Profile of fatty acids, muscle structure and shear force of musculus longissimus dorsi (MLD) in growing pigs as affected by energy and protein or protein restriction followed by realimentation

Effects of Different Dietary Energy Levels on Development, Quality of Carcass and Meat, and Fatty Acid Profile in Male Lambs

This experiment was conducted to study the effects of dietary energy level on the growth performance and meat quality of weaned Alpine Merino lambs. The study ran for a total of 104 days (20-day pretrial, 84-day trial). From three groups of test lambs, we randomly selected ten lambs per group to determine slaughter performance, meat quality characteristics, and organ indexes. The slaughter performances of the lambs improved as the dietary energy level increased. The live weight before the slaughter of the lambs was significantly higher in the high group than in the low and medium groups. The carcass weight was significantly higher in the high group than in the low group. Dietary energy level had little effect on the organ weight of lambs. Meat quality differed among the three dietary energy levels. The muscle yellowness and redness scores decreased significantly as the energy levels increased. The C18:0, C21:0, C20:1, C18:2n6c, and C20:2 contents in the muscle were significantly higher in the high group than in the medium and low groups. The C18:3n6 content in the muscle was significantly higher in the low group than in the medium group. The C20:5n3 content in the longissimus dorsi was significantly higher in the high group than in the medium and low groups. The monounsaturated and unsaturated fatty acid contents in the muscle were significantly higher in the high group than in the low group. A dietary energy level of 10.5 MJ/kg is suitable for fattening weaned male Alpine Merino lambs.

Effects of low-protein diet and feed restriction on mRNA expression of cationic amino acid transporters in porcine skeletal muscles

We investigated the effects of a low-protein diet and feed restriction on the mRNA expression of cationic amino acid transporters (CATs) in the longissimus dorsi (LD), rhomboideus (RH), and biceps femoris (BF) muscles of pigs. Eighteen piglets were divided into three groups: a control (CP21%), low-protein diet (LP, CP16%), and feed-restricted diet (FR, CP21%, 76% feed intake of control pigs) groups. The expression levels of CAT-1 in the LD and BF muscles of LP pigs were higher than that of control pigs, whereas that of FR pigs showed no difference. The CAT-2A expression levels in the RH muscle of FR pigs were higher than that of control pigs. The free lysine concentrations in all muscles of LP and FR pigs were lower than that of control pigs. To examine the factors that affect CATs mRNA expression, we evaluated the effects of lysine, arginine, insulin-like growth factor-I, and dexamethasone on the expression of CATs in C2C12 myotubes. CAT-1 expression levels increased in lysine and/or arginine deprivation. We show that CAT-1 and CAT-2A expression levels in skeletal muscles differ in response to dietary treatments and CAT-1 expression in skeletal muscles appears to increase in response to low free lysine concentrations.

Comparison of the meat quality and fatty acid profile of muscles in finishing Xiangcun Black pigs fed varied dietary energy levels

To study the effects of dietary energy level on the meat quality of different muscles in finishing pigs, 400 Xiangcun Black pigs (BW = 79.55 ± 4.77 kg) were randomly assigned to 5 treatments with varied calculated digestive energy (DE) at 3,050, 3,100, 3,150, 3,200 and 3,250 kcal/kg, respectively. Each treatment had 8 replicates with 10 pigs per replicate. Meat quality, amino acid and fatty acid composition were tested in this study. No differences in average daily gain, average daily feed intake or feed-to-gain ratio (P > 0.05) were observed among dietary treatments. Glycogen concentrations of longissimus dorsi (LD) muscle in DE3150 was higher than those in other groups (P < 0.05). The crude fat concentration of biceps femoris (BF) muscle in DE3250 tended to be higher than that in DE3150 and DE3100 groups (P < 0.05). Pigs in DE3250 and DE3200 had higher fiber density and smaller cross-sectional area of BF muscle than those in DE3150 (P < 0.05). Pigs in DE3150 had the highest Cu concentration in LD muscle compared with those in DE3200, DE3250 (P < 0.05). The C16:1 proportion of LD muscle was lower (P < 0.01) and C20:1 was higher (P < 0.05) in DE3050 than that in the other dietary treatments. The C18:3n6 and C20:3n6 proportions of BF muscle in DE3150 were higher than those in DE 3050, DE3200 and DE3250 (P < 0.05). For LD muscle, mRNA expressions of type I and IIa MyHC in group DE3150 were higher than other treatments (P < 0.01). The LD muscle in DE3150 expressed higher PPARd than in other groups (P < 0.01). Pigs in DE3100 expressed higher FOX1 than in DE3200 and DE3250 (P < 0.05). Sterol-regulatory element binding proteins (SREBPa) mRNA expression decreased linearly when dietary energy level increased in BF muscle (P < 0.01). In conclusion, a 200 kcal/kg decrease in digestible energy for 4 consecutive weeks did not affect growth performance of Xiangcun Black pigs. Furthermore, LD and BF muscle respond differently to dietary energy level, and meat quality was improved by the medium energy level during the finishing phase.

Pork Quality of Two Lithuanian Breeds: Effects of Breed, Gender and Feeding Regimen

Simple Summary

A few highly selected commercial pig breeds have been developed and many different local breeds have been replaced by these modern breeds. With the aim to preserve rare local breeds, the necessity has arisen to find and create the conditions under which local breeds could be more widely used. Therefore, the performance and production qualities of local breeds should be evaluated and highlighted. As the quality of pig production is associated with breeds and effects of other different conditions, the objective of this experiment was to investigate the effects of breed, gender, and feeding level in the finishing phase on the carcass and meat quality of Lithuanian White and Lithuanian Indigenous Wattle pigs reared indoors. Feed restriction during the finishing phase and gender both affected the growth and fatness of pigs. The breed and gender appeared to have an effect on the parameters of meat quality including fatty acid composition. The breed and gender effects on fatty acid composition showed more favorable lipid indices in relation to healthy nutrition in the ham muscles of Lithuanian White pigs compared with Lithuanian Indigenous Wattle pigs and also in the ham muscle and backfat of females compared with castrated males.

Abstract

The diversity of breeds is an important factor influencing carcass and meat quality traits that are also associated with other different effects. The objective of this study was to investigate the effects of breed, gender, and feeding level in the finishing phase on the carcass and meat quality of Lithuanian White and Lithuanian Indigenous Wattle pigs reared indoors. After 60 kg weight, half of the animals from both breeds were fed a restricted diet of approximately 82% of average ad libitum feeding intake, and the other half of pigs were further fed ad libitum to the end of the experiment. Feed restriction during the finishing phase decreased daily gain and weight of pigs at slaughter, and backfat thickness at the tenth rib (p ˂ 0.001, p ˂ 0.01, and p ˂ 0.05, respectively). Lithuanian White pigs demonstrated higher (p ˂ 0.001) growth rate, live body weight at slaughter and carcass weight, and had a higher (p ˂ 0.01) length of carcass and loin area and lower (p ˂ 0.05) backfat thickness at the last rib and at two points at the lumbar area compared with Lithuanian Indigenous Wattle pigs. The semimembranosus muscle of Lithuanian White pigs had relatively (8.1%) lower (p ˂ 0.001) proportions of saturated and 41.2% higher (p ˂ 0.001) proportions of polyunsaturated fatty acids compared with the pigs of the Lithuanian Indigenous Wattle breed, whereas in the longissimus muscle and subcutaneous tissue, the breed only affected the n-6/n-3 ratio (p ˂ 0.01 and p ˂ 0.001, respectively). Gender showed an effect on saturated fatty acids in all the studied tissues, however, the effects on polyunsaturated fatty acids were found in the semimembranosus muscle and subcutaneous tissue (p ˂ 0.05 and p ˂ 0.001) and the effects on monounsaturated fatty acids was found only in the semimembranosus muscle (p ˂ 0.01). These differences in the fatty acid composition of the semimembranosus muscle and subcutaneous tissue of females exhibited more favorable lipid quality indices compared with castrated males (p ˂ 0.001). The semimembranosus muscle of Lithuanian White pigs also showed more favorable lipid quality indices in relation to healthy nutrition compared with Lithuanian Indigenous Wattle pigs (p ˂ 0.001). This study is one of the steps toward the development and utilization of endangered breeds. The obtained information can be used to increase choice in pork production and consumption, and provides new insights for research into the conservation of local breeds.

Effects of Effective Microorganisms on Meat Quality, Microstructure of the Longissimus Lumborum Muscle, and Electrophoretic Protein Separation in Pigs Fed on Different Diets

Simple Summary

Pork is the most popular meat among consumers in Poland, but it can also be a source of pathogens. Therefore, there is a need to find effective prophylaxis in order to ensure that consumers have access to safe food with the desired nutritional qualities and, above all, food that is free of pathogens. In order to meet these expectations, producers use probiotics containing effective microorganisms (EMs) offered in the market. In this study the same probiotic, EM Bokashi, was used for the first time in combination with three nutritional variants with proteins of different origin.

Abstract

The aim of the study was to determine how effective microorganisms influence meat quality, the microstructure of the longissimus lumborum muscle, and electrophoretic protein separation. The study group consisted of 150 piglets divided into three feeding groups: C, E1, and E2. The feeding groups included C—a standard fodder blend with a full share of post-extracted soya meal; E1—a 50%/50% mix of pea and lupine/soya bean in phase I of fattening and a 75%/25% mix of pea and lupine/soya bean in phase II of fattening; and E2—a 50%/50% mix of pea and lupine/soya bean in phase I of fattening and in 100% pea and lupine in phase II of fattening. The experimental factor was the addition of the EM Carbon Bokashi probiotic to the diet (C + EM, E1 + EM, E2 + EM). Influence of the feeding system on the following parameters was also estimated. After slaughter, the meat quality, LL muscle microstructure, and electrophoretic protein separation were assessed. In the C + EM group, a lower water-holding capacity was demonstrated. Meat from pigs fed the effective microorganism additive was much harder in the E1+EM group compared to meat from pigs from the E1 group. A beneficial effect of effective microorganism was found in the E2 + EM group, where less thermal leakage from the meat was demonstrated. A beneficial effect of the feeding system on thermal leakage and loin eye area in the E2 + EM group was demonstrated. In the C + EM group, a lower total number of muscle fibers was demonstrated. The addition of effective microorganism caused an increase in the diameter of fast twitch fibers in the E1 + EM group. In the same group of pigs, effective microorganisms caused a lower proportion of fiber fission. This nutritional variant appears to be the most appropriate for proteins as well, because it led to the most favorable percentage of individual proteins after effective microorganisms supplementation in the longissimus lumborum muscle.

Effects of Protein Restriction on Performances and Meat Quality of Cinta Senese Pig Reared in an Organic System

Simple Summary

Fat contained in meat is an important contributor to sensory traits: it increases meat tenderness and flavor. In commercial pigs, increasing meat’s fat was obtained by feeding, until the fattening period, a diet slightly lower in protein respect to their requirements. Local pig breeds, such as Cinta Senese, are known as obese pigs because their great potential to deposit fat, which is mainly stored in backfat deposits. This study was aimed to assess if protein restriction in growing can further increase meat’s fat without alter overall body fatness of obese pigs. The normal feeding management and the restricted one were compared in two groups of Cinta Senese pigs. Results showed that protein restriction during the growing phase affected only few traits. The restricted animal was more able to use the protein in feeding, but few modifications were found in the chemical composition of meat, including the meat’s fat, that remained unchanged. So, obese genotype might be less responsive to this kind of feeding management.

Abstract

In lean genotypes, protein restriction during growing increases intramuscular fat content without affecting the overall carcass fatness. The present study aims to assess the feasibility of applying this feeding management on an obese pig, the Cinta Senese, since obese genotypes are characterized by great lipogenic potential often leading to excessively high backfat deposits. Twenty pigs of average weight 38 kg, were divided in two groups, the first group was fed a protein restricted diet (9% of crude protein), while the second one a normal diet (13.5% of crude protein). During finishing, both groups were fed the same diet (10% of crude protein). Average daily gain, protein conversion index, backfat thickness, carcass weight, and prime cuts were determined. A loin sample joint was dissected in intermuscular fat, bone, subcutaneous fat, longissimus lumborum, and psoas major. On longissimus lumborum, physical and chemical analysis was carried out. The fatty acid profile of longissimus lumborum and loin subcutaneous fat were determined. Data were analyzed by analysis of variance. Protein conversion index resulted lower in the restricted group, while backfat was slightly greater. Meat quality traits were not affected by feeding management. Slightly modifications in subcutaneous outer layer fatty acids profile were observed. The protein restriction during growing did not seem a suitable mode of feeding management for Cinta Senese pigs.

The effect of periodic energy restriction on growth performance, serum biochemical indices, and meat quality in sheep

Energy is a key factor regulated by the neuroendocrine system. The objective of this study was to compare growth performance, serum biochemical indices, carcass traits, meat quality, and nutrient composition of lambs fed restricted metabolizable energy (ME) intakes to mimic the seasonal changes of the natural grasslands of northwest China. Nineteen male Dorper × Small Tailed Han lambs were assigned to treatments, control (CON) fed at 1.0 MJ/W0.75 × d-1 throughout the 180 d study, and restricted ME (RES) fed by sequentially restricting ME every 30 d (0.56, 0.84, 1.0, 0.84, 0.56, and 0.28 MJ/W0.75 × d-1). Lambs were harvested at the end of the study. Lambs fed the CON diet demonstrated higher (P < 0.05) average daily gain (ADG) compared with RES-fed lambs (158.79 and 57.01 g/d, for CON and RES, respectively), although ADG were lower in each period with the last period being a negative ADG for RES-fed lambs resulting in a loss of body weight. Both treatments demonstrated lower ADG in the last 3 study periods compared with the first 2 periods, which may be explained by cold stress (<-3 °C) increasing the lamb's energy requirement. Feeding lambs a restricted ME diet resulted in lower (P < 0.05) blood serum glucose, triglycerides, total protein, calcium, phosphorus, immunoglobulin G, immunoglobulin M, and immunoglobulin A concentrations compared with CON-fed lambs, but both treatments were similar (P > 0.05) for cholesterol and high-density lipoprotein-cholesterol. Feeding lambs a restricted ME diet increased (P < 0.05) meat pH, while reducing the cooked meat rate compared with CON-fed lambs. Thus, the carcass yield, rib eye muscle area, and shear force were lower (P < 0.05) for RES-fed lambs compared with CON-fed lambs. The meat water concentration was higher (P < 0.05), whereas the concentrations of dry matter, crude fat, crude protein, and carbohydrate were lower (P < 0.05) for lambs fed a RES ME diet compared to CON-fed lambs. These results demonstrate that sequentially restricting ME intake, as natural grasslands might experience during seasonal forage quality and quantity changes, resulted in a reduction of body weight because lambs were mobilizing body reserves as a source of ME. The reduction in concentrations of key serum nutrients, as well as carcass traits and meat composition, demonstrate the body is responding to the meet the lambs ME requirements, which has implications for both meat quality and the animal's physiological functions.

The influence of housing and feeding systems on selected fattening and slaughter parameters of finishing pigs with different genotypes

The aim of the present study was to demonstrate the influence of housing and feeding systems on selected fattening and slaughter parameters of finishers with different genotypes. The experimental population consisted of 1200 finishers in three genetic variants from the Landrace (L), Large White (LW), Duroc (D) and Pietrain (P) breeds: 400 finishers L × [D × P] genotype, 400 finishers LW × [D × P] genotype and 400 finishers [L × LW] × [D × P] genotype. Subgroups were isolated for each genetic variant with the experimental factors: housing system (slatted floor or deep litter) and feeding system (dry or liquid). Selected fattening parameters were analysed: final liveweight (kg), mortality (%), average daily gain (g/day) and feed conversion ratio (kg/kg gain). Additionally, slaughter parameters were analysed: carcass weight (kg), height of longissimus dorsi (LD) muscle (mm), backfat thickness (mm) and lean meat content (%). The housing system strongly affected the final liveweight, average daily gain and carcass weight. To a lesser degree, this factor determined the mortality, feed conversion ratio, height of LD muscle, backfat thickness and lean meat content. The feeding system substantially affected almost all fattening parameters, except for the mortality. Statistical analysis of slaughter parameters showed that the impact of the feeding system was confirmed statistically only in terms of carcass weight. Genotype largely determined the final liveweight, average daily gain, carcass weight and lean meat content. Taking into account interactions of all factors, the most favourable effect in terms of production was to fattening four-way crossbreeds [L × LW] × [D × P] on slatted floors and fed by liquid feeding.

Effect of slaughter weight and sex on slaughter traits and meat quality of Polish autochthonous ZLotnicka Spotted pigs crossbred with Duroc

The aim of this study was to investigate the impact of slaughter weight and sex on slaughter traits and meat quality of Zlotnicka Spotted x Duroc (ZS×D) hybrid fatteners. The material comprised 56 Zlotnicka Spotted × Duroc fatteners (28 barrows and 28 gilts) which were fattened to 245th day of life. Pigs were divided into the following three groups: Group I (n=16) <110 kg; Group II (n=23) ≥110 ≤120 kg, and Group III (n=17) >120 kg. The obtained results revealed influence of the final body weight on slaughter trait values with the exception of meatiness. Fatteners from the group with the highest weight were characterised by the thickest backfat as well as by the greatest height of the loin eye. Slaughter weight exerted a significant impact on protein content, water absorbability as well as on the pH of the longissimus thoracis et lumborum (LTL) muscle. As to the influence of sex on slaughter traits, it was found that gilts were characterised by smaller backfat thickness and higher carcass meatiness than barrows. On the other hand, no effect of the slaughter weight and sex on colour parameters and sensory quality of the LTL muscle was ascertained. All the examined parameters were at high level in all slaughter weight and sex groups. The obtained results suggest that the slaughter of ZS×D crossbreds in groups I and II exerts a beneficial influence on slaughter trait levels and, at the same time, allows maintenance of high meat quality.

The effect of sex, carcass mass, back fat thickness and lean meat content on pork ham and loin characteristics

Abstract. This study was designed to determine the ratio of ham and loin in half-carcasses and the tissue composition of these cuts. The research material consisted of 140 pig carcasses. The experimental materials were derived from the Polish commercial population of fattener pigs. Genetic material representing the most commonly slaughtered fatteners in Poland. Fatteners for the study came from several suppliers. All fatteners were kept in similar farms complying with principles of animal welfare. The right half-carcasses were divided into different groups, regardless of sex, half-carcass mass, back fat thickness and lean meat content class. Ham and loin obtained from carcasses were subjected to a detailed dissection, and the percentage of ham and loin in the carcass and the overall percentage of of the cuts in relation to the entire half-carcass were calculated. Gilts were characterized by a higher content of ham in half-carcasses than barrows (P  ≤ 0.01). The increase in back fat thickness reduced the content of ham in half-carcasses and increased the content of loin (P ≤ 0.01). A similar trend was shown for the lean meat content class parameter. Additionally, interaction (P  ≤ 0.01) between back fat thickness and meat content with respect to the percentage content of loin in carcasses was noted. Gilts were characterised by about a 1.38 % higher proportion of muscles in the ham (P  ≤ 0.05) and a 0.47 % lower proportion of intermuscular fat (P  ≤ 0.01). An average increase of five point in back fat thickness increases the amount of subcutaneous fat with skin (P  ≤ 0.01) and intermuscular fat (P  ≤ 0.01) and reduces muscle (P  ≤ 0.01) and bone (P  ≤ 0.05 and P  ≤ 0.01) levels. The interaction of percentage content of muscles in ham was observed (P = 0.04). The meat content class of carcasses did not only affect the level of bones in ham. It was confirmed that sex affected all the analysed dissection elements of the loin. Back fat thickness and meat content classes were present in almost identical amounts in loin tissues (P  ≤ 0.05 and P  ≤ 0.01). Half-carcass mass showed a strong negative correlation with bone content in ham and loin (r = −0.35 and r = −0.21, respectively). Back fat thickness and meat content strongly and inversely correlated with the content of ham and loin in half-carcasses (r = −0.41 and r = 0.59 for back fat thickness; r = 0.66 and r = −0.57 for lean meat content). Close and inverse correlations of back fat thickness and lean meat content were observed with regard to their content in ham and loin (P  ≤ 0.01).

Factors affecting the tissues composition of pork belly

Bellies derived from the commercial population of pig carcasses are diverse in terms of tissue composition. Knowledge of the factors influencing it and the expected results, permits quick and easy evaluation of raw material. The study was designed to determine the factors affecting the tissues composition of pork bellies and to estimate their lean meat content. The research population (n=140 pig carcasses) was divided into groups according to sex (gilts, barrows), half-carcass mass (<40, 40 to 43.9, 44 to 46.9, ⩾47 kg) and lean meat content class: S (⩾60%), E (55% to 60%), U (50% to 55%), R (<50%). Bellies were subjected to a detailed dissection. Half-carcass mass affected the levels of all the analysed parameters. The only exception was the mass of the fat with the skin in the 40 to 43.9 kg group, for which the value did not differ statistically between the two groups <40 and 44 to 46.9 kg. Decrease in lean meat content affected the growth of the fat and skin mass in a linear way. No differences were observed between class S and E in terms of belly muscle mass. A 0.37% higher share of belly in the half-carcass was found for barrows (P<0.001), although bellies issued from barrows were characterized by a higher proportion of fat with skin compared with gilts (P=0.02). Interactions were observed between sex and half-carcass mass, so the sex of heavy half-carcasses becomes an important determinant for conditioning the muscle content. Equations were calculated and allow a fast and highly accurate determination of the lean meat content in bellies, suggesting they may be used directly in the production line.

A new simple method for estimating the pork carcass mass of primal cuts and lean meat content of the carcass

The aim of this study was to develop regression equations for estimating lean meat content and the mass of primal cuts (ham, loin, shoulder, belly) based on selected linear measurements. The experiment involved a classification of 141 pigs from the Polish commercial pig population, with hot carcass weight ranging between 60 and 120 kg. The study population was characterised by high variability in terms of analysed measurements. Eight measurements were made including: mass of half-carcass, backfat thickness at different points (over shoulder, over last rib, over the middle of M. gluteus medius), width and thickness of the M. longissimus dorsi measured over the last rib, thickness of the lumbar and the gluteal muscle layer located between the spinal cord and beginning of the M. gluteus medius and waist width – the width of the carcass measured at the narrowest point of the lumbar. A subjective five-point scale was used to score difficulties in obtaining linear measurements (workload rate). The lean meat percentage and mass of cuts were determined by dissection. The study enabled equations to be devised for estimating lean meat content with an accuracy greater than most devices used for carcass classification (estimation error 1.67). Regression coefficients for the mass of primal cuts were: 0.92 for ham, 0.87 for loin, 0.87 for shoulder, and 0.74 for belly. The error of equations used to estimate the mass of primal cuts were: 391 g for ham, 447 g for loin, 263 g for shoulder and 257 g for belly. The workload rate for all the developed regression equations ranged from 1.3 to 1.6 points. The outcome of this study was the development of equations to predict carcass value without the need to use expensive classification equipment.