• Journal of Radiation Protection and Research
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• v.31 no.1
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• pp.17-23
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• 2006

The purpose of this study is to provide the guidance necessary for making a selection of error distributions by analyzing influence of statistical distribution for a type of bioassay measurement error on the intake estimation. For this purpose, intakes were estimated using maximum likelihood method for cases that error distributions are normal and lognormal, and comparisons between two distributions for the estimated intakes were made. According to the results of this study, in case that measurement results for lung retention are somewhat greater than the limit of detection it appeared that distribution types have negligible influence on the results. Whereas in case of measurement results for the daily excretion rate, the results obtained from assumption of a lognormal distribution were 10 % higher than those obtained from assumption of a normal distribution. In view of these facts, in case where uncertainty component is governed by counting statistics it is considered that distribution type have no influence on intake estimation. Whereas in case where the others are predominant, it is concluded that it is clearly desirable to estimate the intake assuming a lognormal distribution.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.195-202
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• 2006

Two experiments were conducted to investigate the effect of dietary selenium sources on performance and selenium retention in broiler chickens and laying hens. In experiment 1, the effects of dietary selenium sources and levels on the weight gain, feed intake, feed conversion, and selenium retention of meat in broiler chickens were investigated. for each growth phase, the basal diet was supplemented with 0 (control), 0.12 and 0.24 ppm Se from sodium selenite (SS) and 0.12, 0.24 and 0.60 ppm Se from selenium yeast(SY). Weight gain was significantly increased(P<0.05) in supplemental 0.24 and 0.60 ppm SY compared to the 0.24 ppm SS by diet during day 1 to 35, but feed intake and feed conversion were not affected by the source or the level of Se. Selenium concentrations of breast and leg muscle were significantly increased(P<0.05) in supplemental SS and SY compared to the control, and linearly increased(P<0.05) as dietary. Se level increased by SY, but there was no difference in supplemental 0.12 ppm SS compared to 0.24 ppm SS. In experiment 2, 12-week-experiment using Hy-Line laying hens(31 wk of age) was conducted to compare the effects of selenium sources and levels on egg production, egg weight, daily egg mass, feed intake, feed conversion, egg quality, and selenium retention of egg in laying hens. A corn-soybean meal basal diet was supplemented with 0 (control), 0.06 and 0.12 ppm Se from sodium selenite (SS) and 0.06, 0.12 and 0.30 ppm Se from selenium yeast(SY). Feed conversion was significantly improved(P<0.05) in supplemental 0.06 ppm SS compared to the control, but egg production, egg weight, daily egg mass, and feed intake were not affected by source and level of Se. Haugh unit was not affected by source or level of Se. Yolk color was significantly(P<0.05) higher in supplemental 0.3 ppm SY compared to the control and other supplement in week 12. Eggshell breaking strength was significantly(P<0.05) higher in supplemental 0.06 ppm SY(P<0.05). Thickness of eggshell was not affected by source or level of Se. Se concentrations of egg was significantly improved(P<0.05) in supplemental SS and SY compared to the control, and was significantly increased(P<0.05) as dietary Se level increased by SS and SY, especially SY more effective compared to the SS.

• Korean Journal of Poultry Science
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• v.25 no.4
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• pp.169-175
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• 1998

A feeding trial was carried out to evaluate optimum feeding system to Korean Native Chicken (KNC) with various feeding programs for 64 weeks. Eight hundreds and ten KNC＇one day birds were assigned to three feeding systems, NRC(T1), Japanese Feeding Standard(T2), Korean Feeding Standard(T3). Each treatment had three replicates of 90 birds a replicate. Data were obtained growing performance to 20 week of age and laying performance from twenty one to sixty four week. Viability to 20 week of age was similar to treatments. Growth characteristics by feeding systems were not significantly difference on body weight, feed intake and 50％ egg production days. However, body weight was less about 100g in T2. There were no different on egg production, egg weight, and egg mass during laying period. Feed intake of T1 was 104g daily and showed lower than other treatments, but was not different significantly. Feed conversion was significantly improved in T2(P <0.05) compared to other treatments(P<0.05). Egg production of all treatments was the highest between 27 to 30 week of age. ME intake of T1 was significantly maximized, whereas CP intake was the lowest of all treatments(P < 0.05). Nutrient requirements for egg mass tended to depend on nutrients intake. Interior egg and eggshell characteristics were not different among treatments except yolk color. Fertility and hatchability were similar to treatments, and the results at 39 week of age were higher than at 62 week in all treatments. In conclusion, treatments fed three or four phase feeding would be superior to other treatments during the growing period and suggest 2,800 ㎉/kg ME, 15％ CP for Korean native laying hen.

• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.47-53
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• 1998

This study was conducted to evaluate the nutritional status of elementary school lunch programs. The subjects of this study were consisted of 220 elementary school students in the 5th and 6th grades. Dietary intake of nutrients was assessed by modified 24-hour recall method. The results are summarized as follows : The children' average body weights were 36.3$\pm$7.39kg in boys and 35.7$\pm$8.35kg in girls. Their average heights were 141.9$\pm$5.82cm in boys and 142.5$\pm$5.82cm in girls. Total daily energy and nutrients intakes were below the RDA's, except for intakes of niacin and ascorbic acid. The rate of calorie of carbohydrate : protein : fat was 73:13:14(male) and 70:14:16(female). Score of food habit was poor 43.6% of subjects.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.45-51
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• 2014

This study was conducted to investigate the feeding effects of total mixed fermentations (TMF) with spent mushroom (Flammuliua velutipes) and wet brewer's grain on estimating the productivity and nutrient utilization of Korean black goats. Four experimental groups were set up with each of the 5 animals for a 30-day feeding trial on growth performance. 12 black goats with regard to nutrient digestibility were allocated to 4 groups of 3 animals each by a latin-square design control group (offered concentrate and rice straw) and 3 treatment groups (TMF with 15% spent mushroom and 25% wet brewer's grain (T1), 10, 30% (T2) and 5, 35% (T3)). The average daily gain (ADG) of the control and T1 treatment groups was higher than that of the T3 treatment group (p<0.05). Dry matter (DM) and organic matter (OM) intake (kg/head) for T1 and T2 treatment groups were significantly higher than those of the control group (p<0.05). The digestibility of DM and OM for the control group (62.39~63.39%) and the T1 treatment group (65.02~65.25%) were significantly higher than those of the T3 treatment group (56.39, 59.01%) (p<0.05). Further, nitrogen retention was significantly higher in the T1 treatment group (p<0.05). Thus, these results conveyed that productivity and nutrient utilization were similar between TMF with spent mushroom and wet brewer's grain and commercial feeds. However, this study also suggested that feed must contain 25~30% spent mushroom due to the fact that the productivity of Korean black goats was decreased by increasing the content of spent mushroom.

• Korean Journal of Poultry Science
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• v.13 no.1
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• pp.15-21
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• 1986

An experiment was conducted for 14 days using 108 Manina Brown laying hens of 27 weeks of age to study the effects of dietary phosphorus levels on egg production, feed intake, feed efficiency, time of oviposition, specific gravity and weight of eggs. Hens were divided into 12 pens and each was assigned to one of the three treatments with 4 replications. Each hen was housed in individual cage. Birds on treatment 1 were fed a control diet (0.70% P) continuously and served as control. Hens on treatment 2 received a high phosphorus diet (HP: 2.54% P) between 06:00 and 10:00 and a low phosphorus diet(LP;0.33% P) for the rest of the day, Treatment 3 was fed HP diet for four hours immediately following oviposition and LP diet for the rest of the day. All diets contained a constant level of calcium (4.04 %). Results indicated that egg production, feed intake, feed efficiency were not significantly affected by the treatments. Hens in treatment 3 tended to lay earlier than those in treatments 1 (P〈.0.05 ) and 2 (P〈.0.01 ). There were no significant differences in egg weights among treatments. Egg specific gravity, however, was significantly (P〈0.01) improved by feeding HP diet for 4 hours immediately fellowing oviposition (treatment 3). There was no significant difference in the specific gravity between eggs from the control and treatment 2. There were found a linear relationship for egg weight and a quadratic relationship for egg specific gravity (P〈0.01) with time of oviposition. Specific gravity of eggs tended to be low as the egg weight increased.

• Journal of Animal Environmental Science
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• v.13 no.3
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• pp.153-160
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• 2007

Study for the effect of three different microbial feed additives(henceforth MA-A, MA-B, and MA-C) on feed coversion rate, and physical and chemical characteristics of swine finisher was conducted. MA-B had higher number of Lactobacillus spp. and yeast, compared to any other. The amylase activity of MA-B was also higher than any other. The daily feed intake rates of pigs fed control, MA-A, MA-B and MA-C were 3.15, 3.14, 3.31 and 3.42 kg, respectively. MA-C had the highest weight gain. However, there was no significant difference between treatments. The weights of feces daily excreted by pigs fed control, MA-A, MA-B, and MA-C were 2.14, 2.02, 2.18, and 2.23 kg/day, respectively. The volume of urine daily excreted by pigs fed control, MA-A, MA-B, and MA-C were 3.14, 3.26, 3.27, and $3.41\;{\ell}/day$, respectively. Water content, T-N, $P_{2}O_{5}$, and $K_{2}O$ in swine manure were not significantly different between treatments. The BOD were between 42,576 and $67,450\;mg/{\ell}$ for feces and were between 5,882.5 and $8,657.5\;mg/{\ell}$ for urine, respectively. The SS were between 138,000 and $180,000\;mg/{\ell}$ for feces and were between 875.0 and $1450.0mg/{\ell}$ for urine, respectively.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.871-880
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• 2006

This study was conducted to estimate the maximum amount and time of milk consumption by Holstein calves during two months of pre- weaning period and to compare ad libitum milk feeding with conventional system for their effects on dry feed consumption, nutrient intake, growth performance and occurrence of diarrhea during the pre-weaning phase. Holstein calves (n=20) were alternatively fed colostrum at 10% of their body weight or ad libitum for the first three days (d) and then assigned either to conventional (n=10; calves were fed milk at 10% of their body weight from birth to weaning at d 60 of their age) or ad libitum milk feeding (n=10; calves were fed ad libitum milk from birth to weaning at d 60 of their age). Milk intake as a percent of body weight was increased in ad libitum fed calves from 13.59% at d 1 to 23.50% at d 30 of their age, thereafter it was gradually reduced. Ad libitum fed calves consumed daily 9.8kg milk compared with 4.3kg milk in restricted fed calves(p<0.05). Daily starter and mixed grass hay intake was gradually increased in both groups with the age however; the group differences were noted non-significant up to 40 d of age. Overall from birth to weaning conventionally fed calves ate 18.4, 20 and 18.9% more dry matter, crude protein and total digestible nutrients, respectively than ad libitum milk fed calves (p<0.05). Weight gain was 49, 18.4 and 26% higher in ad libitum milk fed calves than conventionally fed calves during the first month, the second month and from birth to weaning, respectively(p<0.05). Body weight was not significantly different between groups for the first 20 d of age. However, it was significantly higher for ad libitum milk fed calves at d 30, 40, 50, 60 (weaning) and 90 (post weaning) of their age(p<0.05). Similar body weights for both conventionally and ad libitum milk fed calves were observed for the post weaning period at 120, 150 and 180 d of age. Feed efficiency was significantly higher for conventionally fed calves than ad libitum milk fed calves(p<0.05). No sign of diarrhea, fever or cough was observed in calves fed either conventionally or ad libitum milk during the experimental period. In conclusion, calves fed more milk remained healthy and gained higher weight before weaning and maintained this advantage at least up to 90 d of their age.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.61-68
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• 1998

This research was canied out to investigate the effect of castration and injection time of sustained release recombinant bovine somatotropin(SR-rbST) on dry matter intake(DM1) and nutrient intake of surgically castrated 32 Holstein young bulls by growth stage. The main results were as follows: 1. DM intakes were not different between in bull and steer groups, but those in rbSTl and rbST2 were 7.88 and 7.65kg respectively, which were lower 6-9% compared to bull and steer groups. 2. Actual DM intake to DM requirement of Beef cattle(NRC) was 88.5~97.7%, while net energy intake was sufficient for NE requirement in all groups during all growth stage except rbST group during fmishing stage. 3. Overall mean concentrate intake to body weight in steer group was the highest as 1.94%, and then those in rbST groups were 1.87~1.89% which were higher 0.07~0.09% unit than in bull group. 4. Feed conversion ratios(DM) in bull, rbSTl and rbST2 groups were 8.29, 8.18 and 7.60kg respectively, which were improved 12.4, 13.9 and 22.6%, respectively, compared to steer group.

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.219-228
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• 2016

A total of 720 slow-growing Korean meat-type (Hanhyop 3) chicken were used to evaluate the effect of stocking densities and dietary protein levels on growth performance, meat quality, bone mineral composition, and serum corticosterone. Three (6.3, 9.5, and $12.6birds/m^2$) stocking densities and two dietary protein levels (19% and 18%) were factorially ($3{\times}2$) arranged for six treatments. Overall body weight gain (BWG) was highest (p<0.001) at the lowest stocking density ($6.3birds/m^2$). The feed intake (FI) of birds at the highest density ($12.6birds/m^2$) was lower than that of birds at the other densities, but resulted in better feed/gain (F/G). Among 18% protein groups, the overall FI of birds at $9.5birds/m^2$ was higher than that at the lowest density; therefore, birds at $9.5birds/m^2$ had poorer F/G than birds at the lowest density during days 61~75. Difference in F/G among densities was only significant (p<0.05) during days 61~75 but not significant (p>0.05) during days 41~60. Although there were no significant differences (p>0.05) in BWG and F/G between 19% and 18% dietary protein levels, FI of the 18% protein diet was less (p<0.05) than that of the 19% diet. Although there was no difference (p>0.05) in meat TBARS values, meat color differed (p<0.05) with stocking density and dietary protein levels. There was no effect (p>0.05) of stocking density and dietary protein levels on bone mineral composition. Serum corticosterone concentration increased (p<0.05) with increasing stock density but was not affected (p>0.05) by dietary protein levels. This study indicated that a density of $12.6birds/m^2$ is not recommended for slow-growing chickens. Between 19% and 18% dietary protein levels, 18% would be recommended for the Korean Hanhyop 3 chicken in the finishing stage.