• Asian-Australasian Journal of Animal Sciences
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• 제28권4호
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• pp.538-543
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• 2015

This experiment was conducted to measure the effects of olive leaf powder on performance, egg yield, egg quality and yolk cholesterol level of laying hens. A total of 120 Lohmann Brown laying hens of 22 weeks old were used in this experiment. The birds were fed on standard layer diets containing 0, 1%, 2%, or 3% olive leaf powder for 8 weeks. Egg weight and yield were recorded daily; feed intake weekly; egg quality and cholesterol content at the end of the trial. Olive leaf powder had no effect on feed intake, egg weight, egg yield and feed conversion ratio (p>0.05) while olive leaf powder increased final body weight of hens (p<0.05). Dietary olive leaf powder increased yellowness in yolk color (p<0.01) without affecting other quality parameters. Yolk cholesterol content was tended to decrease about 10% (p>0.05). To conclude, olive leaf powder can be used for reducing egg yolk cholesterol content and egg yolk coloring agent in layer diets.

• 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.

• 대한수의학회지
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• 제53권1호
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• pp.43-48
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• 2013

Commercial bivalent killed Salmonella vaccine Salenvac-T has been used in several countries in order to prevent salmonellosis with Salmonella enterica serovars Enteritidis (SE) and Typhimurium (ST) in poultry. However, this vaccine has not been used in poultry farms in South Korea. In this study, we evaluated the efficacy of Salenvac-T vaccine to protect against the challenge of virulent SE and ST, and the effect of the vaccine on egg production and mortality in layer hens. The colonization of liver, spleen and cecum with challenged SE and ST was reduced in vaccinated chickens compared with that of unvaccinated control group. The twice vaccination with Salenvac-T induced elevated antibody responses against both SE and ST detected by enzyme-linked immunosorbent assay (ELISA). The higher average hen-day production was observed in the vaccinated layer hens than in the unvaccinated layer hens without significance. The average mortality was lower in the vaccinated layer hens during the experiment period. The antibody responses to both SE and ST were persistently detected in the vaccinated layers. In summary, vaccination with Salenvac-T reduces colonization of internal organs and induces good antibody responses, thereby results in higher performance and lower egg contamination with SE and ST in layer hens.

• Asian-Australasian Journal of Animal Sciences
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• 제6권3호
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• pp.411-416
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• 1993

We assessed effects of ovine luteinizing hormone (oLH) and follicle-stimulating hormone (oFSH) on the granulose and theca layers from the four largest follicles, $F_1-F_4$ of hens which had been hypophysectomized 12 h before expected ovulation. Ovine LH (0.4 mg), oFSH (0.4 mg) or oLH in combination with oFSH (0.4 mg each) was injected intravenously 6 h after hypophysectomy. Progesterone, testosterone and $estradiol-17{\beta}$ levels of the granulose and theca layers which were removed 6 h after hormone injection, were measured by radioimmunoassay. Progesterone contents of $F_1-F_3$ granulosa layer at 12 h after hypophysectomy were much lower than those of control hens. This reduced progesterone level was restored partially by the injection of oLH alone for $F_1$, while no follicles responded to oFSH treatment. In contrast, the injection of oLH in combination with oFSH resulted in high progesterone content of the granulose layer from all four follicles. Progesterone content of the theca layer was negligible in all treatments. Simultaneous injection of oLH and oFSH also elevated $estradiol-17{\beta}$ level accumulating in the theca layer from all follicles, of which much higher concentrations of $estradiol-17{\beta}$ were observed when comparison were made to each of their corresponding controls. No appreciable change in testosterone contents of two layers was observed in the present experiments. These results suggest that oFSH augments function of oLH to stimulate the production of progesterone in the granulose layer and $estradiol-17{\beta}$ in the theca layer.

• 농업과학연구
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• 제46권3호
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• pp.569-577
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• 2019

The current experiment was conducted to compare nutrient utilization in the aged laying hens with different eggshell strengths or different intensities of brown eggshell color. Two metabolic trials with 96-week-old Hy-Line Brown laying hens were conducted. Twelve hens with a strong eggshell strength (SES) and 12 hens with a weak eggshell strength (WES) were selected and used in the first experiment, whereas 12 hens with dark brown eggshells (DBE) and 12 hens with light brown eggshells (LBE) were selected and used in the second experiment. All hens were fed a common commercial layer diet. Diets included chromic oxide as an indigestible marker to determine the apparent total tract retention (ATTR) of the gross energy (GE), dry matter, acid-hydrolyzed ether extract, nitrogen, neutral detergent fiber, acid detergent fiber, ash, and minerals. The results indicate that the ATTR of Ca in the aged laying hens with SES (59.7%) was greater (p < 0.05) than in the aged laying hens with WES (48.6%). However, the ATTR of the GE and other nutrients was not different between the hens with SES or WES. There were no differences in the ATTR of GE and nutrients between the hens with DBE or LBE. In conclusion, aged laying hens with SES have a greater ability to utilize dietary Ca than those with WES, indicating that the extent of dietary Ca utilization determines the eggshell strength of aged laying hens. However, nutrient utilization in diets may have little impact on eggshell brown coloration in aged laying hens.

• Asian-Australasian Journal of Animal Sciences
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• 제14권4호
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• pp.553-558
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• 2001

The effect of poor feather cover on feed intake and production was examined in two commercial strains of layers (tinted and brown egg) over 91-98 weeks of age. Hens were housed at four per cage ($600cm^2/bird$) in a commercial layer shed which ranged in temperature from 13.2 to $16.8^{\circ}C$. At the start of the experiment 50% of the birds were classified as having poor feather cover. Feather score was highly correlated with feed intake. Poor feather cover on the neck and the back were the best indicators of hens with high feed intake. Feed intake of hens with poor feather cover was 16% higher (p<0.05) than hens with good feather cover. Hens with good feather cover produced more eggs (p<0.05) early in the trial and had a higher (p<0.05) liveweight, but there was no significant differences in egg weight. Feed per dozen eggs was superior (p<0.05) in hens with good feather cover. Feather cover on the back and vent were the best indicators of overall feather score, while the tail, base of tail and vent were the body parts most affected in birds with poor feather cover.

• 농업과학연구
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• 제28권2호
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• pp.70-77
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• 2001

가금티푸스에 저항성을 가진 합성종을 생산하기 위하여 갈색계통인 이사(ISA), 하이라인(Hyline), 로만(Lohman) 3 계통과, 백색계통인 이사(ISA) 및 로만(Lohman) 2 계통의 종계(PS)에 대한 생존율, 사료섭취량, 체중, 성성숙일령, 시산 난중, 및 난질을 조사하였다. 성계 암컷 생존율(34주~66주)은 갈색계통과 백색계통에서 각각 93.3%, 93.5%로 차이가 없었고, 수컷 생존율에도 차이가 없었다(P>0.05). 수당사료 섭취량(21~66주)은 암컷에서 갈색계통과 백색계통이 각각 113.9g과 114.3g으로 비슷한 수준이었으며, 수컷에서도 차이가 없었다. 성계 체중은 암 수 공히 갈색 산란종계 3계통 및 백색 산란종계 2계통간에 유의한 차이가 없었다. 갈색과 백색 산란종계의 체중을 비교해 보면, 갈색 산란종계가 암컷과 수컷 모두 백색 산란종계 에 비하여 무거웠으나, 반복간에 변이가 워낙 커서 유의성은 검출되지 않았다. 성성숙일령은 갈색계통과 백색계통이 각각 147.8일과 140.5일로 갈색계통이 7일정도 늦었다(P<0.05). 산란율은 23-66주에서 갈색과 백색계통이 각각 75.0% 및 81.4%로 백색계통이 약 6% 높았다(P<0.05). 39주령에 갈색란과 백색란의 난질 성적을 비교해보면 Haugh Unit, 난형계수, 난황색, 난중에 있어서는 유의한 차이가 검출되지 않았다. 그러나 난각두께는 갈색 산란계통의 계란이 더 두꺼웠고, 난각강도도 유의하게 강한 것으로 나타났다.

• 한국가금학회지
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• 제22권3호
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• pp.161-166
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• 1995

To evaluate the nutritional values of Spirulina platensis as the protein supplement for laying heo diet, two experimental diets (Control, Spirulina platensis 2%) were prepared. Total 120, 40-wk old ISA Brown layer hens were randomly employed with 15 hens per replicate and 4 replicates per treatment. Hen-day egg production, egg weight, feed intake, intake /egg weight, egg shell thickness, yolk color score and yolk cholesterol content were examined during 6 weeks of experimental period. Hen-day egg production and feed conversion ratio (intake /egg weight) were significantly (P<0.01) improved by the 2% Spirulina plalensis supplementation. However, there were no differences in egg weight and feed intake between hens fed two experimental diets. Egg from hens fed Spirulina platensis 2% diet have more yellowish yolk color than the control egg although there was no difference in egg shell thickness. Yolk cholesterol content was significantly (P

• 한국가금학회:학술대회논문집
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• 한국가금학회 2004년도 제21차 정기총회 및 학술발표회
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• pp.35-36
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• 2004

난백의 높이와 하우유니트(HU)는 저장온도에 관계없이 저장기간이 경과할수록 감소되는 경향이 있었던 반면에 난백의 pH는 반대로 증가하는 경향이 있었다. 일반적으로 $3\;^{\circ}C$에서 저장되었던 계란들은 $10\;^{\circ}C$에서 저장된 계란들보다 HU는 더 높게 나타났던 반면에, 난백의 pH는 더 낮은 것으로 나타났다. 한편 통계적으로 유의한 차이는 아니었지만 무정란은 유정란에 비해서 저장온도에 관계없이 난백의 높이 및 HU는 더 높은 것으로 나타났고, $3\;^{\circ}C$에서 저장된 계란들의 난백의 pH는 무정란이 유정란보다 더 높았으나(P<0.05), $10\;^{\circ}C$에서 저장된 계란들의 경우는 유정란과 무정란간에 별 차이가 없었다. 난각강도는 유정란이 무정란보다 두 온도역 모두 유의하게(P<0.05) 더 컸었다. 그리고 암탉의 수정에 관계없이 난백의 높이와 pH는 부(-)의 상관관계(P<0.01~0.001)가 있었고, 난백의 높이와 HU는 정(+)의 상관관계(P<0.001)를 나타내었다. 이상의 결과를 종합해 보면, 난백의 높이 혹은 HU와 같은 계란의 신선도 변화에 있어서 상대적으로 암탉의 수정 유무보다는 저장기간과 저장온도가 더 중요한 요인인 것으로 사료되며, 일반적으로 저장온도가 낮을수록 HU는 증가되는 반면에 난백의 pH는 반대로 감소되는 것으로 보여진다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권11호
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• pp.1617-1621
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• 2002

Two hundred and sixteen single comb white egg layers of the White Leghorn hens of 24 weeks of age were randomly allocated to 12 groups with three replications of six hens in each. Hens were fed in a factorial arrangement 2${\times}3{\times}$2, on diets containing either 16 or 18% crude protein with 0, 3 or 6% fish meal, replacing groundnut meal with soybean meal. Soybean meal incorporation improved (p<0.05) egg production, feed intake, feed conversion efficiency and egg weights. Egg quality traits of specific gravity, shape index, albumen index, yolk index and shell thickness remained unchanged. Laying performance was significantly (p<0.05) better at 18% than on 16% dietary protein level. Use of fish meal linearly improved egg production and feed conversion efficiency on diets supplemented with groundnut meal and fish meal incorporation showed quadratic improvement on feed conversion efficiency with SBM diets at 16% dietary protein level. Therefore, use of soybean meal as substitute of groundnut meal is recommended in layer diets, at 16% dietary protein level and fish meal incorporation could be beneficial for layers.