• Korean Journal of Veterinary Service
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• v.37 no.3
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• pp.185-190
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• 2014

We investigated the serological prevalence of avian metapneumovirus (AMPV), avian reovirus (ARV), Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) in 760 broiler breeder (38 flocks), in the Jeonbuk province in 2013. This study was conducted to evaluate the immune and infection status of the broiler breeder flocks against AMPV, ARV, MG, MS by an enzyme-linked immunosorbent assay (ELISA). Serological test for AMPV were positive 37 (97.3%) flocks and 712 (93.6%) broiler breeder and geometric mean antibody titers were $16,350{\pm}10,195$, ARV were high positive rate 100% (38/38) flocks and 97.8% (743/760). The seropositive flocks against MG were 71.1% (27/38) and the geometric mean antibody titers were $2,474{\pm}2,045$, whereas the rates of positive flocks against MS were 50.0% (19/38) and the geometric mean antibody titers were $1,469{\pm}1,230$.

• Korean Journal of Poultry Science
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• v.10 no.2
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• pp.113-121
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• 1983

In an effort to understand epizootiological aspects of infectious laryngotracheitis (ILT), a total of 56 chicken flocks in six farms comprised of 35 broiler breeder, 13 commercial layer and 6 layer breeder flocks. were investigated. The farms experienced ILT during the period of one year from June, 1982. In most farms the birds were vaccinated against ILT just before or after the disease outbreak. In two of the farms in which ILT broke out in winter, it was possible to contain the disease in only one or two fleets without transmitting it to the remaining 5 to 7 flocks in the farms by adopting strict isolation procedures for the affected flocks. In regarding inter- flock spreading speed, it took an average of 6 days for flocks rearing on floor and 11 days for those in cages. Among the flecks in rearing cages. transmission among laying flocks was much faster. taking an average of 8 days, compared to non-laying flocks of 17 days, suggesting spreading of the disease by means of egg trays or egg collection process. Peak mortality was observed between 5 and 10 days after from the time of appearance of first dead birds from the disease and the period of mortality, with an average of 18 days, was not influenced by rearing systems, breeds and age of birds. Mortalities in the affected flocks ranged from lo/e to 19.8%, with an average of 6.5 %, and was also not influenced by the above variables except significantly lower mortality in immature broiler breeder flocks (2.9%) compared to immature layer (11.8%) and mature broiler breeder flocks (6.9%). In one breeder farm in which all the birds were kept on floor and ILT broke out in summer, mortality in male birds in all seven flocks of 37 weeks of age or older was as high as twice of that in female birds in the same flocks. This trend was not observed in one 31 weeks old flock and was reversed in another 14 weeks old flock in the farm.

• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.101-105
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• 2016

The present study investigated serological and molecular prevalence of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) infection in unvaccinated broiler breeder farms in Jeonbuk providence. An enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) had been used to determine antibody titers against MG and MS, and genome of these pathogens, respectively. Seventy five percent of farms were seropositive for MG and 94% of farms were seropositive for MS. In addition, the rate of antibody positive flocks against MG were 65.3% (32/49), while the rate of positive flocks against MS were 84.2% (80/95). The geometric mean antibody titers were $802.2{\pm}626$ and $27,726.7{\pm}2426$ against MG and MS, respectively. Interestingly, none of samples was positive for MG genome by PCR, while 94% (farms), 82% (flocks) and 62.6% (broiler breeder) were positive for MS genome by PCR. These findings suggest that the prevalence of MG or MS infection could be higher than expected. Thus, strict prevention program including vaccination and environmental sanitation should be implemented to avoid disease transmission from breeder to broilers as well as transmission among broilers.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.1-6
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• 2002

Eggs obtained from 46 and 42 weeks old meat (Hybro) and layer (Leghorn) breeders flocks, respectively were used to examine the effects of genetic type of birds and egg size (small, medium and large) on variables of eggshell characteristics and hatchability traits. The variables measured were egg weight (EW), egg surface area (ESA) and eggshell characteristics (shell conductance (EC), per cent shell (PS), shell thickness (ST), shell volume (SV), shell density (SD) and hatchability traits (per cent hatchability (HP), early dead embryos (ED), late dead embryos (LD), pips with live embryos (PL) and pips with dead embryos (PD)). Genetic type of bird influenced all egg characteristics and HP of eggs. Eggs produced by the small Leghorn bird had lower EW, ESA, EC, ST, SV and HP than those produced by the heavy Hybro bird. The reduction of HP was associated with an increase in the percentage of ED and PL. Egg size influenced all variables measured except ST. Small size eggs had lower EW, ESA and EC and higher PS and SD than those of large eggs. Medium size eggs produced a higher HP when compared with that of large size eggs. The reduction of HP in large eggs was associated with higher percentage of ED, LD and PL. There were significant interactions between the genetic group of birds and egg size on LD and HP. Large egg size of Hybro birds had higher LD and lower HP than those of small size eggs produced by the same flock. However, There was no difference in HP and LD among the different egg sizes produced by Leghorn birds. It was concluded that genetic make up of birds and egg size influence eggshell characteristics and HP. The type of bird (heavy or small) influences the optimum egg size for successful hatching. Attention should be given to the size and eggshell characteristics of eggs of breeders' flocks for achieving maximum HP.

• Korean Journal of Veterinary Research
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• v.20 no.1
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• pp.59-64
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• 1980

Incidence of avian infectious diseases in breeder chickens was followed serologically. Serum samples were collected during the period of 1978~1979 from breeders throughout country and tested for the presence of antibodies against Salmonella pullorum(SP), Mycoplasma gallisepticum(MG), Avian Infectious Bronchitis virus(AIBV), Infectious Bursal Disease virus(IBDV) and Egg Drop Syndrome Virus(EDS). The tests used serum plate agglutination for SP and MG, immuno-diffusion for AIBV and IBDV and hemagglutination-inhibition test for EDS virus. The results are summarized as follows: 1. Individuals and Hocks incidence rate of Avian Infectious Bronchitis virus were 16.9% and 55.3%. 2. Individuals and Hocks incidence rate of Infectious Bursal Disease virus were 50.1% and 66.4%. 3. Individuals and Hocks incidence rate of sal. pullorum were 17.2% and 65.9%. 4. Individuals and flocks incidence rate of M. gallisepticum were 36.2% and 63.2%. 5. Individuals and flocks incidence rate of Egg Drop Syndrome (BC 14) virus were 14.1% and 46.3%.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.297-302
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• 2002

The effects of eggshell pigmentation and egg size (medium and large) on the spectral properties and characteristics of eggshells were examined in eggs from two genetic groups of breeder flocks. Birds from meat (Hybro, pigmented eggshell, PES) and layer (Leghorn, non-pigmented eggshell, NPES) at 40 and 46 weeks of age, respectively, were used. Measurements of per cent shell (PS), shell thickness (ST), shell volume (SV), shell density (SD), egg shell conductance (EC) and physical dimensions of eggs were made. The spectral properties of eggshells were measured over the wavelength (WL) range of 200 to 1,100 nm. Eggshell absorbed approximately 99.8 percent of the light and transmitted only about 0.12 percent with a maximum light transmission at the near-infra-red region of about 1075 nm. It attenuated shorter WL and transmitted longer WL. Eggshell pigmentation and egg size influenced light transmission into the egg. The NPES had higher EC and transmission of light and lower PS and SD than those of the PES. Large size eggs had higher EC, SD, SV, transmission of light and egg physical dimensions than those of medium size eggs. It is concluded that genetic make up of birds and egg size influenced eggshell characteristics including EC and that, as a consequence, the difference in the spectral properties of eggshells. The pigmentation of eggshell influenced the amount and WL transmitted into the egg. The size and EC of eggs influenced the amount of light transmitted through the eggshell. EC is a good indicator for the ability of eggshell to transmit light.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.563-573
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• 2000

Periodic outbreaks of Newcastle disease (ND) caused by velogenic viscerotropic ND virus (vvNDV) has become a major concern in Korea nowadays. Throughout last epidemic, the winter season in 2000, most chicken flocks infected early, under 2-4 weeks of age, showed high mortality up to 50-100%. Serum samples collected from 201 breeder, 284 layer and 112 broiler chicken flocks were examined to evaluate the efficacy of various vaccination methods and programs routinely used for mass vaccination in the field poultry farms. Despite repeated live vaccination, most poultry flocks vaccinated by drinking water route using nipple water supply system failed to produce solid active immune response to NDV during the growing time. In the present study, we applied the spray vaccination technique using Ulvavac or Desvac sprayer to the experimental poultry flocks and examined the efficacy of live vaccination effects induced by it under field condition. Measurable antibody to NDV as well as early protection against vvNDV challenge were found in poultry flocks vaccinated by spray route. Further, we did not found significant post vaccination reactions caused by spray vaccination if properly administered. These data indicate that the spray vaccination will be safe and reliable mass vaccination method for the prevention of ND.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.237-245
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• 2010

A survey of transovarially transmitted diseases, including salmonellosis [(pullorum disease; PD)/(fowl typhoid; FT)], mycoplasmosis, avian infectious anemia (CIA), and fowl adenovirus infection was conducted in the breeder chickens from August to December in 2009. The numbers of flocks sampled out were: Grand Parents Stock (GPS), 45; Parents Stock (PS) 1,018, Baeksemi breeder (BSB) 54. The seroprevalence of salmonellosis (PD/FT) were 0% (GPS), 3.2% (PS), and 3% (BSB), respectively. A total of 983 chicken farms were affected with FT outbreaks between 2000 and 2008. The incidence of FT in commercial broilers, Baeksemi, commercial layers, native chickens, and broiler breeders was 44.3%, 26.2%, 15.7%, 12.6% and 1.08%, respectively. Of the affected broilers, over 90% birds were under 2 weeks of age, indicating it was possible that they were infected with S. gallinarum via vertical transmission. The sero-positive flocks against Mycoplasma gallisepticum (MG) were 71.1% (GPS), 88.7% (PS), 88.7% (BSB), while the rates of positive flocks against Mycoplasma synoviae (MS) were 86.0% (GPS), 77.0% (PS), and 98.0% (BSB). In GP and parent farms, the detection rates on specific genes of CIA virus were 19/45 (42.2%), and 169/1039 (18.0%), respectively, whereas the seroprevalence of CIA were 86.0% in GPS and 93.7% in PS flocks. In addition, positive flocks of fowl adenoviruses were 4.4% (GPS), 2.7% (PS) and 9.35% (BSB), respectively. As the results, avian mycoplasmosis and CIA have been more prevailing in chicken breeder than avian salmonellosis and fowl adenovirus infection in Korea.

• Korean Journal of Poultry Science
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• v.30 no.1
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• pp.55-59
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• 2003

A necrotizing skeletal myopathy was diagnosed in three flocks of 30,000 thirty-eight-week-old layer breeder chickens. The mortality attributed to the myopathy was 17.7%, 12.3% and 21.1% in flock A, B and C, respectively. Clinically, chickens were showed depression, anorexia, posterior paresis, inability to rise, incoordination, reluctance to move, and leg trembling and weakness. The most striking findings at necropsy was pale streaking in the muscles of the thighs and legs. Microscopic lesions included myofiber degeneration and necrosis with massive cellular proliferation interpreted as sarcolemmal nuclei proliferation. Plasma creatine kinase, asparte aminotransferase and akaline phosphatase were markedly elevated. In conclusion, author suggested that submitted chickens were affected by ionophores poisoning.

• Korean Journal of Veterinary Research
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• v.26 no.2
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• pp.277-282
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• 1986

Reduced egg production with depigmented, chalky deposit, wrinkled and malformed eggs was observed in breeder flecks at the end of 1985 and further spread in laying flocks throughout the country. The disease was identified as Infectious Bronchitis based on serological findings and virus isolation.