Objective: This study was conducted to determine the effect of freeze-thawed cycles (Fresh meat, F-T 1 cycle and F-T 2 cycles) on the quality characteristics of porcine longissimus dorsi muscle. Methods: A total of 20 three-crossbred pigs (Duroc×[Large White×Landrace]) were randomly obtained from a commercial slaughterhouse in Thailand. Muscle samples were immediately taken from 10 to 11th of the longissimus dorsi for histochemical analysis. The muscles were cut into 2.54 cm-thick chops. A minimum of 20 chops were used for each treatment (fresh meat, freeze-thawed 1 and 2 cycles). Individually chops were packaged in polyethylene bags and frozen at –20°C for 6 months followed by thawing in refrigerator at 4°C for 24 h (the 1st freeze-thawed cycle). The freeze-thawed procedure was repeated for two cycles (the 2nd freeze-thawed cycle). Thawing loss, shear force value, citrate synthase activity and muscle fiber characteristics were determined on the muscles. Results: Results showed that increasing of freeze-thawed cycle increased the thawing loss (p<0.01) and citrate synthase activity (p<0.001). Shear force value of fresh meat was higher than freeze-thawed 1 and 2 cycles (F-T 1 cycle and F-T 2 cycles). Freeze-thawed cycles affected muscle characteristics. Muscle fiber area and muscle fiber diameter decreased with an increasing number of freeze-thawed cycles (p<0.001), while the thickness of endomysium and perimysium were increased (p<0.001). Conclusion: Repeated freeze-thawed cycles degraded muscle fiber structure and deteriorated pork quality.

An experiment was conducted to study the blood haematology, muscle pH, and serum cortisol changes in pigs with different levels of drip loss. Two groups (low and high) of 20 animals were selected from 100 pigs based on drip loss. All [Duroc× (Large White×Landrace)] pigs were slaughtered according to standard slaughtering procedures. At exsanguinations, blood samples were taken for the haematological parameters and serum cortisol analysis. The muscle samples were taken from longissimus dorsi muscle to evaluate the muscle pH and drip loss. Haematological parameters of low drip loss group showed higher content of white blood cells and monocytes than high drip loss group (p0.05). Drip loss is mainly affected by the muscle pH decline after slaughter and also might be affected by white blood cells and monocytes.

Background and Aim: The principal cytokines released by the host on infection include pro-inflammatory cytokines such as interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF). These cytokines were regarded as regulators of the host's response to infection. This study aimed to determine the release of pro-inflammatory cytokines from chicken peripheral blood mononuclear cells (PBMCs) following lipopolysaccharide (LPS) stimulation. Materials and Methods: Blood samples were collected from six Betong chickens. To isolate PBMCs, density gradient centrifugation was utilized. PBMC culture in RPMI1640 with 10% fetal bovine serum was stimulated with various concentrations of LPS (0, 0.01, 0.1, and 1.0 μg/mL). The production of TNF-α, IL-1β, and IL-6 was determined using an enzyme-linked immunosorbent assay. Results: When the PBMCs were cultured for 24 h with varying doses of LPS, there was no significant variation in cell viability. TNF-α, IL-1β, and IL-6 levels were measured in Betong chicken PBMC. The release of these cytokines increased considerably as LPS concentration (0.01-1 μg/mL) increased (p<0.05). Conclusion: In vitro studies of the chicken immune response, notably the release of pro-inflammatory cytokines, can be conducted using PBMCs obtained from chicken blood.

Background and Aim: Toll-like receptors (TLRs) comprise microbial sensing receptors present on cell surfaces that are capable of detecting pathogens. The present study aims to examine the expression of TLRs within the peripheral blood mononuclear cell (PBMC) of the Betong chickens. Materials and Methods: Blood samples were harvested from 12 Betong (KU line) chickens. Hematological values were calculated. PBMC was isolated from the blood utilizing a Histopaque solution and stored in a RPMI1640 culture medium. Cell viability was investigated using a Trypan Blue dye exclusion test. DNA was extracted from PBMC and the expression of the DNA's TLRs was examined using a polymerase chain reaction. Results: Hematological values were determined from the blood samples collected in this study obtained from healthy Betong chickens. PBMC that was isolated from the Betong chickens possessed cell viability higher than 95% (95.37±1.06). From the examination of TLRs gene expression, results revealed instances of TLR1.1, TLR1.2, TLR2.1, TLR2.2, TLR3, TLR4, TLR5, TLR 7, TLR15, and TLR21 that were present in the PBMC of Betong chickens. Conclusion: PBMC isolated from the blood of healthy Betong chickens possessed excellent cell quality. All chicken TLRs were discovered within the PBMC of Betong chickens. Hence, PBMC stands out as one of the premier sources for in vitro studies of chicken immune response.

A total of 375 Nile tilapia was subdivided into three groups (125 fish/group), based on weight (600, 800 and 1200 g, respectively). Fish were killed and analyzed for various traits describing meat characteristics. Data was subjected to analysis of variance. Protein percentage of the 600 g weighing Nile tilapia was the highest (P<0.05). Fat percentage of the 1200 g weighing Nile tilapia was higher than that of the 600 g weighing animals (P<0.05). Drip loss percentage of the fillet of the 600 g weighing Nile tilapia was the highest (P<0.05), whereas boiling loss percentage was the highest (P0.05) between groups. Shear force values of raw and cooked fillets were highest with the 1200 g heavy fish (P<0.05. The total collagen content of the fillet of the 1200 g weighing fish was highest (P<0.05). Flavor, juiciness, tenderness and acceptability ratings were lowest with fish weighing 600 g (P<0.05). In conclusion, fat percentages and firmness were higher with increasing the slaughter weight. Also flavor was improved with higher slaughter weight. By modifying the slaughter weight, a certain target meat quality can be achieved.