• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.2
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• pp.78-85
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• 1993

This experiment was carried out to select for the varieties with high environmental adaptability in mountainous pastures of Taekwalyong area, and the evaluation was based on the data of varietal differences of dry matter production and yield components in Tall fescue cutting at various developmental stages in growth period of autumn. The results were summarized as follows; 1. The varieties with high number of tillers per plant(NT) showed a high dry weight of plant(DW) in all autumn cuttings. These varieties(Barce1 and Fuego) may be more adaptable to mountainous pastures of Taekwalyon area than other varieties. 2. The number of tillers per plant(NT) was significantly positive correlated with dry weight of plant (DW), but dry weight of tiller(WT) was not significantly correlated with dry weight of plant(DW) in all autumn cuttings. 3. The multiple regression equations of autumn cutting stages with mean dry weight of plant(DW) and number of tillers per plant(NT) can be used to estimate the cutting time to obtain maximum mean dry weight of plant(DW) and the highest number of tillers per plant(NT). The maximum mean dry weight of plant(DW) and the highest number of tillers per plant(NT) was estimated at the time of 21 Oct. and 26 Oct, respectively. 4. Dead leaves tended to increase greatly after the 2nd cutting(l4 Oct.) in growth period of autumn. 5. The number of tillers per plant(NT) was an important yield component before tiller density achieved equilibrium, but dry weight of tiller(WT, including dead leaves) was of most significant as a yield determinant after maximum tiller density reached in growth period of autumn.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.E
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• pp.72-78
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• 1995

To support some knowledge in planning irrigation system, short or long-term irrigation scheduling or determining irrigation reservoir capacity, it is necessary to estimate peak irrigation requirements and seasonal distribution of water demands for various return periods. In this paper Dry Day Index and Probable Evapotranspiration were evaluated to decide seasonal consumptive use of paddy rice for a design year using several decades' daily rainfall data and 5 years'('82~'86) actual evapotranspiration data, respectively. To obtain Dry Day Index that is defined as the number of probable dry days for a given period, Slade unsymmetrical distribution function was adopted. Dry Day Index was analysed for 5 and 10-day intervals. Each of them was evaluated with return periods of 1, 3, 5, 10 and 20 year. Their singnificance was tested by X$^2$ method. Based on these values, the Probable Evaportanspiration, that is the average daily ET both in dry days and rainy days during a given period, was estimated. Crop coefficient was also determined by the modified Penman equation proposed by Doorenbos & Pruitt.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.83-89
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• 2008

Eighty-four Holstein cows were used to evaluate effects of feeding two diets that differed in dietary cation-anion difference (cationic; +28 or anionic; -138 mEq/kg DM) on prepartum and postpartum dry matter intake (DMI), body weight (BW), body condition score (BCS), serum Ca concentrations and on subsequent milk production and composition. Treatments were in a $2{\times}3{\times}2$ factorial arrangement that included prepartum diet, dry period length (30 d dry, 30 d dry+estradiol cypionate (ECP), and 60 d dry), and prepartum and postpartum bST ($POSILAC^{(R)}$ 10.2 mg/d). No interaction of prepartum diet with dry period length or bST supplementation was detected for any measure evaluated either prepartum or postpartum. No significant effects of prepartum diet on prepartum DMI, BW or BCS were observed. Mean DMI during the first 28 d postpartum were similar for cows fed the cationic or anionic diets prepartum (25.5 vs. 26.1 kg/d). During postpartum wk 1 to 14, no differences in mean BW or BCS were detected due to prepartum diet fed but decreases for both groups were observed during the first 6 wk postpartum. No differences due to prepartum diet were observed for mean milk or 3.5% FCM yields or for milk composition during the first 10 wk of lactation. Similarly, mean milk yield of cows during the first 21 wk did not differ significantly due to prepartum diet fed (38.5 vs. 38.6 kg/d). Overall, cows fed the prepartum cationic or anionic diets had similar mean postpartum serum concentrations of Ca (9.34 vs. 9.35 mg/dl). Subsequent milk production, milk composition and concentrations of Ca did not differ. Importantly, the two prepartum diets were equally satisfactory in minimizing incidence of milk fever and in supporting initiation of lactation, irrespective of dry period length and supplemental ECP and bST.

• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.307-314
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• 2000

This study is to investigate the recurrence characteristics of wet and dry years using over 200 year records of annual rainfall depth including Chosun Age in Korea. As well as analyzing the correlation structure of the raw data, recurrence trends of wet and dry year has been investigated based on several truncation levels (mean, $mean{\pm}0.25stdv.,\;mean{\pm}O.5stdv.,\;mean{\pm}O.75stdv.,\;mean{\pm}stdv.$). Also the transition probability among wet, dry and normal years has been derived for the same truncation levels. and finally the average return periods based on the steady-state probabilities were obtained. This analysis has been applied to not only the entire data but also partial data set of before- and after-the long dry period around 1900 in order to compare and detect the possible difference between the Chukwooki (an old raingauge invented in Chosun age) and the modem flip-bucket style. As a result, Similar pattern of dry and wet year recurrence has been found, but the return period of extremely dry years after the dry period shown longer than that before the dry period. Assuming that the dry and wet years can be defined as $mean{\pm}$ standard deviations, respectively, the return period of the wet years is shown to be about 5~6 years and that of the dry years about 6~7 years.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.689-694
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• 1999

This study estimated average yearly watershed pollutant loading by using SWMM(Storm Water Management Model) which is one of the nonpoint source quality models. Two sites were measured discharge and water quality at dry period and wet period. The rainfall data is used from 1989 to 1998 . During a decade, the average year watershed pollutant loading, which is SS, BOD5 , TN, TP, were 2.39E+06kg, 0.92E +05kg, 2.53E+05kg, 2.66E+04kg respectively. During dry period, SS, BOD5 TN, TP loadings were 1.89E+05kg, 1.7E+05kg, 1.04E+05kg, 1.11E+04kg, and during wet period 1.89E+05kg, 1.17E+05kg, 1.04E+05kg, 1.11E+04kg respectively so wet period loading are more than dry day loadings.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1297-1302
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• 2003

To determine whether the feeding of different species of hay affects the dry-matter intake and the serum cortisol level of sheep, 6 non-pregnant, non-lactating ewes were offered alfalfa (Medicago sativa) hay (Al), oats (Avena sativa) hay (Ot) and perennial ryegrass (Lolium perenne) hay (Pr) under 6 kinds of treatment including 1) change from Al to Ot, 2) Al to Pr, 3) Ot to Al, 4) Ot to Pr, 5) Pr to Al, and 6) Pr to Ot. The experimental design was a 6${\times}$6 Latin square with a 14 day period of which 9 days were a preliminary period and 5 days as a digestion trial period. The change in hay feeding was done abruptly on the first day of each period without an adaptation period. The blood from the jugular vein was collected on the first, third and the last day of each period through a sterile catheter for the analysis of cortisol. The dry-matter intake was recorded daily throughout the period. The mean daily intake of dry matter (DM, g/kg live weight) was significantly different among the 3 species of hay (Al>Ot>Pr; p<0.05). The digestibility of DM for Al and Ot was the same, but that for Pr was significantly lower than Al and Ot (p<0.05). The mean serum cortisol levels were significantly different among the hays (p<0.05). The level for Pr was the highest and that for Al was the lowest. The abrupt change of hay feeding of 6 treatments produced a significant change in the serum cortisol levels. The DM intake was inversely related to the change of the cortisol level. It is suggested that the animal' intake response to different species of hay may be partly motivated by the psychological feelings toward the hay offered.

• Journal of Korea Water Resources Association
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• v.33 no.5
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• pp.519-526
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• 2000

This study is to investigate the recurrence possibility of consecutive dry years such as the long dry period around 1900 in the annual rainfall data at Seoul station. The truncation levels, as the criterion for the dry years, are decided such as to make the occurrence of dry years follow the Poissonian distribution, which assures independent occurrence of dry years. For the truncation level of mean-0.5stdv, the occurrence of dry years is found to satisfy the Poissonian distribution weakly with 99% significance level, but for those of mean-0.75stdv and mean-stdv with 95% significance level. For these truncation levels, the long dry period around 1900 is divided into several short consecutive dry years. The Poisson process has then been applied to derive the occurrence probability of consecutive dry years. For the truncation level of mean-0.75stdv or below, the Poisson process was found to reproduce similar occurrence probabilities to the observed. Especially for the lowest truncation level used in the study (mean-stdv), we could see that the occurrence probability of consecutive dry years estimated for the data collected before the long dry period around 1900 was higher that those for the data collected after the long dry period, thus, it could be concluded that the possibility of long dry periods is decreasing recently.cently.

• Journal of Korea Water Resources Association
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• v.45 no.4
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• pp.409-418
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• 2012

A modified standardized precipitation index was developed by considering the length of dry period and surface run-off effect. The official reports and newspapers on drought from 1973 to 2009 were quantified to evaluate drought indices. The developed index was evaluated using the receiver operating characteristic analysis. In order to suggest improved drought index, we cut the precipitation amount that may do not contribute the mitigation of drought and weight dry period by considering cumulative distribution, decile distribution of dry periods. Drought detection capability of the suggested index has improved by weighting of dry period effects and considering precipitation amounts contributing drought mitigation.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1415-1421
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• 2006

Proper nutritional management during the dry period is required to prevent metabolic disorders during the time of parturition and for potential increase milk yield during early lactation, especially under the heat of summer. The effect of prepartum diets on partitioning of nitrogen (N), calcium (Ca), phosphorus (P), magnesium (Mg) and potassium (K) during dry period and early lactation in summer was investigated. Nine cows were assigned to two groups and fed either control (group C: four cows) or high concentrate (group H: five cows) diets to meet 110% of their requirements before parturition. The proportion of concentrate in control diet was 35%, and that in the high concentrate diet was 45%. After parturition, all cows were fed the same diets ad libitum during lactation. Balance trials were conducted at 9, 8 and 7 days before parturition and at 12, 13 and 14 days after parturition. Before parturition, dry matter intake (DMI), DM and NFE digestibility in group C tended to be lower than those in group H. The retention of N (p<0.01) and P (p<0.05) in group C during the dry period was significantly lower than those in group H. The retention of Mg in group C during the dry period tended to be lower than in group H. The concentration of plasma NEFA in group C tended to be higher than in group H during dry period. The prepartum diet did not have an apparent effect on DMI and milk yield at 2 weeks after parturition and N, Ca, P, Mg and K balance after parturition.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1174-1183
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• 2010

In goats fed on dry forage twice a day, an esophageal fistula was used to investigate the physiological factors present in the marked suppression of dry forage intake that occurs after 40 min of feeding. The animals used in this study were five large-type male esophageal- and ruminal-fistulated goats. Roughly crushed alfalfa hay cubes with any large remaining chunks removed were used as feed for this research. The study was conducted under both normal feeding conditions (NFC) and sham feeding conditions (SFC). In the NFC control, the esophageal fistulae were closed by plugs and the animals ate dry forage in the normal manner. In the SFC treatment, before starting the experiment the plugs for closing the esophageal fistula were removed and the cannulae for collecting boluses were fitted into the fistulae. Therefore, the esophageal boluses were removed via an esophageal fistula before they entered the rumen. In the NFC control, eating rates sharply decreased in the first 40 min of feeding and were subsequently maintained at low levels. However, eating rates in the SFC treatment remained high after 40 min of the feeding period had elapsed and the goats ate continuously during the 2 h feeding period. In comparison with the NFC control ($1,794{\pm}203.80\;g$/2 h), cumulative dry forage intake in the SFC treatment ($3,182{\pm}381.69\;g$/2 h) was 77.4% greater (p<0.05) upon conclusion of the 2 h feeding period. In the SFC treatment, cumulative bolus output ($6,804{\pm}469.92\;g$/2 h) was about twofold the cumulative dry forage intake due to cumulative salivary secretion volume ($3,622{\pm}104.13\;g$/2 h) upon conclusion of the 2 h feeding period. The result indicates that large amounts of secreted saliva during dry forage feeding act in conjunction with consumed feed to form the ruminal load responsible for ruminal distension. The increased plasma total protein concentrations were higher in the SFC treatment than in the NFC control. However, plasma and ruminal fluid osmolalities increased in the NFC control during and after feeding but were mostly unchanged in the SFC treatment. In comparison with the NFC control ($3,440{\pm}548.04\;g$/30 min), thirst level in the SFC treatment ($1,360{\pm}467.02\;g$/30 min) was 60.5% significantly less (p<0.05) upon conclusion of the 30 min drinking period. The results of the present study indicate that In the second hour of the 2 h feeding period, dry forage intake is regulated by factors produced when boluses enter the rumen.