• Asian-Australasian Journal of Animal Sciences
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• 제32권9호
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• pp.1407-1413
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• 2019

Objective: This experiment aimed to investigate the effect of different sources and inclusion levels of dietary fat on productive performance and egg quality in laying hens raised under hot environmental conditions. Methods: A total of 480 Hy-Line Brown laying hens at 31 wk of age were randomly allotted to 1 of 5 experimental diets. The control diet contained 2,800 kcal/kg nitrogen-corrected apparent metabolizable energy with no fat addition. Four additional diets were prepared by adding 2.0% or 4.0% of animal fat (AF) or soybean oil (SO). Energy and nutrient concentrations were consistent among all diets. Diets were fed to hens for 4 weeks. Average daily room temperature and humidity were $26.7^{\circ}C{\pm}1.52^{\circ}C$ and $77.4%{\pm}4.50%$. The heat stress index was approximately 76, indicating that hens were raised under heat stress conditions. Results: Final body weight (BW) was greater (p<0.05) for hens fed diets containing 2.0% or 4.0% AF than for those fed the control diet or diets containing 2.0% or 4.0% SO. The BW gain and feed intake were greater (p<0.05) for hens fed diets containing additional AF or SO than those fed the control diet. Eggshell thickness was the greatest (p<0.05) for hens fed the control diet, but the least (p<0.05) for hens fed diets containing 4.0% SO. Egg yolk color was the greatest (p<0.05) for hens fed the control diet, but the least (p<0.05) for hens fed diets containing 4.0% SO. Conclusion: Inclusion of supplemental fat (AF and SO) in diets exhibits preventative effects on BW loss for hens raised under hot environmental conditions when energy and nutrient concentrations in diets were maintained. The effects were greater for AF than for SO. However, inclusion of supplemental fat in diets decreases eggshell thickness and egg yolk yellowness, possibly due to a reduction in Ca absorption and intake of egg yolk colorants.

• 한국가금학회지
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• 제28권1호
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• pp.1-6
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• 2001

Two experiments were carried out to evaluate the effects of adding phytase on nutrient availability and serum Ca and P level and to determine the effects of phytase on laying performance and egg quality in laying hens. In Exp. 1, twenty four laying hens(1.9kg average body weight and 78.4% egg production) were allotted to four treatments. Treatments included 1) corn-soybean meal based-control diet and 2), 3) and 4) control diet with phytase 200, 400 and 600 unit/kg, respectively. There were no significant effects of treatments on dry matter and nitrogen digestibility(P〉0.05). Ash, Ca and P digestibility in layer fed diet with phytase were greater than those in layer fed control diet(P〈0.05). Laying hens fed diets with phytase 200 and 400 unit retained more Ca than those fed other treatments (P〈0.05). No statistical difference was found for Ca exsretion(P〉0.05). P retention was greater for laying hens fed diet phytase 600 unit than other treaments(P〈0.05). P level in serum was higher for laying hens fed diets with phytase 400 and 600 unit than for laying hens fed other treatments. In Exp. 2, three hundred, IAS Brown layer, 40-week-old, divided into two treatment groups(control vs phytase supplementation without inorganic phosphate in the diets) with five replications per treatment and 30 layers per replication were fed the diets for 6 weeks. Egg production, egg weight and eggshell breaking strength and thickness were not different significantly(P〉0.05). In conclusion, phytase supplementation can be used to increase P utilization and retention in laying hens. Also, phytase supplementation was effective to spare inorganic phosphate in laying hen diets without any adverse effects on production performances.

• 한국가금학회지
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• 제38권3호
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• pp.205-211
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• 2011

본 시험은 밀기울 위주의 환우용 사료로 유도환우한 경우 산란계의 생산성에 미치는 영향을 구명하고자 실시하였다. 공시계는 65주령 White Leghorn 산란계 200수를 이용하였다. 처리구는 환우를 하지 않는 비환우 대조구(CO), 절식 환우구(FW), 기존 환우 사료 급이구(UM), 옥수수-밀기울 위주의 환우 사료 급이구(CW), 밀기울 위주의 환우 사료 급이구(WM)의 총 5처리구, 처리구당 4반복, 반복당 10수씩 완전임의 배치하였다. 환우 개시 전에는 모든 처리구에서 섭취량이 유사하였으나(P>0.05), 1주째 환우용 사료 급이구에서는 섭취량이 감소하였으나(P<0.05), 3주째 이후로는 모든 처리구에서 사료 섭취량에 유의적 차이가 없었다(P>0.05). FW구의 시험계들은 1주째 1,337 g으로 초기 체중에서 18.6%의 체중 손실이 있었으며, UM, CW, WM구에서는 체중 손실이 11.4, 14.2, 17.4%로 나타났다(P<0.05). 1주령에 환우 처리구에서 산란율이 급격히 감소하였으며, FW구에서는 1주째, UM, CW, WM구에서는 2주째에 산란이 급격하게 감소하였으며, FW구에서는 2주째에 산란이 정지되었다. 산란 회복 기간을 보면 FW구는 3주째 산란이 재개되었으며, UM, CW, WM구에서는 4주째 이후로 산란이 회복되었다. 난질(난각 두께, 난각 강도, 호우유니트)은 8주째 환우 처리구에서 대조구에 비해 높게 나타났다(P<0.05). 결과적으로, 밀기울 위주의 환우용 사료는 체중 감소에 효과적이었으며, 난각 강도, 난각 두께 및 Haugh Unit가 크게 향상됨을 보여 주었다.

• 한국가금학회지
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• 제50권3호
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• pp.119-124
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• 2023

본 연구는 산란후기 '우리맛닭' 종계의 사료 내 ME 수준이 체중, 산란율, 종란품질 및 부화율에 미치는 영향을 조사하기 위해 수행되었다. 48주령 '우리맛닭' 종계 암탉 80수를 개별 케이지에 분배한 후 16주간 사양실험을 실시하였다. 처리구는 두 가지 수준의 ME(2,500 kcal/kg, 2,700 kcal/kg)사료를 4반복과 반복 당 10수씩 배치하여 급여하였다. 본 연구결과, 종계의 체중과 사료섭취량은 ME의 수준에 따른 통계적 차이가 없었다. 48~52주령의 종계는 2,500 kcal/kg 처리구에서 2,700 kcal/kg 처리구보다 개선된 산란율을 나타냈다(P<0.05). 그러나 52~64주령의 종계에서는 처리구 간 유의적 차이가 없었다. 종란의 난중, 난각두께 및 난각강도는 처리구 간에 차이가 나타나지 않았다. 종란의 수정률과 부화율은 ME 수준에 따른 차이를 보이지 않았다. 결론적으로 산란후기 '우리맛닭' 종계의 ME 수준을 2,500 kcal/kg으로 낮추어도 생산성 측면에서 에너지 요구량을 충족시킬 것으로 판단된다.

• 한국가금학회지
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• 제48권4호
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• pp.319-325
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• 2021

In this study, we investigated the effects of feeding diets with different levels of energy and nutrient density on the egg quality of laying hens during the pre-peak and peak periods. A total of 192 (Hy-line brown) laying hens were used in a 15-week trial. The hens were randomly allotted to one of four treatments, each with four replicates (12 hens per replication). We assessed the effects of four level of dietary energy (2,710, 2,850, 2,870 and 2,890 kcal/kg) and three levels of nutrient density (Methionine + Cysteine: 0.56%, 0.85%, 0.80% and Crude Protein: 14.5%, 19%, 18%). Differences in the energy and nutrient density contents of diets showed no significant effect (P>0.05) on the average daily gain, average daily feed intake, feed conversion ratio, egg weight, or egg production of hens during the pre-peak and peak periods. However, hens subjected to 2,890 kcal/kg during the pre-peak period were found to lay eggs with significantly thicker shells, and yolk color was found to be significant enhanced in hens fed this diet during the pre-and peak periods. In contrast, we detected no significant effects of dietary energy or nutrient density on the Haugh unit or eggshell strength. In summary, increasing the energy level of diets from 2,710 to 2,890 kcal/kg was found to have positive effects on the shell thickness and yolk color of eggs produced by laying hens.

• 한국축산식품학회지
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• 제43권2호
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• pp.282-304
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• 2023

This study aimed to investigate the effectiveness of carotenoid supplementation on the performance, egg quality, and immunity of laying hens using a meta-analysis approach. The database was searched using Google Scholar and Scopus, from 2012 to 2022. The literature was published in English. 47 Articles were selected for meta-analysis. Analyses were performed using the Open Meta-analyst for Ecology and Evolution (OpenMEE) software. The heterogeneity and data validation against publication bias were analyzed using JASP 0.16.2 software. Overall, the results showed that carotenoid supplementation improved feed intake by 0.32 g/day/hen [95% confidence interval (CI)=0.02 to 0.61], final body weight by 0.33 g/hen (95% CI=0.05 to 0.60), egg production by 0.38% (95% CI=0.14 to 0.63), egg weight by 0.29 g (95% CI=0.09 to 0.5), yolk colour by 2.11 (95% CI=1.71 to 2.51), Haugh unit (HU) by 0.26 (95% CI=0.11 to 0.42), yolk carotenoids by 1.17 ㎍/kg (95% CI=0.59 to 1.75), immunoglobulin A (IgA) by 0.74 mg/L (95% CI=0.18 to 1.29), and lower yolk cholesterol by -0.38 mg/g (95% CI=-0.59 to -0.16). Feed conversion ratio (FCR), eggshell thickness, and white blood cells were unaffected by the application of carotenoids. The heterogeneity analysis showed variability in all studies (<0.05). In conclusion, carotenoid supplementation can elevate productivity, enhance egg quality, and improve immunity. However, based on Kendall's test, there was a publication bias in several parameters, namely FCR, egg weight, HU, yolk carotenoids, and IgA.

• Asian-Australasian Journal of Animal Sciences
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• 제22권10호
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• pp.1391-1399
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• 2009

Two hundred and sixteen 68-week-old Hy-Line brown laying hens were used in a 6-week feeding trial to compare the efficacy of phytases Optiphos (OPT) and Natuphos (NAT), which were isolated from Escherichia coli and Aspergillus niger, respectively. Hens were randomly allotted into six treatments with six replications (six layers in three adjacent cages) per treatment according to their initial BW. The hens were then subjected to one of the following dietary treatments: i) Positive Control (PC; available phosphorus (AP) 0.4%); ii) Negative control (NC; AP 0.2%); iii) NAT1 (NC+250 FTU/kg NAT); iv) NAT2 (NC+500 FTU/kg NAT); v) OPT1 (NC+250 FTU/kg OPT); vi) OPT2 (NC+500 FTU/kg OPT). Feed intake, egg production, egg quality, apparent nutrient digestibility and serum P and Ca concentration were evaluated to compare the effect of the two phytases. Feed intake and eggshell thickness were not affected by the treatments. Superior effects (p<0.05) of OPT were only observed in egg production and egg weight compared with NAT. Characteristics such as eggshell breaking strength, apparent digestibility of N, Ca and P and serum P concentration were equally increased with the supplementation of both phytases (p<0.05), where no significant difference was observed in those characteristics between PC and phytase supplementation at 500 FTU/kg. Equally effective improvements (p<0.05) were also observed in egg production and DM digestibility, where no improvements were observed (p<0.05) between the PC group and the groups with phytase supplementation at 500 FTU/kg. Equal increases in the serum Ca level were observed when the groups with phytase supplementation were compared to the PC group. Overall, the results of this study suggest that NAT and OPT are equally effective at liberating phytate-bound complexes when included in 0.2% available phosphorus diets for 68-week laying hens; either source of phytase can be fed to commercial 68-week laying hens at 500 FTU/kg to correct the negative effects associated with a 0.2% available phosphorus diet. In conclusion, either source of phytase can be fed to commercial first cycle laying hens at 500 FTU/kg to effectively replace inorganic phosphorus when economically justified.

• 한국환경과학회지
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• 제17권5호
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• pp.537-546
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• 2008

The experiment was conducted to determine the effect of the mixed herbal medicine for the substitution of antibiotics on the performance of laying hens. Day old hyline 1,500 layer chicks were randomly assigned to 4 treatments. Control were 600 and three each treatment was 300. Eggs were collected at every weeks for measuring egg production and week 26, 27, 28 for chemical analyses. Chemical analyses were done for fatty acid profile of egg yolks, amino acid, antibiotics residue in eggs(collect eggs after supplying OTC 21ppm/bird/day to control for four day at 26, 27, 28) during the laying period($19{\sim}77wk$). On $0{\sim}4$ week, T-3 showed higher feed intake than those fed the other diets and on $5{\sim}13$ week, T-2 showed highest feed intake among treatments. After birds were moved ($14{\sim}18$ wk) CT-3 showed highest, but for overall rearing period, there was not significantly different among treatments. In conclusion the mixed herbal medicine did not tended to influence palatability to rearing birds. Egg quality(egg yolk color, haugh unit, eggshell breaking strength) showed no difference among treatments. Ratio of unsaturated fatty acid (mg/100g)/saturated fatty acid (mg/100g) was not difference among treatments, but linolenic acid and docosahexaenoic acid(DHA) of the mixed herbal medicine treatments showed higher then control. The antibiotics residue of CT, T treatments egg was not detected and control was not detected or below allowance. In conclusion the mixed herbal medicine can be possible to feed laying hen without antibiotics.

• Animal Bioscience
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• 제34권3_spc호
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• pp.371-384
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• 2021

Objective: Wheat bran (WB) was co-fermented with Aspergillus oryzae and phytase (Phy) to determine whether co-fermentation improve WB phosphorus and fiber utilization in Isa-brown layers. Methods: A total of 112 Isa brown layer were randomly divided into 7 treatments with 8 replicates per a treatment and 2 hens per a replicate. The treatments included basal diet (control), basal diet supplemented with 250 unit/kg Phy (control+Phy), diet with 10% WB (10% WB), diet with 5% WB and 250 unit/kg Phy (5% WB+Phy) diet with 10% WB and 250 unit/kg Phy (10% WB+Phy), diet with 5% fermented WB supplemented with molasses and phy (PCFWH) and 125 unit/kg Phy (5% PCFWH), and diet with 10% PCFWH (10% PCFWH). The intestinal microbial population, intestinal morphology, serum antioxidant enzyme activities, and excreta phosphorus content were assessed. Results: In PCFWH, spore counts, protease activity, xylanase activity, and ferulic acid were 8.50 log/g dry matter (DM), 190 unit/g DM, 120 unit/g DM, and 127 ㎍/g, respectively. Xylobiose and xylotriose were released in PCFWH, while they were not detectable in WB. Antioxidant capacity was also enhanced in PCFWH compared to WB. The 10% WB+Phy and 10% PCFWH groups produced higher egg mass, but hens fed 5% WB+Phy had the lowest amount of feed intake. Eggs from 10% PCFWH had better eggshell weight, eggshell strength, and eggshell thickness. Birds fed with 10% PCFWH also had higher serum superoxide dismutase and catalase activities. Compare to control, 10% PCFWH significantly reduced excreta phosphorus content. Conclusion: Diet inclusion of 10% PCFWH improved egg quality, antioxidant status, and excreta phosphorus content of laying hens.