Genetic parameters for meat quality traits of Australian lamb meat

Genetic parameters were estimated for a range of meat quality traits recorded on Australian lamb meat. Data were collected from Merino and crossbred progeny of Merino, terminal and maternal meat breed sires of the Information Nucleus programme. Lambs born between 2007 and 2010 (n = 8968) were slaughtered, these being the progeny of 372 sires and 5309 dams. Meat quality traits were found generally to be of moderate heritability (estimates between 0.15 and 0.30 for measures of meat tenderness, meat colour, polyunsaturated fat content, mineral content and muscle oxidative capacity), with notable exceptions of intramuscular fat (0.48), ultimate pH (0.08) and fresh meat colour a* (0.08) and b* (0.10) values. Genetic correlations between hot carcass weight and the meat quality traits were low. The genetic correlation between intramuscular fat and shear force was high (− 0.62). Several measures of meat quality (fresh meat redness, retail meat redness, retail oxy/met value and iron content) appear to have potential for inclusion in meat sheep breeding objectives.     

Eating quality of “Vitela Tradicional do Montado”-PGI veal and Mertolenga-PDO veal and beef

Physicochemical and sensory characteristics were measured in veal and beef from the Portuguese Mertolenga breed having 3 quality labels as follows: Mertolenga-PDO beef and veal which apply to purebred animals and “Vitela Tradicional do Montado”-PGI veal which applies to crossbred animals. Measurements were made in longissimus lumborum muscle aged for 6 days. The temperature 3 h post-mortem (T₃), cooking losses and Warner–Bratzler shear force (WBSF) reflected carcass weight (CW) differences between groups. The pigment content was influenced by age, with beef having higher values than veal. WBSF correlated negatively with intramuscular fat in Mertolenga-PDO beef, but not on veal. WBSF correlated positively with cooking losses and negatively with myofibrillar fragmentation index, tenderness, juiciness and overall acceptability. Cooking losses and juiciness were the main contributors for the tenderness differences. Vitela Tradicional do Montado-PGI and Mertolenga-PDO veal had lighter colour and were considered tender. The three meat types were well discriminated based on pH_u, a* and C* parameters by canonical discriminant analysis.     

The expression of genes PKM2 and CAST in the muscle tissue of pigs differentiated by glycolytic potential and drip loss, with reference to the genetic group

The present studies aimed at an analysis of the expression level of genes PKM2 and CAST in Longissimus lumborum [LL] muscle tissue of pigs differing as regards the glycolytic potential [GP] and drip loss [DL] from the LL muscle, with reference to the genetic group. The studies covered a total of 65 pigs: 20 purebred Landrace [L], 22 crossbreeds of Landrace with the Yorkshire [L × Y] and 23 three-breed crosses (Landrace × Yorkshire) × Duroc [(L × Y) × D]. In the case of gene PKM2 one may observe in (L × Y) × D crossbreds, compared to L × Y crossbreds, an increased expression, closely related with the increase in dry matter content, including intramuscular fat, as well as a more favourable progress of glycolytic and energy metabolism during the early time post mortem (pH₄₅ and R₁). Compared with Landrace animals, the lower expression of the CAST gene observed in (L × Y) × D pigs is manifested by a marked improvement of meat quality (R₁ pH₄₅ pH₂₄, pH₄₈), arising from the rate of glycolytic and energy metabolism, typical for normal meat, that in effect results in its higher culinary and technological value.     

Meat quality comparison of Berkshire, Duroc and crossbred pigs sired by Berkshire and Duroc

The object of this study is to specify features determining meat quality of Berkshire and Duroc and influence of these purebreds on meat quality of crossbred pigs. In total, 37 purebred pigs (Berkshire and Duroc: originating from line breeding in Kagoshima Prefecture and Miyagi Prefecture, respectively) and two crossbreeds (LDB and LDD: produced by crossing Berkshire and Duroc boars to Duroc-Landrace sows) were used. Berkshire accumulated more subcutaneous and abdominal fat and had small loin eye muscle area, but accumulated less intramuscular fat than Duroc. There were no differences in meat colour and tenderness between the two purebreds. But Berkshire was less than Duroc in drip loss. As for fatty acid of inner and outer subcutaneous fat, Berkshire contained significantly higher concentration of saturated fatty acids, but had lower concentration of unsaturated fatty acid than Duroc. As a result, the melting point of inner and outer subcutaneous fat and perirenal fat of Berkshire was significantly higher than that of Duroc. Furthermore, though there was no breed difference in concentration of saturated fatty acids of intramuscular fat, Duroc had more oleic acid (C18:1) than Berkshire. Fatty acid concentrations of inner and outer subcutaneous fat and intramuscular fat as well as melting points of both subcutaneous fat layers and perirenal fat were the same in Berkshire and LDB and in Duroc and LDD. These results suggest that there were remarkable differences between Berkshire and Duroc in fat quality traits; also, both breeds as terminal sires influenced crossbred pigs' fat accumulation and fat quality traits.     

The association between acyl-CoA synthetase (ACSL4) polymorphism and intramuscular fat content in (Landrace × Yorkshire) × Duroc pigs

The aim of the study was to check whether different genotypes at acyl-CoA synthetase (ACSL4 locus, SNP G2645A) are associated with pork quality. 132 (Landrace × Yorkshire) × Duroc fatteners were genotyped by originally developed PCR-RFLP method. Upon the slaughter, the samples of longissimus lumborum muscle were taken from each carcass to determine the following parameters: content of water, protein and fat, pH (45 min, 24, 48, 96, and 144 h post mortem), electrical conductivity, drip loss, meat lightness, glycolytic potential, glycogen and lactate contents in meat. Among several associations observed, the highly significant (p<0.01) was found for intramuscular fat (IMF) content. Pigs with genotype GG revealed the highest content of IMF - 2.47%.     

Chemical composition and structural characteristics of Arabian camel (Camelus dromedarius) m. longissimus thoracis

Saudi Arabian camels of four breeds (6 animals per breed) were used to evaluate characteristics and quality of their meat. Chemical composition, fibre cross sectional area, collagen content, muscle metabolism, cooking loss, pH at 24 h post mortem, colour values (except redness) and shear force of Longissimus thoracis (LT) muscle did not differ between the breeds. Elevated pH values and short sarcomeres reduced overall tenderisation, with a difference between myofibril fragmentation index (P < 0.001) and sarcomere length (P < 0.05) between breeds. A positive correlation was observed between the activities of the mitochondrial enzymes (r > 0.49), between the glycolytic activities (PFK and LDH) (r = 0.61) and between Myosin Heavy Chain IIa and LDH activity. The intramuscular fat content was positively associated with redness and muscle oxidative metabolism, whereas shear force had a slight positive association with collagen content and muscle glycolytic metabolism and a negative association with muscle oxidative metabolism and muscle fibre area.     

Effect of beef ultimate pH and large structural protein changes with aging on meat tenderness

This study investigated the effect of ultimate pH (pH_u) in beef on the degradation of large structural proteins during refrigerated storage using SDS-PAGE. M. longissimus dorsi from bull carcasses were selected and classified into three groups: low pH_u (≤ 5.79), intermediate pH_u (5.80–6.19) and high pH_u (≥ 6.2) muscles. Samples were then stored at − 1.5 °C for 1, 2, 7, 14, 21 and 28 days. Meat tenderness was measured at each aging time. Depending on meat pH_u, different protein patterns and degradation rates of structural proteins were found. Rapid changes of large structural proteins took place within 48 h post mortem. Besides titin and nebulin, degradation of filamin was clearly revealed. Two more large protein bands corresponding to myosin family members also exhibited fast decline with storage time. It suggested that the fast degradation of these proteins is a key factor in the improvement of meat tenderness.     

Histological,Biophysical, Physical and Chemical Characteristics of Different Ostrich Muscles

Some characteristics generally related to meat quality were evaluated in several muscles from the leg of the ostrich. Ostrich meat is characterised by a relatively high pH_f and low intramuscular fat content. Although standard slaughtering procedures of ostriches at present comprise the removal of legs within 30 min post mortem from the carcass, relatively long sarcomere lengths and the absence of a linear relationship ( P> 0·05) between sarcomere length and Warner–Bratzler shear measurements (WBS) show that no cold shortening occurs in the different muscles. The means obtained for the Iliotibialis lateralis are representative of the mean of all the individual muscles combined regarding the characteristics muscle fibre diameter, WBS and pigment content. The overall mean for sarcomere length, pH_f and collagen content of all the individual muscles combined can be deduced from determination of these characteristics in the Femorotibialis medius .     

Effect of Duroc content, sex and ageing period on meat and eating quality attributes of pork loin

This study was conducted to determine the effect of percentage Duroc content of entire male and female pigs and ageing period on meat and eating quality attributes of pork loin (M. longissimus thoracis et lumborum). A total of 84 pigs [entire males (n=42) and female (n=42)] of 0% Duroc (100% Large White), 50% Duroc (Duroc×Large White) or 100% Duroc (n=14 pigs per sex×genotype combination) were slaughtered at a liveweight of 100 kg. Steaks from the M. longissimus lumborum of female pigs were aged for either 2 or 7 days post-slaughter and evaluated using a consumer taste panel. Eating quality attributes of tenderness, flavour and overall liking of pork loin steaks from female pigs were not (P>0.05) influenced by Duroc content. Pork from 100% Duroc pigs was juicier (P=0.05) and had a higher (1.84%, P=0.05) intramuscular fat content than pork from 0 and 50% Duroc pigs (1.40 and 1.25%, respectively). Pork from entire male pigs had a lower (P<0.001) intramuscular fat content, was darker (P<0.01) in colour and recorded higher (P<0.01) Warner Bratzler shear force values compared with pork from female carcasses. Ageing pork loin steaks in vacuum bags for 7 days improved tenderness (P<0.01), flavour (P<0.05) and overall liking (P<0.05) compared with steaks aged for 2 days post-slaughter. Ageing of pork steaks for 7 days post-slaughter improved eating quality attributes far more effectively than increasing percentage Duroc content of pigs, which only influenced consumer scores for juiciness.     

Meat quality and intramuscular fatty acid composition of Sanfratellano and Haflinger foals

The goal of the trial was to evaluate meat quality, with an emphasis on intramuscular fatty acid composition, of Sanfratellano foals, compared to that from Haflinger foals,both slaughtered at 18 months of age. Thirty foals, half of Sanfratellano breed and half of Haflinger breed, naturally weaned at 7-8 months, were divided into two homogeneous groups at 15 months of age and fed a finishing diet based on polyphite hay and concentrate. The finishing period lasted three months. Sanfratellano foals showed higher slaughter weight (P<0.05) as well carcass weight (P<0.05) compared to Haflinger foals. Meat physical and proximate analyses did not discriminate the two groups. Normal pH values (5.6-5.7) measured at 4-6 day post mortem were recorded in meat from both groups. Shear force values accounted (range 55-58N) for a favourable tenderness in both groups. The intramuscular fat level was low in both groups (<2.5%) supporting the healthy image of this meat. The proportion of linolenic acid was higher (P<0.01) in Haflinger meat than in Sanfratellano one, thus causing a higher (P<0.05) total n-3 fatty acid content. Overall meat from both groups showed a favourable repartition among saturated (36-37% total FAME's), monounsaturated (33% total FAME's) and polyunsaturated fatty acids (30-31% total FAME's).     

Meat quality of Angus, Simmental, Charolais and Limousin steers compared at the same intramuscular fat content

Meat quality and marbling properties of Angus, Simmental, Charolais and Limousin steers (4×16) were compared at an average intramuscular fat content (IMF) of 3.25% in the M. longissimus dorsi. The steers were fattened on a forage-based diet until the desired, ultrasonically estimated IMF content was reached which resulted in considerably different growth and carcass characteristics. The Angus group showed a growth rate similar to Simmental and Charolais while Limousin grew slower, became oldest and provided the heaviest carcasses and best conformation. Angus carcasses showed the lowest weight but the highest fatness score. Marbling was equal for all breeds. Angus and Charolais provided pale meat with low haem iron content. Angus and Limousin beef was more tender on sensory assessment than Simmental beef, corresponding to differences found in shear force (non-significant) and myofibrillar fragmentation index measured at 48 h post mortem. Flavour was similar among breed groups while juiciness was highest for Limousin and lowest for Angus. The juicier beef simultaneously showed the highest drip but the lowest cooking losses. In conclusion, clear differences in meat quality were observed between breeds despite similar IMF contents.     

Effects of breed, diet and muscle on fat deposition and eating quality in pigs

A study in 192 entire male pigs examined the effects of breed, diet and muscle on growth, fatness, sensory traits and fatty acid composition. There were four breeds: two modern breeds, Duroc and Large White and two traditional breeds, Berkshire and Tamworth. The diets differed in energy:protein ratio, being conventional (C) and low protein (LP) diets, respectively. Muscles investigated were the ‘white' longissimus dorsi (LD) and the ‘red' psoas major (PS). Breed influenced growth rate and fatness, the modern breeds being faster-growing with leaner carcasses. However, the concentrations of neutral lipid fatty acids and marbling fat (neutral lipid + phosopholipid fatty acids) were higher in Berkshire and Duroc, in both LD and PS. Relationships between marbling fat and P2 fat thickness showed clear breed effects, with Duroc having high marbling fat at low P2 and Tamworth low marbling fat at high P2. Breed effects on sensory scores given by the trained taste panel to griddled LD and PS steaks were relatively small. Breed affected the fatty acid composition of intramuscular neutral lipid, with high % values for the saturated fatty acids, 14:0 and 16:0 in Berkshire and Tamworth (fat carcasses) and high values for polyunsaturated fatty acids in Duroc and Large White (lean carcasses). Duroc had particularly high concentrations of the long-chain polyunsaturated fatty acids, 20:5n−3 and 22:6n−3 in phospholipid of both muscles. Diet influenced growth rate and fatness, the LP diet slowing growth and producing fatter meat, more so in the two modern breeds, and particularly in intramuscular rather than subcutaneous fat. This diet produced more tender and juicy meat, although pork flavour and flavour liking were reduced. The PS muscle had higher tenderness, juiciness, pork flavour, flavour liking and overall liking scores than LD. The concentration of phospholipid fatty acids was higher in PS than LD but neutral lipid fatty acid content and marbling fat were higher in LD.     

The association between polymorphism of PKM2 gene and glycolytic potential and pork meat quality

The objective of this study was to investigate the association of PKM2 gene with glycolytic potential and meat quality traits in three groups of fatteners – Landrace, Landrace × Yorkshire and (Landrace × Yorkshire) × Duroc. The present study was conducted on 243 fatteners, free of RYR1^T gene, which 95 were of Landrace breed and the rest were the following crosses: 66 – Landrace × Yorkshire and 82 (Landrace × Yorkshire) × Duroc. It has been stated, that PKM2 gene (independently from the breed) was significantly associated with GP, lactate content, R₁ indicator, pH and drip loss. The presence of TT genotype may lead to increase of GP and lactate content and results in low pH₂₄ and pH₁₄₄ and bigger drip loss measured 96 and 144 h after the slaughter. Except for the landrace fatteners, the association of the PKM2 gene with the glycogen content has not been statistically confirmed. Statistically confirmed interaction shows, that the association of PKM2 gene with glycolytic potential and glycogen content concerns mainly the Landrace pigs. Moreover, a high (almost 89%) conformability of the genotype of PKM2 gene with the RN⁻ phenotype, can serve as an additional argument in favour of the thesis.     

Suitability of three commercially produced pig breeds in Germany for a meat quality program with emphasis on drip loss and eating quality

This study aimed at characterising 606 crossbred pigs of three commercially available breed types in terms of their carcass and meat quality. Breed G and H were German Large White (LW) × German Landrace (LR) sows sired with Pietrain (PI) boars, i.e. PI × (LW × LR). Breed S was 25% Duroc (DU), i.e. PI × (DU × LR). Most of the parameters were affected by breed and/or date of slaughter. The meat of crossbred pigs with 25% Duroc proportion appeared most favourable because of higher intramuscular fat content, lower drip loss and higher sensory liking scores. Conductivity is closely related to drip loss while the data suggests that the relationship is dependent on breed and carcass weight. The application of conductivity and lean meat yield thresholds to select carcasses with uniform and superior meat quality effectively decreased drip loss and increased intramuscular fat content as well as sensory liking scores. The variation of meat quality traits remains high, though.     

Surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry: A tool to predict pork quality

Expression of water soluble proteins of fresh pork Longissimus thoracis from 4 pure breed pigs (Duroc, Large White, Landrace, and Piétrain) was studied to identify candidate protein markers for meat quality. Surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF-MS) was used to obtain the soluble protein profiles of Longissimus thoracis muscles. The pure breeds showed differences among the studied meat quality traits (pH_u, drip loss, androstenone, marbling, intramuscular fat, texture, and moisture), but no significant differences were detected in sensory analysis. Associations between protein peaks obtained with SELDI-TOF-MS and meat quality traits, mainly water holding capacity, texture and skatole were observed. Of these peaks, a total of 10 peaks from CM10 array and 6 peaks from Q10 array were candidate soluble protein markers for pork loin quality. The developed models explained a limited proportion of the variability, however they point out interesting relationships between protein expression and meat quality.     

Carcass and meat quality of selected final hybrids of pigs in the Czech Republic

The objective of this work was to compare the quality of carcass and meat in the selected crossbred pigs used in the Czech Republic. A total of 200 pigs that arose from four crossbreeding was studied; the dam line was in all combination of hybrids represented by Czech Large White × Landrace. Sire line included Large White × Belgian Landrace (I), Hampshire × Pietrain (II), Duroc × Pietrain (III) and Czech meat pig (IV). Influence of crossbreeding on lean meat percentage and muscle depth was statistically highly significant (P<0.001), influence on fat depth was evident (P<0.05). Differences in pH(1) value among the individual final hybrids were not statistically significant but variance of pH(24) value was highly notable (P<0.001). All colour parameters (L(?), a(?), b(?) values), drip loss and exudate also were influenced by hybrid combination (P<0.001). Influence of crossbreeding on intramuscular fat content was not statistically significant (P=0.067). Higher content of intramuscular fat was determined in the hybrids with Duroc breed in sire line. In the whole group, 8.5% pig with PSE defect was found. By comparison of all the various hybridisation, positive influence of Hampshire breed on the carcass quality and negative influence on meat quality was confirmed. On the other hand, meat quality is positively influenced Duroc and Czech meat pig breeds.     

梅山猪与三元杂交猪肌内脂肪含量、μ-钙蛋白酶和蛋白降解对嫩度的影响

目的:比较梅山猪与三元杂交猪(杜洛克猪×长白猪×大白猪)的剪切力、肌内脂肪含量、μ-钙蛋白酶及蛋白降解的差异,分析影响梅山猪肉嫩度的因素。方法:选取6头纯种梅山猪和6头三元杂交猪,取背最长肌为实验材料,采用变性聚丙烯酰胺凝胶电泳和蛋白免疫印迹技术测定μ-钙蛋白酶在宰后45 min的降解和整联蛋白、伴肌动蛋白在宰后成熟1、3、7 d的降解情况。结果:梅山猪肉在宰后成熟1、3、7 d的剪切力值均显著低于三元杂交猪(P0.05),在宰后成熟1 d的肌内脂肪含量显著高于三元杂交猪(P0.05)。在宰后45 min,梅山猪的μ-钙蛋白酶的80 kD百分含量显著高于三元杂交猪,78 k D和76 kD百分含量显著低于三元杂交猪(P0.05),梅山猪的μ-钙蛋白酶的自我降解程度较低,这与梅山猪的蛋白降解情况相一致。梅山猪的整联蛋白在成熟3d的相对光密度值显著高于三元杂交猪(P0.05),宰后成熟3 d和7 d的降解率显著低于三元杂交猪(P0.05),伴肌动蛋白在成熟1 d和3 d的相对光密度值显著高于三元杂交猪(P0.05)。结论:梅山猪的整联蛋白和伴肌动蛋白降解较少,这与μ-钙蛋白酶的降解有关,而μ-钙蛋白酶和蛋白降解对梅山猪肉的嫩度影响不大,梅山猪肉相对较高的肌内脂肪含量解释了其较高的嫩度。     

The influence of carcass backfat and intramuscular fat level on pork eating quality

To evaluate the contribution of fatness level towards pork eating quality, carcass and meat eating quality data were analysed from 721 pigs of three genotypes (with 0, 0.25 and 0.50 Duroc inclusion level). Animals (entire male and female) were reared from 30 to 90 kg liveweight on one of seven feeding regimens which involved combinations of diet formulation and feeding level, so as to produce carcasses of widely differing fatness levels. This experimental design produced coefficients of variation for classification P₂ backfat thickness of 21.11 (mean 11.59 mm, SE 0.093) and intramuscular fat (IMF) of 63.60 (mean 13.4 g kg⁻¹, SE 0.33). The treatments also produced considerable variation for eating quality as assessed by trained sensory panel (1–8 scale) and objectively (shear force) as shown by the following coefficients of variation: shear force 22.01% (mean 334 N, SE 2.77), juiciness 16.12% (mean 4.95, SE 0.297), tenderness 19.65% (mean 5.06, SE 0.370), pork flavour 13.22% (mean 4.56, SE 0.225), abnormal flavour 34.46% (mean 2.02, SE 0.259) and overall acceptability 18.42% (mean 4.78, SE 0.328). Correlation coefficients between carcass fatness measurements and eating quality characteristics were calculated. Although shear force was significantly correlated with both classification P₂(r = −0.213) and IMF (r = − 0.189), taste panel tenderness was not significantly correlated to fatness level. Of the taste panel parameters evaluated, only juiciness showed a significant correlation (P < 0.05) with classification P₂(r = − 0.086). None of the eating quality characteristics as evaluated by taste panel correlated significantly with IMF. These results do not support the belief that fatness level per se has a major influence on pork eating quality. © 2000 Society of Chemical Industry