• Animal Bioscience
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• v.35 no.3
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• pp.475-483
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• 2022

Objective: Methionine (Met) is involved in methyl group transfer besides protein synthesis. As the availability is limited and cost is high for synthetic Met, reductions in its inclusion in broiler diet may be possible by supplementing the low Met diets with methyl donors (MD) like betaine (Bet), folic acid (FA), vitamin B12 (B12), and biotin (Bio). An experiment was conducted to study the effects of supplementing the MD on performance (average daily gain [ADG], daily feed intake, feed efficiency [FE]), anti-oxidant variables, immune responses and serum protein concentration in broilers fed sub-optimal concentrations of dietary Met. Methods: Maize-soybean meal diet was used as control (CD). Different MD like Bet (0.2%), B12 (0.1 mg), FA (4 mg), or Bio (1.5 mg/kg) were supplemented to basal diet (BD) having no supplemental Met. The BD without MD was kept for comparison. Each diet was fed ad libitum to 10 replicates of 25 chicks in each from 1 to 42 d of age. Results: At the end of experiment, the ADG in MD group was higher than BD and lower than CD. The FE improved with FA or Bet compared to the BD. Breast meat weight was higher in Bet compared to the BD, while it was intermediate between BD and CD in other groups. The lipid peroxidation reduced with Bio, B12, or Bet, while the glutathione peroxidase activity improved with Bio or B12 compared to the BD. Lymphocyte proliferation improved with Bet compared to the BD. The serum protein concentrations increased with FA, Bio, or Bet compared to those fed BD. Conclusion: It can be concluded that the ADG can be improved partially with supplementation of MD while the FE improved with FA or Bet. Some MD also reduced the stress indices and improved immune responses compared to the BD fed broilers.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.39.1-39.11
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• 2024

Importance: Salmonella outbreaks linked to poultry meat have been reported continuously worldwide. Therefore, Salmonella contamination of poultry meats in slaughterhouses is one of the critical control points for reducing disease outbreaks in humans. Objective: This study examined the carry-over contamination of Salmonella species through the entire slaughtering process in South Korea. Methods: From 2018 to 2019, 1,097 samples were collected from the nine slaughterhouses distributed nationwide. One hundred and seventeen isolates of Salmonella species were identified using the invA gene-specific polymerase chain reaction, as described previously. The serotype, phylogeny, and antimicrobial resistance of isolates were examined. Results: Among the 117 isolates, 93 were serotyped into Salmonella Mbandaka (n = 36 isolates, 30.8%), Salmonella Thompson (n = 33, 28.2%), and Salmonella Infantis (n = 24, 20.5%). Interestingly, allelic profiling showed that all S. Mbandaka isolates belonged to the lineage of the sequence type (ST) 413, whereas all S. Thompson isolates were ST292. Moreover, almost all S. Thompson isolates (97.0%, 32/33 isolates) belonging to ST292 were multidrug-resistant and possessed the major virulence genes whose products are required for full virulence. Both serotypes were distributed widely throughout the slaughtering process. Pulsed-field gel electrophoretic analysis demonstrated that seven S. Infantis showed 100% identities in their phylogenetic relatedness, indicating that they were sequentially transmitted along the slaughtering processes. Conclusions and Relevance: This study provides more evidence of the carry-over transmission of Salmonella species during the slaughtering processes. ST292 S. Thompson is a potential pathogenic clone of Salmonella species possibly associated with foodborne outbreaks in South Korea.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.69-75
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• 2009

The effects of different packaging methods such as aerobic, vacuum, and wrap packaging, on quality characteristics of fresh chicken breast meat during cold storage were investigated. The results show that crude fat content in aerobic packaging method was significantly (P<0.05) higher compared to the others, whereas moisture, protein and ash contents were not significantly different. pH in wrap packaging was increased with storage time and reached the highest values at 10 days. Both lightness and redness of the meat were increased with storage time, but lightness was significantly (P<0.05) higher in wrap packaging than in the others. Thiobarbituric acid (TBA) and volatile basic nitrogen (VBN) values were increased in all treatments at 10 days. VBN at 5 days were over 20 mg%, and TBA values at 10 days were between 0.82~1.05 mg malondialdehyde/kg meat. TBA showed significantly (P<0.05) lower in vacuum packaging compared to the other methods. Therefore, our results suggested that vacuum packaging decreases lipid oxidation of chicken breast meat, thereby enhancing the shelf life, compared to aerobic and wrap packaging methods.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.149-155
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• 2009

The present study was conducted to compare the carcass yields and meat characteristics of three types of commercial male chicks White mini broilers, Ross broilers and Hy-Line brown chicks under the identical feeding condition. One-hundred 1-d chicks of each type were randomly placed into four pens per group (25 chicks per pen) and fed corn-soybean meal based commercial diets for 35d, 18d or 49d, respectively. At the end of the feeding trial, the birds were sacrificed and subjected to carcass measurements. The dressing percentages of White mini broilers and Ross broilers were significantly higher (P<0.05) than that of Hy-Line brown cockerels. The rate of breast meat of Hy-Line brown cockerels was significantly lower (P<0.05) than those of White mini broilers and Ross broilers. However, Hy-Line brown cockerels showed higher (P<0.05) leg meats than the others. There were no significant differences in serum total cholesterol and the activities of glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase among the groups. The breast meats of White mini broilers presented highest lightness value. The yellowness of breast and redness of leg meats of White mini broilers and Ross broilers were significantly higher (P<0.05) than those of Hy-Line brown cockerels. There were no significant differences in the SOD-like activity and change of pH in edible meats among the groups. The meat color in White mini broilers was significantly higher than that of Hy-Line brown cockerels. No significant differences were observed in term of flavor, tenderness and overall acceptability. In conclusion, the physico-chemical properties and sensory characteristics of edible meats were not greatly affected by genotype if they were similar body weights and kept under the identical feeding condition. But the Hy-Line brown cockerels were less desirable as a meat-type strain due to lower carcass yields and inferior growth and feed conversion ratio.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.139-147
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• 2009

This experiment was conducted to investigate the effect of organic dietary ME and CP on performance, blood composition and meat quality of cross-bred chicks for 15 weeks. Experiments were factorially designed with 3,000, 3,050, and 3,100 kcal of ME/kg, and 21 and 22% CP for the first five weeks; 3,050, 3,100, and 3,150 kcal of ME/kg, and 19 and 20% CP for the second five weeks; and 3,100 and 3,150 kcal of ME/kg, and 17 and 18% CP for the rest of weeks. Each treatment consisted of four replicates. Weight gain increased in treatments with higher ME diets for the first five weeks, but feed intake decreased significantly as dietary ME increased (P<0.05). Feed conversion also improved in chicks fed 3,100 kcal of ME/kg diets compared with those of 3,000, and 3,050 kcal of ME/kg (P<0.05), but was not influenced by dietary protein. Weight gain and feed conversion showed similar tendency for the second five weeks to those of the first five weeks. However, feed conversion improved significantly in 3,100 and 3,150 kcal of ME /kg compared to 3,050 kcal of ME/kg (P<0.05). Dietary protein did not affect the performance at all for this period. Weight gain and feed intake tended to increase in higher ME and lower protein diets from 11 to 15 weeks of age, whereas feed conversion decreased in 3,150 kcal of ME/kg more than 3,000 kcal/kg. No difference was found by CP treatments (P<0.05). There were no interactions in performance, blood composition and meat quality between dietary ME and protein. Further studies need to describe in whole period experiments instead of periodical experiment.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.45-52
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• 2014

This study was conducted to investigate the effect of additions of duck skin as pork fat replacer on the quality characteristics of duck meat sausage during refrigerated storage. The sausage made with only duck meat was severed as the control. Three treatments of sausages were produced with addition levels (T1, 1%; T2, 2% and T3, 3%) of duck skin. Our results showed that the addition of duck skin significantly (p<0.05) decreased the moisture content whereas significantly (p< 0.05) increased the fat content in the sausages. The sausages with duck skin had significantly (p<0.05) higher pH values until 4 weeks of refrigerated storages when compared to the control. CIE $L^*$ value was significantly (p<0.05) higher in T1 and T2 than those of other treatments after 7 days of refrigerated storage. Similarly the sausages with duck skin had significantly (p<0.05) higher CIE $a^*$ values as compared with the control after 4 weeks of refrigerated storage. The sausages with 1% duck skin processed the significantly (p<0.05) highest hardness, springiness, gumminess and chewiness values at all storage days. No differences were found between the control and treatment for color, flavor, taste, texture and overall acceptability. Based on the results obtained in the present study it is suggested that duck skin to levels of 1~2% can be used as fat replacer for manufacture of duck meat sausage with a positive effect on quality and texture characteristics. However, further research in necessary to improve taste and palatability of the products.

• Korean Journal of Poultry Science
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• v.42 no.2
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• pp.101-108
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• 2015

This study investigated the initial pH measured at 15 min post-mortem, ultimate pH, water holding capacity (WHC), and color of meats obtained from five lines of Korean native chicken (KNC) for the development of breed for high-quality meat. In addition, the effect of sex was examined. In total, 595 $F_1$ progeny (Black [B], Grey-Brown [G], Red-Brown [R], White [W] and Yellow-Brown [Y]) from 70 full-sib families were used. Chickens were slaughtered at 20 wk of age and the measurement traits of all breast and thigh meats from 595 chickens were analyzed. The initial pH at 15 min post-slaughter of the breast and thigh meats was affected by the line and sex of Korean native chicken (P<0.05). However, there was no line and sex effect on ultimate pH and WHC of the breast and thigh meat except that the ultimate pH of thigh meat had line effect. Except for the $L^*$ value of breast meat, the meat color was significantly affected by line and sex (P<0.05). The ultimate pH showed consistently negative correlation with the $L^*$ value and positive correlation with the $a^*$ value in breast and thigh meats. Based on the results, we concluded that the line W in male chickens and the line G and W in female chickens may be good candidates for the selection to develop breed for high-quality meat because these lines showed property of high initial pH or/and ultimate pH.

• Korean Journal of Poultry Science
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• v.31 no.3
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• pp.165-170
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• 2004

The objective of this study was to evaluate the carcass and meat quality of broiler chicken when slaughtered after treating with different source of grain(T1, 100% corn; T2, 50% corn + 50% brown rice; T3, 100% brown rice) in broiler diet. The carcass weight was decreased when feeding level of rice increased. The yield of breast was higher in T2(18.6%) than T1(17.3%) and T3(l7.9%). The L values(L *) and b values(b*) in meat color were decreased as the feeding level of rice increased when compared to T1(P < 0.05). Warner-Bratzler shear force(WBS) values were higher in T2 and T3 compared to T1. Cooking loss(%) was increased for T2(23.49%) and T3(24.50%) compared to T1(22.90%). In fatty acid composition, linoleic acid(C18:2, n6) contents were significantly lower in T2(31.89%) and T3(27.89%) when compared to TI(33.21%)(P < 0.05), and the total contents of unsaturated fatty acids(UFA) were 76.85%(T1), 77.22%(T2), or 75.49%(T3). The ratio of n6/n3 was decreased as the level of rice increased in the feed(T1 19.89%, T2 17.73%, and T3 17.01%). In conclusion, the meat quality was not significantly different between T1 and T2 from the results of carcass weight, meat color, WBS, and fatty acid composition; therefore, brown rice can be substituted for 50% of corn in the broiler diets.

• Korean Journal of Poultry Science
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• v.32 no.4
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• pp.245-254
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• 2005

This experiment was conducted to investigate the effect of the supplemental alkali feldspar-ilite(feldspar) on growth performance and meat quality in broiler ducks for 43 days. One hundred eighty broiler ducks were divided into 5 groups of 12ducks. Dietary levels of feldspar 0, 0+antibiotics, 0.5, 1.0 and $1.5\%$ were added to experimental diets of each of the groups. Daily weight gain was slightly increased in 1.0 and $1.5\%$ feldspar treatments. Feed intake was slightly increased at all feldspar treatments. Glucose concentration of serum profile was decreased whereas BUN concentration was significantly increased (p<0.05) at $0.5\%$ feldspar. Cholesterol concentration was decreased at all feldspar treatments, this difference was especially observed in supplemental levels of $0.5\%$ feldspar(p<0.05). Carcass weight was increased at all feldspar treatments. Moisture and crude fat contents of proximate chemical composition in duck meat were decreased at all feldspar treatment, this difference especially was observed in supplemental levels of $1.5\%$ feldspar(p<0.05) on crude fat content. Lightness and yellowness was increased at all feldspar treatment. Cholesterol contents and TBA in meat were decreased, but this parameters were not difference by feldspar treatment. The composition of saturated fatty acids(SFA) was decreased, whereas unsaturated fatty acids(USFA) was slightly increased by feldspar treatment. The Pb content of heavy metal concentrations was increased with compared control, but not difference. The appearance of sensory evaluation was improved by supplemental feldspar, especially in supplemental feldspar, 1.0 and $1.5\%$(p<0.05). The results of this study indicate that the supplemental alkali feldspar may improve the production and meat quality of broiler ducks.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.195-202
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• 2006

Two experiments were conducted to investigate the effect of dietary selenium sources on performance and selenium retention in broiler chickens and laying hens. In experiment 1, the effects of dietary selenium sources and levels on the weight gain, feed intake, feed conversion, and selenium retention of meat in broiler chickens were investigated. for each growth phase, the basal diet was supplemented with 0 (control), 0.12 and 0.24 ppm Se from sodium selenite (SS) and 0.12, 0.24 and 0.60 ppm Se from selenium yeast(SY). Weight gain was significantly increased(P<0.05) in supplemental 0.24 and 0.60 ppm SY compared to the 0.24 ppm SS by diet during day 1 to 35, but feed intake and feed conversion were not affected by the source or the level of Se. Selenium concentrations of breast and leg muscle were significantly increased(P<0.05) in supplemental SS and SY compared to the control, and linearly increased(P<0.05) as dietary. Se level increased by SY, but there was no difference in supplemental 0.12 ppm SS compared to 0.24 ppm SS. In experiment 2, 12-week-experiment using Hy-Line laying hens(31 wk of age) was conducted to compare the effects of selenium sources and levels on egg production, egg weight, daily egg mass, feed intake, feed conversion, egg quality, and selenium retention of egg in laying hens. A corn-soybean meal basal diet was supplemented with 0 (control), 0.06 and 0.12 ppm Se from sodium selenite (SS) and 0.06, 0.12 and 0.30 ppm Se from selenium yeast(SY). Feed conversion was significantly improved(P<0.05) in supplemental 0.06 ppm SS compared to the control, but egg production, egg weight, daily egg mass, and feed intake were not affected by source and level of Se. Haugh unit was not affected by source or level of Se. Yolk color was significantly(P<0.05) higher in supplemental 0.3 ppm SY compared to the control and other supplement in week 12. Eggshell breaking strength was significantly(P<0.05) higher in supplemental 0.06 ppm SY(P<0.05). Thickness of eggshell was not affected by source or level of Se. Se concentrations of egg was significantly improved(P<0.05) in supplemental SS and SY compared to the control, and was significantly increased(P<0.05) as dietary Se level increased by SS and SY, especially SY more effective compared to the SS.