Effect of Conjugated Linoleic Acid Feeding on the Growth Performance and Meat Fatty Acid Profiles in Broiler: Meta-analysis

The effect of conjugated linoleic acid (CLA) feeding on growth performance and fatty acid profiles in thigh meat of broiler chicken was investigated using meta-analysis with a total of 9 studies. Overall effects were calculated by standardized mean differences between treatment (CLA fed) and control using Hedges’s adjusted g from fixed and random effect models. Meta-regression was conducted to evaluate the effect of CLA levels. Subgroups in the same study were designated according to used levels of CLA, CP levels or substituted oils in diets. The effects on final body weight, weight gain, feed intake and feed conversion ratio were investigated as growth parameters. Total saturated and unsaturated fatty acid concentrations and C16:0, C18:0, C18:2 and C18:3 concentrations in thigh meat of broiler chicken were used as fatty acid profile parameters. The overall effect of CLA feeding on final weight was negative and it was only significant in fixed effect model (p<0.01). Significantly lower weight gain, feed intake and higher feed conversion ratio compared to control were found (p<0.05). CLA feeding on the overall increased total saturated fatty acid concentration in broilers compared to the control diet (p<0.01). Total unsaturated fatty acid concentration was significantly decreased by CLA feeding (p<0.01). As for individual fatty acid profiles, C16:0, C18:0 and C18:3 were increased and C18:2 was significantly decreased by CLA feeding (p<0.01). In conclusion, CLA was proved not to be beneficial for improving growth performance, whereas it might be supposed that CLA is effective modulating n-6/n-3 fatty acids ratio in thigh meat. However, the economical compensation of the loss from suppressed growth performance and increased saturated fatty acids with the benefit from enhanced n-6/n-3 ratio should be investigated in further studies in order to propose an appropriate use of dietary CLA in the broiler industry

Proteomic Analysis of the Protective Effect of Early Heat Exposure against Chronic Heat Stress in Broilers

The increasing trend of global warming has affected the livestock industry through the heat stress, especially in poultry. Therefore, a better understanding of the mechanisms of heat stress in poultry would be helpful for maintaining the poultry production. Three groups were designed to determine early heat stress effects during chronic heat stress: CC, raised at a comfortable temperature; CH, chronic heat exposure at 35 &deg;C for 21&ndash;35 days continuously; and HH, early heat exposure at 40 &deg;C for 24 h at 5 days old with 35 &deg;C temperature for 21&ndash;35 days continuously. In this study, proteome analysis was carried out to identify differentially expressed proteins in the liver tissue of broilers under chronic and early heat exposure. There were eight differentially expressed proteins from early heat stress during chronic heat exposure, which were related to actin metabolism. According to KEGG (Kyoto encyclopedia of genes and genomes) analysis, the proteins involved in carbohydrate metabolism were expressed to promote the metabolism of carbohydrates under chronic heat stress. Early heat reduced the heat stress-induced expression changes of select proteins. Our study has shown that early heat exposure suggests that the liver of broilers has various physiological mechanisms for regulating homeostasis to aid heat resistance

Effects of Ripening Duration and Rosemary Powder Addition on Salchichon Modified Sausage Quality

The ripening durations and ingredients for the Salchichon sausages were modified to increase pork rear leg consumption by Korean consumers. The salchichon, a ripened pork sausage, was produced to evaluate the efficacy of two different ripening durations with and without rosemary powder on salchichon sausage quality, and the treatments were: i) 45 days of ripening without rosemary, ii) 60 days of ripening without rosemary, iii) 45 days of ripening with 0.05% rosemary, and iv) 60 days of ripening with 0.05% rosemary. Significant differences were observed in both moisture and fat content for ripening durations, with the highest moisture and least fat content observed in salchichon modified sausage (SMS) ripened for 45 days. Ripening duration and rosemary addition appeared to influence water activity (aw) of salchichon sausages. The aw of SMS ripened for 45 days was 0.80, whereas the other had aw values <0.80. Lactic acid bacteria were predominant, as Korean traditional fermented red pepper paste was added to sausages; however, the Bacillus cereus population was significantly affected by rosemary powder addition. Chewiness and gumminess decreased significantly due to the addition of rosemary powder compared to SMS without rosemary powder, and both 45 days of ripening and rosemary powder addition influenced the hardness of SMS. In conclusion, ripening duration of SMS for 45 days in the presence of rosemary powder provided superior SMS quality with an economical ripening duration compared to that of ripening with rosemary powder or ripening for 60 days

Quality traits, fatty acids, mineral content of meat and blood metabolites changes of broiler chickens after artificial infection with sporulated Eimeria tenella oocysts

This study was to investigate physicochemical characteristics, fatty acids, minerals and hematological alterations in broiler chickens artificially infected with 1 × 104 sporulated oocysts of Eimeria tenella. Results revealed that pH values were decreased (p ˂ .05) in the infected group (IG) at 7 and 9 days post infection (dpi) than those at 5 dpi, although no significant differences between the non-infected group (NIG) and IG. Infection with E. tenella did not affect meat colour parameters except that redness was lower (p ˂ .05) than that in the NIG. Cooking loss was decreased (p ˂ .05) in NIG and IG at 7 and 9 dpi than that at 5 dpi. Thiobarbituric acid reactive substance (TBARS) value was increased (p ˂ .05) in IG at 7 dpi than 5 or 9 dpi and NIG (p ˂ .01). Total protein (TP) and total cholesterol (TC) were significantly lowered in IG at 5 dpi. Other blood parameter results showed decreases of glucose (GLU), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL) in infected chicken at 7 dpi compared to those in the NIG without significance. However, albumin (ALB) level was decreased (p ˂ .01) in the IG compared with NIG at 5 dpi. Levels of aspartate aminotransferase (AST) were lowered (p < .05) in the IG than NIG at 7 dpi. Mineral contents of Ca, Mg, Cu, and Zn were lowered (p ˂ .01) in the IG than those in the NIG at 7 dpi. Based on these results indicate that a low dose of E. tenella has no impact on meat quality traits, fatty acids although it can slightly affect blood parameters and mineral contents.HIGHLIGHTS The low dose of Eimeria tenella has no impact on meat quality traits and fatty acids of broiler meat. A significant increase in some blood parameter is observed in infected broiler chickens at 9 dpi. Mineral contents of Ca, Mg, Cu and Zn decreases in infected broiler meat at 7 dpi

Studies on Intramuscular Fat Percentage in Live Swine Using Real-time Ultrasound to Determine Pork Quality

In the modern pork industry, selection of high intramuscular fat (IMF) in pigs is necessary to improve pork quality. Ultrasound has been used previously to predict subcutaneous fat thickness and IMF in the longissimus muscles of line pigs and Real-time ultrasound has also been reported as a reliable method for estimating IMF in live pigs. So we estimate the correlation between meat quality traits and IMF percentage to investigate the possibility of utilizing real-time ultrasound technology for predicting IMF percentage in line pigs to improve pork quality. The genetic and phenotypic correlations for chemical intramuscular fat (CIMF) and ultrasound intramuscular fat (UIMF) were estimated to be 0.75 and 0.76, respectively. These results suggest that genetic factors strongly influence meat quality. The genetic and phenotypic correlation between UIMF and CIMF were 0.75, 0.76, respectively. The heritability of UIMF and CIMF were 0.48 and 0.50, respectively. So we concluded that CIMF can be replaced with UIMF and Ultrasound machines can be used to test IMF in live swine. In future, UIMF can be utilized to improve pork quality as an alternative to CIMF

Modulatory effect of linoleic and oleic acid on cell proliferation and lipid metabolism gene expressions in primary bovine satellite cells

This study was performed to elucidate the effects of linoleic acid (LA), oleic acid (OA) and their combination (LA + OA) on cell proliferation, apoptosis, necrosis, and the lipid metabolism related gene expression in bovine satellite cells (BSCs), isolated from bovine muscles. Cell viability was significantly increased with the OA and LA treatment. Furthermore, LA + OA enhanced cell proliferation in a dose-dependent manner (10 to 100 µM), whereas it lowered at 250 µM. In addition, a cell-cycle analysis showed that 100 µM of LA and OA markedly decreased the G0/G1 phase proportion (62.58% and 61.33%, respectively), compared to controls (68.02%), whereas the S-phase cells’ proportion was increased. The ratio of G2/M phase cells was not significantly different among the groups. Moreover, analyses with AO/EtBr staining showed that no apoptosis occurred. Necrosis were determined by flow cytometry using Annexin V-FITC/PI staining which revealed no early apoptosis in the cells pretreated with LA or OA, but occurred in the LA + OA group. We also analyzed the mRNA expression of lipid metabolizing genes such as peroxisome proliferator receptor alfa (PPARα), peroxisome proliferator receptor gamma (PPARγ), acyl-CoA oxidase (ACOX), lipoprotein lipase (LPL), carnitine palmitoyl transferase (CPT-1), and fatty-acid binding protein4 (FABP4), which were upregulated in LA or OA treated cells compared to the control group. In essence, LA and OA alone promote the cell proliferation without any apoptosis and necrosis, which might upregulate the lipid metabolism related gene expressions, and increase fatty-acid oxidation in the BSCs’ lipid metabolism

Comparative studies of meat quality traits and the proteome profile between low pH and high pH muscles in longissimus dorsi of Berkshire

This study was conducted to assess the molecular mechanism of meat quality between low and high pH muscles using two-dimensional gel electrophoresis (2DE) with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS) on longissimus dorsi (LD) muscles from Berkshire species, assigned to high (5.92 ± 0.02) and low pH groups (5.55 ± 0.03). The higher pH group had a lower lightness, yellowness, drip loss, shear force, and a higher NPPC (national pork producers council) color than the low pH group. The meat quality changes were related to the altered protein expression between the two groups. Fourteen protein spots were identified by MALDI-TOF/MS and among them, nine proteins involved in meat quality attributes significantly increased: the alpha-crystallin B chain (CRYAB), dual specificity phosphatase 1 (DUSP1), vimentin (VIM) X1 and X2, ATP synthase subunit d, mitochondrial (ATP5H), peroxiredoxin6 (PRDX6), ubiquitin carboxyl-terminal hydrolase14 (UCTH14), and cytochrome c (cyt c). Moreover, the proteins’ translation efficiency was analyzed by their mRNA expression via qPCR. An increase in the mRNA levels of ATP5H, PRDX6, and UCTH14 is consistent with protein expressions. These results may provide valuable information to decipher the molecular mechanism behind meat quality of low and high pH muscles.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author