Effect of Breed and Age on Histopathological Changes in Pig M. Semimembranosus
The aim of the study was to determine the type and extent of histopathological changes in m. semimembranosus of Polish Landrace (PL), Polish Large White (PLW), Duroc, Pietrain, and Puławska pigs at 60, 90, 120, 150, 180 and 210 days of age. Changes in fibre size (atrophy, hypertrophy - giant fibres), changes in fibre shape (angular fibres), degenerative lesions (necrosis with phagocytosis) and connective tissue hypertrophy were evaluated. The presence of giant fibres was the only histopathological change observed in all age groups of PL, PLW, Duroc and Pietrain pigs, with the percentage of pigs with this type of pathology and the frequency of giant, atrophic and angular fibres increasing significantly with age. In Puławska pigs, giant fibres were only found in the oldest pigs aged 210 days. In these animals, giant fibres as well as atrophic fibres (at 180 and 210 days of age) and angular fibres (at 120, 150, 180 and 210 days of age) occurred in the smallest number of animals and were least extensive. Meanwhile, Pietrain pigs were characterized by a greater number of animals, a significantly greater proportion of giant fibres in all analysed age groups, and a greater proportion of atrophic fibres at 180 and 210 days of age compared to the other pig breeds under analysis. For connective tissue hypertrophy and necrosis with phagocytosis, the changes were not extensive. It is concluded that both the advancing age of the animals and selection of the pigs for increased leanness significantly increases the incidence of histopathological changes in muscle tissue, which may directly translate into pork quality.
properties of fermented beef products ripened as entire primal cuts of m. semitendinosus, m. semimembranosus and mm. psoas major and minor. Ann. Anim. Sci., 14: 197-212. Wyszecki G., StilesW.S. (1982). Colour science. Concepts and methods quantitative data and formula. New York, USA, John Wiley, 2nd ed.
The objective of the study was to analyse the effect of breed on characteristics of muscle fibres, parameters of intramuscular connective tissue, collagen content, intramuscular fat (IMF) content and tenderness of semimembranosus muscle in pigs. The study was conducted with 16 Złotnicka Spotted (ZS) and 23 Polish Landrace (PL) fattening pigs slaughtered at 210 days of age. The current study showed that compared to the PL breed, the semimembranosus muscle from the local breed of ZS pigs was characterized by a greater percentage of type I fibres, a smaller percentage of type IIB fibres and a smaller diameter of all the three muscle fibre types analysed, while the muscles of PL pigs had significantly thinner endomysium and perimysium and a more compact arrangement of collagen fibres, with a significantly lower percentage of collagen in the muscle and a lower content of total and soluble collagen compared to the muscles of ZS pigs. Furthermore, meat from ZS pigs was more tender (lower shear force value) and had a significantly higher IMF content compared to meat from PL pigs.
The physico-chemical, biochemical and microbiological changes in raw fermented beef products, manufactured from semitendinosus (ST), semimembranosus (SM), psoas major and minor (PM) muscles during ripening were evaluated. The accumulation of free fatty acids (1550, 2660, 1850 mg/kg) and the increase of lactobacilli (about 0.2 log cfu/g) had an effect on the pH. The low pH (4.9) reduced the coagulase-negative cocci population (0.2 log cfu/g) and affected the free amine groups content (185.2 and 25 μM Gly/kg) in the PM with the lowest fat content (2.9%). At the end of the ripening process the ST contained a similar quantity of water, protein, fat and proteolysis products as the SM, however small peptides were generated in all products. The release of volatile compounds could be affected by the drying mainly due to the increase of fat (free fatty acid transformations) and activity of bacterial cells (amino acid transformations, fermentation under aerobic or anaerobic conditions). The results of a two-way analysis of variance for physico-chemical, biochemical and microbiological attributes showed that all the analysed factors significantly influenced the level of the evaluated variables in the ST, SM and PM products (P<0.01) excluding the type of product and its effect on the fat, ash, 2-phenylethylamine and putrescine content, pH and the coagulase-negative cocci count in the ST and SM. The interactions between the type of product and the ripening period were highly significant, with the exception of the yeasts and the LAB, existing in the external and internal layer of the products.
The aim of this study was to compare major biochemical properties of nutria meat with relevant composition and texture data of rabbit carcasses. The meat from nutria m. semimembranosus (MS; thigh muscle) contained 29.54% dry matter (DM), 20.05% total protein (TP), 7.83% total fat (TF) and 1.23% total ash (TA). The ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA) was lower in nutria than in rabbit meat (0.55-0.58 and 0.93-0.94, respectively). The n-6/n-3 PUFA ratio was 15.3 (MS) and 11.22 (m. longissimus dorsi, MLD; loin) in nutria meat and 7.55 and 8.08 respectively in rabbit meat, which appeared more beneficial for the consumer. Among the most important texture parameters, hardness ranged from 66 for MS to 73 N for MLD, and overall chewiness was 23 N. The collagen content was between 0.68 and 0.72%. The results show that in comparison with rabbit meat, nutria meat has valuable properties and is recommended for the human diet.
The objective of this study was to determine the relationships between intramuscular fat, cholesterol contents and fatty acid composition in the muscles of different animal species. Intramuscular fat, cholesterol and fatty acid composition in 207 muscle samples from 129 animals of different species (pigs, beef cattle, farmed red deer, horses and geese) were determined and analysed. The obtained results indicated unequal relations between intramuscular fat and cholesterol contents and fatty acid proportions in the muscles of different animal species. The increase of intramuscular fat content resulted in higher monounsaturated and lower polyunsaturated fatty acid contents in most muscles of meat producing animals. In all the species higher fatness did not show any increase in cholesterol content and also cholesterol contents were lower as fat increased in m. semimembranosus of pigs and m. pectoralis profundus of horses. The cholesterol content positively correlated with saturated and monounsaturated fatty acids in the longissimus muscle with the lowest fat content found in red deer and beef cattle, whereas the correlations between these measures were negative in m. pectoralis profundus of horses and the breast of goose containing high fat levels. Negative correlations between polyunsaturated fatty acids and cholesterol content were found in the longissimus muscle of red deer and cattle, whereas these correlations in goose breast and horse meat were positive.
The microsomal triglyceride transfer protein via participation in transport of neutral lipids between membrane vesicle is essential for assembly of chylomicrons, low-density lipoproteins (LDL), and very low-density lipoproteins (VLDL). In human and pigs, it has been confirmed that mutations within MTTP locus affected lipid-transfer activity of this protein. The aim of the present study was to establish potential influences of ENSSSCP00000009789.2:p.Leu840Phe polymorphism on a panel of meat texture parameters measured in two muscles: m. longissimus lumborum and m. semimembranosus. The research performed on 410 pigs showed that investigated missense polymorphism was associated with meat texture profile parameters – TPA (hardness, cohesiveness, springiness, resilience, chewiness) as well as firmness and toughness estimated in loin muscle. In whole analyzed population, the meat of pigs with CC genotype was characterized by significantly the lowest value of TPA characteristic and this trend was also confirmed in two breeds (Puławska and Large White pigs). In turn, the results obtained for firmness and toughness parameters in longissimus lumborum were not consistent across the different populations studied. Our research, in connection with previous studies, indicated that the MTTP gene may be considered as a candidate gene responsible for pork quality traits and pinpointed a need for further analysis in order to select useful genetic markers associated with meat quality parameters.
The chemical composition and culinary meat tenderness belong to the most important characteristics determining meat quality and value. The aim of this work was to compare texture profiles and shear force of pork loin (m. longissimus dorsi) and of pork ham (m. semimembranosus) from fatteners of Polish Landrace (PL), Polish Large White (PLW), Duroc, Pietrain and Puławska pig breeds slaughtered at 60, 90, 120, 150, 180 and 210 d of breeding. Meat was roasted at 180°C to inner temperature of 78°C. The intramuscular fat (IMF) content in loin was growing with fattener age (from 1.17% at 60 d to 1.84% at 180 d of life). Between breeds IMF ranged from 0.82% in PLW to 2.29% in Puławska breed. The shear force for loin muscle ranged from 3.42 kG/cm2 at 60 d to 6.54 kG/cm2 at 210 d of life while for and ham muscle 4.4 kG/cm2 at 60 d to 6.78 kG/cm2 at 210 d of life. The hardness (TPA) ranged from 72.29 N at 90 d of life to 109.46 N at 210 d of life. The shear force of loin and ham meat was increasing with age of fatteners and some texture parameters – hardness and chewiness. Nevertheless it seems that the age of 150 days is the time when meat of fatteners is characterized by the highest technological properties. However, the final decision regarding slaughter age should be made taking into account the technological destination of the carcasses. No significant interactions between the animal breed and their age were found for the parameters analysed.
Tenderness is usually associated with the proteolysis occurring in muscles. However, most of the studies concentrate on one muscle only. The aim of this study was to describe the changes in myofibrillar protein percentage proportions during the ageing of 8 bovine muscles. Investigations were conducted on the muscles from different parts of the carcass, from the forequarter: m. pectoralis profundus, m. infraspinatus, m. triceps brachii, m. serratus ventralis, and from the hindquarter: m. biceps femoris, m. semimembranosus, m. semitendinosus and m. longissimus dorsi (thoracis et lumborum). The effect of muscle type was significant for all parameters except for percentage proportions of titin (3000÷3700 kDa), MHC (205 kDa) and protein fractions between <205÷42> kDa. Differences between the muscles varied depending on the analysed proteins and the time of storage. A significant effect of ageing time for titin, nebulin (approx. 800 kDa), proteins of molecular weight of 38 kDa, proteins smaller than 42 kDa and in the range of 3000÷205 kDa, 205÷42 kDa and 38÷20 kDa was observed. The decrease of percentage proportions of titin, nebulin and proteins in the range of 3000÷205 kDa and an increase of protein bands in the range of 38÷20 kDa and proteins below 42 kDa was also observed. During the storage period of beef from the 2nd to the 14th day, the progress of myofibrillar proteolysis was different in each muscle. The changes of tenderness were not related to shear force values. It is probable that the changes in other constituents of meat might influence the tenderness more than those in myofibrillar proteins.
The aim of this study was to perform a comprehensive analysis of the level of fatty acids and selected meat quality traits, as well as their association with fattening and slaughter performance in Polish Landrace pigs. The study was conducted for two muscles: musculus longissimus dorsi and musculus semimembranosus. The study used 100 Polish Landrace gilts. The experimental animals originated from nucleus farms located in Poland. Their parents were animals with a known status of the RYR 1 genotype (all animals were dominant homozygotes). Pigs were fattened, slaughtered and evaluated postmortem in piggeries of the Experimental Stations of the National Research Institute of Animal Production using test station procedures. After reaching 100 kg body weight, pigs were slaughtered and their half-carcasses dissected. Fattening and slaughter parameters were determined. Meat samples were analysed for crude fat using the Soxhlet method. The composition of higher fatty acids was determined by gas chromatography. Research results indicate that saturated fatty acids found in m. longissimus dorsi and m. semimembranosus were positively correlated to n-3 and n-6 PUFA . A similarly high correlation was observed between the level of UFA and n-6 and n-3 PUFA in the loin and ham. The fact that the proportions of some acids (e.g. n-6/n-3 PUFA ) fail to meet WHO standards requires making efforts to improve them. Likewise, selection work is necessary to improve IMF levels in meat. The low correlations between meat quality traits and fattening and slaughter performance suggest that quality parameters should be regarded as independent traits in pig improvement models. In order to limit meat quality traits in pig improvement models, it is necessary to make use of the correlations between them