• 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.

• 한국가금학회지
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• 제15권4호
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• pp.281-286
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• 1988

본 시험은 하절기 산란계 사료에 대하여 고추가루(씨포함)를 0, 0.03, 0.05, 0.08% 첨가하여 산란계의 산란성적과 난각질 및 난황착색도를 측정하기 위한 것으로써 결과를 요약하면 다음과 같다. 1. 산란율에 있어서는 시험기간동안 대조구에 비해 첨가구가 약간 증가 하였으나, 처리간 유의차는 인정되지 않았다. 2. 난중은 대조구와 첨가구 사이에는 유의차가 없었으며, 일영이 증가함에 따라 증가하였다. 3. 산란양은 대조구에 비해 첨가구가 높았으나 처이간 유의차는 인정되지 않았다. 4. 사료섭취양은 대조구에 비해 첨가구가 약 2~3g 더 섭취하는 것으로 나타났고, 사료요구율은 대조구 및 첨가구간 차이가 없었다. 5. 난각질의 경우 난각강도는 대조구에 비해 첨가구가 상당히 높았으며 처리구간 고도의 유의차가 인정되었다(P＜0.01 ). 또한 난각후도는 대조구에 비해 첨가구가 유의적으로 증가하였다 (P＜0.05). 6. 난황착색도는 대조구에 비해 첨가구는 고도의 유의차가 인정되었으나(P＜0.01) 첨가구간 유의차는 인정되지 않았다. 이상의 결과를 종합하여 보면 사료 중 고춧가루 첨가는 0.05%$T_2$수준이 적당하다고 사료된다.

• 한국가금학회지
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• 제35권3호
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• pp.303-311
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• 2008

본 실험은 Cu-methionine chelate(Cu-Met)와 Cu-soy proteinate(Cu-SP)가 산란계의 생산성과 소장내 미생물 균총 및 면역 체계에 미치는 영향을 조사하기 위해 실시하였다. 사양시험은 39주령의 산란계(Hy-line $Brown^{(R)}$) 960수를 선별하여 A형 2단 4열 케이지에 대조구 포함 총 6처리구로 구성하여 처리당 4반복, 반복당 40수씩(2수 수용 케이지 20개) 난괴법으로 임의 배치하였다. 시험 기간 동안 물과 사료는 자유 섭취하게 하였으며, 일반적인 점등 관리(자연 일조+조명; 16 hr)를 실시하였다. 시험구는 대조구, 항생제구(avilamycin 6 ppm), Cu- Met 50(Cu-methionine으로 Cu 50 ppm), Cu-Met 100(Cu- methionine으로 Cu 100 ppm), Cu-SP 50(Cu-soy proteinate로 Cu 50 ppm) 그리고 Cu-SP 100(Cu-soy proteinate로 Cu 100 ppm) 등 총 6처리였다. 일계 산란율(Hen-day egg production)과 산란지수(Hen-house egg production)는 Cu 첨가구들과 항생제 첨가구들이 대조구에 비해 높은 경향을 보였는데, 특히 Cu-Met 100 구는 대조구에 비하여 유의적으로(P<0.05) 높았으며 Cu 처리구들 간에 종류나 첨가 수준에 따른 차이는 유의하지 않았다. 난중에서는 항생제구와 Cu-SP 첨가구들이 대조구보다 무거운 경향을 보였고, Cu-Met 첨가구들보다는 유의하게(P<0.05) 무거웠다. 난각 강도, 난각 두께, 난각색, 난황색, Haugh unit 등 계란 품질에 있어서 처리구간에 유의적인 차이는 나타나지 않았다. Leukocytes와 erythrocytes 관련 모수들은 평균 적혈구 혈색소량(MCH)을 제외한 모든 항목에서 처리간에 유의적인 차이는 나타나지 않았다. MCH는 Cu-SP 100이 대조구와 비교하여 유의적으로 높았다(P<0.05). 혈청 IgG와 IgA의 농도는 처리구간에 유의적인 차이는 나타나지 않았다. 간 내 구리의 함량은 처리간에 유의한(P<0.05) 차이가 있었는데, 구리의 첨가 수준이 높을수록 높아지는 경향이 있었으며 같은 첨가 수준에서는 Cu-SP 첨가구들이 Cu-Met 첨가구들보다 높은 경향이 있었다. 소장 내용물 중 Cl. perfringens의 수는 항생제와 Cu 첨가구들이 대조구에 비해 적었고 E. coli 수는 첨가구들에서 감소하는 경향이 있었으며, Lactobacilli 수는 Cu 첨가구들이 대조구나 항생제구와 비교하였을 때 많았다. 결론적으로 Cu-Met와 Cu-SP는 산란계의 산란율 개선에 있어서 항생제와 유사한 효과를 나타내었다. Cu-SP는 Cu-Met보다 난중을 유의하게 증가시켰으나 다른 항목들에 있어서는 Cu 공급원(Cu-Met vs Cu-SP)과 첨가수준(50 vs 100 ppm)에 따른 유의적 차이는 없었다.

• 농업과학연구
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• 제46권4호
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• pp.991-997
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• 2019

This study was conducted to investigate the laying period performance of two crossbred Korean native chicken (KNC) grand parent stock (GPS) layer during 20 to 40 weeks. A total of 351 20-week-old KNC GPS were allocated in a completely randomized design to give 4 birds per each cage. The chickens were fed commercial diets [i.e., week 20 - 32, crude protein (CP) 18.0% and metabolizable energy (ME) 2,850 kcal/kg; week 32 - 40, CP 17.0% and ME 2,800 kcal/kg)] and fresh water during the whole experiment period ad libitum basis. Body weight, age of sexual maturity, egg weight, hen-day egg production (HDP) and feed conversion ratio (FCR) were measured during the experiment period (week 20 - 40). The results show no significant difference in the Body weight, age of sexual maturity, egg weight, and hen-day egg production (HDP) except for egg weight. 1B had a higher egg weight on week 36 only. We expect that the reason why most factors showed no significant difference is the lack of nutrients caused by limited feeding which follows the standard feeding system for the grand-parent stock. These results provide basic information for laying data in 2-way crossbred Korean native chickens.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.48-54
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• 2006

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid) has been used as feed additives in poultry industries to improve production and control coccidiosis. The effect of high dietary levels of Roxarsone (ROX) on the performance and function of internal organs and the kinetics of recovery as well as its after-effects were examined in laying hens. The inclusion rates of ROX were 0, 100, 200, 300, and 400 mg per kg feed. Inclusion up to 200 mg did not show any adverse effects (p>0.05), whereas in the 300 and 400 mg groups, significant effects, particularly in the latter, were observed for three weeks after ROX addition (p<0.05). Recovery of the physical appearance occurred soon after ROX addition was withdrawn. Recovery of performance and internal organs, however, appeared to be dependent on the amount of residual ROX in the body; as the amount of ROX decreased, the toxic effect of ROX also decreased. In the third week after the withdrawal of ROX, complete recovery was observed in the lower dosage groups (100 or 200 mg groups) (p>0.05), whereas in the higher dosage groups (300 or 400 mg groups), recovery took at least five weeks; when complete recovery was observed in egg production and in liver weight (p>0.05). On the other hand, ROX might have damaged the liver and other tissues. The recovery of liver weight was probably due to accumulation of fatty particles rather than repair. It appeared, therefore, there were little after-effects of ROX on the hen's physical appearance, but some internal organs were probably damaged.

• 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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• 제22권5호
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• pp.694-699
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• 2009

The present study was conducted to evaluate the effect of chilled drinking water on the productivity of laying hens under constant high ambient temperature. A total of seventy-two, 123-day-old Hy-line brown layers was divided into two equal groups. The first group (UDWG) was given unchilled water ($23.0{\pm}2.5^{\circ}C$) as a control, and the second group (CDWG) was given chilled water ($16.0{\pm}0.5^{\circ}C$). The laying hens were kept at $30^{\circ}C$ constant temperature with 50% relative humidity and were exposed to 17 h of light per day. Feed intake, egg production, egg quality (egg weight, shell weight, shell thickness, egg color, yolk color, and Haugh unit), and blood samples were collected and analyzed. The results showed that the feed intake of CDWG laying hens was significantly higher (11.64%) than the UDWG counterparts (p<0.01). Egg production of CDWG was also significantly higher (11.27%) than the UDWG counterparts (p<0.001). Furthermore, we observed that the CDWG laying hens had significantly higher (11.72%) levels (p<0.10) of blood calcium, with a corresponding value of 21.92 mg/dl compared to the UDWG hens (19.62 mg/dl). The higher calcium concentration in the CDWG animals may contribute to increased egg production. The CDWG laying hens also contained higher (12.53%) phosphorus concentrations in blood compared to the UDWG (4.22 mg/dl vs. 3.75 mg/dl), although not statistically different (p>0.10). Egg weight and egg quality were not affected by chilled drinking water. In conclusion, providing chilled drinking for laying hens under high ambient temperature improved feed intake and egg production.

• Journal of Animal Science and Technology
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• 제65권2호
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• pp.351-364
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• 2023

The experiment was carried out to study the effect of Korean wild ginseng adventitious root supplementation on the laying performance, egg quality, cytokine expression, ginsenoside concentration, and microflora quantity of Institut de selection Animale (ISA) brown laying hens at 24 weeks old. A total of 90 laying hens were subjected to a completely randomized design at three treatments, five repetitions and six laying hens per replicate. The experiments were divided by diets into the basic feed (CON), basic feed + 0.1% wild ginseng (WG1), and basic feed + 0.5% wild ginseng (WG2). The feeding trial was carried out over a duration of 12 weeks after an initial acclimation period of 2 weeks. Feeds and water were administered ad libitum in mash form, and light was available for 16 hours per day. At the end of study, henday egg production (HDEP), average egg weight (AEW), and egg mass (EM) were increased (p <0.05) in WG2 at week 12. Feed conversion ratio (FCR) was decreased (p < 0.05) in WG2 at week 12. The ginsenoside content in egg yolk was increased (p <0.05) in laying hens in the WG2 treatment at week 12. Relative expression of tumor necrosis factor alpha (TNF-α) was reduced (p < 0.05) in the WG supplemented diets at week 12. The fecal microflora quantity of Lactobacillus was increased (p < 0.05) in WG2 at week 8 to week 12, and Escherichia coli (E. coli) was significantly decreased (p < 0.05) in the WG2 at week 12. We concluded that the result observed in the HDEP, AEW, EM and FCR was due to an increase in ginsenoside content, leading to an improvement in the TNF-α, and fecal microflora quantity such as Lactobacillus and E. coli in the WG2 supplemented diets. We therefore recommend the use of WG at application level 0.5% per basal diet for optimum laying performance in layer hens.

• Asian-Australasian Journal of Animal Sciences
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• 제31권11호
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• pp.1766-1772
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• 2018

Objective: This experiment was to investigate the effect of increasing levels of apparent metabolizable energy ($AME_n$) on the laying performance, egg quality, blood parameters, blood biochemistry, intestinal morphology, and apparent total tract digestibility (ATTD) of energy and nutrients in diets fed to laying hens. Methods: A total of three-hundred twenty 33-week-old Hy-Line Brown laying hens (Gallus domesticus) were evenly assigned to four experimental diets of 2,750, 2,850, 2,950, and 3,050 kcal $AME_n/kg$ in pens with floors covered with deep litter of rice hulls. There were four replicates of each treatment, each consisting of 20 birds in a pen. Results: $AME_n$ intake was increased (linear, p<0.05) with inclusion level of $AME_n$ in diets increased. Feed intake and feed conversion ratio were improved (linear, p<0.01), but hen-day egg production tended to be increased with an increasing level of $AME_n$ in diets. During the experiment, leukocyte concentration and blood biochemistry (total cholesterol, triglyceride, glucose, total protein, calcium, asparate aminotransferase, and alanine transferase were not influenced by increasing level of $AME_n$ in diets. Gross energy and ether extract were increased (linear, p<0.01) as the inclusion level of $AME_n$ in diets increased. Conclusion: Laying hens fed high $AME_n$ diet (i.e., 3,050 kcal/kg in the current experiment) tended to overconsume energy with a positive effect on feed intake, feed conversion ratio, nutrient digestibility, and intestinal morphology but not on egg production and egg mass.

• Preventive Nutrition and Food Science
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• 제1권1호
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• pp.99-105
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• 1996

Effects of conjugated linoleic acid(CLA), known as an effective anticarcinogen in several aminal models, on the egg production and egg weight of laying hens, and the weight gains of broilers were investigated. CLA was synthesized from corn oil by the alkaline isomerization method and purified by the low-temperature precipitation method. Diets for laying hens and for broilers were synthesized to meet the specification of their NRC standard rationals. Two separated experiments(Experiment I and II) were conducted for laying hens. in experiment I, 45 hens(300 days of age) were divided into 15 hens per treatment group; each hen was housed in wired cage located in a temperature and humidity-controlled house and adopted to the control diet. One week later, each group was subjected to one the four treatment groups for 5 weeks : control, 1.0% CLA, 2.5% CLA and 5.0% CLA diets. Diet and water were ad libitum. The condition of experiment II was the same as that of experiment I except for the addition of 5% corn oil diet and the extension of feeding period to 7 weeks. Egg production, egg weight and feed intake were recorded every week. Forty-five broilers(10day of age) were adopted to the control diet for a week and then switched to the treatment diets for 5 weeks : control, 1.0% CLA, 2.5% CLA, 5% CLA and 5% corn oil, Body weight and feed intake of broilers were measured every week. Diets supplemented with various amounts of CLA enhanced the egg production and increased the egg weight regardless laying hen's age(150 days or 300 days) as compared to control diet. The most effective diet for the egg production and egg weight of young hens(150 days of age) was found to be 1.0% CLA diet, but relatively higher CLA diet(2.5% CLA) was required for old hens (300 day of age) to obtain similar results as seen in younger hens. All hens treated with CLA ate greater amount of feed than control hens. Broilers treated with various amount of CLA ate less feed as compared to control ones, but the body weight gain was greater than the control broilers. These results indicate that CLA enhanced the egg production and agg weight of laying hens, and increased the body weight gain of broilers with less diet consumption.