• 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.

• 한국가금학회지
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• 제21권3호
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• pp.195-205
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• 1994

Effects of the addition of \beta-glucanase to barley-based layer diets were examined by feeding 200 Leghorn layers with corn-based (Control) and \beta-glucanase supplemented diets (Barley+ Enzyme). The results obtained are sumrrarized as follows. 1. There were no siginificant (P>0.05) differences in hen-day egg production(%) and average egg weight between two treatments, indicating that the \beta-glucanase supplemented barley could successfully replace the commonly used corn in the layer diets. 2. Although there was no statistical difference (P>0.05) between two treatments, the daily feed consumption was numerically high in layers fed the barly diet compared to the corn-based diet. 3. Availabilities of crude fat and crude fiber of the barley diet were significantly poor (P<0.05) as compared to corn diet. 4. The \beta-glucarase supplementation depressed the viscosity of barley diets and excreta from therm. 5. Both serum and egg yolk cholesterol were not significantly affected by the addition of \beta-glucarase in the barley based diet. Our data indicate that the barley grain supplemented with \beta-glucarase can be sucessfully used as an energy source of layer diet when there is a price advantage. Although some possibilities to produce low cholesterol egg were recognized in this study, further studies pertaining to long-term feeding experiment and elucidaton of the metabolic interrelationship between serum and yolk cholesterol, are required to confirm the result.

• 대한수의학회지
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• 제42권2호
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• pp.253-260
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• 2002

Fowl red mite, Dermanyssus gallinae, is the most important ectoparasite affecting egg layers worldwide. More than 35 compounds have been used for fowl red mite control. Although some of them are efficient, several compounds are unsuitable in terms of food safety and environmental problems. Some compounds are efficient in theory but inadequate in practice. It is also expensive in material and labor to control effectively. Effective doses are very close to toxic doses and repeated treatment is required. Repeated, long term treatment of compounds on fowl red mite populations, may cause heritable resistance against the mites. In this study, antigenicity of fowl red mite and house dust mite, Dermatophagoides pteronyssinus, were identified by SDS-PAGE, silver staining, Western blotting and ELISA to investigate immune effects against fowl red mite using somatic antigens of fowl red mite and house dust mite. By SDS-PAGE, silver staining and Western blotting, several common antigens (110, 60, 56, 49, 46 kDa) of both fowl red mite and house dust mite were recognized. To identify immune effect of somatic antigens of fowl red mite and house dust mite, sixty white leghorn broilers(1 week old) were used. Among sixty white leghorn broilers, twenty were immunized with fowl red mite somatic antigens(Group I), twenty immunized with house dust mite antigens(Group II), and twenty were control group without antigen(Group III), respectively. After immunization, it was identified that antibody titers were increased both in group and II. Then all groups were challenged with fowl red mites. After 2 months, measurements of body weights, packed cell volume(PCV), ELISA OD values and numbers of mites were significant(p<0.05). These results suggest that fowl red mite and house dust mite, which are easy to collect and maintain, can be good vaccine candidates against fowl red mite in chicken.

• 농업과학연구
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• 제9권1호
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• pp.314-356
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• 1982

산란계(産卵鷄)의 주요(主要) 경제형질(經濟形質)의 효율적(效率的)인 개량(改良)을 위(爲)하여 지금까지는 체중(體重), 초산일령(初産日令), 산란계(産卵鷄) 및 난중(卵重)을 기초(基礎)로 하여 선발(選拔)하여 왔으나, 실제(實際) 가식부분(可食部分)은 난황(卵黃) 및 난백(卵白)이므로 이들에 대한 유전적(遺傳的) 모수(母數)를 추정(推定)하여 난황(卵黃) 및 난백(卵白)의 중량(重量)을 선발지수(選拔指數) 추정(推定)에 이용(利用)하므로서 선발(選拔)의 정확도(正確度)를 높일 수 있는 가능성(可能性)을 구명(究明)하기 위(爲)하여 본(本) 연구(硏究)를 실시(實施)하였다. 공시계(供試鷄)는 국립종축장(國立種畜場) 대전지장(大田支場)에서 폐쇄군(閉鎖郡) 육종방법(育種方法)에 의(依)해서 개량(改良)되어온 S. C. W. Leghorn종(種) 351수(首)와 R. I. Red종(種) 326수(首)가 사용(使用)되었고, 난구성분(卵構成分)은 총(總) 6,097개(個)가 조사(調査)되었으며, 각(各) 형질(形質)들은 1979년(年) 3월(月) 1일(日)부터 500일간(日間) 조사(調査) 분석(分析)되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권4호
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• pp.524-530
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• 2012

Laying hens were fed commercial diets added with supplemented fat (SFAT) at 0.6, 1.2, and 1.8% in order to study the long term dietary effects - on - their productive performance from 22 to 75 wk of age. Five hundred and seventy six Single Comb White Leghorn hens were assigned to one of the four dietary treatments. The experimental phase consisted of three periods of 18 wk each. The final body weight and gain of hens fed on diets with SFAT at 1.2% and 1.8% were lower (p<0.05) than those hens given no SFAT. The SFAT at the 1.2% and 1.8% levels improved egg production rate, egg weight and mass, as well as FCR. Mortality and feed consumption were not affected by dietary SFAT. Administration of a diet with SFAT significantly decreased the cracked-broken egg ratio (p<0.01). The beneficial effects of SFAT on egg production performance were particularly more pronounced at intermediate and later ages. Hence, SFAT by period interactions were significant for all traits studied except feed intake. Hens fed SFAT deposited significantly higher abdominal fat than those on the no-SFAT diet. As a result, SFAT at 1.2% and 1.8% inclusion levels provided benefits in terms of efficient table egg production.

• 한국가금학회지
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• 제37권2호
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• pp.117-123
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• 2010

본 연구는 저단백질, 저에너지 사료를 이용한 유도 환우가 산란계의 생산성에 미치는 영향을 구명하고자 실시하였다. 공시계는 산란율이 80% 이상인 61주령 White Leghorn 산란계 80수(평균 체중 $1.75{\pm}0.13$ kg)를 이용하여 12주 동안 시험을 실시하였다. 시험 설계는 환우를 하지 않는 비환우 대조구(CO), 비급이 환우구(10일 동안의 절식구, FW), 급이 환우구1(3주 동안 저단백질-저에너지 환우용 사료 급이구, LO) 그리고 급이 환우구2(3주 동안 표준 환우용 사료 급이구, ST)의 총 4처리구로 나누었으며, 처리구당 2반복, 반복당 10수씩 총 80수를 완전 임의 배치하였다. FW구에서는 2주째 초기체중에서 26.5%의 체중 손실이 있었으며, LO구와 ST구에서는3주째각각 17.3과 14.2%의 체중손실이 있었다(P<0.05). 환우구의 시험계들은 환우가 종료되고 산란 말기 사료를 급여한 1주 후에 체중이 회복되기 시작하여, 7주째는 처리구간에 환우 전 체중으로 회복되었다. 심장 무게 비율은 CO, FW, LO 및 ST구에서 각각 0.47, 0.43, 0.46 그리고 0.46%로 나타났으며, 간 무게 비율은 각각 2.56, 1.30, 1.47 및 1.52%로 비환우 대조구에 비해 환우 처리구에서 무게가 감소하였다(P<0.05). 난포수란관 무게 비율은3.95, 1.17, 1.54 및1.67%로 간과 유사한 경향을 보였다(P<0.05). LO구와 ST구는 환우 기간 중에 사료 섭취량이 감소하였으며, 5주째 이후부터는 사료 섭취량이 대조구와 유사하게 증가하였다. 산란율은 1주령에 환우 처리구에서 감소하였으며, FW구에서는 2주째, LO구에서는 3주째, ST구에서는 4주째에 산란이 정지되었다. 산란 회복 기간을 보면 FW구는 4주째, LO구와 ST구는 5주째 산란이 재개되었으며, FW구는 6주째에 50.6%로 산란율이 50% 정도가 회복되었고, LO구와 ST구는 8주째에 각각 66.1과 71.6%로 산란율이 50%가 넘게 회복되었다. 난중은 약 67.5 g 정도로 모든 처리구에서 유사하게 나타났다. 난각두께는 CO, FW, LO 및 ST구에서 각각 0.41, 0.47, 0.46, 0.46 mm로 환우 처리구에서 높게 나타났다(P<0.05). 난각 강도는 FW구와 LO구는 각각 3.83과 3.81 kg/$cm^2$로 CO구에 비해 높게 나타났으나, CO구와 ST구는 각각 3.54와 3.78 kg/$cm^2$로 유의적인 차이가 없었다. 호우유니트는 4처리구에서 각각 75.6, 81.1, 80.6 및 79.9로 환우 처리구에서 높게 나타났다. 따라서 사료의 에너지와 단백질 함량을 낮추어 산란계의 생산성에 미치는 영향을 최소화하여 환우를 유도할 수 있다고 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제10권6호
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• pp.657-664
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• 1997

432 Babcock ISA white leghorn pullets reared for 8 weeks on a standard managemental conditions were exposed to feed/nutrient and light restrictions from 9 to 20 weeks of age. Four feeding regimes i. e. 100, 85 or 70 percent of the recommended allowance and low energy (2,500 Kcal/kg) low protein (13% CP) ration were fed each in the three light regimes i. e. (A) Natural day light starting from 13.24 hr/day at 8 weeks of age and ending 10.41 hr/day at the end of 20 weeks; (B) Constant 11 hr/day light and (C) starting with 13 hr/day at 8 weeks and decreasing @ 20 min/week till 20 weeks of age. At the age of 20 weeks all the birds were shifted to separate cages under uniform lighting feeding and management. During the 21st week light was increased to 12 hr a day and thereafter with an increase of 30 min per week, increased to 16 hr a day at the age of 29 weeks. From 20 weeks onward till 72 week age, all the birds were offered commercial layer rations ad libitum, prepared according to climatic conditions. The results of the study revealed that birds reared under natural and constant light had higher weights than decreasing light, yet they could not out perform during production period. The effect of feed and nutrient restriction, on the other hand, was found significant during rearing as well as production period. The birds exposed to higher level of feed and those exposed to nutrient restriction were lighter in weight. The 100% fed birds laid their first egg at an early age. However, those reared on 85% of the recommendation excelled all other groups in terms of produced number of eggs, egg mass, hen housed and hen day production and net returns.

• Journal of Animal Science and Technology
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• 제55권2호
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• pp.131-139
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• 2013

The aim of this study was to assess the effects of housing systems on physiological and immunological responses as stress indicators in laying hens. A total of 500 White Leghorn aged 16 weeks were allotted into ten conventional cages (10 birds/cage and 810 $cm^2$/bird) and four floor pens (100 birds/pen and 2,800 $cm^2$/bird) for 24 weeks. The hens housed in conventional cages with higher stocking density resulted in a significantly (P<0.05) lower BW compared with those housed in floor pens with lower stocking density without affecting the relative weights of immune organs between housing conditions. In plasma biochemical values, cholesterol and corticosterone were significantly (P<0.05) lower in the hens housed in floor pens compared with those housed in conventional cages. In pro-inflammatory cytokines, hepatic interleukin (IL)-10 and interferon-gamma (IFN-${\gamma}$) levels were significantly (P<0.05) higher in the hens housed in conventional cages compared with those kept in floor pens. Splenic and thymic IFN-${\gamma}$ expression was significantly (P<0.05) up-regulated in the hens kept in conventional cages compared with those kept in floor pens without affecting IL-1, IL-10, lipopolysaccharide- induced tumor necrosis factor-${\alpha}$ factor (LITAF) and inducible nitric oxide synthase (iNOS). In the bursa of Fabricius, IL-10 and iNOS expression of the hens housed in conventional cages were significantly (P<0.05) higher compared with those of the hens housed in floor pens. In conclusion, layers housed in conventional cages enhanced plasma cholesterol, corticosterone and some pro-inflammatory cytokines in the immune organs compared with those in floor pens.

• Animal Bioscience
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• 제34권5호
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• pp.886-894
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• 2021

Objective: An experiment was conducted to study the effect of graded concentration of digestible lysine (dLys) on performance of layers fed diets containing sub-optimal level of protein. Methods: Five diets were formulated to contain graded concentrations of dLys (0.700%, 0.665%, 0.630%, 0.593%, and 0.563%), but similar levels of crude protein (15% CP), energy (10.25 MJ ME/kg) and other nutrients. A total of 3,520 hens (26 wk of age) with mean body weight of 1,215+12.65 g were randomly divided into 40 replicate groups of 88 birds in each and housed in an open sided colony cage house. Each diet was offered ad libitum to eight replicates from 27 to 74 wk of age. The performance was compiled at every 28 d and the data for each parameter were grouped into three phases, that is early laying phase (27 to 38 wk), mid laying phase (39 to 58 wk), and late laying phase (59 to 74 wk of age) for statistical analysis. Results: Egg production, egg mass and feed efficiency (feed required to produce an egg) were significantly improved by the dLys level during the early and mid laying phases but not during the late phase. Whereas feed intake was significantly reduced by dLys concentration during mid and late laying phases but not during early laying phase. The egg weight was not affected by dLys concentration in any of the three phases. Conclusion: Based on best fitted statistical models, dietary requirements of dLys worked out to be 0.685%, 0.640%, and 0.586% during early phase, mid phase, and late egg laying phase, respectively. The calculated requirement of dLys for the respective production phases are 727 mg/b/d during the early and mid laying phases and 684 mg/b/d during the late laying phase in diets containing 15% CP.

• 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.