• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.10a
• /
• pp.145-149
• /
• 2004

It is necessary for managing a perfect process for degasing aluminum molten metal according to the increase of a grade of aluminum and its alloy products. There are some methods that have been used to manage a degasing process in recent years, such as an injection method that uses aluminum molten metal powder and chemicals supplier and input method that supplies argon and nitrogen, or chlorine gas by using a gas blow-tube. However, these methods show some problems, and it shows that it is a difficult process to handle. pollution due to the producing a lot of toxic gases like chlorine and fluoride gas. irregular effects, and lowering work efficiency due to the excessive processing time. The problems that are the most fatal are the producing a lot of sludge due to the reaction of aluminum molten metal with chemicals. loss of metals, and decreasing the life of refractory materials. In order to solve these problems. this paper develops a technology that is related to aluminum continuous casting molten metal and monolithic degasing apparatus. A degasing apparatus developed in this study improved the exist ing methods and prevented environmental pollution wi th smokeless. odor less, and harmlessness by using a new method that applies argon and nitrogen gas in which the methods used in the West and Japan are eliminated. The developed method can significantly reduce product faults that are caused by the production of gas and oxidation because it uses a preprocessed molten metal with chemicals. In addition. the amount of the produced sludge can also be reduced by 60-80% maximum compared with the existing methods. Then. it makes it possible to minimize the loss of metals. Moreover. the molten metal processing and settling time is also shortened by comparing it with the existing methods that are applied by using chemicals. In addition, it does much to improve the workers' health, safety and environment because there is no pollution. The improvement of productivity and prevent ion effects of disaster from the results of the development can be summarized as follows. It will contribute to the process rationalization because it does not have any unnecessary processes that the molten metal will be moved to an agitator by using a ladle and returned to process for degasing like the existing process due to the monolithic configuration. There are no floating impurities due to the oxidation caused by the contact with the air as same as the existing process. In addition. it can protect the blending of precipitation impurities. Because it has a monolithic configuration. it can avoid the use of additional energy to compensate the temperature decreasing about 60t that is caused by the moving of molten metal. It is not necessary to invest an extra facilities in order to discharge the gas generated from a degasing process by using an agitator. The working environment can be improved by the hospitable air in the factory because the molten metal is almost not exposed in the interior of the area.

• Journal of Mushroom
• /
• v.15 no.3
• /
• pp.111-117
• /
• 2017

The mushroom species Cordyceps militaris has been studied and cultivated as a medicinal mushroom due to its multiple valuable biological and pharmaceutical activities. For breeding new strains of C. militaris, multiplex PCR assays were performed using primers specific for its mating type genes, MAT1-1 and MAT1-2. Mating types and mating status were confirmed, as evidenced by DNA bands at 233-bp and 191-bp for MAT1-1 and MAT1-2 respectively. The novel 'Dowonhongcho 2ho' was developed through mating; they were found to possess high-quality fruiting bodies when grown in artificial media. The stromata of the new strain were club-shaped, with a bright orange-red color, and measured 7.1 cm in length. They had an average cordycepin content of 0.33%. Compared to 'Dowonhongcho,' the new strain had a 7% higher yield, as well as firm fruiting bodies. The optimum temperature for mycelial growth was $20{\sim}25^{\circ}C$, and the optimum temperature for stroma development was $18{\sim}22^{\circ}C$. The fruiting bodies developed after 49.1 days from inoculation. The use of mating type molecular markers improved the breeding efficiency of the new strain 'Dowonhongcho 2ho.' Thus, they may be valuable for artificial cultivation and industrial-scale production of C. militaris with excellent characteristics.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.12
• /
• pp.1705-1711
• /
• 2004

Three experiments were conducted to investigate the interaction of breed-by-chitosan supplementation on the major economic traits in broiler chickens. In experiment 1, one-day-old broiler chicks were fed ad libitum on a basal diet (CON-group) or basal diet containing chitosan at an inclusion level of 10.5 mg/bird/day (EXP-group). The EXP-group birds in experiments 2 and 3 were supplemented from 15 day-old by the same amount of chitosan used in experiment 1. In experiment 1, the mean body weight of the EXP-group chickens was significantly (p<0.05) heavier in comparison with those of CON-group birds from day 21 of the experiment. Especially in 35 day-old mean body weight, the EXP-group birds of Arbor Acres, Peterson, and Ross were significantly (p<0.05) heavier by 121.8 g, 118.5 g, and 242.8 g than the CON-group birds, respectively. However, the mean body weights in experiments 2 and 3 did not significantly differ between the CON-group birds and the EXP-group birds fed with chitosan supplementation from day 15 post birth. In the comparisons among breeds on the mean body weight at 35 day-old, the birds of Arbor Acres were significantly (p<0.05) heavier than ones of Peterson or Ross; however, there were no significant differences between Peterson and Ross or Cobb and Ross birds in overall in the experiments. The mean 15-35 d FCR of the EXP-group birds in experiment 1 were significantly (p<0.05) lower at least in two of the three breeds (Arbor Acres and Ross breeds) than that of the CON-group birds. None of the mean 15-35 d FCR in either experiment 2 or 3 showed significant differences between groups within a breed. In all three experiments, the differences amongst breeds in the mean 15-35 d FCR were not great either. Significant differences were not generally shown in the mean percentage of abdominal fat deposition between groups within a breed in overall experiments except in the Cobb breed in experiment 3. The mean percentages of abdominal fat deposition were significantly (p<0.05) lower in Ross birds than in Arbor Acres or Peterson birds and in Cobb birds than in Ross birds. By the results of the analysis of variance, the interaction of breed-by-diet (chitosan) supplementation on any of the major economic traits including mean percentage of abdominal fat deposition was not significant in overall experiments. Results of these experiments indicate that dietary supplementation with chitosan for the improvement of growth or feed conversion ratio in broilers has an efficacy when the supplementation begins from day-old.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.5
• /
• pp.682-686
• /
• 2002

Ten growing male buffalo calves (aged 6-8 months, average body weight $88.2{\pm}0.57$ kg were divided randomly into two groups. Animals in group I were fed on concentrate mixture A (CP 20.2%, TDN 77.4%) and urea- ammoniated wheat straw (UAWS) while the animals in group II were fed on concentrate mixture B (CP 17.9%, TDN 77.6%) and HCl plus urea treated wheat straw (HCl UAWS) to meet their nutrient requirement for 500 g gain/d as per Kearl (1982). This feeding practice lasted for 120 days, during which fortnightly body weight were recorded to assess their growth rate. A metabolism trial was conducted after 90 days of experimental feeding to compare the digestibility of nutrients, their balance, plane of nutrition and relative cost of feeding in two groups of animals. Results revealed a significant increase in the CP content of ammoniated wheat straw due to addition of HCl viz 12.1% from 7.5%. There was a decrease in the intake of DM (p<0.05), OM (p<0.05), EE (p<0.05), NDF (p<0.01), ADF (p<0.01), cellulose (p<0.01) and hemicellulose (p<0.01) in group II as compared to group I. The digestibility (%) of DM, OM and CP was significantly (p<0.01) more in group II, whereas the digestibility (%) was significantly more for NDF (p<0.05) and hemicellulose (p<0.01) in group I than group II. There was no significant difference in the N, Ca and P balance in two groups. Intake of total DM (g/d) or (g/kg $W^{0.75}$) was significantly (p<0.01) more in group I as compared to group II, whereas the intake of DCP and TDN (g/d or g/kg $W^{0.75}$) was alike in two groups. The total body weight gain (kg), average daily gain (g/d) and feed conversion efficiency were significantly (p<0.01) more in UAWS fed group as compared to HCl UAWS fed group. Feeding cost (Rs./kg. weight gain) was significantly (p<0.05) more in group II as compared to group I. It is concluded that HCl UAWS is not suitable for the feeding of growing buffalo calves as it reduced the growth rate in comparison to UAWS fed buffalo calves.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.10
• /
• pp.1389-1393
• /
• 2001

A study was carried out to investigate the nutritive value and utilization of three grass species, batiki grass (lschaemum aristatum var. indicum), guinea grass (Panicum maximum) and signal grass (Bracharia decumbens) by growing goats. Eighteen growing crossbred goats $(Anglo-Nubian{\times}Fiji\;local)$ of between 9-11 months of age and pre-trial average live weight of $9.50{\pm}1.60kg$ were divided on the basis of weight to three treatment groups in a completely randomized design. The grasses constituted the diets and they were harvested fresh and chopped into pieces before they were offered to the goats. Chemical composition of the grasses, DMI, body weight gain (BWG) and apparent nutrient digestibility coefficients were measured. The grasses had similar DM content. The CP content of the grasses was in the range of 8.3-11.2%. Crude fiber (CF) content was between 30.9-35.2%. Ether extract (EE) was low with a range of 1.2-1.8%. Nitrogen free extract (NFE) was similar (40.9%) for batiki and guinea grasses, while signal grass had more NFE content (51.1%). The grasses are good sources of minerals (ash). OM content was higher in signal grass while guinea and batiki grasses had similar OM content. The goats on signal grass had higher DMI than those on batiki and guinea grasses (p<0.05). The goats on batiki grass had lower average BWG (p<0.05) than those on guinea and signal grasses. Nutrients digestibility were significantly (p<0.05) higher in the goats on signal grass compared to those on guinea and batiki grasses. The goats on guinea grass were better (p<0.05) in the digestibility of CP, OM, NFE and ME than those on batiki grass. However, goats on batiki were significantly better (p<0.05) in digestibility of CF than those on guinea grass. Signal and guinea grasses had more DCP than batiki grass. DE was lower in batiki grass (p<0.05) than in guinea and signal grasses. There was no significant difference (p>0.05) between batiki and guinea grasses in TON. Data obtained in this experiment demonstrated that signal grass is better than guinea and signal in the nutrition of growing goats in the tropical environment of Samoa. It had the highest nutritive value, better apparent digestibility coefficients which have better growth rate and feed efficiency. In ranking, signal grass was better than guinea and batiki grasses, while guinea grass was better than batiki in nutritive value in the parameters measured. For future pasture establishment in Samoa, signal grass is recommended for consideration because of its higher nutritive value as a replacement for batiki, the most predominant grass.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.7
• /
• pp.1003-1009
• /
• 2000

Four young swamp buffalo cows of similar age ranging in body weight (W) between 280 to 380 kg and trained for doing physical exercise were used in two consecutive experiments, each using a latin square design, to determine energy expenditure for draught. The experiments consisted of field trials using 4 levels of work load, i.e. no work as control and loads amounting 450 to 500 Newton (N) continuous traction for respectively 1, 2 and 3 h daily for 14 consecutive days for experiment 1, and no work, traction loads equaling 5, 10 and 15% of W for 3 h daily for 14 days for experiment 2. Heart rate during rest and exercise was monitored using PE-3000 HR monitor. Cows were fed only king grass (Penisetum purpuroides) ad libitum and were subjected to balance trials. Body composition was estimated in vivo by the body density method and daily energy expenditure (EE) was calculated from ME minus RE. RE was calculated from the changes in body-protein and -fat measured before and immediately after the 14 d experimental period assuming an energy equivalent of 39.32 MJ/kg fat and 20.07 MJ/kg protein. $E_{exercise}$ ($EE_{work}\;-\;EE_{resting}$), which was the energy spent for doing the traction during 1, 2 and 3 h was 7.13, 15.45 and 19.90 MJ, respectively. $EE_{work}$ for the 1 h treatment group was 39.75 MJ/d equivalent to 1.30 times $EE_{resting}$. The values for the 2 and 3 h treatment groups were 1.75 and 1.86 times resting energy requirement, respectively. Absolute efficiency of work in all exercise trials of experiment 2 was around 27.28%. The increases of daily $E_{exercise}$ values were correlated to elevation of heart rate (HR) according to the equation $E_{exercise}=(0.270HR^{0.363}\;-\;1)$ MJ, while draught force related to heart rate according to the equation DF (N)=6.66 HR - 361.62. Blood glucose and triglyceride levels were gradually elevated with time during the course of exercise. Mean values of blood glucose were 91.7, 115.0 and 116.2 mg/dl for cows after 1, 2 and 3 h pulling loads at 15% W respectively as compared to 88.2 mg/dl prior to work. In the same order and treatment, mean blood triglyceride concentrations were 13.5, 13.3 and 14.8 mg/dl, and 11.5 mg/dl for control. For blood lactate, the values were 1.68, 1.63 and 1.66 mM, and 0.80 mM for control. Glucose was used as the major source of energy during the initial phase of exercise, but for prolonged work, fat will replace carbohydrate as the main substrate. Accumulation of lactate persisted for some time at the end of the exercise trials.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.6
• /
• pp.908-913
• /
• 1999

This experiment was conducted in three trials to evaluate optimal ambient temperature for a novel milk replacer feeding system designed for early-weaned pigs, compared to commercial dry diets fed within a conventional hot nursery. A total of 165 PIC genotype pigs were weaned at $13.89{\pm}0.7$ days of age and allotted to one of two dietary treatments in three trials based on weight and litter origin. Each trial consisted of pigs fed dry diets (DD) and pigs fed milk replacer (MR) which was offered in one of 3 different ambient temperatures. Pigs fed milk replacer were housed in a specialized nursery building in which one half of each pen contained an enclosed hover that was thermostatically maintained at $32^{\circ}C$ while the exterior ambient temperature (where milk was fed) was set at either 17 (trial 1), 24 (trial 2) or $32^{\circ}C$ (trial 3). Pigs fed dry diets with the conventional nursery were maintained at $30^{\circ}C$ for each trial. From d 21 to d 49, all pigs were fed DD within a standardized hot nursery environment. During the first week (d 14-21), pigs fed MR showed increased ADG from 214% to 228% over control pigs fed DD (p<0.001), regardless of ambient temperature. As ambient temperature was increased from 17 to 24 to $32^{\circ}C$, ADG of MR-fed pigs was increased by 214%, 220% and 228% over those of pigs fed DD, respectively. ADFIs of MR-fed pigs at $17^{\circ}C$, $24^{\circ}C$, and $32^{\circ}C$ compared with pigs fed DD were increased by 108%, 139% and 164% from d 14 to d 21, respectively. Fed efficiency (G/F) of MR-fed pigs at $17^{\circ}C$, $24^{\circ}C$, and $32^{\circ}C$ compared with pigs fed DD were 199%, 162% and 139% of those of pigs fed DD, respectively. As ambient temperature increased, diarrhea scores showed a slight tendency to increase. The advantage of MR feeding was greater when the ambient temperature was higher, but G/F was impaired with increased ambient temperature. We conclude that ambient temperature within the specialized nursery influenced behavior, MR feed intake, and probably piglet energy expenditure. There were no differences between MR-fed and DD-fed pigs for ADG, ADFI and G/F in the subsequent growth period (d 21 to d 49, p>0.05). Maximal advantage of MR feeding was obtained at the intermediate ($24^{\circ}C$) ambient temperature during the overall period (p<0.05). Results from this experiment indicate that a milk replacer feeding system utilized in the early postweaning period can maximize pig growth performance, and that ADG, ADFI and G/F were affected by different ambient temperatures within MR-fed pigs. The high or low temperatures could not support the maximal growth of pigs fed MR.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.6
• /
• pp.877-883
• /
• 2006

A feeding trial was conducted on commercial broilers for a period of 35 days to determine the individual and combined effects of aflatoxin (AF) and T-2 toxin (T-2) on performance, organ weights and immune status. The efficacy of dietary glucomannan-containing yeast product (GYP) ($Mycosorb^{(R)}$) and hydrated sodium calcium aluminosilicate (HSCAS) in preventing the adverse effects of aflatoxin and T-2 toxin was also evaluated. Twelve dietary treatments ($4{\times}3$ factorial) comprising two dietary levels each of AF (0 and 2 mg/kg), T-2 toxin (0 and 1 mg/kg), GYP (0 and 1 kg/ton) and HSCAS (0 and 10 kg/ton) were tested on 720 commercial broiler chickens divided at random into 36 replicates of 20 chicks each (10 males and 10 females). Weight gain and feed intake were recorded weekly. Organ morphology and antibody titers for Newcastle disease (ND) and infectious bursal disease (IBD) were measured on the $35^{th}$ day. AF and T-2 toxin individually decreased weight gain and increased feed conversion ratio (FCR) (p<0.05). AF alone (p<0.05) increased weights of liver, kidney, gizzard and spleen and reduced thymus and bursal weights. T-2 toxin (p<0.05) increased liver and gizzard weights and decreased thymus weight. Both AF and T-2 toxin when fed individually affected ND and IBD titers in a significant manner. Significant interactions between AF and T-2 toxin were observed for their additive effects on weight gain, FCR, organ weights and antibody titers. Addition of GYP (p<0.05) improved weight gain, feed conversion efficiency and restored the organ weights. Antibody titers against ND and IBD were significantly improved with the supplementation of GYP. Supplementation of HSCAS (p<0.05) resulted in improvement in weight gain and restored organ weights in the groups fed AF alone, but not in T-2 toxin fed groups. HSCAS inclusion did not influence FCR in toxin fed groups. Addition of HSCAS (p<0.05) improved the antibody titers against ND and IBD only in AF fed groups. Thus, the results indicate that addition of GYP is effective in averting the individual and combined toxicity of aflatoxin and T-2 toxin in commercial broilers, while HSCAS is effective only against aflatoxin.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.1
• /
• pp.142-148
• /
• 2016

The present study investigated the effects of back-fat thickness at d 107 of gestation and housing types during gestation on reproductive performance and behavior of sows. A total of 64 crossbred sows ($Landrace{\times}Yorkshire$) in their 3 to 4 parities were allotted to one of four treatments (n = 16) over two consecutive parities. During each parity, sows were assigned to two gestational housing types (stall or group housing) and two level of back-fat thickness (<20 or ${\geq}20$) at d 107 of gestation. Gestating sows were transferred from gestational crates to stalls or pens (group housing) 5 weeks before farrowing. All sows were moved to farrowing crates on d 109 of gestation. At weaning, back-fat thickness changes were lesser (p<0.05) in sows having back-fat thickness <20 mm than that of sows with ${\geq}20mm$ back-fat thickness at 107 d of gestation. Group housed sows had greater (p<0.05) feed intake and shorter (p<0.05) weaning-to-estrus interval than that of sows in stalls. At weaning, back-fat thickness changes were lesser (p<0.05) in group housed sows than that of sows in stalls. The number of piglets at weaning, growth rate and average daily gain were greater (p<0.05) in group housed sows than that of sows in stalls. During gestation, walking duration was more (p<0.05) in group housed sows. Group housed sows had lesser (p<0.05) farrowing duration and greater (p<0.05) eating time than that of sows in stalls. Result obtained in present study indicated that sows with ${\geq}20mm$ back-fat thickness at 107 days had better reproductive performance. Additionally, group housing of sows during last five week of gestation improved the performance and behavior and reproductive efficiency of sows.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.1
• /
• pp.90-96
• /
• 2008

We compared the effects of supplementing $L-lysine{\cdot}SO_4$ to L-lysine HCl on growth performance, nutrient digestibility and nitrogen retention in weaning pigs. A total of 96 crossbred pigs, weaned at $21{\pm}3$ days of age and with an average initial body weight (BW) $6.23{\pm}0.01kg$, were given one of 4 treatments, which translated into 6 replicates of 4 pigs in each pen. The animals were randomly assigned to four dietary treatments according to a randomized completely block design (RCBD) as follows: 1) control-no synthetic lysine, lysine deficient (0.80% total lysine); 2) L-C (= 0.2% L-lysine HCl); 3) K-L-S (= 0.332% $L-lysine{\cdot}SO_4$, A company); 4) C-L-S (= 0.332% $L-lysine{\cdot}SO_4$, B company). Diets were formulated with corn, soy bean meal, and corn gluten meal as the major ingredients, and all nutrients except the lysine met or exceeded NRC requirements (1998). The lysine content of supplemented synthetic lysine was the same in all treatment groups except the control. No clinical health problems associated with the dietary treatments were observed. During the entire experimental period, body weight, average daily gain (ADG) and feed efficiency (G:F ratio) increased (p<0.01) in pigs fed the experimental diets supplemented with L-lysine??HCl or $L-lysine{\cdot}SO_4$ produced by A company, irrespective of the two synthetic lysine sources. Although the supplementation of $L-lysine{\cdot}SO_4$ produced by B company tended to improve the ADG and G:F ratio, significant differences were not seen among all treatments and tended to be lower than the L-C (L-lysine HCl) and K-L-S ($L-lysine{\cdot}SO_4$ groups using the product from A company). The digestibility of crude protein (CP) was increased by the supplementation of synthetic lysine (p<0.05), irrespective of the L-lysine source (L-C, K-L-S, C-L-S). The results of this study showed that ADG, G:F ratio, and CP digestibility improved when $L-lysine{\cdot}SO_4$ or L-lysine HCl was supplemented into the weaning pigs' diet. There was a clear difference in efficacy between the two $lysine{\cdot}SO_4$ products based upon the growth performance of weaning pigs. Consequently, the bioavailability of $lysine{\cdot}SO_4$ products should be evaluated before supplementation of synthetic lysine in swine diets.