• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.625-636
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• 2005

This study was conducted to determine effects of different ratios (3.5, 3.0 and 2.5) of nonfibrous carbohydrate (NFC) to ruminally degradable protein (RDP) on in vitro fermentation and lactation performance of dairy cows and optimum ratio of NFC to RDP in dairy rations. In vitro trial was conducted up to 12 hr with ruminal fluidtaken from ruminally cannulated Holstein cows. The level of dietary NFC did not affect ruminal pH. The ammonia-N concentration was not significantly different among treatments until 6 hr incubation, however, it was significantly (P < 0.05) decreased as the ratio of dietary NFC to RDP increased on 9 and 12 hr incubation. For volatile fatty acids, concentrations of both acetate and propionate were significantly (P < 0.05) increased on 3 hr incubation as dietary NFC contents of treatments increased, in other incubation times, they had no significant differences among treatments. Valerate and A:P ratio were not affected by the ratio of NFC to RDP. Isoacids and total VFAs were significantly (P < 0.05) increased with increasing dietary NFC contents and their values were highest in the treatment of 3.0 ratio. Meanwhile, for in vivo trial, 18 Holstein lactating cows were allotted to treatments in three groups of 6 cows. They were employed for 24 weeks to investigate nutrient intakes, and milk yield and composition according to different ratios of dietary NFC to RDP. Intakes of dry matter and energy were significantly (P < 0.01) increased, but NDF intake was significantly (P < 0.01) decreased as the ratio of dietary NFC to RDP increased. Milk yield for the ratio of 3.5 (32.7 kg) was significantly (P < 0.05) higher than those of other treatments. Milk fat (%) was significantly (P < 0.05) higher for the treatments of 3.0 (3.79 %) and 2.5 (3.79 %) than that (3.48 %) for the ratio of 3.5, but milk fat yield was not different among treatments. Contents and yields for milk protein and solids-not fat were linearly (P < 0.01) increased as the ratio of dietary NFC to RDP increased. However, milk urea nitrogen concentration was significantly (P < 0.05) decreased with increasing dietary NFC levels. Our results showed that the increasing level of NFC in the diet of dairy cows enhanced ruminal fermentation, N utilization and milk production and suggested that maximal fermentation and lactation performance were achieved when the dietary ratio of NFC to RDP was more than 3.0 in dairy rations.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.137-142
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• 2008

This study was conducted to investigate the effect of single or mixed supplementation of bacterial and fungal phytase using 45-wk-old 450 Hy-Line Brown laying hens housed in individual cages for 12-wk period. The birds were reallocated to have similar egg productivity by examining the egg production for one wk before starting the experiment. Two sources of phytase, bacterial (BP) and fungal (FP), were used either in single or mixture to determine the effects of these phytase. Five dietary treatments consisted of control (BP 0, FP 0), T1 (BP 300, FP 0), T2 (BP 300, FP 300), T3 (BP 300, FP 3000), and T4 (BP 0, FP 3000). The DPU was used for phytase activity in this experiment. The nonphytate phosphorus (NPP) content of control was 0.30%, and those of phytase treatments were set to 60% of the Control. Experimental diets were fed ad libitum throughout the experimental period. The lighting schedule of 17L7D was employed. The egg production was not different between control and bacterial phytase treatments, but the T4 showed significantly low productivity compared to control (P<0.05). No difference was found in average egg weight among all treatments. The daily egg mass did not show any statistical differences among all treatments: however, it was significantly low in T4 compared to ther control during the latter half of the experiment (P<0.05). No significant difference was found among treatments in terms of feed intake, feed conversion and egg quality. The digestibilities of dry matter, crude protein, and fat digestibility were similar regardless of the treatments. No significant trends were detected in Ca and P availability. In conclusion, the BP level of 300 DPU contributed to achieve 40% reduction of recommended nonphytate phosphorus addition. The synergistic effect of bacterial and fungal phytase was not confirmed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.4
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• pp.234-248
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• 1998

Seven box cores from the disposal areas located in the southern part of the East Sea (Stations Band B') and in the offshore to the east of Pusan (Stations J and J'), and from their surrounding areas (Stations J2, J6 and H) were collected to investigate the effect of dumped wastes on the foraminiferal assemblages. The species diversity indices [S, H(S), E] of foraminifera and the total number of foraminifera show significant differences between the ocean waste disposal areas and their adjacent areas. Ocean waste disposal areas located in southern part of the East Sea (Stations Band B') show not only smaller number of foraminifera species but also lower values of coarse fraction content in the sediment and the number of benthic and planktonic foraminifera than the surrounding areas. Another ocean disposal area located offshore Pusan (Station J') contains abnormally greater number of planktonic (approximately 300 000 individuals/lO g dried sediment) and benthic (approximately 300, 000 individuals/10 g dried sediment) foraminifera compared to those of the adjacent areas. The waste dumped at Station J' probably acts as a nutrient causing the greater number of foraminifera. Station J shows low species diversity indices [S, H(S)]. The number of benthic foraminifera decreases from the surface to the downcore at Station J, which indicates that Station J is under stress. However, Stations J', J2 and J6 are under stable conditions as evidenced by the greater species diversity indices [S, H(S)] compared to other stations. No foraminifera were found with biological disease or abnormal chambers, which commonly occur in extremely stressed environment, in both the ocean disposal and adjacent areas. The organic matter decay of the wastes dumped in the study areas has not made the bottom water corrosive.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.50-56
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• 2015

Italian ryegrass is generally cultivated by a winter forage in a paddy field, the harvest season overlaps with rice transplantion in some cases. In addition, farmers can miss the optimal seedtime for Italian ryegrass because of the rainy season. Therefore, this research was conducted between October 2012 and June 2013 in Kwangjin, Korea to examine the effect of spring-seeding on the yields and quality of Italian ryegrass for the determination of an alternative if the optimal seedtime is missed. This trial consists of four different seeding dates (15 February, 25 February, 5 March, and 15 March) and three varieties (Kowinmaster, Kowinearly, and Green farm). The Italian ryegrass varieties "Kowinmaster," "Kowinearly," and "Green farm" were sown on February 15. The heading date of each variety showed from May 12 to May 9 and interval time of five days but the Treatment of March 15 planting date showed three days interval. The Kowinmaster variety, planted on February 15, was 93.0 cm taller on March 15 with a height of 105.7 cm. The Kowinearly and Green farm varieties planted on February 15 were of a similar height on February 25 and received a poor lodging score when planted quickly. The dry matter (DM) yield of the Kowinearly planted on February 15 was high but that of Green farm was low at 6,609 kg/ha and a difference was not shown between the varieties. The DM yield was different for those varieties planted on February 15 and March 15 (P<0.05). The crude protein content (CPC) of those varieties planted on February 15 showed an average of 8.8%, while those that were planted on March 15 showed an average that was about 2.3% higher at 11.1%; furthermore, the latter also showed lower acid detergent fiber (ADF) and total digestible nutrient (TDN) contents, by 2.1% and 1.5%, respectively. The relative feed value was about 5.9% higher, depending on the seeding date, as well as being slower and showing less difference between the varieties. According to this study, Italian ryegrass planted in a paddy field of the southern region of Korea on February 25 will produce a high-quantity yield with nutritive value.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.17-25
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• 2015

The following experiments were used to evaluate the effect of seeding method and pre-emergence herbicides on weed control and the production of the $sorghum{\times}sudangrass$ [sorghum bicolor (L.) Moench] hybrid under field and in vitro conditions. Under the in vitro condition, we evaluated how different kinds of herbicides affect the rate of seed germination and the growth of early seedlings in the $sorghum{\times}sudangrass$ hybrid treated with herbicides. Simazine, alachlor, and methabenzthiazuron were used, and their concentration levels were 0%, 40%, 70%, and 100%. The germination ratio of the seeds was reduced by the application of simazine, methabenzthiazuron, and alachlor compared with the control (distilled water). The alachlor application severely decreased the sorghum germination ratio. However, seed germination was not greatly influenced by the concentration level of the herbicides. Root and shoot length were increased in the following order: control > simazine > methabenzthiazuron > alachlor. Overall, alachlor significantly reduced root length more than shoot length. The differential tolerance of the $sorghum{\times}sudangrass$ hybrid to pre-emergence herbicides by seeding method was then tested under the field condition. The plants were severely injured by the alachlor application, leading to a great reduction in the number of stems. However, for the simazine and methabenzthiazuron applications the number of stems lost was slightly lower than it was for the alachlor and simazine + alachlor applications. In the seeding method, drilling was more effective in reducing herbicide injury than broadcasting. All of the herbicides effectively controlled weeds. The simazine and methabenzthiazuron applications showed a significantly higher dry matter (DM) yield. However, the alachlor and simazine + alachlor applications severely reduced the DM yield. This result suggests that the alachlor application has a significant effect on plant production. Similarly, the total digestible nutrient (TDN) yield was greatly reduced by the alachlor and simazine + alachlor applications. From the results presented above, we concluded that the yield of DM was the highest for broadcasting with no herbicide. and drilling was the most-effective way to reduce herbicide injury. The simazine application was the most-effective herbicide, showing the highest forage yield and TDN yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.1
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• pp.75-84
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• 2011

This study was conducted to investigate the effect of harvest stage of corn on the quality of square baled corn silage manufactured with corn grown in paddy land of Department of Animal Resources Development, National Institute of Animal Science, RDA from 2009 to 2010. Corn "Kwangpyungok" was harvested at three different growth stages (milk, yellow ripen and ripen stage) and ensiled at each harvest time. Square baled corn silage was manufactured by use of square silage wrapping compressor. Each treatment was replicated three times. The content of crude protein (CP) of corn in square baled corn silage decreased with delayed maturity, but the content of ADF (acid detergent fiber), NDF (neutral detergent fiber), TDN (total digestible nutrient) and in vitro dry matter digestibility (IVDMD) were not changed. The content of moisture, pH and the nutritive values at three different harvest stages were not influenced by the method of silage manufacture and inoculant. The content of lactate of square baled corn silage harvested in milk stage of corn was significantly increased, as compared with that of round baled corn silage (P<0.05), but in stage of yellow ripen was significantly decreased (P<0.05). The content of acetate in square baled corn silage significantly decreased with delayed harvest maturity, as compared with that of round baled corn silage (P<0.05). Flieg's score of square baled corn silage harvested in milk stage of corn was slightly higher than that of round baled corn silage, but Flieg's scores in yellow ripen stage and ripen stage were not influenced by the method of silage manufacture. Flieg's score with delayed maturity was not influenced by the method of silage manufacture and inoculant. The manufacture of square baled corn silage was proved to be suitable for the fermentation of corn silage. Therefore, this study suggest that square baled corn silage can be a way of new silage manufacture technique.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.2
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• pp.109-116
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• 2012

This study was carried out to determine the forage quality, production, and regrowth of Phragmites communis as a native grass according to growth stages. Experiment 1 was conducted in Ansan from May 2009 to April 2010 (7 stages), and experiment 2 was conducted in Cheonan from May to November 2011 (10 stages). In experiment 1, forage quality decreased rapidly with advance of growth from May. When harvested on late May, July, September and April of the following year, the contents of crude protein were 7.7%, 4.6%, 3.7%, and 2.2%, respectively. Relative feed value (RFV) were 80.2, 65.1, 61.8 and 52.8, and lignin contents were 7.1%, 9.9%, 12.0%, and 13.2%, respectively. In experiment 2, significantly higher forage yields were observed when harvested from late June to mid July. On the other hand, forage quality decreased with delayed harvest as was in experiment 1. Good regrowth of Phragmites communis was observed when harvested earlier than in August. When harvested on late May, June, July, August, September, October and November, the dry matter (DM) yields were 7,329 kg/ha, 12,527 kg, 9,593 kg, 8,279 kg, 7,649 kg, 5,822 kg and 5,540 kg, and in vitro digestible DM (IVDDM) yields were 3,924 kg/ha, 5,264 kg, 4,273 kg, 3,322 kg, 3,352 kg, 2,195 kg and 1,887 kg, respectively. Forage quality grades of Phragmites communis were 4th grade in May, 5th grade from June to Sept., and 6th grade in Oct., Nov., or in Apr. of the following year. However, all regrown Phragmites communis ranked the 4th in quality. In conclusion, we recommend that Phragmites communis should be harvested from late June to mid July (no later than the end of July) to obtain good forage quality with digestible nutrient contents greater than rice straw. Regrowth of Phragmites communis was poor, and more than 70% of annual forage yields were out of the first harvest. Therefore, we recommend only one harvesting per year for good regrowth and stable production of Phragmites communis.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.382-393
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• 2009

The objectives of this study were to characterize long-term annual and seasonal trophic state of Topjeong Reservoir using conventional variables of Trophic State Index (TSI) and to determine the empirical relations between the trophic parameters. For the analysis, we used water quality dataset of 1995$\sim$2007, which is obtained from the Ministry of Environment, Korea and the number of parameters was 9. Annual ambient mean values of TN and TP were 1.78 mg $L^{-1}$ and 0.03 mg $L^{-1}$, respectively and TN : TP ratios averaged 76, indicating that this system was nitrogen-rich hypertrophic, and was probably phosphorus-limitation for algal growth. Therefore, nitrogen varied little with seasons and years, and total phosphorus (TP) varied depending on season and year. Monsoon dilutions of TP occurred in August and monthly fluctuations of suspended solid (SS) was similar to those of chlorophyll-$\alpha$ (CHL). Annual mean values of BOD and $COD_{Mn}$ were 1.61 mg $L^{-1}$ and 4.23 mg $L^{-1}$, respectively and the interannual values were directly influenced by the intensity of annual rainfall. There were no significant differences in the trophic variables between the two sampling sites. Mean values of Trophic State Index (TSI, Carlson, 1977), based on TN, TP, CHL, and SD (Secchi depth), turned out as eutrophic state, except for the TN (hypertrophic). Regression analyses of log-transformed seasonal CHL against TP and TN showed that variation of the CHL was explained 37% by the variation of TP ($R^2$=0.37, p<0.001, r=0.616), but not by TN ($R^2$=0.03, p>0.05). Regression coefficient of $Log_{10}$CHL vs $Log_{10}SD$ was 0.330 (p<0.003, r=0.580), indicating that transparency is regulated by the organic matter in the system. Results, data suggest that one of the ways controlling the eutrophication would be a reduction of phosphorus from the watershed.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.219-226
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• 2006

The wastes (the needle leaves and branches) produced from thinning the forest were fermented under an anaerobic condition (pine silage) to utilize as a forage source of ruminants. An in situ trial was conducted with two ruminally fistulated Korean native cows by 4 replicates (2 bags per cow), and in vivo digestibility of pine silage was estimated with five Korean native steers by 5 replicates in incomplete double turn-over design. In order to investigate feed efficiency and carcass traits, forty eight Korean native bulls were assigned to four treatments (0%, 25%, 50%, 75% of pine silage) with a completely randomized design in 12 pens accommodating 4 animals per pen. The amounts of concentrate and roughage allowed to experimental animals were in the range of 2.5% and 0.6% of body weight, respectively. Animals had freely accessed to mineral block and water in stanchion barn.An in situ crude protein digestibility of the roughage sources when suspended for 48 hrs in the rumen was higher for feeding the pine silage than the rice straw, whereas NDF digestibility was vice versa. No differences between the treatments were observed in in vivo digestibilities of dry matter, crude protein and NDF. Daily body weight gain was significantly (P<0.01) higher for the pine silage substitutions compared with the rice straw feeding except for the 25% silage feeding. The pine silage feeding did not affect feed efficiency.In carcass traits, marbling score tended to be higher for the 50% pine silage treatment than the other treatments while back fat thickness tended to be the thinnest for the rice straw feeding. From these results, it may be recommended to substitute pine silage, as a forage source, for rice straw by 50 percent.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.7-12
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• 2009

This experiment was conducted to compare the agronomic characteristics and productivity in introduced forage pea cultivars at the experimental field. The experiment was arranged in a randomized block design with three replications. The forage pea used in this study were two cultivars ('Livioletta', 'Austrian Pea') and one Chinese milk vetch cultivar (Chinese domestic cultivar). Flowing of 'Livioletta' cultivar was May 16th and 'Austrian Pea' cultivar was 18th May, 20 days later than the former. The 'Livioletta' cultlvar showed stronger than winter hardiness of 'Austrian Pea' cultivar. Dry matter (DM) content of 'Liviotetta' and 'Austrian Pea' cultivars were 22.5% and 20.9% chinese milk vetch showed the lowest content with 17.7%. 'Austrian pea' cultivar showed the highest DM yield with 5,617 kg/ha but the DM yield of 'Livioletta' cultivar was low with 3,652 kg/ha. The yield of CP (crude protein) and TDN (total digestible nutrient) set high at 'Austrian Pea' cultivar. And 'Livioletta' and 'Austrian Pea' cultivars showed CP content with 15.5% and 14.4% but Chinese milk vetch with 19.3%. The acid detergent fiber (ADF) and neutral detergent fiber (NDF) content of 'Austrian Pea' cultivar were 23.2% and 40.3%. Therefore 'Austrian pea' cultivar seems to be suitable varieties in paddy field as winter forage crops.