• Journal of The Korean Society of Grassland and Forage Science
• /
• v.3 no.1
• /
• pp.17-25
• /
• 1982

To clarify the direct effect of potassium and interactions with nitrogen and phosphorus on the yield of pasture plants, fertilizer experiment with varied levels of potassium and nitrogen treatment to grass single seeding, legume single seeding and grass-legume mixed seeding, was conducted for three years from 1977 to 1980. The summary of obtained experimental result may be described as below: 1. Potassium application, at any level of amount, did not show its effect to the establishment of plant population, however potash application responded to help winter hardiness at grass single seeding plot. 2. Potassium effect on the fresh yield at grass single seeding was distinct however, not clear effect was observed at legume single seeding and grass-legume mixed seeding plots. 3. For drymatter yield, the highest yield at legume single seeding was recorded 1.152 Kilograms per 10a are at treatment #4 and the highest yields of grass-legume mixed seeding and grass were recorded 1,093 kilograms (Treatment #3) and 834 kilograms (Treatment #5) respectively. 4. In observation of plant succession, they were found that orchardgrass and tall fescue have increased at grass single seeding plot and Alfalfa was dominant over 90 per cent of plant population at legume single seeding and grass-legume mixed seeding plots. It seems that potash effect was distinct in increasing orchardgrass population. 5. The results of this experiment shown that the maximum yield from grass single seeding was obtained at the plat where applied 20-20-30 kg/10a, $N-P_2O_5-K_2O$ and the maximum yield from legume single seeding was obtained at the plot applied with 8-20-20 kg/10a, $N-P_2O_5-K_2O$. 6. Fertilizer cost for producing one kilogram of dry matter in this experiment was lowest at treatment #1 of grass-legume mixed seeding and highest at treatment #5 of grass single seeding. The largest gross income was obtained from the plots where phosphate application was omitted. 7. From the results of this experiment, it may be recommended that economically optimum fertilizer application for grass single seeding will be 20-20-20- kg/10a, $N-P_2O_5-K_2O$ and for legume single seeding and grass-legume mixed seeding will be 8-20-20 kg/10a, $N-P_2O_5-K_2O$.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.27 no.1
• /
• pp.29-36
• /
• 2007

A study was conducted to determine the trace minerals (Cu, Fe, Cd, Zn, Mo, Se, Mn, Cr, Co, Ni) levels in pasture soils and forages collected in Jeju area. Chemical characteristics and total or soluble trace minerals levels in 187 pasture soil samples (76 very dark brown and 111 black soils) were measured. Total trace minerals contents in hay samples of 60 Italian ryegrass, alfalfa and mixture grasses each were assessed. The pasture soils of Jeju were characterized to have low pH (5.1) and to contain low levels of available $P_2O_5$ (20.5 mg/kg) and exchangeable Ca, Mg, K, Na (2.6, 0.9, 0.5, 0.2 cmol+/kg, respectively) when comparing to upland soils of Jeju or Korean mainland. All trace elements in total or soluble analysis of pasture soils were detected, and there was a big difference between total and soluble levels. The pasture soils tended to have the higher total Fe, Mn, Ni and Zn contents. Cr in all forages was not detected, but other trace minerals levels showed normal range. The hay samples of Italian ryegrass and mixture grasses produced in Jeju tended to contain higher Mn (105 vs 23 mg/kg) and lower Mo (2.7 vs 4.9 mg/kg) than those of alfalfa hay imported from USA. Results show that trace minerals of pasture soils and forages in Jeju seem to be not deficient, indicating that supplementation of some trace minerals are not always necessary in diets for grazing animals and should be done after careful evaluation of diets with regard to concentrations and biological availability of essential elements.

• Korean Journal of Poultry Science
• /
• v.35 no.2
• /
• pp.171-176
• /
• 2008

Animal welfare advocates, claim that the induced molting by fasting be avoided. This study was conducted to evaluate the effect of molting induced by various feeding methods on productivity and egg quality in laying hens. We used 400 flocks of 60-week-old leghorn laying hens in four treatments(five replicates of 20 hens each): fasting method (C), feeding single corn grain diet (T1), feeding single wheat bran diet (T2) and feeding single alfalfa meal diet (T3). As the result of the experiment, egg production and daily egg mass significantly decreased only in T1 compared with the control during the $1{\sim}4th$ week after the secondary egg laying (P<0.05). Although the amount of feed intake was significantly less in T1 group during the $1{\sim}4th$ week compared to the control, no significant difference was detected during the total period (P>0.05). In addition, no significant difference of feed conversion was observed between treatment groups. In terms of egg quality, the egg shell thickness was significantly improved in T1 group than the control group by feeding only corn at the 10th and 14th week after the secondary egg laying (P<0.05), but the significant decrease was observed at the corn (T1) and wheat bran (T2) fed treatment groups than the control group at the 26th week of the experiment (P<0.05). The eggshell strength and haugh unit did not show any difference by the molting methods. Egg yolk color was significantly decreased in T1 and T2 group than the control group at the 6th week (P<0.05). However, T1 and T2 group resulted to show significantly high egg yolk color at the 18th week of the experiment (P<0.05). As the result of the experiment, no large difference was observed in the productivity by the feeding molting method and by the fasting induced molting method. In addition, the single diet fed feeding induced molting method by using alfalfa revealed to show more satisfactory trend than the corn or wheat bran single diet fed feeding induced molting methods even if no statistically significant difference was found in terms of egg productivity.

• Journal of Life Science
• /
• v.15 no.6 s.73
• /
• pp.871-878
• /
• 2005

This experiment was performed to examine the allelopathy effect of allelochemical substance on the crop plants. According to the experiment of the allelochemical substances in Hypochaeris radicata by HPLC, there are the differences at each part of plants. However, it is ascertained that there are 14 kinds of phenolic compounds ingredients that are $\rho$-hydroxybenzoic acid, chlorogenic acid, catechin, caffeic acid, syringic acid, salicylic acid, $\rho$-coumaric acid, ferulic acid, naringin, hesperidin, myricetin, trans-cinnamic acid, quercetin and naringenin. The chemicals like caffeic acid, ferulic acid, and naringenin are commonly included. The result of the chemical experiment shows that there are the differences at each season and part of plants. The leaves in May and blossoms and roots in July contain lots of phenolic acids. It is very high contents such as salicylic acid 2085.6 ${\mu}g/g$ and quercetin 1522.0 ${\mu}g/g$, especially in roots of plants. The result on the growth of crop plants treated by the aqueous extract of Hypochaeris radicata shows that the value of the control group and the test group are same in some cases. However, because the treat value of test group is towel'than that of control group in all items of the experiment, it is cofirmed that the growth of crop plants was inhibited and that the inhibitory effect was increased as its density of treatment was increased. The result of change in quantity shows that there are the differences at each kind of crop plants, but the inhibitory effect was increased as its concentration of treatment was increase with entire. As results, it is confirmed that H. radicata has the allelopathy effect to the crop plants. Especially the inhibitory effect on growth is high in gramineous crop, italian ryegrass and leguminous crop. purple alfalfa.

• Research in Plant Disease
• /
• v.18 no.4
• /
• pp.277-289
• /
• 2012

The total number of requests and associated specimens for the diagnosis of virus infection were 573 and 2,992, respectively, on crops from agricultural places of farmers, Agricultural extension services and so forth for 5 years from 2007. The total number of virus tests was 13,325. The number of species of viruses infected on the submitted crops was 21 in 2007, 15 in 2008, 23 in 2009, 21 in 2010 and 17 in 2011. The newly recorded viruses were Tobacco leaf curl virus (TbLCV) in 2007, Tomato yellow leaf curl virus (TYLCV) in 2008, Impatience necrotic spot virus (INSV) and Radish mosaic virus (RaMV) in 2009, and Beet western yellows virus (BWYV) in 2010. Forty virus species including Alfalfa mosaic virus were detected over 5 years. The ten most frequently detected virus species were Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV), Tomato leaf curl virus (TYLCV), Cucumber green mottle mosaic virus (CGMMV), Broad bean wilt virus 2 (BBWV2), Zucchini yellow mosaic virus (ZYMV), Melon necrotic spot virus (MNSV), Pepper mild mottle virus (PMMoV), Watermelon mosaic virus (WMV) and Pepper mottle virus (PepMoV). The types of crops submitted from agricultural places were 51 in total and the ten most frequently submitted crops were red pepper, tomato, paprika, watermelon, melon, rice, cucumber, corn, radish and gourd. The total request rate for the top 10 crops and top 20 crops was 81.6% and 94.2%, respectively. Eight pepper infecting virus species included CMV, and the average infection rate was 24.6% for CMV, 18.9% for PMMoV and 14.7% for TSWV. Seven kinds of double infection were detected in pepper including BBWV2+CMV at 14.7% on average, and four types of triple infection including BBWV2+CMV+PepMoV at 0.9% on average. Six virus species detected on tomato including TYLCV, and the average infection rate was 50.6% for TYLCV, 14.5% for TSWV and 10.9% for Tobacco leaf curl virus (TbLCV). The mixed infection of CMV+TSWV on tomato was 3.9% on average and of Tomato mosaic virus (ToMV)+TYLCV was 0.4% on average. Five viruses detected on watermelon included MNSV and the average infection rate was 37.0% for MNSV, 20.4% for CGMMV, 18.1% for ZYMV and 17.8% for WMV. The mixed infection rate on watermelon was CMV+MNSV and WMV+ZYMV having an average infection rate of 0.7% and 5.0%, respectively. The average infection rates on melon were 77.6% for MNSV, 5.6% for CMV and 3.3% for WMV. Mixed infections of CMV+MNSV occurred on melon with an average infection rate of 13.5%.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.5
• /
• pp.667-673
• /
• 2009

Ninety six intact male sheep (12 months old with mean live weight of about 35 kg) were used to assess the effects of restricted feeding on intake, digestion, nitrogen balance and metabolizable energy (ME). The animals were selected from two known Iranian small and large body size breeds: 48 Sangsari (S) and 48 Afshari (A), and were divided into two equal groups: restricted (R) and a control (C). Each group had 48 sheep (24 each breed). The experiment had a duration of 15 and 75 days adaptation and treatment periods, respectively. The animals were individually placed in metabolism cages and fed a diet based on pelleted concentrate mixture consisting of alfalfa, barley grain, cottonseed meal and barley straw. The animals in group C were fed ad libitum, while animals in group R were fed at maintenance level and maintained a relatively constant live weight. During the experiment, the average daily weight gain (ADG) of S and A animals in R group was 0.34 and -0.25 g/d (0.02 and -0.02 $g/kg^{0.75}/d$), respectively. While that of S and A animals in C group was 174.4 and 194.4 g/d (10.16 and 11.48 $g/kg^{0.75}/d$), respectively. Nitrogen (N) was determined by both measured and regression methods. Animals of R group stayed at about zero N balance (0.01 and -0.00 g $N/kg^{0.75}/d$ for S and A animals, respectively). The N retention of animals of both S and A breeds in C group were similar (0.45 and 0.46 g $N/kg^{0.75}/d$, respectively). Digestible organic matter intake (DOMI) and ME requirement for maintenance (MEm) were measured by both constant weight technique and regression method by regressing N balance on DOMI and ME intake on ADG. The measured DOMI during constant weight was 24.61 and 24.27 g $DOMI/kg^{0.75}/d$ and the calculated DOMI from regression equation was 24.24 and 24.22 g $DOMI/kg^{0.75}/d$, for S and A animals, respectively. The measured MEm was 402 and 401 kJ $ME/kg^{0.75}/d$ and the calculated MEm from regression analysis was 398 and 400 kJ $ME/kg^{0.75}/d$ for S and A breeds, respectively. There were no significant differences between both measured and regression techniques. There was no significant difference between S and A breeds for DOMI, N retention, MEm, digestibility and metabolizability values. Digestibility values for OM, GE and CP and metabolizability were significantly (p<0.05) higher in restricted feeding sheep compared with that of sheep fed ad libitum.

• Korean Journal of Veterinary Research
• /
• v.28 no.1
• /
• pp.179-185
• /
• 1988

Present study was undertaken in order to evaluate the lead contents of various feedstuffs produced in Korea and the effect of the burning of gasoline by automobiles on the lead contents. Ninety-one samples near and 95 far road were collected from 9 regions(Do). All of the samples were washed, dry-ashed and analyzed for lead content using atomic absorption spectrophotometer. The mean values obtained were checked for significance of difference using computer. The results obtained were summerized as follows: 1. The lead content in ${\mu}g/g$ of agriculture-byproducts were measured with the following mean values and ranges(in parentheses). Rice bran: $2.07{\pm}1.67$ (0-5.00), rice hull $1.84{\pm}1.18$ (0-3.71), rice straw, $1.27{\pm}1.09$ (0-3.62), soybean pod:$4.55{\pm}3.13$ ($1.13{\pm}10.43$), and wheat bran: $1.69{\pm}0.86$ (0-3.65). 2. The lead content in ${\mu}g/g$ of pasture plants were measured with the following mean values and ranges. Kudzu:$2.71{\pm}1.74$ ($0.38{\pm}8.75$), leed: $2.03{\pm}1.61$ (0-4.54), lespedeza:$4.73{\pm}5.93$ (0-31.25), sagebrush: $4.08{\pm}3.75$ (0-12.18), Korean-grass: $2.11{\pm}1.38$ (0-5.50), maizestalk: $2.62{\pm}2.35$ (0-8.65), clover: $3.83{\pm}2.97$ (0-12.19), alfalfa: $7.14{\pm}0.97$ (4.46-9.25), and timothy: $5.86{\pm}4.79$ (0-9.25). 3. Fourteen samples (22.2%) out of 63 agriculture-byproduct samples and 42 (34.2%) out of 123 pasture plant samples showed lead content of more than $3{\mu}g/g$ which are said to be the upper limit value for cattle. 4. No significant difference between the mean lead contents of near road, and those of far road was recorgnized. 5. The regional mean values for all kinds of samples collected in Kyungbuk and Kyungnam were significantly (p<0.05, p<0.10) higher compared to those in Chungnam and Jejudo.6. From these results it may be concluded that the burning of gasoline by automobiler did not affect on the lead contentes of washed feedstuffs produced in Korea at present.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.7
• /
• pp.986-993
• /
• 2001

In balance experiments with rats either 25 or 50% of the casein protein in the control diet was replaced with one of the following eight sun-dried tropical biomass products: water spinach plants (WS) (Ipomoea aquatica Forsk), leucaena leaves (LL) (Leuceana leucocephala), duckweed plants (DW) (Lemma minor L.), groundnut foliage (OF) (Arachis hypogaea L.), trichantera leaves (Tric) (Trichantera gigantea), indicago leaves (Ind) (Indigofera hirsuta), mungbean foliage (Mb) (Phaseolus aureus), and cassava leaves (CL) (Manihot esculenta Crantz). The experiment included 102 rats with six individuals per treatment group. In three of the 16 biomass treatment groups, feed intake and weight gain of the rats were unacceptably low, and therefore they were excluded from the statistical evaluation, The crude protein (CP) content of the biomass products varied between 20.9% (Tric) and 33.2% (DW), whereas the content of NDF varied between 18.5% (Ind) and 32.2% (DW) of dry matter (DM). The total content of essential amino acids (g/16 g N) was comparable with that of alfalfa meal, except for GF and Tric, which were inferior. Between plant species, differences in dietary digestibility of organic matter (dOM) and CP (dCP) were observed (p<0.001). Also, the replacement level negatively influenced dOM and dCP (p<0.001). The lowest values for dOM (p<0.001) were observed for diets including biomass products with the highest content of NDF (OF, Tric, Mb, LL). Digestibility of CP was negatively affected by level of protein replacement. Significant (p<0.001) differences were found in N-retention and biological value among diets with different biomass products. The most favourable overall results were obtained for DW, WS and CL. The main factors affecting the nutritive value of the diets tested were their NDF content, dCP and AA profile of the biomass. Also antinutritive component(s) may have influenced the process of digestion and metabolism of some of the biomass products.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.6
• /
• pp.812-818
• /
• 2009

This study evaluated the effects of live yeast and yeast cell-wall mannan-oligosaccharide supplementation onperformance and nutrient digestibility during early lactation in cows fed a diet based on a mixture of corn silage and alfalfa hay as forage sources. Eight multiparous Holstein dairy cows (average days in milk, 27${\pm}$6) were used in a replicated 4${\times}$4 Latin square design. Diets contained 45% forage and 55% concentrate on a dry matter (DM) basis and treatments were: i) basal diet without additive (Control), ii) basal diet with 32 g/d of mannan-oligosaccharides (MOS), iii) basal diet with $1.2{\times}10^{10}$ colony forming units per day (cfu/d) of live yeast (Saccharomyces cerevisiae CNCM 1-1077; SC), and iv) basal diet with a mixture of MOS (32 g/d) and SC ($1.2{\times}10^{10}$ cfu/d; MOS+SC). Treatments had no effect (p>0.05) on DM intake and yields of milk, 3.5% fat-(FCM) and energy-corrected milk (ECM), and on milk fat percentage, body condition score and blood metabolites. Compared with the Control, only supplementation of SC resulted in numerically higher yields of FCM (41.9 vs. 40.1 kg/d) and ECM (41.8 vs. 40.3 kg/d), and milk fat percentage (3.64 vs. 3.43%). While the MOS diet had no effects on performance compared to the Control, the combination treatment MOS+SC increased milk protein percentage (p<0.05). Also, the MOS supplementation, both alone or in combination with SC, numerically increased milk fat percentage. The SC supplementation increased apparent digestibility of DM and crude protein while the MOS supplementation did not affect digestibility. Concentrations of total volatile fatty acids (VFA) and ruminal pH were similar across treatments. Overall results indicated that supplementation of MOS produced variable and inconsistent effects on rumen metabolism and performance, whereas SC supplementation improved nutrient digestibility and numerically increased FCM and ECM yields, which could not be enhanced by the combined supplementation of MOS+SC. According to our experimental condition, there was no effect of MOS alone or in combination with SC on dairy cow performance.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.27 no.4
• /
• pp.361-370
• /
• 1982

The effects of climatic factors on organisms lire variable and complex, and it, however, can be interpreted in terms of those on the distribution and those on the population densities. The distribution of an organism may largely be determined by the temperatures, except some temporal organisms which are depended on the air mass movements. Population density of an organism is determined by various climatic factors, such as previous winter temperature, temperature of growing season and rainfall. The start of growing season of the rice plants has been shifted to earlier since last decade in Korea. This may mean that the overall climatic condition during the growing season might be considerably different from those in past years, and such a difference in climatic conditions might have close relation with the recent status of the diseases and insect pests through direct effects on the physiology and population dynamics of the organisms, as well as through on the biotic associations of the pest organisms. The white back planthopper and brown planthopper have become the key insect pests in Korea in recent years. They are migratory and have high reproductive pontentials and more generations than average residential insects. The synchronization of the migrants and physiological condition of the rice plants seems to be the important factors in relation to the recent outbreaks of these insects; the high reproductive rate can be obtained with the growth stage of rice being 30-50 days after transplanting. The modication of the microclimate associated with high plant density and some other introduced new cultural techniques also have some relation with the outbreak. The key diseases of the rice are the blast disease, sheath blight and the bacterial leaf blight. For the rice blast, the seedling blast and leaf blast during the early growing season and the neck blast, have become more serious, the former may be related to hotbed nursery and the later may be related to the high humidity in early August, and synchronization of the heading time which has been shifted to early part from middle or late part of August. In general, for the rice diseases, the development of the new races have been the most serious which are largely resulted from the introduction of the new varieties, but it also seems to be related with the prolonged periods of the favorable condition associated with the shifted growing seasons. In general, the diseases and insect pest problems have become much more variable and complex, and control measures should be based on the thorough knowledge of the ecology of the pest organisms, that is, effects of various environmental factors on the disease cycle; spore release, spore deposition, infection, colonization and sporulation of the disease organisms, and those on the development, reproductive potentials, dispersal, age specific responses of the insects. The well organized real-time pest management systems, such as alfalfa weevil management system developed at the Purdue University in U.S., is the prime importance for the implementation of the pest management principles.