• Asian-Australasian Journal of Animal Sciences
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• v.12 no.5
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• pp.783-787
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• 1999

To study the effects of different extrusion conditions of barley on growth performance, nutrient digestibility and nutrient excretion in feces, a total of 150 growing pigs ($Landrace{\times}Duroc{\times}Large$ White; average 24.4 kg body weight) were allotted to five treatments, in a completely randomized block design. The experimental diets were based on corn-soybean and 30% of barley was included in each diet; barley was the only extruded ingredient. The treatments were 1) no extrusion (Control); 2) extrusion at $100^{\circ}C$ without preconditioning (ENLT); 3) extrusion at $150^{\circ}C$ without preconditioning (ENHT); 4) extrusion at $100^{\circ}C$ with preconditioning (ECLT); 5) extrusion at $150^{\circ}C$ with preconditioning (ECHT). Temperature in the barrel was controlled within ${\pm}5^{\circ}C$ by feed rate with the addition of water at the rate of $3{\ell}\;per\;min$. in the extruder for each treatment. For the 6 week experimental period, extrusion of barley improved the average daily gain (ADG) and digestibilities of dry matter, crude protein and gross energy in growing pigs. As compared to control, significant improvements in ADG (p<0.05) were shown in the groups of feeding extruded barley at high temperature (ENHT and ECHT). There were also significant differences in the digestibilities of DM, CP and P between extrusion temperatures. Barley extruded at high temperature gave better digestibilities of DM, CP and GE than barley extruded at low temperature. Extruded barley diet groups showed significantly (p<0.05) lower excretions of DM, nitrogen (N) and P per kg gain as compared to the ground barley group. DM, N and P excretion per kg gain were also significantly lower in pigs fed barley extruded at $150^{\circ}C$ than at $100^{\circ}C$. In conclusion, extrusion considerably improved the nutritive value of barley and it appeared that temperature is the most important variable.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.80-87
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• 2016

In this work, we conduct a thermal pointing error analysis of the observation satellites considering seasonal and daily temperature variation with interpolated temperature based on prescribed average temperature (PAT) method. Maximum 200 degree temperature excursion is applied to the observation satellites during on-orbit operation, which cause the line of sight (LOS) to deviate from the designated pointing direction due to thermo-elastic deformation. To predict and adjust such deviation, the thermo-elastic deformation analysis with a fine structural finite element model is accomplished with interpolated thermal maps calculated from the results of on-station thermal analysis with a coarse thermal model. After verifying the interpolated temperatures by PAT with two benchmark problems, we evaluate the thermal pointing error.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.2
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• pp.68-74
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• 2019

'Choyoung', a winter forage triticale cultivar (X Triticosecale Wittmack), was developed at the Department of Rice and Winter Cereal Crop, NICS, RDA in 2015. The cultivar 'Choyoung' has the leaves of medium width, long length and green color and a medium grain of brown color. The heading date of the cultivar 'Choyoung' was April 30 which was 2 days earlier than that of check cultivar 'Shinyoung'. Its tolerance or resistance to cold, wet injury, powdery mildew, and leaf rust was similar to those of the check cultivar. But the resistance to the lodging of cultivar 'Choyoung' was stronger than that of the check. The average forage fresh and dry matter yield of cultivar 'Choyoung' at milk-ripe stages were 40.5 and $15.7MT\;ha^{-1}$, respectively, which were similar to those (40.3 and $16.1MT\;ha^{-1}$) of the check cultivar. The silage quality of 'Choyoung' was higher than that of the check cultivar 'Shinyoung' in crude protein content (5.9%), while was similar to the check cultivar 'Shinyoung' in acid detergent fiber (33.9%), neutral detergent fiber (57.3%), and total digestible nutrients (62.2%). It showed a grain yield of $5.59MT\;ha^{-1}$, which was 38% higher than that of the check cultivar 'Shinyoung' ($4.05MT\;ha^{-1}$). This cultivar is recommended for fall sowing forage crops in areas in which average daily minimum mean temperatures in January are higher than $-10^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.666-672
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• 1997

Twenty years' daily mean air temperature data was used to calculate the critical early seeding date(CESD), the optimum heading date(OHD), the critical late heading date for stable ripening(CHDR) and the critical late ripening date(CLRD) for rice seeded on dry paddy in different agroclimatic zones in Korea. The CESD was defined as the first day with mean air temperature of 13$^{\circ}C$, and the OHD as the first day of the 40 consecutive days with mean air temperature of 22$^{\circ}C$ or above after heading. The CHDR was defined as the date after which the cumulative daily mean air temperature would be at least 76$0^{\circ}C$. Lastly, the CLRD was defined as the last day when daily mean air temperature remains above 15$^{\circ}C$. This information was used for the estimation of periods from the earliest date of seeding to optimum heading date, the latest possible date of heading and the latest possible date of ripening in respective regions. For instance, in Suwon, those respective periods mentioned were found to be 104days, 124days, and 165days.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.731-737
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• 2016

To understand the characteristics and strength of the cold water that has caused damage to marine-culturing farms around Guryongpo, in the southwestern part of Korea, surface and water column temperatures were collected from temperature loggers deployed at a sea squirt farm during August-November 2007 and from a Real-time Information System for Aquaculture environment operated by NIFS (National Institute of Fisheries Science) during July-August 2015 and 2016. During the study period, surface temperature at Guryongpo decreased sharply when south/southwestern winds prevailed (the 18-26th of August and 20-22nd of September 2007 and the 13-15th of July 2015) as a result of upwelling. However, the deep-water (20-30m) temperature increased during periods of strong north/northeasterly winds (the 5-7th and 16-18th of September 2007) as a result of downwelling. Among the cold water events that occurred at Guryongpo, the mass death of cultured fish followed strong cold water events (surface temperatures below $10^{\circ}C$) that were caused by more than two days of successive south/southeastern winds with maximum speeds higher than 5 m/s. A Cold Water Index (CWI) was defined and calculated using maximum wind speed and direction as measured daily at Pohang Meteorological Observatory. When the average CWI over two days ($CWI_{2d}$) was higher than 100, mass fish mortality occurred. The four-day average CWI ($CWI_{4d}$) showed a high negative correlation with surface temperature from July-August in the Guryongpo area ($R^2=0.5$), suggesting that CWI is a good index for predicting strong cold water events and massive mortality. In October 2007, the sea temperature at a depth of 30 m showed a high fluctuation that ranged from $7-23^{\circ}C$, with frequency and spectrum coinciding with tidal levels at Ulsan, affected by the North Korean Cold Current. If temperature variations at the depth of fish cages also regularly fluctuate within this range, damage may be caused to the Guryongpo fish industry. More studies are needed to focus on this phenomenon.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.6
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• pp.801-806
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• 2016

The objectives of this study were to evaluate the effects of different supplemental levels of Saccharomyces cerevisiae fermentation product (SCFP; Original XP; Diamond V) on lactation performance in Holstein dairy cows under heat stress. Eighty-one multiparous Holstein dairy cows were divided into 27 blocks of 3 cows each based on milk yield ($23.6{\pm}0.20kg/d$), parity ($2.88{\pm}0.91$) and day in milk ($204{\pm}46d$). The cows were randomly assigned within blocks to one of three treatments: 0 (control), 120, or 240 g/d of SCFP mixed with 240, 120, or 0 g of corn meal, respectively. The experiment was carried out during the summer season of 2014, starting from 14 July 2014 and lasting for 9 weeks with the first week as adaption period. During the experimental period, average daily temperature-humidity index (measured at 08:00, 14:00, and 20:00) was above 68, indicating that cows were exposed to heat stress throughout the study. Rectal temperatures tended to decrease linearly (p = 0.07) for cows supplemented with SCFP compared to the control cows at 14:30, but were not different at 06:30 (p>0.10). Dry matter intake was not affected by SCFP supplementation (p>0.10). Milk yield increased linearly (p<0.05) with increasing levels of SCFP. Feed efficiency (milk yield/ dry matter intake) was highest (p<0.05) for cows fed 240 g/d SCFP. Cows supplemented with SCFP gained (p<0.01) body weight, while cows in the control lost body weight. Net energy balance also increased linearly (p<0.01) with increasing levels of SCFP. Concentrations of milk urea nitrogen (p<0.01) decreased linearly with increasing levels of SCFP, while no difference (p>0.10) was observed among the treatments in conversion of dietary crude protein to milk protein yield. In summary, supplementation of SCFP alleviated the negative effect of heat stress in lactating Holstein dairy cows and allowed cows to maintain higher milk production, feed efficiency and net energy balance. Effects of SCFP were dose-dependent and greater effects were observed from higher doses.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.195-201
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• 2001

Sowing date experiments were carried out by employing a rice variety "Kwanganbyeo" in both field and phytotron with natural daylength. In phytotron, temperatures were controlled at daily mean of 21$^{\circ}C$ and 24$^{\circ}C$. The responses of final leaf number and beading date were analyzed in relation to daylength during photo-sensitive period (PSP). Based on the component models predicting the final leaf number and leaf appearance rate, a rice phenology model was established and verified. Days from sowing to flowering (DSF) were shortened and final number of leaves (FNL) increased as sowing dates were delayed from 25 April to 5 June in field and phytotron. The increased leaf appearance rate (LAR) and the reduced FNL, respectively, due to the higher temperature and the shorter daylength in delayed sowings in the field brought about greater shortening of DSF than in the phytotron where only FNL was reduced by shorter daylength in delayed sewings. FNL showed very close relationship with the average daylength during PSP of six-leaf stage to panicle initiation, being well fitted to the following rational function ($R^2$=0.98):(equation omitted) where D is daylength and a, b, and c are the constants that were estimated as 14.694, -0.992, and -0.068 in Kwanganbyeo, respectively. The rice phonology model, which was composed of two component models for LAR and FNL, predicted DSF very accurately. The differences between the observed and predicted DSF was less than two days in the sewing date field experiments in 1999 and 2000 of which data were not used for the model construction.struction.

• Research in Plant Disease
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• v.25 no.4
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• pp.196-204
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• 2019

Rice panicle blast occurred severely in southern provinces of Korea in 2014. The proportion of panicle blast incidence area to cultivated area of rice were 11.0% and 14.6% in Jeollanam-do and Gyeongsangnam-do, respectively. To identify the causal factors of the outbreak, we investigated weather conditions in August, amount of cultivated area of mainly grown cultivars, and nitrogen contents in plants with different disease incidences in 2014. 'Saenuri,' 'Ilmibyeo,' 'Unkwang,' 'Dongjin 1 ho,' 'Nampyeongbyeo,' and 'Hwangkeumnuri' were mainly grown cultivars. Monthly average of daily air temperature in August 2014 was 3.2℃ and 3.1℃ less than 2018 in Haenam and Miryang, respectively. Rainfall in August 2014 was 70.0% and 42.0% greater than 2018 in Haenam and Miryang, respectively. The numbers of blast warning days in August calculated nationwide using a forecast model for blast infection were higher in 2014 than in 2018, and they were in high level throughout the country in 2014. Nitrogen contents in plant samples from high-incidence plots were significantly higher than those from low-incidence plots. Consequently, excessive use of nitrogen fertilizers was the main factor for the disease outbreak at the level of specific farms, in addition to the collective cultivation of susceptible cultivar, low temperatures and frequent rainfalls in August.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.250-258
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• 2004

An experiment was conducted to examine the effect of a high environmental temperature on the performance, conformation, and carcass characteristics of pigs and the influence of diet. Thirty-six three-way crossed castrated male pigs with average initial body weight of 50.4 kg were used in the experiment. The pig were allocated to the following treatments: two environmental temperatures (20 and $30^{\circ}C$)${\times}$three dietary energy levels (2,980, 3,300 and 3,600 kcal/kg)${\times}$three protein levels (12.8, 15.2 and 17.2%). Daily weight gain was lighter (p<0.01) and feed: gain ratio lower (p<0.05) in pigs at $30^{\circ}C$ than for pigs at $20^{\circ}C$ The pigs at $30^{\circ}C$ were significantly taller with deeper bodies (p<0.05) and significantly longer (p<0.05) both vertically horizontally in the planum nasal when kept at $30^{\circ}C$. The width of body and the circumference of the neck were greater (p<0.05) at $20^{\circ}C$. The lean meat of the loin, middle section, ham, and hind section were significantly greater (p<0.05) in pigs kept at $30^{\circ}C$ and the belly was significantly heavier. The total unsaturated free fatty acids were significantly higher (p<0.05) in the body fat of pigs kept at $20^{\circ}C$ than in that of pigs at $30^{\circ}C$. The results indicated that when pigs are given very restricted same amounts of feed, they may need less energy to maintain their body temperature under moderately high environmental temperature ($30^{\circ}C$); consequently, their performance is better than that of pigs under optimum environmental temperature. The results showed very clearly that weight gain of pigs increased with increasing of dietary protein and energy content. The increasing of dietary protein content seemed more significant when content increasing to 17.2% compared with the 12.8 and 15.2% protein content treatments. The increasing of dietary energy content was more significant when content increasing to 3,600 compared with the other low energy content treatments.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.229-237
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• 2019

This study was conducted to estimate annual reference evapotranspiration (ET₀) for the agro-climatic zones for rice paddy fields in South Korea between 1980 and 2015. The daily ET₀ was estimated by applying the Penman-Monteith method to meteorological data from 61 weather stations provided by Korean Meteorological Administration (KMA). The average of annual ET₀ from 1980 to 2015 was 1334.1±33.89 mm. The ET₀ was the highest at the Southern Coastal Zone due to their higher air temperature and lower relative humidity. The ET₀ had significantly increased with 2.81 mm/yr for the whole zones over 36 years. However, the change rate of it was different among agro-climatic zones. The annual ET₀ highly increased in central zones and eastern coastal zones. In terms of correlation coefficient, the temporal change of the annual ET₀ was closely related to variations of four meteorological factors (i.e., mean, minimum temperatures, sunshine duration, and relative humidity). The results demonstrated that whole Korean agro-climatic zones have been undergoing a significant change in the annual ET₀ for the last 36 years. Understanding the spatial pattern and the long-term variation of the annual ET₀ associated with global warming would be useful to improve crop and water resource managements at each agro-climatic zone of South Korea.