• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.206-211
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• 1983

This study was carried out to compare the feed utilization between pelleted and all-mash diet of similar composition by growing chickens. Day-old broilers (Hubbard) and egg-type chickens(Hy-line) of commercial strain were employed in this experiment. The results obtained were summarized as follows. 1. The chickens fed pelleted diets were heavier than those of birds fed all-mash diets. The Hubbard broilers and Hy-line chickens fed pelleted diets weighed 2,702g and 812g respectively, at 9 weeks of age. In comparison, the Hubbard broilers and Hy-line chickens fed all-mash diets weighed 2,571g and 777g respectively, at 9 weeks of age. 2. The pellet-fed chickens consumed more feeds than birds fed all-mash diets in both types of strain. Feed efficiencies (gain/feed) of Hubbard and Hy-line chickens were 0.38 and 0.26 in pellet feeding groups, and 0.36 and 0.25 in all-mash feeding groups, respectively. The Hy-line chickens fed pelleted diets drank more water than birds fed all-mash diets. 3. Pellet feeding groups produced more dry matter excreta as compared with all-mash feeding groups, reflecting the pattern of feed consumption by these chickens. Nitrogen retention ratio of the Hubbard and Hy-line chickens were 57-67% and 65-73%, respectively. Chickens fed pelleted diets showed 1-4% higher nitrogen retention than chickens fed all-mash diets. 4. The ME/GE ratio of the Hubbard and the Hy-line at 8 weeks of age were 73.4-74.3% and 82.8-83.8%, respectively. Pellet feeding groups showed 1% higher ME/GE ratio than all-mash feeding groups. 5. The dietary productive energy calculated from respiratory quotient was $94.1-102.6kca/kg^{\frac{3}{4}}$ BW/day in pellet feeding groups. The ratios of PE/GE were 41.3-48.9% in pellet feeding groups and 39.0-45.8% in all-mash feeding groups. 6. It appears that pelleting the all-mash diet increases feed consumption and body weight gain of growing chickens. Feed efficiency and energy utilization were also improved by pelleting process. More research work should be done to establish the relationship clearly between feed pelleting and heat increments.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.168-171
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• 2003

Generally RF AGC (Roll Force Automatic Gauge Control) controls the roll gap using the variation of rolling force caused by the roll eccentricity and the entry thickness of material, but RE AGC takes the bad effect of the roll eccentricity. The Feed-forward (FF) AGC method, which controls the next stand roll gap by the estimation of the thickness variation due to skid mark is needed to supplement the shortage of RF AGC. In this paper, an adaptive filtering method which takes account of the kind of material, the final objective thickness and the rolling speed is proposed to predict skid mark thickness variation. In addition, an improved estimation method of control point using a speedometer and looper angle is suggested. Via on line test, the performance improvement of the suggested FF AGC method is verified.

• Journal of Welding and Joining
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• v.24 no.5
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• pp.67-73
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• 2006

Laser welding is suitable for welding to the aluminum alloy sheet. In order to apply the aluminum laser welding to production line, parameters should be optimized. In this study, the optimal welding condition was searched through the genetic algorithm in laser welding of AA5182 sheet with AA5356 filler wire. Second-order polynomial regression model to estimate the tensile strength model was developed using the laser power, welding speed and wire feed rate. Fitness function for showing the performance index was defined using the tensile strength, wire feed rate and welding speed which represent the weldability, product cost and productivity, respectively. The genetic algorithm searched the optimal welding condition that the wire feed rate was 2.7 m/min, the laser power was 4 kW and the welding speed was 7.95 m/min. At this welding condition, fitness function value was 137.1 and the estimated tensile strength was 282.2 $N/mm^2$.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1360-1363
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• 2003

A feeding trial was conducted on pigs to study the effect of La on their growth performance. Sixty barrows were randomly assigned to two groups (each of which included three replicates) and they were fed same basal diet supplemented with 0 or 100 mg/kg lanthanum (La) respectively for 30 d. Blood samples were collected and analyzed to study the growth hormone secretion pattern. La residues in selected organs were analyzed to test the safety level. The results showed that average daily gain and feed conversion ratio of pigs were increased by 12.95% (p<0.05) and 6.78% (p<0.05) respectively with the supplementation of La. Blood samples analysis showed that peak amplitude, base-line level and mean level of growth hormone in serum were elevated by 80.42% (p<0.05), 70.99% (p<0.05) and 64.91% (p<0.05) respectively. No significant difference of La residues was found in selected organs between the control and La-treated group.

• Animal Bioscience
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• v.36 no.4
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• pp.619-628
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• 2023

Objective: This study aimed to determine and compare the apparent ileal digestibility (AID) and the standardized ileal digestibility (SID) of amino acids (AA) in soybean meal (SBM), cottonseed meal (CSM), and low-gossypol cottonseed meal (LCSM) fed to broiler chickens and laying hens. Methods: Three semi-purified diets containing the identical crude protein concentration at 20% were formulated to contain SBM, CSM, or LCSM as the sole source of N. A N-free diet was also formulated to estimate the basal ileal endogenous losses of AA for broilers and hens. A total of 300 male Ross 308 chicks at one-day-old and 144 Hy-Line Brown laying hens at 30-week-old with initial egg production rate of 88.3%±1.0% were randomly allocated into 1 of 4 dietary treatments, respectively. Results: CSM and LCSM showed more Arg and Cys+Met while less Lys, Ile, Leu, and Thr relative to SBM. Significant interactions existed between species and experimental diets for AID (except for Arg, Asp, Glu, Gly, and Pro) and SID (except for Arg, His, and Phe) of most AA. Most AA in diets showed higher AID (except for Lys) and SID (except for Lys, Met, and Ser) in broilers relative to laying hens. The AID and SID of all AA were significantly different between the three diets. In broilers, the AID and SID of most indispensable AA except for Arg in SBM and LCSM was higher than CSM. In laying hens, the AID and SID of most indispensable AA except for Arg, Met+Cys, and Phe in SBM was higher than CSM and LCSM. Conclusion: The accurate determination of AID and SID of AA in CSM and LCSM for broilers and layers benefits the application of CSM and LCSM in chicken diets. The cottonseed by-products CSM or LCSM showed the species-specific AA digestibility values for broilers and layers.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1196-1200
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• 2008

An experiment was conducted to evaluate the physiological changes of laying hens subjected to feed removal during induced molting while received probiotics in the drinking water. Post-molt performance and egg quality criteria were also studied. Ninety 78-week-old Hy-line W36 laying hens were divided into two treatment groups according to equal body weight and subjected to induced molting by continuous feed removal until around 30% BW reduction. The experiment lasted 12 wks consisting of 4-wk molting and 8-wk post-molt periods. Treatment 1 received no probiotics and was considered as the control. Treatment 2 was similar to the control except that hens received probiotics in the drinking water at 400 mg/L during feed deprivation. The results indicated that hens in both groups went out of production by Day 5. However, hens received probiotics reached 5 and 50% egg production sooner than the control (30 and 52 days vs. 31 and 54 days). Starvation during molting increased heterophil to lymphocyte (H/L) ratio, hematocrit and plasma T4 and $Na^+$ levels while plasma T3 and Cl- levels were decreased. Probiotics had no significant impact on BW reduction during molt. Post-molt egg production and egg mass were higher in hens which previously received probiotics, but these responses were not significant. However, feed conversion ratio was significantly better in hens which received probiotics. Hematocrit, plasma thyroid hormone concentrations (T3 and T4) and plasma $Na^+$, $K^+$ and Cl- levels during molting were not significantly influenced by supplementation of probiotics. However, H/L ratio showed a significant (p<0.05) reduction in birds which received probiotics suggesting beneficial effects of this product for feed-deprived laying hens. No significant difference was observed in post-molt egg quality criteria.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.12
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• pp.1667-1673
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• 2017

Antibiotics have long been of great benefit for people, both in the medical treatment of human disease and in animal food where they improve the growth performance and feed utilization during animal production. Antibiotics as in-feed supplements affect all stages of pork production, including the gestation, nursing, growing, and finishing stages, although the effects show stage-dependent differences. However, the use of antibiotics in animal feed has become a worldwide concern. This review describes why sub-therapeutic levels of antibiotic additives in animal feed have become an integral part of animal feeding programs for more than 70 years, particularly in pork production. It also discusses the threat of the long-term use of sub-therapeutic levels of antibiotics in pork production. In recent years, the effectiveness of in-feed antibiotics has tended to decrease. This review analyzes this change from various perspectives. First, the equipment used at pig farms has improved dramatically and is more sanitary. Worldwide, more pig farms use pig farrowing crates, gestation crates, piglet nursery crates, flooring devices, piggery ventilation and cooler systems, automatic pig feeders, piggery heating equipment, and artificial insemination systems. In addition, scientists have replaced the use of antibiotics with organic acids, fermented mash, probiotics, prebiotics, minerals, oligosaccharides, enzymes, herbs/flavors, and protein/amino acids, and have improved management and husbandry techniques. In addition, animal welfare legislation has been aimed at improving the quality of the floors and living space, ensuring that animals have permanent access to fresh water, and setting a minimum weaning age. Finally, the prospects and the possibility of replacing antibiotics in pork production are described, in line with recent research results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.2
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• pp.143-150
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• 2000

In this paper, an optimum size for the inset cut feed of microstrip antennas has been determined by using the finite-difference time domain method. At first, the return losses of microstrip antennas having various shapes and types of the inset cut feeds have been computed numerically for a given frequency and a substrate. Then an optimum size of the inset cut feed has been determined by iterative computation procedure for a given condition. It was found that the optimum width of the inset cut feed is about 0.42 times of the width of 50Ω feed line and the optimum length of the inset cut feed is about 0.36 times of the length of the antenna patch. These results are proved by the experimental data obtained from the measurements of many fabricated antennas. It was also found that the optimum size of the inset cut feed is independent on the frequency, the height and the dielectric constant of the antennal substrate.

• Korean Journal of Veterinary Service
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• v.44 no.3
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• pp.141-148
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• 2021

The objective of this research was to evaluate the immune response to Salmonella Gallinarum experimentally infected layers fed with Guanosine 5'-monophosphate-chelated calcium and iron feed additives. Hy-Line brown, 34 week-olds layers were assigned to 3 groups; Group 1: basal diet feed, Group 2 (CaFe-GMP): basal diet feed mixed with chelated calcium and iron, and Group 3 (Fe-OCHT): basal diet feed mixed with chitosan for 4 weeks. There were challenged with 1.0×10⁸ CFU/mL of the cultured Salmonella Gallinarum (SG) by oral administration on 28th feeding days. After SG challenge, Flow cytometric profiles showed that the CD4+/CD8+ T lymphocyte activation of Group 2 was much higher than Group 1 and Group 3 (P<0.05). In addition, the levels of interleukin-2 (13.37 mg/dl) and interferon-γ (2.35 mg/dl) in Group 2 were higher than Group 1 and Group 2. Populations of Lactic acid bacteria (3.5×10¹⁰ CFU/g) from cecum was highest observed in group 2. Re-isolation of SG from cecum in group 2 (8×10⁵ CFU/g) was lower than group 1 (1.83×10¹⁰ CFU/g). The result of this study demonstrated that CaFe-GMP feed additive may be one of the potential candidates to control salmonellosis and functional feeds in layers.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.4
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• pp.279-284
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• 2007

Nowadays, due to development of automatic control devices and various sensors, one operator can freely handle several remote plants and processes. Automatic diagnosis and warning systems have been adopted in various fields, in order to prepare an operator's absence for patrolling plants. In this paper, a Bayesian networks based on-line diagnosis system is proposed for a wastewater treatment process. Especially, the suggested system is included learning structure, which can continuosly update conditional probabilities in the networks. To evaluate performance of proposed model, we made a lab-scale five-stage step-feed enhanced biological phosphorous removal process plant and applied on-line diagnosis system to this plant in the summer.