• Food Science of Animal Resources
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• v.38 no.5
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• pp.835-850
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• 2018

The dramatic improvements in the growth rate and breast muscle size and yield in broilers through the intensive genetic selection, and the improvement in nutrition and management over the past 50 years have introduced serious abnormalities that influenced the quality of breast meat. The abnormalities include pale-soft-exudative (PSE) conditions, deep pectoral muscle (DPM) myopathy, spaghetti meat (SM), white striping (WS), and woody breast (WB) that have serious negative implications to the broiler meat industry. The incidences of PSE and DPM have been known for several decades, and their prevalence, etiology and economic impact have been well discussed. However, other abnormalities such as SM, WS and WB conditions have been reported just for few years although these conditions have been known for some time. The newly emerging quality issues in broilers are mainly associated with the Pectoralis major muscles, and the incidences have been increased dramatically in some regions of the world in recent years. As high as 90% of the broilers are affected by the abnormalities, which are expected to cause from $200 million to $1 billion economic losses to the U.S. poultry industry per year. So, this review mainly discusses the histopathological characteristics and biochemical changes in the breast muscles with the emphasis on the newly emerging abnormalities (SM, WS, and WB) although other abnormalities are also discussed. The impacts of the anomalies on the nutritional, functional, mechanical and sensory quality of the meat and their implications to the poultry industry are discussed.

• Korean Journal of Poultry Science
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• v.39 no.1
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• pp.17-25
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• 2012

Coccidiosis control programs such as vaccines or in-feed anticoccidials are commonly practiced in the poultry industry to improve growth performance and health of commercial broiler chickens. In this study, we assessed the effects of various coccidiosis control programs (e.g., in ovo vaccination, synthetic chemicals, and antibiotic ionophores) on immune status of broiler chickens vaccinated against infectious bronchitis virus and Newcastle disease virus (ND) and raised on an Eimeria-contaminated used litter. In general, the levels of ${\alpha}$-1-acid glycoprotein, an acute phase protein, were altered by the treatments when measured at 34 days of age. Splenocyte subpopulations and serum antibody titers against ND were altered by various coccidiosis control programs. In-ovo-vaccinated chickens exhibited highest mitogenic response when their spleen cells were stimulated with concanavalin A (Con A) at 7 days of age. It is clear from this study that the type of coccidiosis control program influenced various aspects of innate and adaptive immune parameters of broiler chickens. Further studies will be necessary to delineate the underlying relationship between the type of coccidiosis control program and host immune system and to understand the role of other external environmental factors such as gut microbiota on host-pathogen interaction in various disease control programs.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.249-253
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• 2019

Various factors negatively affect poultry production, including a multitude of avian pathogens. Among them, Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) cause world-wide economic losses in the poultry industry. Although respectively, MG and MS induce chronic respiratory disease and synovitis in poultry, these pathogens often manifest as clinically inapparent infections and many countries are therefore having difficulties effectively eradicating them. In this study, five broiler breeder farms in Korea were investigated for the presence of Mycoplasma infection from 2016 to 2018. Serum samples were collected for detection of antibodies to mycoplasma species using an enzyme-linked immunosorbent assay (ELISA) kit. Additionally, the production index and feed conversion rate of broilers were recorded. According to this investigation, broiler breeder farms in 2018 were serologically negative for Mycoplasma infection with broilers exhibiting a high production index and low feed conversion rate. Thus, eradicating mycoplasma in poultry farms is critical for improving chick quality and overall poultry production.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.12
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• pp.1796-1804
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• 2016

The high incidence of deaths during transport for slaughter is associated with poor welfare and represents a considerable loss to the poultry industry. In the period from 2009 to 2014, all shipments of broiler chickens to poultry processing plants were monitored in the Czech Republic and the numbers of chickens transported and those dying as a result of their transport were recorded and analysed. Overall transport-related mortality of broiler chickens transported for slaughter in the Czech Republic was 0.37%. It ranged from 0.31% to 0.72%, the increase approximately corresponding to the increasing transport distance. Statistically highly significant (p<0.001) differences were found when comparing transport-related mortality rates in individual seasons of the year. The greatest mortality (0.55%) was associated with transports carried out in winter months whereas the lowest death losses (0.30%) were found in chickens transported for slaughter in summer months. Our study revealed greater transport-related mortality rates in broiler chickens transported for slaughter in the Czech Republic than expected when considering earlier studies. The most pronounced increases were found in transports for shorter distances and in winter months. However, an increase was found at all transport distances monitored except for distances exceeding 300 km and all seasons except for summer. Furthermore, a general increasing tendency in chicken losses during the monitored period was found. The particularly alarming finding is that the mortality of broiler chickens being transported to processing plants has been showing a long-term increasing tendency over the last two decades. Further research should focus on the identification of specific factors leading to such high and growing mortality rates and developing practical guidelines to improve the welfare of the birds in transit accordingly.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.27-37
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• 2020

As domestic meat consumption increases, the broiler production industry has been larger and denser. The concentration of particulate matter (PM) and harmful gases generated is also increasing inside livestock house. However, the current research status of PM exposed to farm workers and the health effects are in the early stage. To understand PM concentration affecting workers in the broiler house, field monitoring was conducted according to its size distributions. Concentrations of PM₁₀, PM_2.5, and TD (Total Dust) were monitored using personal air samplers with teflon filter during working and moving periods considering the ventilation systems of 6 broiler houses. The purpose of this study is to monitor the PM concentration in the experimental broiler houses operated by forced ventilation system generally used in Korea and to evaluate the regional concentrations through airflow pattern. The PM concentrations were increased from inlet to outlet vents resulting in 1,872 of TD, 1,385 of PM₁₀, and 209 ㎍/㎥ of PM_2.5, respectively. The TD and PM₁₀ concentrations were increased when the workers and broilers were moving. Among them, the particle size that occupied the largest amount of PM was 13.75 ㎛. These results suggest that personal protection equipments are important to reduce the health effect from PM inhalation.

• Korean Journal of Poultry Science
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• v.35 no.1
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• pp.85-99
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• 2008

Avian reovirus (ARV) is a causative agent of viral arthritis/tenosynovitis, and malabsorption syndrome in broiler. The characteristics of malabsorption syndrome caused by ARV are diarrhea, poor feed conversion and stunting. Therefore, ARV infection has been recognized as one of the most important disease in the poultry industry because of economical losses. However, few study of ARV infection in broiler industry has been conducted in Korea. To evaluate the presence of ARV infection in broiler farms, epidemiological survey such as serological test and virus isolation has been conducted. For the serological survey using ELISA method, we selected five broiler farms which were located at different area and had a history of growth retardation, lameness, diarrhea and poor feathering. From these farms serum samples were collected at 1 day, 14 days and market age. All these farms had no history of vaccination against ARV. In addition to serological survey, we tried to isolate ARV from birds of designated farms at market age and collected feces and tissue samples such as cecal tonsil, intestine and liver. We were identified ARV by RT-PCR and transmissible electron microscopy. The samples were inoculated into 9-day-old embryonated eggs via the chorioallantoic membrane to observe the pock formation. For the pathogenicity test of ARV isolates, we inoculated with the isolates to the right footpad of 3-week-old SPF chicks and observed clinical signs and pathological changes for 14 days after challenge. Most broilers sampled for serological survey have maternal antibodies which were widely distributed at 1 day and decreased by 14 days. However, at the market age several broiler farms showed fairly high antibody titer against ARV. This increase of antibody titer at market age means the possible infection of ARV during the grow-out period. Among total 15 samples for the isolation of ARV. 2 samples were positive by RT-PCR and finally identified as a ARV. We inoculated these isolates in the SPF birds and observed that the antibody titer was increased from 7 days after challenge. However, we did not find any clinical signs both control and challenge groups. Based on the above results, it is clear that the ARV infection has been circulated in the broiler industry and caused significant economic losses. Further study is needed to evaluate the virulence of the isolates in the digestive system of broiler and the molecular characteristics of isolates.

• Journal of Life Science
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• v.31 no.12
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• pp.1079-1087
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• 2021

To analyze gut microbiota of livestock in Korea and compare taxonomic differences, we conducted 16S rRNA metagenomic analysis through next-generation sequencing. Fecal samples from broiler chickens, pigs, and cattle were collected from domestic feedlots randomly. α-diversity results showed that significant differences in estimated species richness estimates (Chao1 and ACE, Abundance-based coverage estimators) and species richness index (OUTs, Operational taxonomic units) were identified among the three groups. However, NPShannon, Shannon, and Simpson indices revealed that abundance and evenness of the species were statistically significant only for poultry (broiler chickens) and mammals (pigs and cattle). Firmicutes was the most predominant phylum in the three groups of fecal samples. Linear discriminant (LDA) effect size (LEfSe) analysis was conducted to reveal the ranking order of abundant taxa in each of the fecal samples. A size-effect over 2.0 on the logarithmic LDA score was used as a discriminative functional biomarker. As shown by the fecal analysis at the genus level, broiler chickens were characterized by the presence of Weissella and Lactobacillus, as well as pigs were characterized by the presence of provetella and cattele were characterized by the presence of Acinetobacter. A permutational multivariate analysis of variance (PERMANOVA) showed that differences of microbial clusters among three groups were significant at the confidence level. (p=0.001). This study provides basic data that could be useful in future research on microorganisms associated with performance growth, as well as in studies on the livestock gut microbiome to increase productivity in the domestic livestock industry.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1510-1510
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• 2001

NIRS uses reflectance signals resulting from bending and stretching vibrations in chemical bonds between carbon, nitrogen, hydrogen, sulfur and oxygen. These reflectance signals are used to measure the concentration of major chemical composition and other descriptors of homogenized and freeze-dried whole broiler carcasses. Six strains of chicken were analyzed and the NIRS model predictions compared to reference data. The results of this comparison indicate that NIRS is a rapid tool for predicting dry matter (DM), fat, crude protein (CP) and ash content in the broiler carcass. Males and females of six commercial strain crosses of broiler chicken (Gallus domesticus) were used in this study (6$\times$2 factorial design). Each strain was grown to 16 weeks of age, and duplicate serial samples were taken for body composition analysis. Each whole carcass was pressure-cooked, homogenized, and a representative sample was freeze-dried. Body composition determined as follows: DM by oven dried method at 105$^{\circ}C$ for 3 hours, fat by Mojonnier diethyl ether extraction, CP by measuring nitrogen content using an auto-analyzer with Kjeldhal digest and ash by combustion in a muffle furnace for 24 hour at 55$0^{\circ}C$. These homogenized and freeze-dried carcass samples were then scanned with a Foss NIR Systems 6500 visible-NIR spectrophotometer (400-2500nm) (Foss NIR Systems, Silver Spring, MD., US) using Infra-Soft-International, ISI, WinISl software (ISI, Port Matilda, US). The NIRS spectra were analyzed using principal component (PC) analysis. This data was corrected for scatter using standard normal “Variate” and “Detrend” technique. The accuracy of the NIRS calibration equations developed using Partial Least Squares (PLS) for predicting major chemical composition and carcass descriptors- such as body mass (BM), bird dry matter and moisture content was tested using cross validation. Discrimination analysis was also used for sex and strain identification. According to Dr John Shenk, the creator of the ISI software, the calibration equations with the correlation coefficient, $R^2$, between reference data and NIRS predicted results of above 0.90 is excellent and between 0.70 to 0.89 is a good quantifying guideline. The excellent calibration equations for DM ($R^2$= 0.99), fat (0.98) and CP (0.92) and a good quantifying guideline equation for ash (0.80) were developed in this study. The results of cross validation statistics for carcass descriptors, body composition using reference methods, inter-correlation between carcass descriptors and NIRS calibration, and the results of discrimination analysis for sex and strain identification will also be presented in the poster. The NIRS predicted daily gain and calculated daily gain from this experiment, and true daily gain (using data from another experiment with closely related broiler chicken from each of the six strains) will also be discussed in the paper.

• Korean Journal of Veterinary Service
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• v.39 no.1
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• pp.21-28
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• 2016

Protozoan parasite, the genus Eimeria, causes an intestinal disease, coccidiosis, in young broilers. Coccidiosis induces significant economic loss in poultry production. This study was designed to identify the prevalence of Eimeria spp. in broilers in Gyeonggi province, Korea. Fecal samples from broilers at 94 farms were collected in two chicken slaughterhouses between March and June 2015. Eimeria infection was determined by microscopic examination and PCR using ITS-1 region. The prevalence of Eimeria was 58.5% (55 of 94). E. acervulina was identified in 96.4% of samples, E. tenella in 81.8%, E. maxima in 12.7%, E. praecox in 12.7%, E. brunetti in 5.5%, E. necatrix in 1.8%, and E. mitis in 1.8%. Body weight (BW) of broilers infected with both E. tenella and E. acervulina ($mean=1.53{\pm}0.19^Bkg$) was significantly lower than broilers with E. acervulina positive/E. tenalla negative ($mean=1.74{\pm}0.07^Akg$) or Eimeria negative ($mean=1.65{\pm}0.15^Akg$) (Duncan's multiple range test, P<0.01). High prevalence of Eimeria tenella and the impact on the broiler body weight shows the importance of this protozoa in broiler industry. Development of the periodic monitoring strategy and systemic management for the purpose of the prevention/eradication of Eimeria infection among broilers is required.

• Korean Journal of Organic Agriculture
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• v.19 no.4
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• pp.565-575
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• 2011

Recently, the use of antibiotics to improve animal productivity in livestock industry was strictly restricted. For these reason, probiotics have been regarded as one of promising materials for an antibiotic alternative. In this study, we investigated how the probiotics influences on the performance of broiler chicken via meta-analysis. Eighteen researches from 1997 to 2010 were used for meta-analysis. The standard summary effects were calculated via fixed effect model and random effect model (Borenstein et al., 2009). Heterogeneity was calculated by using the Cochran's Q statistics (Kook et al., 2009) and publication bias was calculated via Egger's regression (Lee et al., 2011). In fixed model average daily gain, body weight serum protein content and cecal LAB showed positive effect significantly. Feed intake, feed/gain and serum cholesterol showed significant negative effect. In serum triglyceride, negative effect was found but significance was not shown. In random model, average daily gain body weight and cecal LAB showed positive effects with significance and feed/gain and serum cholesterol represented significant negative effects. Publication bias was found only in feed/gain.