• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.3
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• pp.201-205
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• 1994

The objectives of this research are to determine the seasonal and varietal differences of total digestible nutrients(TDN) and in vitro dry matter digestibility(1VDMD) of tall fescue grown in Takwalyon areas, based on the data of preceding paper(Lee et al. 1994b). The results are may be summarized as follows : 1. The values of total digestible nutrients(TDN) and in vitro dry matter digestibility(1VDMD) in 1st cutting were lower than the values of 2nd and 3rd cutting, and it was due to different stages of growth and seasonal difference of climatic conditions in this areas. 2. The relative yield(RY) had negative significantly correlation with in vitm dry matter digestibility(1VDMD) of 1st cutting. 3. Total digestible nutrients(TDN) indicated high positive significant correlation with in vitro dry matter digestility (IVDMD) in all cuttings. 4. The variety of Johnstone showed a high values of total digestible nutrients(TDN) and in vitm dry matter digestibility(1VDMD) of 2nd and 3rd cutting, but Fuego was lower than the other varieties.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.333-342
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• 2021

This study attempted to compare total digestible nutrients (TDN) calculated as Rohweder, NRC, and Waldo and Peiqiang methods and TDN measured as digestibility of in vivo appearance. Rohweder method showed that the TDN of rice straw and timothy were 54.32% and 57.79%, respectively. In NRC method, the digestibility of neutral detergent fiber (NDF) and TDN of rice straw were 50.76% and 53.15%, respectively. When NRC method was applied in Timothy, the digestibility of NDF and TDN were 51.53% and 55.22%, respectively. Waldo and Peiqiang method calculated the results through the rumen in situ test. NDF digestibility of rice straw and timothy was 44.61% and 51.82%, which was different from the results of NRC method. In addition, TDN was predicted to be 48.85% for rice straw and 55.41% for timothy. In the in vivo apparent digestibility experiment, the digestibility of NDF and TDN in rice straw was 41.10% and 44.79%, respectively. In timothy, the digestibility of NDF and TDN were measured as 51.29% and 58.18%, respectively. As a result of a series of studies, rice straw was found in Rohweder and NRC methods showed higher TDN than other methods. In this study, there was a difference in rice straw by measurement method, but there was no difference in timothy. Therefore, when evaluating the value of feed in order to provide roughage to ruminant, calculation methods must be modified and supplemented. In addition, TDN should be considered to apply several evaluation methods instead of one method.

• Food Science of Animal Resources
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• v.39 no.3
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• pp.388-401
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• 2019

This study was conducted to investigate the effect of the total digestible nutrients (TDN) level of commercial concentrates on growth performance, carcass characteristics, and meat composition of late fattening Hanwoo steers. A total of 28 steers were randomly assigned to one of four dietary groups; T1 (73.30% TDN), T2 (74.50% TDN), T3 (76.40% TDN), and T4 (77.10% TDN). Average daily gain (ADG) was slightly but not significantly higher in the T2 than in the other treatments. Dry matter intake (DMI) and feed conversion ratio (FCR) were higher in the T2 than in the other treatments; however, the differences were not statistically significant. Carcass back fat thickness was thicker in the T4 and marbling score was higher in the T2 than in the other treatments; however, the differences were not statistically significant. The TDN level of concentrates had no effect on the physicochemical characteristics and fatty acid composition of the longissimus muscle. The finding of this study indicate that less than 74% or greater than 75% TDN in the commercial concentrate did not contribute to improve ADG, FCR, marbling score; therefore, in the present study, the recommendable TDN level in the commercial concentrate for late fattening period was 74% to 75% in terms of growth performance and marbling score of Hanwoo steer.

• Korean Journal of Organic Agriculture
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• v.31 no.4
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• pp.461-468
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• 2023

Supplying an appropriate amount of feed is an economical and environmentally friendly by increasing the nutrient digestibility of livestock and reducing nutrients released from overfeeding. Therefore, this study was conducted to determine the nutrient digestibility according to dietary feeding levels of Hanwoo steers. Three treatments in feeding trial were used feeding amount based on the maintenance energy level of the Korean feeding standard for Hanwoo (2022): 100% (control, CON), 140% (treatment 1, TRT1), and 190% (treatment 2, TRT2). The experiment was designed in replicate 3×3 balanced Latin square designs using six Hanwoo steers. In this study, energy value was predicted according to treatment groups. In addition, nutrient digestibility and energy value were measured through a feeding trial to Hanwoo steers. All energy values, including total digestible nutrients and digestible energy, were predicted to decrease linearly with increasing feeding levels. TRT2 showed lower digestibility than CON for dry matter, crude protein, non-fiber carbohydrates, and total digestible nutrients in the feeding trial (p<0.05). However, there was no significant difference between CON and TRT1. Total digestible nutrients (TDN) and digestibility of feed are set based on the maintenance energy. However nutrient digestibility and TDN decreased when feeding level increased by more than 190% compared to maintenance energy in this study. Therefore, it is necessary to correct the TDN by considering the feeding level when mixing the feed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.99-99
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• 2022

This study was carried out to select the excellent silage maize varieties customized for paddy cultivation that is vulnerable to lodging and waterlogging in the central and region. Ten varieties (Kwangpyeongok, P3394, etc.) were sown with 3 replicates in Suwon, Gyeonggi-do. It was sown twice in April and June of each year in 2020-2021 and harvested during the yellow ripe stage suitable for silage. The number of days to flowering stage in lowland condition increased up to 11 days compared to that in upland condition. In April seedling, varieties that showed a relatively small decrease in biomass production and total digestible nutrients (TDN) under lowland condition compared to upland condition were Gangdaok and Kwangpyeongok in 2020, and Dacheongok, Gangdaok and Kwangpyeongok in 2021. Kwangpyeongok, Gangdaok, and Sinhwangok showed relatively higher biomass production and TDN than the other varieties under lowland compared to upland in both 2020 and 2021. Our results suggest that Kwangpyeongok and Gangdaok are suitable silage maize varieties for lowland cultivation in the central region of Korea.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.831-842
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• 2021

Accurate measurements of feed energy values have a positive effect on the control of feed intake for animals, the formation of prices, and on economic profits. However, few studies have attempted to measure the energy values of domestic roughages and to validate an energy value prediction model. The purpose of this study is to build a database through measurements of the nutrient digestibility and digestible energy results of roughages used in Korea and to evaluate the domestic applicability of the National Research Council (NRC) estimation model. Oat hay, annual ryegrass, tall fescue, barnyard millet, and concentrates for beef cattle were used in the test. As a result of an in vivo digestibility trial, the total digestible nutrients (TDN) of oat hay, annual ryegrass, tall fescue, and barnyard millet were found to be 68.73, 55.02, 55.71, and 52.89%, respectively. As a result of comparing the estimated values using the NRC equation with the in vivo results, there was a difference of 3.55 to 6.84%P in the TDN. Inferred from this result, it is considered that TDN calculations using the NRC equation can be reasonable for the test feeds used in this study. These results can be utilized when revising the Korean Standard Tables of Feed Composition, which provides a comprehensive overview of Korean feed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.2
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• pp.123-134
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• 1997

The effects of cutting 6equency and nitrogen fertilization on feed values of reed canarygrass were investigated in uncultivated rice paddy and the attemp was made to estimate the economical and efficient levels of nitrogen fertilization for the increased production of nutrients in reed canarygrass. The results are summarized as follows; 1. Crude protein(CP) content was higher at 1st cut of all treatments(12.5% in 3 cutting 6equency; 19, 7% in 4 cutting frequency; 22.5% in 5 cutting kquency). However, Total Digestible Nutrients(TDN) and Relative Feed Value(RFV) in 3 and 4 cutting 6equencies were higher at 3rd cut(63.5%, 126.8) and 4th cut(65.7%, 146.4) respectively in which the contents of Neutral Detergent Fiber(NDF) and Acid Detergent Fiber(ADF) were lowest. In 5 cutting frequency, 1st cut showed the highest TDN and RFV as 70.5% and 232.4 respectively. 2. The level of nitrogen fertilization affected CP content of reed canarygrass. Nitrogen fertilization of 120kgl halcut showed high CP contents of 11.4, 14.7 and 16.5% in 3, 4 and 5 cutting eequency respectively. In 3 and 4 cutting frequency, TDN and RFV were highest with nitrogen fertilization of 90kg/ha/cut where NDF and ADF were lowest, however those in 5 cutting frequency were highest with nitrogen fertilization of 30kg/ha/cut. 3. The yields of CP varied according to the number of cutting frequency and those were 0.45~0.65 in 3 cutting hquency, 0.35~0.50 in 4 cutting frequency, and 0.19~0.67tond/ha in 5 cutting 6equency respectively and TDN was 2.09~3.60, 1.64~2.77 and 0.73~2.96tons/ha respectively. 4. The ratios between the yields of CP and TDN were 5.48, 4.60 and 4.34 in 3, 4 and 5 cutting 6equency respectively and it indicates lower ratio in result of higher number of cutting 6equency. 5. Higher nitrogen fertilization increased the yields of CP and TDN. The yields of CP were higher in 5 cutting frequency as 1.55~2.62tons/ha than of 3(1.20~1.91tons/ha) and 4 cutting frequency(1.35-2.23tons/ha). The yields of TDN were 6.31~9.93, 5.99~9.99 and 7.16~10.57tons/ha in 3, 4 and 5 cutting frequency respectively. 6. The levels of nitrogen fertilization for high production efficiency of crude protein(kg CPYkg N) was estimated as 113.4~302.5kg/ha and it resulted in 1.44~2.09ton/ha of CP yields. The levels of nitrogen fertilization for high production efficiency of dry matter was 199.2-361.3kgha in which nitrogen were fertilized below 400kg/ha and it resulted in 1.64~2.17ton/ha of CP yields. 7. The levels of nitrogen fertilization for high production efficiency of total digestible nutrients(kg TDNYkg N) were 149.9~294.1kg/ha in 3 and 4 cutting kequency and it resulted in 8.66~8.89ton/ha of TDN yileds. With the levels of nitrogen fertilization for high production efficiency of dry matter of 199.2~361.3kg/ha, TDN yields were high as 8.77~9.94ton/ha.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.607-616
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• 2003

This study was conducted to determine the effect of feeding a total mixed ration(TMR) of broiler litter(BL) and bakery by-product(BB) with additional BL or rice straw incorporated at 10% of dietary DM as a roughage source on behavior pattern, nutrient intake, digestibility, digestible nutrient intake, ruminal and blood parameters, and N balance of sheep. All the treatment diets were formulated to be isoenergetic[total digestible nutrients(TDN) 66.9%]. Compared with the conventional formulated feed - rice straw feeding system(control), feeding TMR with BL(T1) or rice straw(T2) at 10% of dietary DM resulted in reduced eating, ruminating and total chewing time(P<0.05), similar DM intake, low(P<0.05) digestible DM, OM, fiber and total nutrients intake, low(P<0.05) nutrients digestibilities except EE, similar ruminal characteristics(pH, VFA concentrations and ratios, efficiency of carbohydrate fermentation, NH3-N), and favorable N digestion and retention. There were no differences in the above parameters between T1 and T2 with the exception of increased(P<0.05) eating, ruminating and total chewing time for T2. These results suggested that a TMR of BL and BB with or without rice straw may replace the conventional formulated feed and rice straw in ruminant diets successfully and furthermore feeding the TMR with rice straw made sheep behavior pattern more favorable.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.285-290
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• 1995

This experiment was conducted to investigate the effects of wheat bran addition on the fermentative quality and dry matter digestibility(Dh4D) of rye silage. This hexbage was ensiled by the conventional methods in small glass silo of 0.82 liter with addition of wheat bran of 0%, 5%. 01%, and 15%. mpectivery.The samples of rye silage were determined the pH, lactic acid, acetic acid and butyric acid. The DMD was evaluated by pepsin-cellulase technique method. The energy values (total digestible nutrients. TDN : digestible energy, DE : metabolizable energy, ME) were calculated by DMD. The results obtained were as follows : 1. The pH and butyric acid of rye silage were reduced with increasing of wheat bran addition, but the contents of lactic acid and total acid were increased. 2. TDN, DE and ME were increased with high rate of wheat bran addition. 3. Regression equation and correlation coefficients between Flieg's score(X) and DMD(Y) of silage were Y =48.7+0.157X(r=0.917, p<0.01). 4. Regression equation and correlation coefficients between level of wheat bran(X) and Flieg's score(Y) of silage were Y= 18.3+5.56X(r=0.929, p<0.01).

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.144-147
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• 2011

The main nutritional problem of sorghum${\times}$sudangrass hybrid (Sorghum bicolor${\times}$Sorghum sudanese) silage is low quality and palatability. This experiment was conducted to evaluate whether organic com grain and crushed rice addition of sorghum${\times}$sudangrass hybrid silage increases forage quality of the silage. The sorghum${\times}$sudangrass hybrid silages with added com grain and crushed rice were similar to conventional com silage in moisture content. However organic sorghum${\times}$sudangrass hybrid silage had low pH values. Silage added with gain and byproduct had higher crude ash, acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents than control com silages, while its non-fiber carbohydrate (NFC) and total digestible nutrients (TDN) showed the opposite results. Lactic acid, butyric acid and lactic percentage of total organic acid (L/T) of sorghum${\times}$sudangrass hybrid silages were higher than those of com silage, but acetic acid was higher than control. In vitro dry matter digestibility (IVDMD) of com silage was higher than other sorghum silages. Feed intake of sorghum${\times}$sudangrass hybrid silage added with crushed rice was highest among silages. Therefore, these data indicate that crushed rice and com grain added sorghum${\times}$sudangrass hybrid silage could be recommended as the most effective treatment for increasing silage quality and palatability.