• 한국동물학회:학술대회논문집
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• 한국동물학회 1995년도 제16회 생물과학 심포지움 강연록
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• pp.68-73
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• 1995

Most female Great Tits lay one egg each day until the clutch is complete. However, some exceptions are found. “Pause day/s” most frequently occur after the 1st egg is laid. In general, egg-size increase with laying sequence, but there is year-to-year variation. The relationship between egg size and laying sequence is found more significantly in relatively larger clutches than in smaller ones. Great Tits tend to advance the hatching of their chicks by starting to incubate earlier in relation to clutch completion as the breeding season progresses. hatching asynchrony affects chick´s growth rate, but when the effect of laying date on hatching asynchrony is controlled, the effect of hatching asynchrony on growth rate is not found. These findings support the ´hurry-up´ hypothesis.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제32권11호
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• pp.1715-1724
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• 2019

Objective: As laying hens become aged, laying performance and egg quality are generally impaired. One of the practical methods to rejuvenate production and egg quality of aged laying hens with decreasing productivity is a forced molting. However, the changes in intestinal microbiota after forced molting of aged hens are not clearly known. The aim of the present study was to analyze the changes in excreta bacterial communities after forced molting of aged laying hens. Methods: A total of one hundred 66-wk-old Hy-Line Brown laying hens were induced to molt by a 2-d water removal and an 11-d fasting until egg production completely ceased. The excreta samples of 16 hens with similar body weight were collected before and immediately after molting. Excreta bacterial communities were analyzed by high-throughput sequencing of bacterial 16S rRNA genes. Results: Bacteroidetes, Firmicutes, and Proteobacteria were the three major bacterial phyla in pre-molting and immediate post-molting hens, accounting for more than 98.0%. Lactobacillus genus had relatively high abundance in both group, but decreased by molting (62.3% in premolting and 24.9% in post-molting hens). Moreover, pathogenic bacteria such as Enterococcus cecorum and Escherichia coli were more abundant in immediate post-molting hens than in pre-molting hens. Forced molting influenced the alpha diversity, with higher Chao1 (p = 0.012), phylogenetic diversity whole tree (p = 0.014), observed operational taxonomic unit indices (p = 0.006), and Simpson indices (p<0.001), which indicated that forced molting increased excreta bacterial richness of aged laying hens. Conclusion: This study improves the current knowledge of bacterial community alterations in the excreta by forced molting in aged laying hens, which can provide increasing opportunity to develop novel dietary and management skills for improving the gastrointestinal health of aged laying hens after molting.

• 한국가금학회지
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• 제14권2호
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• pp.113-123
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• 1987

본 연구는 백색레그흔 산란계에 있어서 초산후 일령의 1일중 방란시간의 경과가 란중, 란각질, 란형계수에 미치는 영향을 구명하기 위하여 1986년 9월 1일부터 1987년 1월 6일까지 약 4개월간에 걸쳐 산란계 150수를 가지고 시험을 실시한 결과, 초산후 일령이 경과함에 따라 방란비율이 오전중에는 감소했고 오후에는 증가했다. 란중은 270일령까지는 증가속도가 빨랐으나 그 이후에는 둔화되었다. 란각두께는 일령이 경과함에 따라 얇아졌고 란각강도도 일령이 경과됨에 따라 저하되었으며 란형계수는 커졌다. 1일중 방란시간이 늦어짐에 따라 란중은 점차 가벼워졌으며 발란시간에 대한 란중의 회귀계수는 -0.6788--0.4170로 방란시간이 1시간 늦어짐에 따라 란중은 0.4170-0.6788g이 가벼워졌다. 란각두께는 방란시간이 1시간 늦어짐에 따라 0.00377-0.00643mm씩 두꺼워졌으며 란각강도는 방란시간이 1시간 늦어짐에 따라 0.0287-0.0349kg/$\textrm{cm}^2$씩 향상되었다. 그러나 란형계수는 방란시간과 서로 상호관계가 없는 것으로 사료된다.

• 한국가금학회지
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• 제33권2호
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• pp.127-131
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• 2006

본 시험은 expanding 가공 기술이 산란계의 생산성, 계란 품질과 영양소 소화율에 대하여 알아보고자 실시하였다. 49주령 Hy-line Brown 270수를 공시하였고, 6주간 시험을 실시하였다. 1) MS(mash), 2) EC(expanded crumble) 및 3) EP( expanded pellet) 으로 3처리구로 구성하였으며, 처리 당 15반복, 반복당 6수씩 완전임의 배치하였다. 산란율은 EC와 EP 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타났다(p<0.05). 그러나 난중은 처리구간에 유의적인 차이는 없었다(p>0.05). 난각 강도는 EC와 EP 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타내었지만(p<0.05), 난각 두께는 처리 구간에 유의적인 차이를 나타내지 않았다(p>0.05). 난황색은 EC 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타났다(p<0.05). 난황 계수는 EC와 EP 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타났다(p<0.05). Haugh uint에 있어서 처리구간의 유의적인 차이는 없었으나(p>0.05), 변화량에 있어서 EP 처리구가 가장 높게 나타났다(p<0.05). 영양소 소화율에 있어서 건물, 칼슘, 인 소화율에 있어서 EP 처리구가 소화율을 개선시켰다(p<0.05). 본 연구 결과는 2차적인 사료 가공 기술이 산란계에 서 계란 품질과 영양소 소화율을 개선하였다.

• 한국축산식품학회지
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• 제30권3호
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• pp.449-457
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• 2010

본 시험에서는 산란계에 대한 인진쑥, 녹차, 오미자, 겨우살이의 혼합 비율을 달리한 3종 추출물의 사료 내 첨가 급여가 난 생산성, 계란 품질, 혈액 특성 및 계란 저장성에 미치는 영향을 조사하기 위하여 35주령 산란계(Hy-Line Brown) 160수를 공시하여 4처리 4반복, 반복 당 10수씩 배치하고 10주간 사양시험을 실시하였다. 시험처리는 대조구(C)와 시험 사료에 혼합 비율을 달리한 3종의 추출물을 200 ppm 수준으로 첨가한 약용식물 추출물 처리구(T1, T2, T3)를 두었다. 산란율, 일 산란량 및 사료 요구율은 대조구에 비해 모든 처리구에서 유의하게 개선되었다(p<0.05). Haugh unit 및 난황색은 처리구 간 차이는 있었으나 전반적으로 대조구에 비해 유의하게 증가하였다(p<0.05). 난각질에서는 유의한 차이가 관찰되지 않았다. 혈액 내 총 콜레스테롤 함량은 대조구에 비해 모든 처리구에서 유의하게 감소하였으며(p<0.05), 중성 지방은 유의성은 나타나지 않았으나 감소하는 경향을 보였다. 간 및 신장 기능의 이상 여부를 나타내는 혈액 생화학 지표 역시 유의하게 감소하거나 감소하는 경향을 보였다(p<0.05). 혈액 총 항산화 활성은 대조구에 비해 다소 증가하는 경향을 보였으나 유의성은 인정되지 않았다. 저장 기간에 따른 Haugh unit 및 지방과 산화물가의 변화를 조사한 결과, 계란 보관 14일, 21일째에 Haugh unit이 대조구에 비해 유의하게 높았으며(p<0.05), 3일 및 7일째 역시 통계적 유의성은 인정되지는 않았으나 추출물 처리시 저장 기간에 따른 Haugh unit의 저하를 감소시키는 경향을 관찰하였다. 지방과산화물가 역시 처리 구간 차이는 있었으나 대조구에 비해 유의하게 감소하는 것을 확인할 수 있었다(p<0.05). 본 연구 결과, 인진쑥, 녹차, 오미자, 겨우살이의 혼합 비율을 달리한 약용식물 추출물의 산란계 사료 내 첨가급여는 계란 생산성을 향상시키고, 건강 유지에 긍정적인 영향을 미쳤으며, 난황색 및 Haugh unit 등의 계란 내부품질을 개선시켰을 뿐만 아니라, 저장 기간에 따른 계란의 품질 저하를 감소시켜 사료 첨가제로서의 이용 가능성을 제시하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.573-581
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• 2006

This experiment was conducted to determine the effects of supplemental methionine, lysine, choline, and sulfur on laying performance, metabolic parameters, and egg quality of hens fed diets containing sorghum (Sorghum vulgare) during the peak laying period. Lohman layers (n = 144), 30-wk of age as 6 replicate cages of 4 hens, were allocated randomly to receive basal diets containing either 22% corn (B) or 22% sorghum (BS) and diets BS plus 0.57% methionine, 0.66% lysine, 0.47% choline, or 0.05% sulfur for 98 d. Feed intake (FI) and egg production (EP) were recorded daily, egg weight (EW) was measured bi-weekly, and body weight (BW) was measured monthly. A sample of 12 eggs from each experimental group was collected every month to evaluate egg quality. At the end of the experiment, blood samples were collected for metabolite concentrations. Data were analyzed using one-way ANOVA as repeated measures and significant differences between the experimental groups were assessed using Duncan's Multiple Range test. Partial replacement of corn with sorghum in the basal diet did not affect BW, EP, and FCR but increased FI by 5.7% and EW by 2.4%. The effects of additives on laying performance were variable. Except for serum total protein (STP) concentration, other metabolic parameters were not affected by partial replacement of corn with sorghum in the basal diet. Hens fed diet BS had lower SPT concentration than hens fed diet B. Except for methionine supplementation, other supplements ameliorated depression in STP concentration. The additives did not affect other metabolic parameters. Egg quality responses to the experimental diets were also variable. Partial replacement of corn with sorghum in the basal diet did not affect eggshell characteristics (both thickness and stiffness), whereas it had variable effects on inner egg quality parameters (increased yolk index, depressed yolk color, and unaltered albumen index and Haugh unit). In conclusion, laying hen diets could include low-tannin sorghum (0.26%) up to 22% without necessitating extra supplements to overcome compromised performance.

• Asian-Australasian Journal of Animal Sciences
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• 제24권10호
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• pp.1425-1434
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• 2011

This experiment was designed to evaluate the effects of the processing method of common vetch seed (CVS) (Vicia sativa) on laying performance, egg quality, metabolic parameters and liver histopatology during the peak production period in hens. Lohman layers, 46 wk of age in 6 replicate cages each containing 4 hens, were allocated randomly to one of four dietary treatments. Diets were control (C) diet containing no common vetch and experimental diets containing 25% raw common vetch (RCV), 25% soaked in water for 72 h with exchange of water every 24 h (SCV) and 25% soaked&boiled at $100^{\circ}C$ for 30 minute common vetch (SBCV). Inclusion of RCV into the diet deteriorated all laying performance variables. SCV did not alleviate the adverse effect of raw common vetch on feed intake, egg weight, feed conversion, final weight and weight change. SCV partially alleviated egg production (p<0.001). SBCV diminished the adverse effect on feed intake, egg weight, feed conversion, final weight and weight change compared to raw vicia sativa (p<0.001). No significant difference was detected between SBCV and the control group in terms of egg production, feed conversion, final weight and weight change. Regardless of the processing method, all the common vetch groups had lower shell strength compared to the control group. Haugh units did differ between all groups (p<0.001). Inclusion of RCV and SCV into the basal diet decreased triglyceride, cholesterol, total protein and serum glucose concentrations (p<0.001). Hovewer, inclusion of SBCV into the basal diet increased these parameters. Liver samples were stained with Hematoxylin and eosin (HE) and evaluated by light microscopy. A biopsy of native liver tissue was used as a control. No histopathologic finding was present in the control group. Raw V. sativa compared with the control caused lipid accumulations in hepatocytes, severe congestion of hepatic blood vessels, inflammation, increased numbers of Kupffer cells and sinusoidal dilatations. Whereas, the livers from groups given treated V. sativa showed only different degrees of sinusoidal dilatations. Findings from the present study point out the risk of increased hepatic damage due to use of raw Vicia sativa. Increasing treatment of V. sativa lead to a decrease of liver damages. Inclusion of raw and soaked vetch seeds in rations affected adversely all parameters examined in laying hens. But alleviation was observed when soaked and boiled vetch seeds (SBCV) were fed. The results of these experiments indicated that soaked&boiled Vicia sativa seeds may safely be used at a 25% level in rations of laying hens.

• 한국축산식품학회지
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• 제28권5호
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• pp.667-674
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• 2008

This study was conducted to investigate the effects of germinated and fermented unmarketable soybean (GFS) on laying performance and egg quality in laying hens. A total of two hundred laying hens were divided into 5 groups (5 treatment $\times$ 4 replication $\times$ 10 birds each) and fed with the experimental diets for 8 wk as follows: control, GFS free; T1, GFS 0.15%; T2, GFS 0.3%; T3, GFS 1%; T4, GFS 2%. The laying performance, egg quality, blood profiles, cecal microbial population, isoflavone content in egg yolk were investigated. There were no significant differences laying performance, relative liver and spleen weights, egg yolk color, eggshell color among groups. Eggshell strength in groups fed with diets containing GFS increased, but not significantly. Eggshell thickness significantly increased in the GFS-supplemented group. No significant differences were observed in the blood profiles and intestinal microflora after supplementation. The decrease of Haugh unit during storage was alleviated by feeding of GFS (p<0.05). The concentrations of malondialdehyde in groups fed with GFS were decreased as compared with control (p<0.05). Isoflavones in the egg yolk were detected in group fed with diet containing 2% GFS. These results showed that unmarketable GFS could be used as a favorable feed additive and feedstuff for production of quality enhanced and isoflavone fortified eggs.

• 한국생태학회:학술대회논문집
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• 한국생태학회 2002년도 VIII 세계생태학대회
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• pp.107-111
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• 2002

During the breeding season of 1998, breeding ecology of the Great Reed-Warbler (Acrocephalus arundinaceus orientalis) was studied at Yangsoo-ri and Yongdam-ri of the Yangpyung-gun, Kyunggi province, Korea. Egg-weight (CV: 6.25) was more variable than either length or breadth, and breadth was the least variable of the measures. Significant variations In overall egg-weight occurred between clutches, and that more of the total variation in egg-weight and shape are due to inter-clutch variation as to intra-clutch variation when the data were pooled. The last egg tends to be larger than the remaining eggs in the clutch of the Great Reed-Warbler, suggest- ing the Great Reed-Warbler may adopt the brood-survival strategy. When method 3 was used, the most common incubation period is 12 days. In the Great Reed-Warbler, the length of the incubation period was related to clutch-size when method 1 (r=0.485, p<0.05) and method 2 (r=0.621, p<0.01) were employed, but not related to egg weight. The average number of days of hatching asynchrony was 2.5, raging 0.5∼2.5. Asynchronous hatching was related to the clutch size (r=0.66, p<0.01). Hatching sequence was closely related to the laying sequence (r=0.93, p<0.001), suggesting Great Reed-Warblers incubate their eggs before clutch completion. The effect of egg weight on hatching asynchrony was found in Great Reed-Warblers (t-test, p<0.01).