• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.437-443
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• 2010

To be economically profitable, the poultry industry demands an increase in stocking density, which could adversely affect chicken welfare. The current study was performed to investigate the effect of stocking density on stress-related, heat shock protein genes (HSP70 and HSP90), 3-hydroxyl-3-methyl-glutaryl coenzyme A reductase (HMGCR) gene and telomere length in broiler chickens. Seven-day-old broiler chickens were housed at High (0.0578 $m^2$/bird), Standard (0.077 $m^2$/bird) and Low (0.116 $m^2$/bird) stocking densities with 8 replicates each until 35 d of age. The growth performance, such as body weight gain and average daily feed intake, was found to be significantly (p<0.05) higher in the Low density group, but these parameters did not show any difference between the High and Standard groups. Other growth performance, such as feed conversion ratio and final feed intake, showed no difference among the treated groups. The expression levels of HSP70 and HMGCR were found to be elevated with the increase of stocking density. The expression level of these genes was significantly (p<0.05) higher in the High density stocked group compared with the other groups, whereas the expression levels were not significantly different between the Low and Standard groups. The expression levels of HSP90 did not show any significant changes among the treated groups. The telomeric length of the birds housed in High density was reduced significantly (p<0.05) when compared to that of the birds in Low density. These results clearly indicate that birds stocked at high density show physiological adaptive changes indicative of stress at gene transcriptional and telomere levels.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.1028-1037
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• 2015

Unique organoleptic characteristics such as rich flavors and chewy texture contribute to the higher popularity of native chicken in many Asian areas, while the commercial broilers are well-accepted due to their fast-growing and higher yields of meat. Sensory attributes of foods are often used to evaluate food eating quality and serve as references during the selection of foods. In this study, a three-phase descriptive sensory study was conducted to evaluate the sensory attributes of commercial broiler (BR) and Taiwan native chicken (TNC) breast meat, and investigate correlations between these sensory attributes and instrumental measurements. The results showed that for the first bite (phase 1), TNC meat had significantly higher moisture release, hardness, springiness, and cohesiveness than BR meat. After chewing for 10 to 12 bites (phase 2), TNC meat presented significantly higher chewdown hardness and meat particle size, whereas BR meat had significantly higher cohesiveness of mass. After swallowing (phase 3), TNC meat had higher chewiness and oily mouthcoat and lower residual loose particles than BR meat. TNC meat also provided more intense chicken flavors. This study clearly demonstrates that descriptive sensory analysis provides more detailed and more objectively information about the sensory attributes of meats from various chicken breeds. Additionally, sensory textural attributes vary between BR and TNC meat, and are highly correlated to the shear force value and collagen content which influence meat eating qualities greatly. The poultry industry and scientists should be able to recognize the sensory characteristics of different chicken meats more clearly. Accordingly, based on the meat's unique sensory and physicochemical characteristics, future work might address how meat from various breeds could best satisfy consumer needs using various cooking methods.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1531-1539
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• 2009

This study compared the nutritional value of canola (B. napa) and mustard (B. hirta) press cakes obtained from the biodiesel industry as ingredients for use in diets fed to broiler chickens. A total of 210, one-day old, male broiler chicks were randomly assigned to one of seven dietary treatments. The control diet was based on wheat and soybean meal and contained 15% canola meal. For the experimental diets, 5, 10 or 15% of the canola meal was replaced with an equal amount of either canola or mustard biodiesel press cake. Dry matter and neutral detergent fiber digestibility were significantly higher for birds fed diets containing either canola or mustard biodiesel press cake compared with canola meal. Dry matter and neutral detergent fiber digestibility of the canola biodiesel press cakes was higher than the mustard biodiesel press cakes. Ether extract digestibility and nitrogen retention were significantly higher for birds fed canola biodiesel press cake compared with canola meal and mustard biodiesel press cake. Body weight gain and feed intake did not differ between birds fed canola or mustard biodiesel press cake and canola meal. In addition, there was no significant difference in body weight gain or feed intake between birds fed diets containing canola or mustard biodiesel press cake. Feed conversion was significantly improved for birds fed either canola or mustard biodiesel press cake compared with canola meal. Mortality was unaffected by treatment. Since the performance of broilers fed canola biodiesel press cakes was essentially the same as that of broilers fed canola meal, it is difficult to justify a premium to be paid for canola biodiesel press cake over that paid for canola meal. In addition, there was no difference in the performance of broilers fed biodiesel press cake obtained from canola or mustard seed. As mustard seeds are generally available at a lower price than canola seed, there may be some incentive to use mustard rather than canola seed for producing biodiesel press cake for use in poultry production.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.541-551
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• 2012

The effects of dietary additives and holding time on resistance and resilience of broiler chickens to Clostridium perfringens challenge were investigated by offering four dietary treatments. These were a negative control (basal), a positive control (Zn-bacitracin) and two dietary additives, mannanoligosaccharides (MOS), and acidifier. Two holding times included (a) immediate access to feed and water post hatch (FED) and (b) access to both feed and water 48 h post hatch (HELD). Chicks fed Zn-bacitracin had no intestinal lesions attributed to necrotic enteritis (NE), whereas chicks fed both MOS or acidifier showed signs of NE related lesions. All dietary treatments were effective in reducing the numbers of C. perfringens in the ileum post challenge. The FED chicks had heavier body weight and numerically lower mortality. The FED chicks also showed stronger immune responses to NE challenge, showing enhanced (p<0.05) proliferation of T-cells. Early feeding of the MOS supplemented diet increased (p<0.05) IL-6 production. The relative bursa weight of the FED chicks was heavier at d 21 (p<0.05). All the additives increased the relative spleen weight of the HELD chicks at d 14 (p<0.05). The FED chicks had increased villus height and reduced crypt depth, and hence an increased villus/crypt ratio, especially in the jejunum at d 14 (p<0.05). The same was true for the HELD chicks given dietary additives (p<0.05). It may be concluded that the chicks with early access to dietary additives showed enhanced immune response and gut development, under C. perfringens challenge. The findings of this study shed light on managerial and nutritional strategies that could be used to prevent NE in the broiler industry without the use of in-feed antibiotics.

• Journal of Veterinary Science
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• v.19 no.6
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• pp.759-770
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• 2018

Fowl adenovirus (FAdV) is distributed worldwide and causes economic losses in the poultry industry. The objectives of this study were to determine the hexon and fiber gene changes in an attenuated FAdV isolate from Malaysia in specific pathogen-free chicken embryonated eggs (SPF CEE) and its infectivity in commercial broiler chickens. SPF CEE were inoculated with 0.1 mL FAdV inoculum via the chorioallantoic membrane (CAM) for 20 consecutive passages. The isolate at passage 20 (E20), with a virus titer of $10^{8.7}TCID_{50}/mL$ ($TCID_{50}$, 50% tissue culture infective dose), was inoculated (0.5 mL) into one-day-old commercial broiler chicks either via oral or intraperitoneal routes. The study demonstrated that 100% embryonic mortality was recorded from E2 to E20 with a delayed pattern at E17 onwards. The lesions were confined to the liver and CAM. Substitutions of amino acids in the L1 loop of hexon at positions 49 and 66, and in the knob of fiber at positions 318 and 322 were recorded in the E20 isolate. The isolate belongs to serotype 8b and is non-pathogenic to broiler chickens, but it is able to induce a FAdV antibody titer. It appears that molecular changes in the L1 loop of hexon and the knob of fiber are markers for FAdV infectivity.

• Animal Bioscience
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• v.34 no.4
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• pp.652-661
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• 2021

Objective: Wooden breast (WB) is a novel myopathy affecting modern broiler chickens, which causes substantial economic losses in the poultry industry. The objective of this study was to evaluate the effect of WB abnormality on meat quality, redox status, as well as the expression of genes of the nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway. Methods: A total of 80 broilers (Ross 308, 42 days of age, about 2.6 kg body weight) raised at Jiujin farm (Suqian, Jiangsu, China) were used. Twelve unaffected (no detectable hardness of the breast area) and twelve WB-affected (diffuse remarkable hardness in the breast muscle) birds were selected from the commercial broiler farm according to the criteria proposed by previous studies. Results: The results indicated that WB showed histological lesions characterized by fiber degeneration and fibrosis, along with an increase of muscle fiber diameter (p<0.05). Moreover, higher pH value, lightness, yellowness, drip loss and cooking loss were observed in the WB group (p<0.05). Compared with the normal breast (NOR) group, the WB group showed higher formation of reactive oxygen species (p<0.05), increased level of oxidation products and antioxidant activities (p<0.05), accompanied with mitochondrial damages and lower mitochondrial membrane potential (p<0.05). Meanwhile, the relative mRNA expressions of Nrf2 and its downstream antioxidant genes including heme oxygenase-1, NAD(P)H qui none dehydrogenase 1, glutathione peroxidase, superoxide dismutase, and glutamate-cysteine ligase were higher than those of the NOR group (p<0.05). Conclusion: In conclusion, WB myopathy impairs meat quality by causing oxidative damages and mitochondrial dysfunction in broilers, even though the activated Nrf2/antioxidant response element pathway provides protection for the birds.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.441-458
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• 2023

The poultry industry, which produces excellent sources of protein, suffers enormous economic damage from diseases. To solve this problem, research is being conducted on the early detection of infection according to the behavioral characteristics of poultry. The purpose of this study was to evaluate the potential of a non-movement behavior observation method to detect sick chickens. Forty 1-day-old Ross 308 males were used in the experiments, and an isolator equipped with an Internet Protocol (IP) camera was fabricated for observation. The chickens were inoculated with Salmonella enterica serovar Gallinarum A18-GCVP-014, the causative agent of fowl typhoid (FT), at 14 days of age, which is a vulnerable period for FT infection. The chickens were continuously observed with an IP camera for 2 weeks after inoculation, chickens that did not move for more than 30 minutes were detected and marked according to the algorithm. FT infection was confirmed based on clinical symptoms, analysis of cardiac, spleen and liver lesion scores, pathogen re-isolation, and serological analysis. As a result, clinical symptoms were first observed four days after inoculation, and dead chickens were observed on day six. Eleven days after inoculation, the number of clinical symptoms gradually decreased, indicating a state of recovery. For lesion scores, dead chickens scored 3.57 and live chickens scored 2.38. Pathogens were re-isolated in 37 out of 40 chickens, and hemagglutination test was positive in seven out of 26 chickens. The IP camera applied with the algorithm detected about 83% of the chickens that died in advance through non-movement behavior observation. Therefore, observation of non-movement behavior is one of the ways to detect infected chickens in advance, and it appears to have potential for the development of remote broiler management system.

• Food Science of Animal Resources
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• v.42 no.2
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• pp.313-320
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• 2022

Brazil is considered as a great broiler feet exporter, especially for the Chinese trade. Contact lesions at the tibiotarsal region are responsible for economic losses and there is no model for its classification, thereby this study presents a fast and practical grade system to be used in the poultry industry and proposes these lesion characterizations into three different grades. For this, correlation was made between macroscopic, histological findings and microbiological quantification (Escherichia coli, Staphylococcus spp., Streptococcus spp. and sulphite-reducing clostridia) from contact lesions in the tibiotarsal region of 112 broiler carcasses, divided in four groups (n=28), accordingly to the lesion's intensity. There were no significant differences in microbiological quantification among the groups (p>0.05) except for the grade 3 group, as grade 1 and 2 lesions were in the early stages and histopathological changes such as ulceration were not observed. In grade 3 lesion group, it was observed bacterial cocci grume and ulceration at the articular region and significantly higher microbiological count (p<0.05) for E. coli and Staphylococcus spp. In conclusion, the visual standard proposed in this work, correlated and confirmed by the histopathologic, and microbiologic characterization, allows to precise and fast ascertainment of the contact lesion grade in the tibiotarsal regions of broiler carcasses. Moreover, it should be highlighted that grades 1 and 2 alterations are not caused by an inflammatory process caused by pathogenic agents and should not be considered a public health risk.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1314-1317
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• 2011

To evaluate the effects of pulsed electric field (PEF) application on scalder and chiller water on Campylobacter contamination, four different treatments under three different water conditions including hard scalder water ($55^{\circ}C$), soft scalder water ($45^{\circ}C$) and chiller water, were applied as follows: i) a control treatment with no salt and no electric treatment, ii) a PEF only treatment, iii) a PEF treatment with 0.5% salt water, and iv) a PEF treatment with 1% salt water treatment. The use of PEF in hard scalding water showed an effect of reducing Campylobacter when compared to the control during the 200 s timeframe. With the addition of salt, the intervention caused at least 5.81 log CFU/ml reduction of Campylobacter counts after 200 s of PEF exposure. Similar effects were observed under soft scalding conditions. Campylobacter reductions were evident under chilling conditions with up to 2.00 log for PEF only, 5.77 log for PEF+0.5% salt and 2.69 log for PEF+1% salt treatment in water. Therefore, the current PEF setting for the scalder and chiller water can be successfully used to reduce pathogenic loads of Campylobacter on broiler chicken carcasses, and further research may be necessary to apply it in the poultry processing industry.

• The Korean Journal of Food & Health Convergence
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• v.6 no.4
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• pp.11-16
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• 2020

Footpad dermatitis (FPD) can be considered as a threat for poultry production due to it causes losses due to condemnation in slaughterhouse. The prevalence and the severity of FPD in broiler breeders increase over time with development of poultry industry. The condition is produced by multifactorial including include drinker design and management, diet composition, house (temperature and humidity levels), litter (type, quality, and quantity) and gut health. Bacterial infections can be associated. FPD lesions can develop in less than a week. FPD is a variable size of inflammatory lesion of the footpad in commercial poultry characterized by necrotic lesions on the plantar surface of the footpad of poultry. These lesions can be exposed after removal of fecal mass and litter stuck on it. There are considerable and numerous interactions between the environment and the genetic traits. Prevention depends mainly on improvement of litter condition. Genetic selection against footpad dermatitis must be contributed to reduce pain and suffering for particular bird experiencing contact dermatitis as well as to avoid economic losses. The objective of this review is to collect different literature written about FPD to be available to students, researchers and veterinarian in poultry practical.