• Animal Bioscience
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• v.36 no.1
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• pp.75-83
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• 2023

Objective: The objective of this study was to describe a methodological procedure to quantify the heat production (HP) partitioning in basal metabolism or fasting heat production (FHP), heat production due to physical activity (HPA), and the thermic effect of feeding (TEF) in roosters. Methods: Eighteen 54-wk-old Hy Line Brown roosters (2.916±0.15 kg) were allocated in an open-circuit chamber of respirometry for O₂ consumption (VO₂), CO₂ production (VCO₂), and physical activity (PA) measurements, under environmental comfort conditions, following the protocol: adaptation (3 d), ad libitum feeding (1 d), and fasting conditions (1 d). The Brouwer equation was used to calculate the HP from VO₂ and VCO₂. The plateau-FHP (parameter L) was estimated through the broken line model: HP = U×(R-t)×I+L; I = 1 if t<R or I = 0 if t>R; Where the broken-point (R) was assigned as the time (t) that defined the difference between a short and long fasting period, I is conditional, and U is the decreasing rate after the feed was withdrawn. The HP components description was characterized by three events: ad libitum feeding and short and long fasting periods. Linear regression was adjusted between physical activity (PA) and HP to determine the HPA and to estimate the standardized FHP (st-FHP) as the intercept of PA = 0. Results: The time when plateau-FHP was reached at 11.7 h after withdrawal feed, with a mean value of 386 kJ/kg^0.75/d, differing in 32 kJ from st-FHP (354 kJ/kg^0.75/d). The slope of HP per unit of PA was 4.52 kJ/mV. The total HP in roosters partitioned into the st-FHP, termal effect of feeding (TEF), and HPA was 56.6%, 25.7%, and 17.7%, respectively. Conclusion: The FHP represents the largest fraction of energy expenditure in roosters, followed by the TEF. Furthermore, the PA increased the variation of HP measurements.

• 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.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.27-38
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• 2009

To investigate the feasibility of refuse derived fuels (RDFs) combined of sewage sludge and combustible wastes such as substitutive fuels instead of a stone coal, several different RDFs made with different mixtures of sewage sludge and combustible wastes were analyzed by various experiments. The combustion characteristics for the RDFs were investigated by analyzing fuel gases, and heating values were also measured by a bomb calorimeter. The fundamental properties such as moisture contents, ratios of combustible materials, amounts of ashes, heavy metals, ratios of each chemical elements and heating values were analyzed in accordance with mixing ratios of wt(%) for researching the characteristics of the RDFs. $RDF_{k-1}$ was made of mixing materials which were dried sewage sludge, food wastes and combustible wastes. $RDF_{k-2}$ was made of mixing materials which were peat-moss, tar and sewage sludge. Combustion experiments were carried out at the optimal conditions which were m=2 under air-fuel condition and $850^{\circ}C$. The retention times in the combustor were set at 5, 10 and 15minutes. 50 g of RDFs was put in the combustor for each experiments. The ranges for heating values of $RDF_{k-1}$ with different mixing ratios were from 6,900 kcal/kg to 8120 kcal/kg. The ranges for heating values of $RDF_{k-2}$ with different mixing ratios were from 4,014 kcal/kg to 8,050 kcal/kg. As a result of this study, the heating values, moisture contents, components of chemical elements and mixing ratios of the materials in RDFs had big effects on the efficiency of the combustion. In $RDF_{k-1}$, the higher amounts of combustible wastes in the mixtures, the higher heating values, concentrations of $C_xH_y$ and amounts of ashes were produced. In $RDF_{k-2}$, the higher tar amounts in the mixtures caused the higher heating values, amounts of ashes, concentrations of CO gas and CxHy.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.255-262
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• 2006

Two experiments were conducted to investigate the effect of dietary organic selenium levels on performance and selenium retention in broiler chickens and laying hens. In experiment 1, the effects of dietary organic selenium levels on the weight gain, feed intake, feed conversion, and selenium retention of meat and liver in broiler chickens were investigated. For each growth phase, the basal diet was supplemented with 0 (control), 0.60, 1.20, 1.80 and 2.40 ppm Se from selenium yeast(SY). Weight gain, feed intake, and feed conversion were not affected by the selenium addition in diets. Breast muscle Se levels were linearly increased (P<0.05) as dietary Se level increased by SY. Selenium concentration of liver tissue was increased (P<0.05) in supplemental SY compared to the control, and was increased (P<0.05) in supplemental 1.20, 1.80 and 2.40 ppm SY compared to the 0.60 ppm SY. In Experiment 2, 12-week-experiment using Hy-Line laying hens (68 wk of age) was conducted to examine the effects of dietary organic selenium on egg Production, egg weight, daily egg mass, feed intake, feed conversion, egg quality, and selenium concentration of eggs. A corn-soybean meal basal diet was supplemented with 0 (control), 0.30, 0.60, 0.90 and 1.20 ppm Se from selenium yeast (SY). Egg Production was significantly improved(P<0.05) in supplemental 0.30 and 0.90 ppm SY compared to the control and 0.60 ppm SY during week 1 to 12, but daily egg mass, feed intake, and feed conversion showed no difference in supplemental SY and control. Haugh unit, yolk color and eggshell breaking strength showed no difference in supplemental SY and control. Eggshell thickess was significantly (P<0.05) higher in supplemental 0.60 and 1.20 ppm SY compared to the 0.90 ppm SY in week 9. Egg Se levels were linearly increased (P<0.05) as dietary Se level increased by SY.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.157-163
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• 2007

To examine the effects of dietary organic selenium and vitamin E supplementation on egg production, egg weight, daily egg mass, feed intake, feed conversion, egg quality, lipid-soluble antioxidative capacity (ACL) in egg yolk, and selenium retention of egg in laying hens, Hy-Line laying hens of 77 wk old were replaced in the individual cage for 12 week. A corn-soybean meal based diet was supplemented with 0 (control), vitamin E 100 IU/kg and the combination of 0.9 ppm Se from selenium yeast (SY) and vitamin E 50, 100 and 150 IU/kg. Egg production and daily egg mass were significantly increased (P<0.05) in supplemental vitamin E 100 IU, and 0.9 ppm SY + vitamin E 50 IU than control for the whole experimental period. However, feed intake and feed conversion were not affected by supplemental vitamin E and SY. Haugh unit was significantly (P<0.05) higher in supplemental vitamin E 100 IU and 0.9 ppm SY + vitamin E 50 IU than control, 0.9 ppm SY + vitamin E 100 and 0.9 ppm SY + 150 IU in week 5. Haugh unit of the eggs during storage decreased significantly(P<0.05) from day 1 to day 11. However, Haugh units of the eggs from 0.9 ppm SY + vitamin E 150 IU treated groups did not decreased significantly until day 5. Yolk color was significantly (P<0.05) higher in 0.9 ppm SY + vitamin E 50 and 0.9 ppm SY + 100 IU than other treatment groups in week 1. Selenium concentrations of egg were significantly increased (P<0.05) in 0.9 ppm SY + vitamin E than control and vitamin E 100 IU groups. Lipid-soluble antioxidative capacity (ACL) in egg yolk was significantly (P<0.05) higher in supplemental combination of 0.9 ppm SY + vitamin E 150 IU when compared to those of other treatment groups.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.189-194
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• 2006

This study was conducted to investigate the effects of natural mineral complex supplementation on egg production and characteristic in laying hens. A total of two hundred forty laying hens were randomly allocated into four treatments with ten replications for six weeks. Dietary treatments included 1) CON (control, basal diet) 2) M0.5 (basal diet + 3% chitosan + 0.5% natural mineral complex), 3) M1.0 (basal diet + 3% chitosan + 1.0% natural mineral complek) and 4) M1.5 (basal diet + 3% chitosan + 1.5% natural mineral complex). In the egg production, the M1.5 treatment was significantly higher than other treatments(P<0.05). However, egg weight was significantly higher in M0.5 treatment than CON and M1.0 treatments(P<0.05). Egg shell breaking strength was higher in M1.5 treatment than M0.5 treatment. Egg shell thickness was the highest in M1.5 treatment compared to other treatments(P<0.05). The hens 134 M0.5 diet were improved egg yolk color compared to those fed other diets(P<0.05). The Haugh unit, CON and M1.0 treatments showed significantly different results compared to those of M1.5 treatment(P<0.05). The M1.5 treatment had higher Ca and Fe concentration in blood and higher K concentration in yolk than CON(P<0.05). In conclusion, supplementation of natural mineral complex in laying hen diets influenced on egg production, egg shell qualify and mineral concentration in blood and yolk.

• Korean Journal of Poultry Science
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• v.44 no.4
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• pp.267-274
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• 2017

This study was conducted to investigate the effect of feeding with dietary silicate based complex mineral (SCM) on the performance of laying hens. SCM at five levels (0%, 0.2%, 0.4%, 0.6% and 0.8%) was added to commercial diets, and fed to four hundred fifty Hy-Line Brown from fifty four to sixty five weeks of age. Egg production increased as the addition of dietary SCM to basal diets increased up to 0.6% (P<0.05). Furthermore, Feed intake increased in a manner similar to that of egg production (P<0.05). However, there was no difference in feed efficiency among the treatments. Eggshell thickness and breaking strength were significantly higher for the chickens fed with SCM than control from sixty weeks old to the end of experiment (P<0.05). Similarly, albumen height and Haugh unit were significantly higher for the chickens fed with SCM compared to those of control group (P<0.05). AST of birds fed SCM showed significantly higher than control (P<0.05). However, blood neutral fat level tended to increase in SCM treatments. Moreover, bone mineral density increased with SCM addition up to 0.4% (P<0.05). IL-2 (Interleukin-2) and IL-6 (Interleukin-6) levels appeared to be improved in the chickens fed with SCM addition diets, although not statistically different from all treatments. The results of this study indicated that the optimum SCM for improving the performance, egg quality and immunological competence of laying hens from 54 to 65 weeks of age was 0.6%.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.349-355
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• 2018

This study was aimed at predicting the yield of paprika (Capsicum annuum L.) through analyzing the growth characteristics, yield pattern and greenhouse environment. In the greenhouse of the Gyeongnam area (667 m above sea level), the red paprika 'Cupra' and the yellow paprika 'Fiesta' were grown from July 5, 2016 to July 15, 2017. The planting density was $3.66plants/m^2$ and attracted 2 stems. During the cultivation period, the average external radiation of the glasshouse was $14.36MJ/m^2/day$ and the internal average temperature was controlled as $20.1^{\circ}C$. After 42 weeks of planting, the growth rate of 'Cupra' was 7.3 cm/week and that of 'Fiesta' was 6.9 cm/week. The first fruit setting of 'Cupra' appeared at 1.0th node and 'Fiesta' at 2.7th node. The first harvest of 'Fiesta' was 11 weeks after planting and 'Fiesta' was 14 weeks. Comparing the yield per 10 a until the end of the cultivation in July, 'Fiesta' was 19,307 kg, which was 2.4% higher than that of 'Cupra'. And the fruit weight ratio of over 200 g of 'Cupra' was 27.7% which was 7.7% higher than that of 'Fiesta'. The average required days to harvest after fruit setting of 'Cupra' was 72.6 days and 'Fiesta' was 63.8 days. According to the relationship between the average required days to harvest and the cumulative radiation (during from fruit setting to harvest), the more radiation increases the less required days to harvest increases after February. In terms of yield, 'Cupra' increased in yield as the cumulative radiation increased, while 'Fiesta' showed an irregular pattern. Cumulative radiation from fruit setting to harvest was negatively correlated with required days to harvest after February in both cultivars. But in relation to yield, there were difference between 'Cupra' and 'Fiesta'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.333-345
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• 2017

The potato tuber is known as a rich source of essential nutrients, used throughout the world. Although potato-breeding programs share some priorities, the major objective is to increase the genetic potential for yield through breeding or to eliminate hazards that reduce yield. Glycoalkaloids, which are considered a serious hazard to human health, accumulate naturally in potatoes during growth, harvesting, transportation, and storage. Here, we used the AMMI (additive main effects and multiplicative interaction) and GGE (Genotype main effect and genotype by environment interaction) biplot model, to evaluate tuber yield stability and glycoalkaloid content in six potato cultivars across three locations during 2012/2013. The environment on tuber yield had the greatest effect and accounted for 33.0% of the total sum squares; genotypes accounted for 3.8% and $G{\times}E$ interaction accounted for 11.1% which is the nest highest contribution. Conversely, the genotype on glycoalkaloid had the greatest effect and accounted for 82.4% of the total sum squares), whereas environment and $G{\times}E$ effects on this trait accounted for only 0.4% and 3.7%, respectively. Furthermore, potato genotype 'Superior', which covers most of the cultivated area, exhibited high yield performance with stability. 'Goun', which showed lower glycoalkaloid content, was the most suitable and desirable genotype. Results showed that, while tuber yield was more affected by the environment, glycoalkaloid content was more dependent on genotype. Further, the use of the AMMI and GGE biplot model generated more interactive visuals, facilitated the identification of superior genotypes, and suggested decisions on a variety of recommendations for specific environments.