• Korean Journal of Veterinary Service
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• v.38 no.3
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• pp.167-171
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• 2015

Pathogenic microorganisms were monitored on the chicken carcasses in slaughterhouse of Jeonbuk area. It was conducted to evaluate the microbiological quality on 204 chicken carcasses. Staphylococcus (S.) aureus was isolated in largest number and its ration was 41.2%, Salmonella spp. 6.4%, Campylobacter (C.)jejuni 7.4%, C. coli 7.4%. Serotype of Salmonella (S.) spp. was identified as S. Infantis 46.1%, S. Enteritidis 23.1%, S. Typhimurium 7.7%, S. Montevideo 7.7%. In breed chickens, Salmonella spp. was detected broiler 4.1%, white semi-broiler 8.0% Korean native chicken 12.0%. C. jejuni was isolated broiler 7.4%, white semi-broiler 12.0%, Korean native chicken 0%, C. coli, broiler 7.4%, white semi-broiler 0%, Korean native chicken 18.1% and S. aureus, broiler 38.8%, white semi-broiler 40.0%, Korean native chicken 51.5%.

• Korean Journal of Veterinary Service
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• v.24 no.3
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• pp.217-222
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• 2001

Hemagglutination inhibition(HI) titers of Newcastle disease(ND) were measured to investigate the vaccination times on three different species of broiler chicks in Chonbuk province. Each 330 of Cobb, Ross and White-semi broiler chicks were selected from 11 broiler farms. The primary vaccine were sprayed in hatchery at one day old chicks. Secondary and tertiary vaccine were used by drinking water at 7 to 24 days old chicks. The ND antibody titer were measured by HI from each different species of broiler chicks at the marketing date. Total average HI titers of Cobbs vaccinated with primary ones, secondary and tertiary ones were recorded 1.86, 1.52 and 2.76, respectively. The antibody titers were shown to 2.22, 2.13, 3.07 in terms of vaccination of Ross broiler chicks. They were also 2.56, 2.65 and 2.78 in terms of vaccination of White-semi broiler chicks. The value HI titer were not statistically different of all treatments. The results of this experiment suggested that HI titer of sera is scored less than defensive value of ND antibody titer at more than two times of vaccination.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1482-1498
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• 2000

This paper reviews the meat-type chicken breeding with local breeds in China. The quality chickens are defined as purebred final products of local breeds, and semi-quality chickens as crossbreds of local breeds with specialized broiler (sire or dam) lines from western breeding organizations. The present status of the chicken production and the market in China, in comparison with the western countries, is reviewed, indicating that there is large market demand for (semi-) quality chickens in the present and future China. Breeding for (semi-) quality chickens emphasizes the sensory quality of chicken meat. The present status of breeding for (semi-) quality chickens with the local breeds is illustrated, including breeding goals and the existing breeding programs. The potential role of local breeds in breeding programs in China is discussed in relation to both providing higher quality (than commercial hybrid broilers) of chicken meat for the local market and meeting the objectives of genetic resource conservation. Besides, further research topics on breeding for (semi-) quality chickens are suggested.

• Korean Journal of Agricultural Science
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• v.48 no.1
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• pp.171-178
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• 2021

A comparative study was conducted to examine the effects of mixed and separate gender feeding on growth performance of Korean native chickens (KNC) against a white semi-broiler (WSB) and a commercial broiler (CB) over five weeks. 576 chicks were used with eight birds per cage in a randomized complete block design with 18 replicates per breed. For the KNC lines, three groups of male (M), female (F) and mixed-gender (FM) were used. Fresh water and feed were supplied on an ad-libitum basis. Birds were fed a standard starter (d 1 - 22) and grower diet (d 23 - 35). Body weight (BW), feed intake, and shank length (SL) were measured weekly. From the BW and feed consumed data, the average daily feed intake (ADFI), average daily gain (ADG), and feed conversion ratio (FCR) were calculated. The commercial broiler showed higher performance (p < 0.05) for all the indices measured for the entire period. The CB group consumed more feed and were more feed-efficient thus grew faster. This group was followed by the white semi-broiler and the KNC, in order. An intra-breed comparison for KNCs revealed that the males showed better growth performance with longer SL (p < 0.05) compared to the female and mixed-gender groups. The results showed that other than the breed type, mixed and separate gender feeding impacted on the growth performance of the two lines of Korean native chickens. Males for both lines of KNC generally performed better for the parameters measured, as determined by a greater BW and reduced FCR.

• Korean Journal of Veterinary Service
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• v.35 no.2
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• pp.91-97
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• 2012

The strategy for infectious bursal disease (IBD) control and its success rate under field conditions depends on hygiene management, IBD field pressure, level, and variation in maternally derived IBD antibodies. This study investigated the level of IBD-specific antibody by ELISA and the prevalence of IBD virus by PCR in broilers, white-semi broilers, and Korean native chickens raised in Jeongeup, Jeonbuk. IBD-specific maternally derived antibodies were measured from 698 chickens and the mean titers of maternal antibodies were $3,572{\pm}1,402$ in broilers, $1,262{\pm}762$ in white-semi broilers, and $1,932{\pm}912$ in Korean native chickens. At 2 weeks after vaccination, the geometric mean antibody titers of broiler, white-semi broiler, and Korean native chicken were $582{\pm}427$, $3255{\pm}1,080$, and $1,023{\pm}499$, respectively. According to sequence analysis of the variable virion protein 2 gene, 4 isolates were found to be very virulent IBDV, 9 isolates classical virulent, and 2 isolates intermediate plus vaccine strain.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.719-727
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• 2021

This study was conducted to evaluate the effects of mixed and separate gender feeding on the growth performance and carcass traits of Korean native chickens (KNC) compared to white semi-broilers (WSB) and a commercial broiler (CB) from hatching to 35 days. Here, 240 chicks were used with eight birds per cage in a randomized design with six replicates per breed. For the KNC lines, three groups of males (KNC-M), mixed-gender birds (KNC-FM) and females (KNC-F) were used. The two-phase feeding program used here consisted of a starter phase (days 1 - 21: crude protein [CP] 20% and metabolizable energy [ME], 3,050 kcal·kg^-1) and a grower phase (days 22 - 35: CP 18%, 3,100 kcal·kg^-1) for a commercial broiler. The WSB and CB were fed the only starter commercial diet. Fresh water and feed were provided ad-libitum. The results revealed that the KNC group had a lower (p < 0.05) body weight (BW) from day 7 and day 35 compared to that of the CB. Furthermore, the KNC group showed a lower (p > 0.05) average daily gain (ADG) relative to that of the CB during the entire experimental period. No difference (p > 0.05) was observed in the shank length among the treatments. There were also no significant differences in the growth performance or carcass traits between the KNC-M and WSB groups or in the genders of the KNC group.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.305-312
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• 2019

This study investigated the effect of diet supplementation with pine cone extracts (pine cone ethanol extract: PCEE; pine cone ethanol-hexane extract: PCEHE) on growth performance, digestive organ characteristics and intestinal microbiota of semi-broiler. Twenty two-weeks-old semi-broilers were divided into four dietary groups (n=5/group; control(-): no antibiotics and pine cone extracts; control(+): 2% antibiotics [20 g/kg basal diet]; PCEE: 2% PCEE [20 g/kg basal diet]; PCEHE: 2% PCEHE [20 g/kg basal diet]). Chicks were reared and their diets were supplemented accordingly for 16 days. Final weight, weight gain and feed intake were lowest (P<0.05) in semi-broilers whose diet was supplemented with pine cone extracts, but both PCEE and PCEHE groups showed lower (P<0.05) feed conversion ratios compared to the control(-) group. Gizzard and small intestinal weight were also lower (P<0.05) in both PCEE and PCEHE groups than in the control(-) group. Intestinal length and villus height were similar for all treatments. Furthermore, cecal microbiota was not improved by PCEE and PCEHE supplementation. These findings suggest that diet supplementation with pine cone extracts improves the feed conversion ratio and affects the digestive organ weight of semi-broilers.

• Korean Journal of Agricultural Science
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• v.48 no.1
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• pp.133-140
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• 2021

The aim of this study was to evaluate the growth performance between two different crossbred strains of Korean native chickens denoted as 1A and 2A compared to white semi broilers and Ross (RR) from hatching to 40 days. In total, 576 one-day-old chicks were allocated in a completely randomized design to give 18 replicate cages each (eight chicks per cage). The two-phase feeding program consisted of the starter (day 1 - 21: Crude protein [CP] 20% and metabolizable energy [ME], 3,050 kcal·kg^-1) and the grower (day 22 - 40: CP 18%, 3,100 kcal·kg^-1). The results revealed that 1A and 2A had a lower (p < 0.05) body weight (BW) from day 1 to day 40 compared with the other groups. A lower (p < 0.05) average daily gain (ADG) was observed in 1A and 2A during the entire period when compared with the other groups. The 1A and 2A groups had the minimum (p < 0.05) average daily feed intake (ADFI) compared with the other groups for the whole period. The RR had an improved (p < 0.05) FCR compared with the other groups during the whole period. The 1A and 2A groups were observed to have the lowest (p < 0.05) shank length compared with the other groups during the entire period.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.351-359
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• 2019

The purpose of this study was to compare the growth performance, nutrient digestibility, fecal microflora, blood profiles and meat quality of broilers, Korean native chickens and white semi broilers under identical feeding conditions. Sixty 1-d chicks of each type were randomly placed into 12 pens per cage (5 chicks per cage) and fed commercial diets for 28, 49, and 28 days, respectively. The broilers showed a significantly higher (p < 0.05) growth performance from 0 to 4 weeks compared with the other types. Korean native chickens had a significantly higher (p < 0.05) digestibility of dry matter and nitrogen than that of the other species. The blood glucose was significantly higher in the Korean native chickens compared to the other species, and the blood cholesterol was significantly lower. The Lactobacillus content in Korean native chickens was significantly higher (p < 0.05) compared to the other species, and the E. coli content in the broilers was significantly higher (p < 0.05) than in the Korean native chickens and white semi broilers. In terms of meat quality, the breast meat of the broilers had a high water content and pH level. The breast meat of the white semi broilers had a significantly lower (p < 0.05) shear force than that of the other species. In conclusion, there was an interspecific physiological difference due to the age and body weight of the chickens. The broilers had a higher growth performance and meat quality compared to the Korean native chickens and white semi broilers.

• Animal Bioscience
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• v.34 no.4
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• pp.680-691
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• 2021

Objective: This study was conducted to investigate the effect of fermented cottonseed meal (FCSM) on growth performance, carcass traits, and fat deposition in white-feather broiler chickens. Methods: A total of 480 male one-day-old white-feather broiler chickens were selected randomly and divided into four groups with six replicates of 20 chickens in each. The experimental chickens were fed diets including 3%, 6%, or 9% FCSM fermented by Candida tropicalis until 42 days old. In the experiment, the chickens of the control group were fed soybean meal. Results: FCSM supplementation linearly decreased the feed conversion ratio from d 15 to 21 and d 36 to 42, respectively (p<0.05). The percentage of carcass and semi-eviscerate increased in response to dietary FCSM supplementation at d 21 (p<0.05). The percentage of eviscerated and semi-eviscerate of 3FCSM was higher than that in other groups at d 35 (p<0.05). At the age of 42 d, the percentage of carcass increased in a quadratic way among increasing FCSM in diets (p<0.05). The subcutaneous fat thickness linearly decreased with the increasing levels of FCSM at d 21 (p<0.05). Gompertz and Logistic functions provided a better fit on abdominal fat and subcutaneous fat, respectively. The best fitted equation predicted that the maximum growth rate of abdominal fat weight and subcutaneous fat thickness occurred at d 28. FCSM had no significant effects on the shape of growth curve of abdominal fat weight and subcutaneous fat thickness, but reduced the height of the curve. Birds receiving the 6FCSM diet for 21 d had smaller adipocyte surface and lower serum glucose as well as triglyceride concentration. Conclusion: FCSM is beneficial for broiler chickens as it positively affects their growth and carcass in addition to altering their fat deposition.