• Animal Bioscience
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• 제34권11호
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• pp.1766-1775
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• 2021

Objective: The oxidative stress status and changes of chicken ovary tissue after shading were studied, to determine the mechanism of the effect of shading on follicular development. Methods: Twenty healthy laying hens (40 weeks old) with uniform body weight and the same laying rate were randomly divided into two groups (the shading group and normal light group). In the shading group, the cage was covered to reduce the light intensity inside the cage to 0 without affecting ventilation or food intake. The normal lighting group received no additional treatment. After 7 days of shading, oxidative stress related indicators and gene expression were detected. Results: Analysis of paraffin and ultrathin sections showed that apoptosis of ovarian granulosa cells (GCs) increased significantly after light shading. Enzyme linked immunosorbent assay results revealed that the levels of total antioxidant capacity, malondialdehyde, superoxide dismutase (SOD), glutathione, catalase (CAT), and other substances in the sera, livers, ovaries, and follicular GCs of laying hens increased significantly after shading for 7 days; and reactive oxygen species (ROS) levels in the livers of laying hens also increased significantly. ROS in the serum, ovarian and GCs also increased. After shading for 7 days, the levels of 8-hydroxy-2 deoxyguanosine in the sera and ovarian tissues of laying hens increased significantly. Cell counting kit-8 detection showed that the proliferation activity of GCs in layer follicles decreased after shading for 7 days; the expression level of the anti-apoptotic gene B-cell lymphoma-2 in ovarian tissue and follicular GCs was significantly reduced, and the expression levels of pro-apoptotic caspase 3 (casp3), and SOD, glutathione peroxidase 2 (GPX2), and CAT were all significantly increased. Conclusion: Oxidative stress induced by shading light has a serious inhibitory effect on follicular development during reproduction in laying hens.

• Animal Bioscience
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• 제34권2호
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• pp.256-264
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• 2021

Objective: The purpose of this experiment was to investigate the effects of the Agaricus bisporus stem residue (ABSR) on the performance, nutrients digestibility, antioxidant activity of laying hens, and its effects on egg storage to determine the appropriate dosage of ABSR, so as to provide a scientific basis for the effective utilization of ABSR. Methods: A total of 384 53-wk-old Nongda III layers were randomly divided into six treatments, four replicates in each treatment and 16 birds in each replicate. The control treatment was fed with basic diet, while experimental treatments were fed with diets of 2%, 4%, 6%, 8%, and 10% ABSR respectively. The experimental period was 56 d. Results: The results showed that compared with the control treatment, ABSR had no significant effect on laying performance (p>0.05). The crude protein and total energy digestibility of experimental treatments was significantly higher than those of control treatment (p<0.05). When eggs were stored for 1 wk, 2 wk, and 3 wk at 25℃, there were no significant differences in egg storage between the experimental treatments and the control treatment (p>0.05). The superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity in the serum of the experimental treatments were significantly higher than those of the control treatment (p<0.05), and the malonaldehyde (MDA) content did not change dramatically. SOD activity in yolk of experimental treatments was significantly higher than that in control treatment (p<0.05); MDA content in yolk was markedly lower than that in control treatment (p<0.05). The activity of GSH-Px and SOD in yolk of experimental treatments was significantly higher than that of control treatment stored at 25℃ for 21 d, and the content of MDA was significantly lower than that of control treatment (p<0.05). Conclusion: ABSR can be used to improve the antioxidant activity of laying hens without affecting laying performance.

• Animal Bioscience
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• 제36권11호
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• pp.1727-1737
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• 2023

Objective: The poultry industry is a primary source of animal protein worldwide. The gut microbiota of poultry birds, such as chickens and ducks, is critical in maintaining their health, growth, and productivity. This study aimed to identify longitudinal changes in the gut microbiota of laying hens from birth to the pre-laying stage. Methods: From a total of 80 Hy-Line Brown laying hens, birds were selected based on weight at equal intervals to collect feces (n = 20 per growth) and ileal contents (n = 10 per growth) for each growth stage (days 10, 21, 58, and 101). The V4 regions of the 16S rRNA gene were amplified after extracting DNA from feces and ileal contents. Amplicon sequencing was performed using Illumina, followed by analysis. Results: Microbial diversity increased with growth stages, regardless of sampling sites. Microbial community analysis indicated that Firmicutes, Proteobacteria, and Bacteroidetes were the dominant phyla in the feces and ileal. The abundance of Lactobacillus was highest on day 10, and that of Escherichia-shigella was higher on day 21 than those at the other stages at the genus level (for the feces and ileal contents; p<0.05). Furthermore, Turicibacter was the most abundant genus after changing feed (for the feces and ileal contents; p<0.05). The fecal Ruminococcus torques and ileal Lysinibacillus were negatively correlated with the body weights of chickens (p<0.05). Conclusion: The gut microbiota of laying hens changes during the four growth stages, and interactions between microbiota and feed may be present. Our findings provide valuable data for understanding the gut microbiota of laying hens at various growth stages and future applied studies.

• 한국가금학회지
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• 제13권1호
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• pp.23-30
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• 1986

닭의 산란기를 I기(25-40 주령), II기(41-55주령), III기(56-69주령)의 3기로 구분하고 각 산란기에서의 에너지대사를 측정하여 얻은 결과는 다음과 같다. 1. 산란계의 절식시 열생산량(FHP)은 대사체중당 산란 I기 81.5Kcal, IIrl 76.1Kcal, IIIrl 97.5Kcal였다. 즉 FHP는 산란기에 의하여 변화하고 특히 III기의 FHP가 높게 나타났다. 이 현상은 III기에 공시계의 우모가 손상 또는 탈락하여 열손실을 크게 한 때문으로 생각된다. 2. 호흡시험에 있어서 사료 ME섭취량과 에너지 축적량(ER)과의 회귀식에서 구한 유지를 위한 ME 요구량(MEm)은 산란I, II, III기에 있어서 각각 대사체중당 123Kcal, 111Kcal, 131Kcal 였으며, 전기간 평균 119Kcal였다. 또 생산을 위한 ME의 정미이용효율(NAME)을 산란I기 76%, II기 79%, III기 74%, 전 기간 평균에선 79%였다. 즉 산란 III기는 I기 또는 II기에 비하하여 MEm가 높고 NAME가 낮은 성적을 보이고 있다.

• 한국가금학회지
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• 제44권4호
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• pp.235-243
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• 2017

This experiment was aimed at investigating the effects of dietary supplementation with fermented rice bran (FRB) or fermented broken rice (FBR) on egg-laying performance, egg quality, blood parameters, and cholesterol level in egg yolk of Hy-Line Brown egg-laying hens. Altogether, 144 Hy-Line Brown egg-laying hens (32-week-old) were randomly allocated to one of 4 dietary treatment groups, with 4 replicates per treatment. Of them, 3 treatments diets were prepared by supplementing the basal diet with 0.1% probiotics (PRO), 1% fermented rice bran (FRB), or 1% fermented broken rice (FBR) at the expense of corn. Hen-day egg production was higher (P<0.05) in PRO and FRB treatment groups than in the basal treatment groups. However, feed intake, egg weight, egg mass, and feed conversion ratio did not differ among the treatment groups. Additionally, supplementation with FRB or FBR did not affect eggshell strength, eggshell thickness, egg yolk color, and Haugh unit during the feeding trial. There was no significant difference in leukocyte count. Total cholesterol level was lower (P<0.05) in the FRB treatment group than in the basal treatment groups. Asparate aminotransferase, alanine transferase, glucose, and albumin levels were unaffected by dietary supplementation with FRB or FBR. Egg yolk cholesterol level was lower (P<0.05) in the FRB and FBR treatment groups than in the basal treatment groups. In conclusion, dietary supplementation with FRB or FBR improved egg-laying performance, and reduced the levels of total serum cholesterol and cholesterol in egg yolk of Hy-Line Brown egg-laying hens.

• 한국가금학회지
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• 제33권1호
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• pp.41-47
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• 2006

본 연구는 산란계의 생산성과 계란의 품질에 미치는 지렁이 분말(EWM)의 첨가 효과를 구명하기 위해서 실시되었다. 총 360수의 55주령의 산란계를 공시하여서 EWM 0(대조구), 0.3, 0.6%를 첨가한 사료로 5주 동안의 사양 시험을 실시하였다. 계란은 매일 수집하여 난중을 측정하였고 산란율 및 사료 요구율은 시험기간 동안 매주 단위로 조사하였다. 뿐만 아니라 시험 마지막 주에는 계란의 품질도 측정하였다. 산란율과 일일 평균 산란량은 EWM 0.3 및 0.6% 급여 모두 대조구에 비해서 증가하는 경향이 인정되었지만, 0.3 % 와 0.6%처리구간에는 차이가 인정되지 않았다. 한편 사료 섭취량과 사료 요구율은 처리구간에 차이는 인정되지 않았다. 난각 두께, 강도, 색 및 난황색은 EWM 0.3 및 0.6% 처리구 모두 대조구와 비교해서 개선되는 경향이 인정되었다. 산란 1일째, haugh unit는 처리구간에 차이는 인정되지 않았지만, 보관기간에 따른 haugh unit의 변화는 EWM 급여구에서 커졌다. 지렁이분말(EWM)중의 As, Cd, Cr, Hg 및 Pb는 각각 4.41, 1.23, 1.18, 0.00 및 3.39ppm검출되었지만, 계란중에는 검출되지 않았다. 결론적으로 55주령의 산란계에 0.3%지렁이 분말(EWM)의 첨가는 산란계의 생산성 및 계란의 품질을 개선시킬 가능성이 인정된다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.831-837
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• 2013

An experiment was conducted to investigate the effects of dietary supplementation of Rhodobacter capsulatus KCTC-2583 on egg-yolk and serum cholesterol, egg production and quality parameters during the late laying periods in hens. A total of 160 Hy-Line Brown layers (54 wk-old) were randomly allotted to 4 treatment groups on the basis of laying performance. Each treatment had 4 replicates with 10 birds each (40 birds per treatment). Two hens were confined individually with cage size $35{\times}35{\times}40$ cm and each 10 birds (5 cages) shared a common feed trough between them forming one experimental unit. Dietary treatments were; basal diet supplemented with 0 (control), 0.05, 0.10 and 0.15% R. capsulatus KCTC-2583. Experimental diets were fed in meal form for 56 d. Dietary supplementation of increasing levels of R. capsulatus KCTC-2583 reduced (linear, p<0.05) egg-yolk cholesterol and triglycerides (d 28, 42 and 56) concentrations. Also, serum cholesterol and triglycerides (d 21, 42 and 56) concentrations were linearly reduced (p<0.05) with increasing dietary R. capsulatus KCTC-2583. Laying hens fed a diet supplemented with increasing levels of R. capsulatus KCTC-2583 had increased (linear; p<0.05) overall egg production, egg weight, egg mass and feed efficiency. However, dietary treatments had no effect (linear or quadratic; p>0.05) on feed intake of laying hens. At d 28 and 56, breaking strength and yolk colour of eggs were linearly improved (p<0.05) in laying hens fed dietary increasing levels of R. capsulatus KCTC-2583. Dietary treatment had no effects (linear or quadratic; p>0.05) on albumin height, shell thickness and shell weight at any period of experiment. These results indicate that dietary supplementation of R. capsulatus KCTC-2583 has the potential to improve the laying hen performance and lead to the development of low cholesterol eggs during late laying period in Hy-Line Brown hens.

• 한국가금학회지
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• 제48권1호
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• pp.1-12
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• 2021

본 연구는 종계의 품종, 산란 연령 및 종란의 보관 기간이 발생 병아리의 강건성에 미치는 영향을 살펴보고자 한 것이다. 시험은 황갈색 재래종, 토착 로드아일랜드종 및 토착 레그혼종을 이용하여 산란 초기(27~29주)와 산란 후기(50~52주) 때 생산한 종란을 각각 3일, 7일 및 14일 보관 후 부화하여 발생한 병아리를 대상으로 하였다. 분석 항목으로는 부화 시간, 발생 후 병아리의 생산능력 및 장기 무게를 조사하였고, 병아리의 생리적 활성도 파악을 위하여 IL-6 유전자 발현율 및 텔로미어의 상대적 길이를 분석하였으며, 스트레스 반응 정도를 알기 위하여 HSP 유전자 발현율 및 H/L ratio를 분석하였다. 분석 결과, 종계의 품종과 산란 시 연령이 발생 병아리의 강건성에 영향을 미치는 것으로 나타났고, 종란의 보관 기간은 병아리의 강건성에 크게 영향을 미치지 않는 것으로 나타났다. 공시된 토종닭 품종 중 토착 레그혼종 병아리가 가장 강건성이 약한 것으로 나타났는데, 이는 생존율이 저조하고 상대적으로 작은 심장을 가지며, 모든 생리활성지표가 낮고 스트레스 반응 지표들이 높았기 때문이다. 비록 산란 초기에 생산한 병아리들이 산란 후기에 생산한 병아리에 비해 생존율은 낮았지만, 생존 개체들의 생리활성지표가 높고, 스트레스 반응 지표들이 낮아 산란 후기 때 생산한 병아리에 비해 강건성이 높은 것으로 판단된다. 이상의 결과로부터 강건성이 높은 병아리를 얻기 위해서는 강건성이 강한 품종을 선정하여야 하고, 산란 후기에 생산한 병아리의 이용은 가급적 피하는 것이 바람직할 것으로 사료된다.

• 한국가금학회지
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• 제13권1호
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• pp.1-14
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• 1986

본 연구에서는 산란종계 육종개발에 필요한 기초자료를 얻기 위하여 산란종계 6계통을 양면교잡시켜 생산된 후대 3,759수를 가지고 교잡에 의한 잡종강세효과와 결합능력을 추정하였다. 공시계는 국립종축원 대전지원에서 보유하고 있는 White LKeghorn종 6계통에서 생산된 36개 조합의 양면교잡종을 이용하여 1984년 5월 11일부터 1985년 9월23일까지 500일간 수행하였으며, 수정율, 부화율, 육추율, 유성율, 성계생존율, 초산일령, 초산시 체중, 평규란중, 생존계산란율, 산란지수 및 사료요구율 등을 조사하였다. 조사된 각 형질에 대한 기록을 분석하여 교잡에 의한 잡종강세효과, 일반결합능력, 특수결합능력, 상반교잡효과 등을 추정하였다. 분석방법은 Griffing(1956)의 Model I 모형을 이용하여 추정하였다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 1. 조사된 형질의 일반능력은 수정율이 94.76%, 부화율이 74.05%, 육추율이 97.47%, 육성율이 99.72%, 생존율이 93.81%, 초산일령이 150일, 초산시체량이 1,505g, 평균란중이 60.08g, 생존계산란율이 77.11%, 산란지수가 269.8개, 사료요구율이 2.44로 나타났다. 2. 잡종강세의 크기는 수정율에서 -1.66%로 부의 방향으로 나타났으며 부화율에서 9.58%, 육추율에서 0.26%, 생존율에서 1.83%, 초산일령에서 -3.87%, 초산시체중에서 3.63%, 평균란중에서 0.96, 산란율에서 4.23%, 산란지수에서 6.4%, 그리고 사료요구율에서 -0.85%로 나타나 수정율과 체중을 제외한 모든 형질에서 바람직한 개량방향으로 잡종강세효과를 보여 주었으며, 비교적 유전력이 낮은 부화율, 사란능력에서는 잡종강세효과가 컸고, 유전력이 비교적 높은 란중은 잡종강세효과가 적었다. 3. 결합능력의 분석에서 얻어진 결과는 다음과 같다. 1)수정율 일반결합능력, 특수결합능력 및 상반교잡효과는 중요하지 않은 것으로 나타났으며, 수정율은 유전적 요인보다는 환경적인 요인에 의해 영향을 많이 받는 것으로 나타났다. 부화율에서는 일반결합능력이 큰 비중을 차지하였으며 특히 K와 V계통의 상가적 유전효과가 크게 추정되었다. 2) 사료요구율과 평균란중은 일반결합능력이 특히 중요하였으며 특수결합능력과 상반교잡효과도 중요하게 나타났다. 사료요구율은 F, K, B 계통에서 우수하였으며, 란중은 F, B 계통이 우수하게 나타났다. 4) 초산일령은 일반결합능력, 특수결합능력 및 상반교잡효과가 모두 중요하게 나타났으며, V$\times$E, F$\times$K, B$\times$F의 교배조합이 우수하였고, 초산시체중은 일반결합능력이 특히 중요하게 나타났으며 특수결합능력과 상반교잡효과도 중요하게 나타났다. 초산시체중을 가벼운 쪽으로 개량하고자 할 때 K, F, E 계통이 우수하였다. 5) 산란율과 산란지수는 일반결합능력, 특수결합능력, 상반교잡효과가 모두 중요하였으며, F$\times$K, $A\times$K, $K\times$A 조합에서 우수하게 나타났다. 4. 일반적으로 일반결합능력이 중요하게 나타난 형질은 부화율, 초산시체중, 평균란중, 산란율, 산란지수, 사료요구율이었고 특수결합능력이 중요하게 나타난 형질은 육추율, 성계생존율, 초산일령, 산란율, 산란지수였으며, 상반교잡효과가 중요하였던 형질은 초산일령이었다.

• 한국동물위생학회지
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• 제26권1호
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• pp.51-56
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• 2003

Avian pneumoviros(APV), also known as avian rhinotracheitis virus(ARTV), affects both turkeys and chickens and is known to be the primary causative agent of turkey rhinotracheitis (TRT). The aim of this study was to establish the presence or absence of antibodies to avian pneumovirus in the commercial poultry population of Korea. For this purpose, chicken serum samples were obtained and tested by an enzyme-linked immunosorbent assay (ELISA). The tested serum was collected in laying hens with reduction of egg production or normal in Gyeongbuk province. A total of 184 sera representing 42 different poultry farms of the Gyeongbuk region of Korea were included in this study. Laying hens of 16 different farms with reduction of egg production and laying hens of 26 different farms with clinically healthy at the time of serum sampling were considered positive to antibody against APV. In the farms with reduction of egg production, positive farm to antibody against avian pneumovirus were 11 of 16 different farms(68.8%) and positive sera were 47(58.8%) of 80 different serum. In the farms with clinically healthy flock, positive farm to antibody against avian pneumovirus were 12(46.2%) of 26 different farms and positive serum sample were 39(37.5%) of 104 different sera. According to the results tested to 42 different farms in 14 city, 8 of 14 city have flocks with antibody positive laying hens against APV, 1 of 14 city have antibody suspicious and 5 of 14 city shown antibody negative, respectively.