• KOREAN POULTRY JOURNAL
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• v.52 no.11
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• pp.183-187
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• 2020

• KOREAN POULTRY JOURNAL
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• v.52 no.9
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• pp.154-157
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• 2020

• KOREAN POULTRY JOURNAL
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• v.52 no.5
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• pp.152-155
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• 2020

• KOREAN POULTRY JOURNAL
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• v.52 no.1
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• pp.168-171
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• 2020

• Animal Bioscience
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• v.35 no.8
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• pp.1109-1120
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• 2022

Antibiotics used to be supplemented to animal feeds as growth promoter and as an effective strategy to reduce the burden of pathogenic bacteria present in the gastro-intestinal tract. However, in-feed antibiotics also kill bacteria that may be beneficial to the animal. Secondly, unrestricted use of antibiotics enhanced the antibiotic resistance in pathogenic bacteria. To overcome above problems, scientists are taking a great deal of measures to develop alternatives of antibiotics. There is convincing evidence that probiotics could replace in-feed antibiotics in poultry production. Because they have beneficial effects on growth performance, meat quality, bone health and eggshell quality in poultry. Better immune responses, healthier intestinal microflora and morphology which help the birds to resist against disease attack were also identified with the supplementation of probiotics. Probiotics establish cross-feeding between different bacterial strains of gut ecosystem and reduce the blood cholesterol level via bile salt hydrolase activity. The action mode of probiotics was also updated according to recently published literatures, i.e antimicrobial substances generation or toxin reduction. This comprehensive review of probiotics is aimed to highlight the beneficial effects of probiotics as a potential alternative strategy to replace the antibiotics in poultry.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1174-1179
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• 2009

An experiment was conducted to study the effect of post-hatch feed deprivation on yolk sac utilization andsubsequent performance of young broiler chickens (280) up to 35 days of age. The experimental treatments included access to feed at 8 h intervals after hatch, up to 48 h (0, 8, 16, 24, 32, 40 or 48 h). Water was offered ad libitum to all the groups immediately after placement. Results indicated that chicks with access to feed immediately after hatch used up the residual yolk more quickly. Access to feed between 8-24 h post-hatch, supported faster utilization of residual yolk compared to those chicks that remained unfed for 40-48 h (p<0.05). Further, deprivation of feed up to 24 h did not alter the lipid and protein contents in residual yolk, but fasting of chicks beyond 24 h (32, 40 and 48 h) led to retention of higher lipid and lower protein content in the yolk sac (p<0.05). At 7 days of age, the weights of proventiculus and gizzard were not affected by feed deprivation up to 48 h. However, the liver, pancreas and jejunum recorded significantly (p<0.05) heavier weights in chicks that were fed during the initial 24 h period compared to delayed feeding (32-48 h). Chicks fed within 24 h after hatch gained significantly (p<0.05) higher weight at 5 weeks of age than those that received feed between 32 and 48 h. Feed deprivation for 48 h was more detrimental to growth than 24-40 h. This study revealed the significance of early posthatch feeding (<24 h) on faster utilization of yolk sac nutrients and optimum development of intestines and organs, culminating in improved weight gain (>10.5%) of broilers at 5 weeks of age.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.248-255
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• 2012

Three levels of boron (0, 30, 60 ppm) were supplemented in practical corn-soybean based starter and grower diets, containing either adequate or inadequate Ca or P. A total of 1,800, 1-day-old sexed broiler chicks were assigned to six dietary treatments and fed with the experimental diets for 42 days. Boron improved the overall feed conversion ratio, but increased body weight only at 21 days of age (p<0.01). Boron decreased feed intake in the case of feeding on a diet deficient in Ca and P, and tended to increase feed intake when birds received a diet adequate in Ca and P, signifying significant boron by Ca-P interaction (p<0.01). Mortality was not influenced by boron (p>0.05). Dietary Ca and P deprivation reduced body weight and feed consumption significantly, but did not influence the feed conversion ratio and mortality (p>0.05). Serum Ca level, ALP and ALT activities were not influenced either by dietary Ca and P deficiency or boron supplementation. Serum P content increased with respect to boron at 30 ppm. Bone breakage strength was not affected by dietary variables. Tibia ash, Ca and P were increased in response to the supplementation diet with 30 ppm boron, whereas 60 ppm showed no effect in most cases. Accordingly, the dietary boron supplementation of 30 ppm significantly decreased fecal Ca and P excretion, while there was a numerical decline in the 60 ppm boron as compared to the 0 ppm boron group. Data presented herein indicated that boron, either at the 30 ppm or 60 ppm supplementation level, was effective in conversion of feed to body weight, whereas only boron at 30 ppm contributed to the mineralization of bone thereby augmenting more Ca and P while excreting less through faeces.

• Korean Journal of Poultry Science
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• v.8 no.1
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• pp.31-36
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• 1981

This study was conducted to investigate how much total feed cost can be curtailed by the application of linear programming compared with the conventional hand calculating method in determining the feed formula in feed mill. Data were collected from a feed mill producing 19 different kinds of feed and having capacity of producing 5,000 tons of feed a month. According to the results of analysis, the least-cost feed formulation by linear programming showed a decrease of 4,793,172 won monthly in total feed cost as compared with the conventional hand calculating method. But, to confirm the results of this study, it is necessary to conduct further emperical studies.

• Korean Journal of Poultry Science
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• v.25 no.3
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• pp.147-155
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• 1998

Dietary levels of fermented poultry manure(FPM) 0%, 5%, 10% and 20% were included in experimental diets. It is to examine the effects of diets containing different levels of FPM on the performance of broiler chicks, including the nutrient availabilities, compared with that of the commercial diet. In order to evaluate the nutritive value of FPM, feeding and metabolism trials were conducted with a total of 160 broiler chicks for a period of 4 weeks. Contents of CP, crude fat, crude ash, crude fiber and NFE of FPM were 19.43, 2.43, 15.44, 16.57 and 38.31 %, respectively. Although there were no statistical difference in the body weight gain among treatments, weight gain achieved by the group fed diets of 5% substitution of FPM was slightly better than others. The amount of feed intake was significantly higher for FPM included groups than for control group, especially in the group fed diets of 10% substitution of FPM. The feed efficiency tended to be better for the control group than the FPM groups. The feed efficiency tended to get worse as the levels of FPM increased. The digestibility of DM, CP and NFE tended to be similar among treatments, especially it was lower for the group fed diets of 20% substitution of FPM compared with that of another groups. In conclusion, up to 10% substitution of FPM to the diet can be utilized effectively as a broiler feed ingredient, without adversely affecting growth performance.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.206-210
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• 2017

Objective: A study was conducted to test six threonine (Thr) levels (0.39%, 0.44%, 0.49%, 0.54%, 0.59%, and 0.64%) to estimate the optimal dietary Thr requirements for Longyan laying ducks from 17 to 45 wk of age. Methods: Nine hundred Longyan ducks aged 17 wk were assigned randomly to the six dietary treatments, where each treatment comprised six replicate pens with 25 ducks per pen. Results: Increasing the Thr level enhanced egg production, egg weight, egg mass, and the feed conversion ratio (FCR) (linearly or quadratically; p<0.05). The Haugh unit score, yolk color, albumen height, and the weight, percentage, thickness, and breaking strength of the eggshell did not response to increases in the Thr levels, but the albumen weight and its proportion increased significantly (p<0.05), whereas the yolk weight and its proportion decreased significantly as the Thr levels increased. Conclusion: According to a regression model, the optimal Thr requirement for egg production, egg mass, and FCR in Longyan ducks is 0.57%, while 0.58% is the optimal level for egg weight from 17 to 45 wk of age.