Shear Force Values Research Articles

Evaluation of Guanidinoacetic Acid Supplementation on Finishing Beef Steer Growth Performance, Skeletal Muscle Cellular Response, and Carcass Characteristics.

This study elucidated the effects of dosage-dependent guanidinoacetic acid (GAA) supplementation on growth performance, muscle responses, and carcass characteristics in finishing beef steers. Thirty crossbred Red Angus beef steers (395 ± 28.09kg) were randomly assigned one of three treatments during a 146-day feedlot study: basal diet without GAA supplementation (CONTROL), 1g of GAA per 100kg of BW daily (LOWGAA), and 2g of GAA per 100kg of BW daily (HIGHGAA). Individual feed intake was monitored daily, growth performance parameters were collected every 28 days, and longissimus muscle (LM) biopsies occurred every 56 days. In biopsied LM, greater (P = 0.048) mRNA expression of IGF-1 was observed in LOWGAA steers on d 112 compared to the CONTROL group. LOWGAA steers also exhibited greater expression of myosin heavy chain (MHC) I compared to CONTROL steers (P < 0.05) and MHC IIA compared to both CONTROL and HIGHGAA treatment groups (P < 0.01) on d 112. GAA supplementation resulted in no change in carcass characteristics, serum and LM tissue metabolites, LM composition, and Warner-Bratzler shear force (WBSF) values (P > 0.05). Data collected from this study demonstrate the influence of GAA supplementation on the gene expression of MHC isoforms and their role in skeletal muscle growth, differentiation, and muscle fiber-typing.

Mimicking Mechanics: A Comparison of Meat and Meat Analogs

The texture of meat is one of the most important features to mimic when developing meat analogs. Both protein source and processing method impact the texture of the final product. We can distinguish three types of mechanical tests to quantify the textural differences between meat and meat analogs: puncture type, rheological torsion tests, and classical mechanical tests of tension, compression, and bending. Here, we compile the shear force and stiffness values of whole and comminuted meats and meat analogs from the two most popular tests for meat, the Warner–Bratzler shear test and the double-compression texture profile analysis. Our results suggest that, with the right fine-tuning, today’s meat analogs are well capable of mimicking the mechanics of real meat. While Warner–Bratzler shear tests and texture profile analysis provide valuable information about the tenderness and sensory perception of meat, both tests suffer from a lack of standardization, which limits cross-study comparisons. Here, we provide guidelines to standardize meat testing and report meat stiffness as the single most informative mechanical parameter. Collecting big standardized data and sharing them with the community at large could empower researchers to harness the power of generative artificial intelligence to inform the systematic development of meat analogs with desired mechanical properties and functions, taste, and sensory perception.

Dietary Tributyrin Improves Growth Performance, Meat Quality, Muscle Oxidative Status, and Gut Microbiota in Taihe Silky Fowls under Cyclic Heat Stress.

Heat stress adversely affects poultry production and meat quality, leading to economic losses. This study aimed to investigate the effects of adding tributyrin on growth performance, meat quality, muscle oxidative status, and gut microbiota of Taihe silky fowls under cyclic heat stress (CHS) conditions. In this study, 120-day-old Taihe silky fowls (male) were randomly divided into six dietary treatments. These treatments included a normal control treatment (NC, fed a basal diet), a heat stress control treatment (HS, fed a basal diet), and HS control treatments supplemented with 0.04%, 0.08%, 0.16%, and 0.32% tributyrin, respectively. The NC treatment group was kept at 24 ± 1 °C, while the HS treatment birds were exposed to 34 ± 1 °C for 8 h/d for 4 weeks. Results showed that CHS decreased growth performance and compromised the meat quality of broilers (p < 0.05). However, tributyrin supplementation improved ADG and FCR in broilers exposed to CHS (p < 0.05). Additionally, tributyrin supplementation resulted in increased shear force value and GSH-Px activity, as well as a decrease in drip loss, ether extract content, and MDA content of the breast muscle in broilers under CHS (p < 0.05). Furthermore, tributyrin supplementation up-regulated the mRNA expressions of Nrf2, NQO1, HO-1, SOD, and GSH-Px of the breast muscle in broilers exposed to CHS (p < 0.05). Based on these positive effects, the study delved deeper to investigate the impact of 0.16% tributyrin supplementation (HS + 0.16%T) on the cecum microbiota. The HS + 0.16%T treatment showed an increase in the relative abundance of Rikenellaceae_RC9_gut_group (p < 0.05) and a trend towards an increase in Lactobacillus (p = 0.096) compared to the HS treatment. The results indicate that supplementation successfully improved the growth performance and meat quality of Taihe silky fowls. Furthermore, tributyrin supplementation, particularly at levels of 0.16%, improved meat quality by enhancing muscle antioxidant capacity, which is believed to be associated with activation of the Nrf2 signaling pathway.

The correlation between Smac, IAPs and mitochondrial apoptosis, muscle tenderness during postmortem aging of Oula Tibetan sheep meat

Oula Tibetan sheep meat has rich nutritional value but relatively poor tenderness. Recently, apoptosis of muscle cells has gradually become a research hotspot for improving meat tenderness during postmortem aging. Smac can promote the decrease of IAPs expression in tumor cells, thereby inducing mitochondrial apoptosis. However, the relationship between Smac, IAPs and mitochondrial apoptosis, muscle tenderness during postmortem meat aging is still unclear. Thus, the aim of this work was to explore the relationship between Smac, IAPs and mitochondrial apoptosis as well as muscle tenderness during postmortem meat aging. Smac concentration, IAPs concentration, pH value, ATP content, SDH activity, MPTP opening degree, MMP, caspase-3/9 activity, apoptotic rate, MFI and shear force value of Oula Tibetan sheep meat were measured at different aging times and correlation analysis was performed. Correlation analysis revealed that Smac, IAPs were markedly related to mitochondrial apoptosis and muscle tenderness during postmortem aging of Tibetan sheep meat. The results suggest that Smac may regulate IAPs to promote mitochondrial apoptosis and muscle tenderization in Oula Tibetan sheep meat during postmortem aging.

Quality Variation of Pork Bellies by Cutting Manner and Quality Grade

In the meat industry, the quality grading system is commonly applied to classify carcasses based on quality and value. Presently, to facilitate consumer convenience, pork bellies are prepared into slices and retailed in supermarkets and butchers. The objective of this study was to assess the effect of quality grade (QG) and retail cutting manner on the quality properties of pork bellies. Thirty-two bellies with different QGs: QG1+, 1, 2, and off-grade (n = 8 each) randomly collected from a commercial slaughterhouse were used. Each belly was cut into 3 portions: A (5–10th rib, cranial edge), B (11–15th rib), and C (without rib, caudal edge) according to the commonly used retail cutting manner. Samples were subjected to chemical composition, quality traits, and aroma analysis. Fat content was highest in QG1+ and lowest in off-grade and distributed at a higher level in portions A and B than in portion C in all QGs (p &lt; 0.05). Off-grade was associated with higher shear force and chewiness values and lower levels of palmitic and stearic acids, regardless of the cutting portion. The bellies used in this study exhibited variations in chemical composition and quality properties not only among the QGs but also across the cutting portions within each QG.

Meat tenderness in Australian lamb: Data editing, environmental variation and their effects in genetic parameter estimation

Breeding for meat quality increases the value of lambs and requires reliable genetic parameters to achieve balanced genetic progress. Meat tenderness, accomplished by selecting for lower shear force, is an important eating quality trait because of its relationship with consumer satisfaction. Factors influencing shear force, include the pH and temperature decline post-mortem which can contribute towards higher shear force values and increased variation across contemporary groups. This study explored if genetic parameters for shear force change when post slaughter covariates and heterogeneous variance are corrected for, using data from 32,223 animals from different sheep breeds. Results showed that removing extreme individuals and contemporary groups with high mean shear force values reduced residual variance, followed by a smaller reduction in additive genetic variance and little effect on heritability. Results show that edited data performed better at predicting progeny performance and reduced potential bias introduced in the genetic evaluation due to data quality. The effect of including post-slaughter covariates in the genetic analysis was tested by estimating different model predictability through regression of estimated breeding values against offspring performance, showing that the model including hot carcass weight performed better followed by the one including both carcass weight and C-site fat depth. Our results highlight that historic and current in-plant recording practices do not provide the capacity to account for non-genetic factors associated with abattoir environment that might be impacting the ability to accurately calculate shear force breeding values. In that sense, genetic evaluation can be improved by applying more rigorous data editing.

Dietary metabolizable energy and crude protein levels affect Taihe silky fowl growth performance, meat quality, and cecal microbiota during fattening

The effects of dietary metabolizable energy (ME) and crude protein (CP) on the growth performance, meat quality, and cecal microbiota of Taihe Silky Fowl (TSF) during fattening were investigated. In total, 900 twelve-week-old female fowl were randomly allocated to 9 treatments (5 replicates per group, 20 fowl per replicate), and were fed a 3 × 3 factorial arrangement of treatments diets (ME: 11.30, 11.93, or 12.56 MJ/kg; CP: 15%, 16%, or 17%). As ME increased, the average daily feed intake (ADFI, P<0.001), feed conversion ratio (FCR, P<0.001), pectoral and thigh shear forces (P<0.05), pectoral and thigh muscle fiber diameter (P<0.001) decreased significantly, while muscle fiber density increased (P<0.001). Pectoral muscle fiber diameter was lower and muscle fiber density higher at 16% CP than 15% or 17%. As ME increased, pectoral crude fat content increased significantly (P = 0.007). Pectoral crude protein, total amino acid (TAA), and essential amino acid (EAA) content were higher at 15% dietary CP than 16% or 17%. As ME increased, pectoral inosine monophosphate (IMP, P = 0.006), uridylic monophosphate (UMP, P = 0.003), guanylic monophosphate (GMP, P = 0.009), and adenosine monophosphate (AMP, P <0.001) decreased significantly, while hypoxanthine riboside (HxR, P = 0.045) increased. As dietary CP increased, IMP (P = 0.019), AMP (P <0.001), and HxR (P = 0.024) increased significantly. Cecal microbiota composition varied with dietary ME: 12.56 MJ/kg ME increased the abundance of Bifidobacteriaceae, and 15% CP increased that of Paraprevotella. These findings suggest that 12.56 MJ/kg dietary ME and 15% CP can enhance growth performance, improve meat quality by reducing shear force, enhancing flavor and nutritional value, and benefit for intestinal microbiota in fattening TSF.

PSVII-20 Effect of starch content in the concentrate of finishing bison on meat nutritional composition, quality, and palatability

Abstract According to the Saskatchewan Bison Association, in the last few years producers have not been able to fill the increasing demand for bison meat. Indeed, one of the main challenges faced by the bison industry is their ability to produce a consistent product in a relatively short period of time. Hence, it is necessary to optimize the productivity and profitability of feeding bison calves while ensuring the quality of the end product. This study aimed to evaluate the effects of different starch contents in the concentrate of finishing bison on meat nutritional composition, quality, and palatability. Yearling bison bulls [n = 48; commercial Wood × Plains, 435 ± 13.4 kg body weight (BW)] were homogenously distributed into 12 pens (4 bulls/pen) based on BW, and each pen randomly assigned (n = 6) to receive either a high- [51.4% dry matter basis (DM); n = 24 bison bulls) or moderate-starch (25.8% DM; n = 24 bison bulls) concentrate, alongside free access to water and grass hay bales. After 156 d of feeding, bison bulls were slaughtered in a commercial abattoir in AB, Canada. At 3 d postmortem, color values were measured at the ribeye between the 11 and 12th ribs. Subsequently, striploins from the left carcass sides were collected, weighed, vacuum packaged, and transported under refrigeration conditions to the AAFC-Lacombe Research and Development Centre, AB, Canada. On d 6 of ageing, striploins were unpacked and weighed to measure purge losses, and pH was collected. Subsequently, six 2.5-cm thick steaks were obtained for further nutritional analyses (minerals, cholesterol, vitamin B3, protein, fat, moisture, and fatty acids), shear force, color in retail display for 4 d, and descriptive sensory and flavor profile analyses performed by trained panelists. The dietary starch content did not affect the nutritional composition as well as the pH, 3-d color values, moisture losses, and shear force value of the bison meat (P &amp;gt; 0.1). However, the high-starch concentrate increased the meat luminosity (L*) after 4 d in retail display (P &amp;lt; 0.05) and initial and overall tenderness (P &amp;lt; 0.001), and decreased the amount of perceived connective tissue (P &amp;lt; 0.001). Additionally, spongy and rubbery textures were less frequently found by trained panelists in meat from bison fed a high-starch than a moderate-starch concentrate (P &amp;lt; 0.01 and 0.05, respectively). Regarding meat flavor, the high-starch concentrate decreased salty taste (P &amp;lt; 0.05) and burnt and livery aromas (P = 0.071 and 0.069, respectively) but increased metallic flavor (P &amp;lt; 0.01) and bitter taste (P = 0.076). In conclusion, the starch content in the concentrate of finishing bison did not affect the meat nutritional value. However, some positive effects on meat color and palatability were found when feeding bison a high-starch concentrate.

76 Camera vision grading and objective tenderness outcomes of steers fed lubabegron fumarate for the final 56 d of the feeding period

Abstract Limited research has compared no beta-agonist, ractopamine and lubabegron in feedlot cattle. We evaluated carcass quality and yield variables using a camera grading instrument and also examined objective tenderness outcomes. Treatments were negative control (no beta-ligand; CON), Optaflexx (ractopamine hydrochloride, 300 mg·steer-1·d-1 for 35 d; OPT), and Experior (lubabegron fumarate, 36 mg·steer-1·d-1 for 56 d + 4 d removal; 0EXP) fed for 198 d. Additional EXP treatments investigated total days on feed (DOF) of 184 d (-14EXP), 212 d (+14EXP) and 226 d (+28EXP). Carcasses (n = 2,517) were instrument graded 24 h post-mortem. Longissimus tenderness and lipid content were evaluated in a subset (n = 361) of carcasses via slice shear force and ether extract. Statistical analyses were conducted using mixed models; pen was the experimental unit, treatment was the fixed effect, block was a random effect, and means were separated with the Tukey-Kramer adjustment. Longissimus muscle area (LMA) was 4.0 to 6.2 cm2 larger (P &amp;lt; 0.01) for steers fed EXP compared with CON, which did not differ from OPT. Weight corrected LMA (LMA:HCW) was 1.3 cm2/100 kg larger (P &amp;lt; 0.01) for -14EXP compared with CON. Marbling score was 31 to 39 points lower (P &amp;lt; 0.01) for -14EXP compared with CON and OPT, whereas 0EXP, +14EXP and +28EXP were similar to CON and OPT. Total number of fat pieces within the longissimus did not differ (P = 0.11) across treatments, however number of fat pieces in the lateral one-half of the longissimus decreased (P ≤ 0.03) for -14EXP and +28EXP, whereas +14EXP tended (P = 0.09) to decrease compared with CON. Total meat area was 3.7 percentage points greater (P &amp;lt; 0.01) for -14EXP compared with CON; +14EXP and +28EXP tended (P = 0.07) to be greater than CON. Total fat area was 1.6 to 1.8 percentage points less (P ≤ 0.02) for 0EXP, +14EXP, and +28EXP when compared with CON. Compared with CON, dorsal-ventral longissimus distance increased (P &amp;lt; 0.01) by 3.3 to 5.4% for -14EXP, 0EXP, +14EXP and +28EXP. Medial-lateral longissimus distance increased 1.9 to 2.5 % (P &amp;lt; 0.01) for +14EXP and +28EXP compared with CON, whereas -14EXP tended (P = 0.08) to increase. Percentage intramuscular fat (IMF) was similar (P ≥ 0.44) for +14EXP, +28EXP, and OPT compared with CON, whereas 0EXP tended (P = 0.09) to be less. Marbling score and IMF were moderately correlated (r = 0.66). Slice shear force values were 20.1% greater (P &amp;lt; 0.02) for +14EXP compared with CON, whereas 0EXP tended (P = 0.09) to be greater and +28EXP, -14EXP and OPT were similar (P ≥ 0.28) to CON. These findings illustrate the effect of EXP on carcass traits and tenderness in feedlot cattle.

Exploring the effects of ageing on instrumental and sensory characteristics of meat from Lidia breed females: A comparative study of two commercial types

The aim of this study was to assess the influence of ageing on instrumental and sensory qualities in Longissimus thoracis et lumborum (LTL) from heifers (n = 200) and cows (n = 100) of Lidia breed. The animals were slaughtered as heifers (24–48 months) or cull cows (> 48 months). For instrumental analysis, pars Thoracis aged at 7, 14 and 28 days was used; for sensory analysis, pars Lumborum aged at 14 and 28 days was evaluated. Heifers showed redder and yellower meat (P < 0.05) and cows showed slightly higher Water Holding Capacity (WHC): Thawing Loss (TL) = P < 0.05; Drip Loss (DL) = P < 0.01; Pressure Loss (PL) = P < 0.01; Cooking Loss (CL) = P < 0.05. Ageing generated changes in meat colour, with increases in lightness (L*, linear pattern, P < 0.001) and oscillations in a* and b* (quadratic patterns; P < 0.05 and P < 0.001, respectively). Ageing affected TL (increasing, P < 0.001) and PL (decreasing, P < 0.05), and generated a significant improvement in Warner Bratzler Shear Force (WBSF) values (P < 0.001). Commercial type revealed changes in consumer panel ratings for flavour (P < 0.05), juiciness (P < 0.01), tenderness (P < 0.001) and overall acceptability (P < 0.001), with better results in these parameters for cull cows. In contrast to the usual, ageing did not affect the sensory traits. There was no significant interaction between commercial type and ageing time, except for beef flavour, which worsened with ageing (P < 0.05).

Influence of Long-Term Freezing of Carcasses in Pre- and Post-Rigor Mortis Stages on the Technological and Nutritional Parameters of the Longissimus lumborum Muscle of Botucatu Rabbits.

The aim was to assess the impact of long-term storage on the quality of Botucatu rabbit meat frozen in pre- and post-rigor stages. The stability of the technological and nutritional parameters of Longissimus lumborum (LL) muscle was analyzed over 12 months. In the post-rigor phase, the dorsal LL surface showed a higher level (p < 0.05) of redness and saturation, while the ventral surface showed a higher level (p < 0.05) of yellowness compared to the pre-rigor LL muscle. During storage, the redness and saturation in the LL muscle decreased (p < 0.05), while the yellowness increased (p < 0.05) on both dorsal and ventral surfaces. In the first six months, the pre-rigor meat had a higher pH (p < 0.05) compared to the post-rigor meat. The fresh meat showed higher (p < 0.05) shear force values in the post-rigor stage. Over the 12-month study period, the lipid oxidation, myofibrillar fragmentation index, gross energy, and levels of protein, fat, and carbohydrates increased (p < 0.05), while the shear force, mineral content, and moisture decreased (p < 0.05). Thus, rigor mortis affects meat color in Botucatu rabbits. Fresh meat in the pre-rigor stage is softer, moister, and less acidic than post-rigor meat after 24 h of chilling. Long-term freezing enhances tenderness, regardless of the rigor phase at freezing, preserving its physical, chemical, and nutritional quality, with minor changes in color, lipid oxidation, and chemical composition.

Dynamic Performance Analysis of Precast Segment Column Reinforced with CFRP Subject to Vehicle Collision

With the extensive use of a precast segment column in the field of engineering, impact resistance performance has gradually attracted attention, as many accidents have caused huge economic losses and casualties. This study explored the dynamic response and failure modes of a prefabricated segment column both with and without Carbon Fiber-Reinforced Polymers (CFRPs). Firstly, numerical models of a precast segment column and CFRP-wrapped steel column under impact loads were developed, and the modeling method’s accuracy was fully verified. Then, numerical models of a bridge precast segment column with and without CFRPs under vehicle collision were established, and the differences in the dynamic performances between the precast segment column with and without CFRPs are explored. Finally, the effects of impact velocity, concrete strength, and CFRP thickness on the dynamic performance of a precast segment column are considered. The results indicate that in the case of a vehicle collision, multiple cross-sectional positions form highly complex stress states. At 100 km/h, the differences in bending moment and shear force values between reinforced and unreinforced precast segment columns at the impact section are 7.6% and 7.1%, respectively. At this velocity, the peak impact force also increases by 15.8% as the local stiffness of the precast segment column increases after reinforcement with a CFRP. The bottom segment of the precast segment column with a CFRP is crushed, and the precast segment column experiences shear failure under vehicle collision.

Effect of Age, Deboning Time of Carcass, and Different Cooking Conditions on the Woody Breast Myopathies in Chicken: A Meta-Analysis.

This meta-analysis review undertakes a comprehensive examination of various approaches for identifying myopathic fillets and meticulously evaluates the effects of bird age, deboning time, and different cooking and storage conditions on woody breast (WB) myopathic conditions in broiler deboned fillets. The data, meticulously collected from 20 articles based on predefined inclusion criteria sourced from various databases and online resources, reveal significant insights. For instance, the analysis uncovers that deboning time significantly affects Meullenet-Owens Razor Shear (MORS), Blunt Meullenet-Owens Razor Shear (BMORS), and descriptive analysis values (p < 0.001). Instrumentation techniques, such as compression force and shear force, along with different cooking conditions, strongly impact BMORS shear force values (R2 = 86.80%), with significance levels ranging from 0.01 to 0.001. Deboning time also substantially impacts MORS shear force values (R = 64.03%). In contrast, the effects of deboning time, bird age, and cooking conditions on descriptive sensory evaluation are minimal when compared to woody breast fillets (age of birds: R2 = 26.53%; cooking conditions: R2 = 32.57%; deboning time: R2 = 10.06%). The overall effect of bird age on chicken breast meat quality shows significant differences for the evaluated parameters (Hedges' g [95% CI] = -0.72 [0.17, 1.26], I2 = 93%, p < 0.01). The sous vide cooking method significantly affects shear force energies and sensory descriptive evaluation for woody breast fillets (Hedges' g [95% CI] = 5.30 [-50.30, 83.40], I2 = 98%, p < 0.01). These findings, with their significant implications, provide valuable insights for optimizing processing conditions in the poultry industry to reduce woody breast occurrences and enhance meat quality, instilling confidence in the robustness of the research.

Investigation of the Overall Damage Assessment Method Used for Unmanned Aerial Vehicles Subjected to Blast Waves

With the aim of investigating the assessment methodology for the overall damage effects on an unmanned aerial vehicle (UAV) subjected to a blast wave, the failure criteria for the typical UAV was formulated through an analysis of the structural strength design standards. Specifically, the shear force associated with wing failure can serve as a critical parameter for assessing the overall damage inflicted on the UAV by blast waves. According to the design load criterion of the aircraft, the shear force value corresponding to the overall failure of the typical UAV was calculated. Numerical simulations were conducted to investigate the mechanical response of UAV structures under blast wave loading generated by a 500 g explosive. Combining the critical shear force values obtained from theoretical calculations with the numerical simulation results, two distances between the explosives and the UAV that could produce different damage effects were estimated, namely 1 m and 2.5 m. Subsequently, static explosion experiments with equivalent explosive charges were performed, revealing different damage effects on a typical UAV at two specific distances. The numerical simulation results were highly consistent with the experimental observations, further validating the scientific and rational basis for using shear force as a primary parameter in assessing overall structural damage to fixed-wing UAVs.

Comparison of Muscle Fiber and Meat Quality Characteristics of Beef Strip Loin, Tenderloin, and Round Cuts among Jeju Black Cattle, Hanwoo, and Their Crossbreeds.

This study assessed and compared meat quality and fiber characteristics of longissimus lumborum (LL), psoas major (PM), and semimembranosus muscles among Hanwoo (HW), Jeju black (BL), and their crossbred (BH) cattle. Twelve carcasses from each breed (36 in total) were used in this study. BL and BH had higher moisture and crude ash contents and lower crude fat and protein contents than HW, regardless of the muscle type. BL had higher CIE a*, cooking loss, and shear force values than did the other breeds for all muscle types. The muscle fiber size (cross-sectional area) of BL and BH was larger than that of HW for all muscle types. Type IIX was the dominant muscle fiber type in both BL and BH, regardless of muscle type; however, HW had the highest composition of type I compared to the other types (IIA, IIAX, and IIX) in PM. Higher total fiber density was observed in the LL and PM muscles of HW than in those of BL and BH. Meat quality and muscle fiber characteristics of BL and BH were distinct from those of HW.

Electrical stimulation and wet ageing effects on the carcass and meat quality of Australian rangeland goats

Medium voltage electrical stimulation and wet ageing periods effects on the carcasses and meat quality of Australian rangeland goats were investigated. 64 rangeland goats were slaughtered as 2 equal consignments, wherein half were exposed to post-dressing electrical stimulation (300 V, 500 ms pulse width, 45 s) and half were not (control). Carcass and pH decline parameters and glycogen concentration were recorded. At 24 h post-mortem, fresh colour was measured and longissimus lumborum muscles (LL) removed. Within carcass, paired LL were halved and allocated to each of 4 ageing periods (1, 2, 4, or 21 d). There were no significant effects from electric stimulation on LL pH at 18 °C, LL temperature at pH 6, LL pH at 24 h post-mortem, semitendinosus pH at 24 h post-mortem, and LL glycogen concentration. There were no significant interactions between stimulation and ageing period on cooking loss, particle size, purge loss, sarcomere length, shear force, and ultimate pH. Independent to stimulation, shear force, particle size, and cooking values declined as ageing period increased. Purge loss was highest after 21 d of ageing. Colour stability was unaffected by ageing, although all CIE colour coordinates varied across the 74 h total retail display period. There were negative linear relationships found between LL glycogen concentrations and LL temperature at pH 6, ultimate pH, and sarcomere length. These findings suggest there to be little benefit to post-dressing electrical stimulation of rangeland goat carcasses, when applied independent to or in combination with ageing.

Longitudinal and transversal intramuscular variation of muscle fiber and meat quality characteristics in bovine M. longissimus thoracis et lumborum

This study evaluates longitudinal and transversal intramuscular variations in muscle fiber and meat quality characteristics in bovine M. longissimus thoracis et lumborum (LTL). The LTL muscles (n = 5) from the left side of the beef carcass were cut at intervertebral segment intervals (between 1st thoracic vertebra (TV) and 6th lumbar vertebra (LV)). The pennation angle demonstrated an increasing trend from the anterior to posterior regions regardless of the medial (M-zone) and lateral (L-zone) regions (P < 0.05). The M -zone had a higher pennation angle than the L-zone in the TV and 1st LV (P < 0.05). The cross-sectional area (CSA) of muscle fibers, excluding type I, was larger in the posterior region than the anterior region (P < 0.05). A larger CSA of type I/IIA, IIA, IIAX, and IIX was observed on the lateral side than on the medial side of the 13th TV (P < 0.05). Fiber types were more oxidative (types I and IIA) in the anterior region and more glycolytic (types IIA/IIX and IIX) in the posterior region. Fat content was higher in the anterior region than in the posterior region (P < 0.05). The lowest redness, yellowness, and Warner-Bratzler shear force values were observed in the middle of the muscle, whereas the lightness value was lower in the posterior region regardless of the transversal region (P < 0.05). Therefore, bovine LTL muscles exhibit unique morphological properties and contribute to understanding meat quality associated with morphological and muscle fiber characteristics in relation to their intramuscular variations.

Effect of dried cauliflower leaf meal (Brassica oleracea var botrytis) dietary supplementation on the growth performance, carcass and meat characteristics of rabbits.

The purpose of this study is to investigate the effect of feeding cauliflower leaf meal (CLM) on growth performance, nutrient utilization, carcass characteristics, histopathology and economics of rabbit production. A total of eighteen 45-day-old Newzeland White rabbits were randomly divided into three groups and fed with control (0%), 20% and 30% CLM in concentrate mixture and feeding trial continued for 3 months. Growth performance was recorded upto the end of the trial. On completion of the growth study, a digestibility trial was conducted to assess the digestibility of nutrients. Afterwards, all the experimental rabbits were slaughtered to evaluate the carcass and meat quality, and to examine histological changes in the viscera. The cost of production was calculated on the basis of partially replacing wheat bran with CLM. Results showed that the body weight gain, feed intake, feed conversion ratio and digestibility of nutrients were similar among the groups of rabbits. Further, dressing percentage, wholesome cut yield, chemical composition of meat, sensory evaluation, water holding capacity and shear force value were also comparable among all groups. However, total phenolic content, vitamin A and E, and polyunsaturated fatty acid were significantly (p < 0.05) higher and 2-Thiobarbituric acid reactive substance was significantly (p < 0.05) lower in 30% CLM-fed group. Histopathological study showed no pathological changes in viscera of rabbits fed with CLM. Moreover, the cost of production was significantly (p < 0.05) lower in 30% CLM-fed group of rabbits. The present work shows that the 30% CLM can be incorporated in concentrate mixture in rabbit diet without affecting growth performance or meat quality and successfully used in rabbit nutrition, which will be cheaper with enhanced keeping quality of meat.

Effects of sodium lactate injection on meat quality and lactate content in broiler chickens: emphasis on injection method and dosage

This study aims to develop an experimental model of high lactate levels in broilers to mimic the condition of birds under stress or diseases and evaluate its consequent effects on meat quality. The injection sites and dosage effects were compared separately in 2 experiments. Experiment 1 includes 3 injection sites: intraperitoneal injection, intramuscular injection, and subcutaneous injection. Experiment 2 was a dosage experiment based on the results of Experiment 1: sodium lactate intraperitoneal injection group with 1.5, 3, 6 mM concentration. The results showed that injecting sodium lactate intraperitoneally, intramuscularly, or subcutaneously all significantly decreased body weight and breast muscle weight while elevating lactic acid levels in both the blood and breast muscle of broilers. Moreover, all 3 injection methods caused a significant reduction in pH24h and an increase in the shear force value of breast muscle. In addition, dose-response experiments of intraperitoneal injection showed that a concentration of 3 mM and 6 mM were significantly decreased body weight and breast muscle weight in broiler chickens, accompanied by a notable increase in breast muscle lactate content. Compared to the control group, intraperitoneal injections of 1.5 mM, 3 mM, and 6 mM sodium lactate treatments significantly reduced the yellowness values of the breast muscle. As the dose of sodium lactate increased, the shear force value of the breast meat exhibited linear and quadratic increments, while the drip loss decreased linearly. Intraperitoneal injection of 3 mM sodium lactate also significantly reduced the pH24h of broiler breast muscle. In addition, an increased dose of lactate injections up-regulated the glycolytic pathway responsible for endogenous lactate production in the breast muscle by upregulating the expression of phosphofructokinase, pyruvate kinase and lactate dehydrogenase A. In conclusion, intraperitoneal injection of sodium lactate at 3 mM directly increased breast muscle lactate levels, providing a valuable method for establishing a high-level lactate model in poultry.

Sausage Quality during Storage under the Partial Substitution of Meat with Fermented Oyster Mushrooms.

The increasing global demand for meat production, driven by a rapidly expanding population and changing dietary preferences has prompted the search for protein-rich, sustainable, and healthier meat alternatives. In this context, edible mushrooms are viewed as advantageous substitutes for meat, offering a viable solution. This study aimed to investigate the effects of partially replacing (25% and 50%) pork meat in sausage samples with fermented oyster mushrooms (Pleurotus ostreatus), which were subjected to various pretreatments. Six different pretreatments were applied to fresh oyster mushrooms as follows: blanching in water, steaming, oven-cooking, microwave treatment, high hydrostatic pressure treatment, and ultraviolet light treatment. The effects of mushroom replacement on the moisture, pH, lipid oxidation, color, and textural properties of sausages during the 4-week refrigerated storage period were evaluated. The results revealed that replacing pork meat with fermented oyster mushrooms resulted in an increase in moisture content and b* values and a decrease in pH, L*, a*, and shear force values, proportional to the mushroom percentage. The lipid oxidation findings suggest that the antioxidant capabilities of fermented oyster mushrooms were influenced by the pretreatment methods applied to the mushrooms, exhibiting varying levels of effectiveness.