles of Angus-cross heifers finished either on a high-concentrate ration in Washington, USA, (US cattle, n = 15) or on pasture in New Zealand (NZ cattle, n = 16). Half of the NZ cattle were of a similar age to the US cattle (NZAge) and half were of a similar weight (NZWt). Intramuscular fat levels were higher for the LL muscle and for the US cattle but only within the LL muscle (P < 0.05). Aspects of the fatty-acid patterns that are of relevance to human nutrition tended to favour the pasture-finished NZ cattle with lower n − 6/n − 3 fatty acid ratios (P < 0.001), higher concentrations of an anticarcinogenic conjugated linoleic acid (C18:2 c9,t11) (P < 0.05) and its precursor (trans-vaccenic acid, TVA) (P < 0.01), and lower levels of the 18-carbon trans monounsaturated fatty acids other than TVA (P < 0.01). Concentrations of 20 of the 22 fatty acids analysed differed significantly between the two muscles. When values were adjusted to a common intramuscular fat level by covariance, most of the group differences remained, but a number of the muscle differences became non-significant. For almost half the fatty acids considered, there was a significant interaction between treatment group and muscle, which indicates that the results for one muscle do not necessarily apply to other muscles, although the ranking of the groups was usually the same for both muscles.     

The effects of consuming docosahexaenoic acid (DHA)-enriched eggs on serum lipids and fatty acid compositions in statin-treated hypercholesterolemic male patients

The purpose of this study was to investigate the effects of consuming a novel docosahexaenoic acid (DHA)-enriched shell egg on the serum lipid levels and ω − 3 polyunsaturated fatty acids (n − 3 PUFA) of serum phospholipid in statin-treated hypercholesterolemic patients. Fifteen subjects were randomly divided into two treatment groups and consumed either two control or two novel DHA-enriched eggs during two organized breakfast periods of 21 consecutive days each using a double-blinded, cross-over design. The novel enriched eggs from feeding the specialty ration provided 217 mg of DHA and 629 mg of total n − 3 PUFA per day. Total serum cholesterol levels were unchanged with either egg consumption and no significant alterations in lipid levels were found due to a treatment effect. The novel egg group exhibited a significant rise in eicosapentaenoic acid (EPA) plus DHA levels in serum phospholipid (by 23%) which can be related to a reduced risk for fatal ischemic heart disease. Consumption of this novel egg offers an alternative food option for more than doubling current sub-optimal DHA intakes in North America.     

Meat quality characteristics of springbok (Antidorcas marsupialis). 4: Sensory meat evaluation as influenced by age, gender and production region

The effects of age, gender and production region on the sensory characteristics of springbok M. longissimus dorsi (LD) were investigated in 19 springbok, which originated from two Nature Reserves in the Free State Province of South Africa and were divided into age (adult, sub-adult) and gender categories. The sensory characteristics evaluated were game meat aroma, juiciness, residual tissue, tenderness and game meat flavour. Age, gender and production region had an effect (P < 0.05) on different sensory ratings of the meat. Whereas production region influenced (P < 0.05) the game meat aroma, initial juiciness, sustained juiciness and residual tissue ratings of the meat, gender and age had a significant effect on only the residual tissue rating of the meat. An interaction (P < 0.01) between age, gender and production region was observed for the tenderness attribute where the males from the Gariep Nature Reserve were the only gender that showed a significantly higher tenderness rating in the sub-adult than in the adult category. Sensory ratings were linearly correlated with certain physical and chemical attributes. Warner–Bratzler shear force (kg/1.27 cm diameter) values were inversely correlated with the sensory attributes of tenderness (r = −0.70, P < 0.01), residual tissue (r = −0.68, P < 0.01) and sustained juiciness (r = −0.43; P < 0.05). Age-related effects on perceived tenderness were minor in comparison with pH effects. As the pH₂₄ of the meat increased, tenderness (r = −0.46, P < 0.05) and sustained juiciness (r = −0.54, P < 0.05) decreased significantly. No significant linear correlations were observed between the intramuscular fat (IMF) content and the sustained juiciness ratings of the meat. It can be concluded that production region had some influence on sensory characteristics of springbok meat, whilst the influence of age and gender were negligible.     

Changes in carcass composition and meat quality when selecting rabbits for growth rate

Sixty rabbits from the 23rd generation (group S) of a line selected for growth rate were compared to sixty rabbits from the 7th generation of the same line (group C) to study possible relevant changes in carcass composition and meat quality due to the selection and the consequent decrease in degree of maturity at slaughter weight (2000 g). The only relevant changes in carcass composition were an increase in kidneys, liver and dissectible fat percentages and a decrease in meat to bone ratio of the hind leg. In m. Longissimus, group S had lower yellowness of the carcass and higher redness and yellowness of the meat. ICDH activity increased and the aldolase:ICDH ratio decreased. In the hind leg, group S had higher values of PUFA, PUFA/SFA ratio and n − 3 fatty acids.     

AMP-activated protein kinase is negatively associated with intramuscular fat content in longissimus dorsi muscle of beef cattle

Marbling, or intramuscular fat, is an important factor in meat quality. As a key regulator of lipid metabolism, AMP activated protein kinase (AMPK) may be associated with intramuscular fat accumulation. Our objective was to evaluate the relationship among AMPK and its associated signaling mediators, with marbling and lean growth in beef cattle. Steers with high intramuscular fat content (High IMF, 5.71 ± 0.36%, n = 5) and low intramuscular fat content (Low IMF, 2.09 ± 0.19%, n = 5) were selected. High IMF was associated with increased tenderness (P < 0.05) and backfat thickness (P < 0.01). Muscle weights were higher in Low compared to High IMF (P < 0.05). High IMF steers had a reduced AMPK activity (P < 0.01), reduced acetyl-CoA carboxylase phosphorylation (P < 0.05), and reduced total mTOR (P = 0.02) content. Data provide evidence that AMPK is involved in IMF deposition in beef cattle.     

Nutritional and sensory properties of dry fermented sausages enriched with n-3 PUFAs

Enrichment of dry fermented sausages with n − 3 fatty acids through a partial substitution of pork backfat by deodorised fish oil resulted in improved nutritional properties with regard to conventional sausages, without affecting sensory properties and oxidation status. The developed products supplied 0.64 g EPA/100 g and 0.46 g DHA/100 g product, and showed PUFA + MUFA/SFA ratio of 1.76 and n − 6/n − 3 ratio of 2.97. No signs of oxidation were found in any type of sausages, control and modified. None of the dienals and trienals reported as secondary lipid oxidation products and typical for fish oil were detected in the modified sausages. Instrumental colour differences were detected, however, without relevance in the sensory analysis. The sensory evaluation panel did not find differences in general acceptability. The modified dry fermented sausages can be considered a technologically viable functional food.     

Temperature shows greater impact on bovine Longissimus dorsi muscle glycogen debranching enzyme activity than does salt concentration

The degradation of glycogen progresses by the co-operation of two enzymes: glycogen phosphorylase (phosphorylase) and glycogen debranching enzyme (GDE). We studied the effect of temperature (4–42 °C) and salt concentration (0–3% NaCl) on bovine M. longissimus dorsi GDE activity. GDE activity (n = 4) decreased significantly with decreasing temperature from about 40–4 °C. GDE exhibited 52% activity at 25 °C and 11% at 4 °C compared to its optimum activity measured at 39 °C. In rapidly chilled meat, the reduction in GDE activity may substantially delay the rate of glycolysis. However, residual GDE activity at 4 °C seems sufficient to enable the attainment of normal ultimate pH if the available time is long enough. An increase in salt concentration from 0% to 2% and to 3% induced a significant (P < 0.001) increase in the ultimate pH of ground bovine meat (n = 6), but showed no effect on GDE activity.     

Estimation of factors influencing fatty acid profiles in light lambs

Fatty acid composition of intramuscular, intermuscular, subcutaneous, omental and kidney knob fat depots of eighty male light lambs (±21 kg live weight) from five Spanish sheep breeds was analysed. Fat depot, anatomical depot location (internal, external and intramuscular), breed (Spanish Merino, Grazalema Merino, Churra Lebrijana, Segureña and Montesina), weaning type (weaning at 45 days after birth or no weaning) and subcutaneous fat thickness factors were analyzed using a statistical model to quantify their contribution to the variation of each fatty acid. Production system was the main factor to explain variations in overall fatty acid profiles (34.68%). However, for several fatty acids and indices (arachidonic, linoleic, PUFA, n − 3/n − 6) anatomical depot location was the most significant factor. Feeding system explained 65.49% of CLA variance, indicating a strong influence of suckling period length on CLA deposition in lambs’ fat. Moreover, due to the lack of interaction between anatomical depot location or depot and breed type or weaning system for total CLA, for future research only one depot would be enough to study the effect of those factors on CLA levels.     

Meat quality of lambs of indigenous dairy Greek breeds as influenced by dietary protein and gastrointestinal nematode challenge

The effect of dietary protein and gastrointestinal (GI) parasitism on growth and meat quality of lambs was assessed using 60 animals. The lambs were randomly allocated to one of three treatment groups (n = 20): group A, which served as control, group B that was regularly treated with albendazole and group C, which was given supplementary feeding with dietary protein. The three groups of lambs grazed into a pasture (Lolium perenne), which was contaminated with L₃ larvae of GI nematodes. Lamb growth and condition score were assessed at 21-day intervals. After 126 days grazing all lambs were slaughtered and their carcasses were assessed for conformation and fatness and their ultimate pH was measured. Four carcasses from each group were randomly selected for meat quality measurements including physical analysis as well as colour, moisture, total fat, protein content and fatty acid composition. Parasitic challenge was assessed by means of faecal egg counts of lambs, pasture larvae and numbers of adult nematodes in the GI tract of lambs at slaughter. Growth rate of group B was higher (P < 0.01) than that of group A and resulted in significantly (P < 0.01) heavier carcasses. The produced carcasses had similar fatness, but differed significantly (P < 0.05), in their conformation; carcasses of group C scored higher than either those of group B or group A, respectively. There was a significant difference in the colour attributes (L^*) with group A being significantly lighter (P < 0.05) and in pH (P < 0.01); Group B had the highest values. Carcasses of group C had the highest (P < 0.05) amounts of intermuscular fat compared to those of group B and A, respectively. The proportion of C16:1n-7 and C18:2n-6 was higher (P < 0.05) in subcutaneous fat tissue whereas the proportion of C18:0 was higher (P < 0.05) in muscle tissue. In conclusion, the present results showed that the increased protein content in the diet of growing lambs, grazing on a pasture infected with GI nematode larvae, resulted in the production of acceptable carcasses.