• Asian-Australasian Journal of Animal Sciences
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• v.13 no.1
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• pp.96-114
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• 2000

Genetically selected beef cattle are fed high-energy diets in intensive production systems developed in industrial countries. This type of feeding can induce rumen dysfunctions that have to be corrected by farmers to optimise cost-effectiveness. The risk of rumen acidosis can be reduced by using slowly degradable starch, which partly escapes rumen fermentation and goes on to be digested in the small intestine. Additives are proposed to stabilise the rumen pH and restrict lactate accumulation, thus favouring the growth of cellulolytic bacteria and stimulating the digestion of the dietary plant cell wall fraction. This enhances the energy value of feeds when animals are fed maize silage for example. Supplementation of lipids to increase energy intake is known to influence the population of rumen protozoa and some associated rumen functions such as cellulolysis and proteolysis. The end products of rumen fermentation are also changed. Lipolysis and hydrogenation by rumen microbes alter the form of fatty acids supplied to animals. This effect is discussed in relation with the quality of lipids in beef and the implications for human health. Conditions for optimising the amount of amino acids from microbial proteins and dietary by-pass proteins flowing to the duodenum of ruminants, and their impact on beef production, are also examined.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.852-856
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• 2006

Four lactating Holstein cows were used in a $4{\times}4$ Latin-square design to determine the effects of various levels of whole cottonseed (WCS) in diets on parameters including milk (yield and fat content), rumen fluid (pH, ammonia and TVFA) and blood (${\beta}$-carotene, vit. A, vit. E, urea, $NH_3$, Ca, P and Mg levels). Cows consumed 0, 1, 2 or 3 kg WCS per day. No significant differences were observed among the groups on analysed parameters except plasma vitamin E concentration. In addition, when the amount of cottonseed was increased, milk yield and milk fat content also tended to increase but this increase was not statistically significant. In conclusion, feeding of WCS up to 3 kg per day with ad libitum maize silage did not cause negative effects on milk yield, milk fat and blood vitamin levels in the short term in dairy cows.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.100-100
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• 2022

This study was conducted in 2021 using Kwangpyeongok and Gangdaok, that showed good yield performance both under upland and lowland conditions in the previous year. The experiments were carried out by sowing on April 22, May 14, May 30, June 19, and July 10, with aim to determine optimum sowing date in central region of Korea. The growing degree days (GDD) required to read the flowering stage were 1375.5-1725.3℃ for upland and 1582.7-1982.4℃ for lowland condition. The lowest GDD was observed in July 10 sowing regardless of ridge formation both under lowland and upland conditions for Kwangpyeongok. However, Gangdaok showed the lowest GDD under no-ridge in lowland and high-ridge in upland, both of which were sown on June 19. The difference in GDD between no-ridge and high-ridge treatment was little depending on the sowing date. In both lowland and upland, there was no significant difference between no-ridge and high-ridge treatments in stover dry matter, ear dry matter, and TDN between no-ridge and high-ridge treatments. Under upland condition, no significant difference in biomass and TDN was observed among sowing date treatments and between varieties. Under lowland condition, biomass production was severely reduced in May 30 sowing treatment, whereas no varietal difference was observed. Reduced biomass in May 30 sowing treatment may be due to excess waterlogging and lodging by rainfall.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.56-68
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• 1981

A maize line was selected in 1979 among 1000 Korean local maize lines collected in 1977. The selected maize line was characterized by having three to four tillers and eight to 10 ears on each individual plant. The line was assumed to have a great potential as a silage crop. The investigation was conducted as one of the serial studies on the Korean maize collected lines to provide basic information on the genetic variabilities of the multi-eared and tillered (MET) line and on other agronomic characters, prior to use the line as material for future breeding works for silage crop. The MET line and Suwon #19, single cross hybrid, as check variety were planted on May 1, 15 and 30, in three different levels of plant populations. The results obtained were summarized as follows: 1. The genetic variabilities of multi-ear and tillering habits were greater than environmental variabilities. 2. Total dry leaf weight of individual plant of MET line was also significantly higher than that of Suwon #19. 3. The mean number of tillers and ears bearing on the individual plant of MET line varied greatly with plant densities. The number of tillers and ears was on the average 2.9 and 7.0, respectively, when planted in 60cm. by 60cm. 4. The total dry matter and dried stem weight of the individual plant on MET line were comparable to those of Suwon #19. 5. The kernel weight from the individual plant of MET line was 5 to 40% less than that of Suwon #19, depending upon the plant densities. 6. The Kernel to stover ratio was higher for Suwon #19 than for the MET line. (41% to 35%). 7. The MET line had shown first tiller two weeks after planted on May 1. The second and third tillers appeared three to five days after the appearance of the first tiller. 8. The MET line was very specific in tillering habits. All the tillers were borne on the first few nodes of main stem below the soil surface. 9. The tillering habits of MET line were vigorous in the early part of the growing season, but less vigorous in the later part of the growing season. The number of efficient tillers bearing useable ears, was around two to three, when planted in 60cm. by 60cm. 10. The difference of plant height between main stem and first few tillers was around 10cm. 11. The ear size of MET line was around one-third of the major corn belt hybrids. The shape of ear of MET line was conical, with different diameter. 12. The kernel of the MET line was flinty with small soft starch patches on the endosperm part. 13. The 100 kernel weight was around 15gr., which is about one half of the major high yielding hybrids. 14. The ear height of MET line was comparatively higher than that of Suwon #19. 15. Significantly high and positive phenotypic correlation coefficients were obtained among major plant characters. 16. The growth rate of MET line was slower than that of Suwon #19. 17. MET line and Suwon #19 were both heavily infected with black streaked mosaic virus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.3
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• pp.251-256
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• 1981

Silage yield and nutritional values of a locally collected Korean corn line with high tillering and earing characteristics were investigated at plant densities from 2778 to 8333 plants/ l0a. This line and a non-tillering and nonprolific corn as a check were grown at four plant densities and at three planting dates. The Korean local line abbreviated as MET had the highest dry matter per l0a. The highest dry matter of the MET line compared with the check hybrid was due to the highest dry leaf weight of the MET line. The highest dry leaf weight of the MET line was due to the increased number of tillers of the MET line. Other plant parts such as ear weight, kernel weight and cob weight of the MET line were lower than those of the check hybrid. The dry husk weight per l0a of the MET line was higher than that of the check hybrid, probably due to the increased number of ears in the MET line. The total embryo production per 10 a of the MET line was significantly higher than that of the check hybrid. The increased portion of embryo of the MET line is probably responsible for the higher TON values of the MET line. No interaction between variety x planting dates or planting density was found, indicating that the MET line and check hybrid were both the same in effects of planting dates and densities. Both line and hybrid showed the highest dry matter production when the planting density was high and planting dates was early. When silage was made from either MET line or check hybrid the nutritional values in terms of crude protein, crude fat, fiber, and ash contents of the MET line were similar to those of the check hybrid. But the TON of the MET line was higher than that of the check hybrid, while the OCP of the MET line lower than that of the check hybrid. Amino acid contents of the MET line were also comparable to those of the check hybrid, while lysine content of the MET line was 10% higher than that of the check hybrid.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.1
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• pp.50-57
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• 2016

This study was conducted to determine the effect of mathematical transformation on near infrared spectroscopy (NIRS) calibrations for the prediction of chemical composition and fermentation parameters in corn silage. Corn silage samples (n=407) were collected from cattle farms and feed companies in Korea between 2014 and 2015. Samples of silage were scanned at 1 nm intervals over the wavelength range of 680~2,500 nm. The optical data were recorded as log 1/Reflectance (log 1/R) and scanned in intact fresh condition. The spectral data were regressed against a range of chemical parameters using partial least squares (PLS) multivariate analysis in conjunction with several spectral math treatments to reduce the effect of extraneous noise. The optimum calibrations were selected based on the highest coefficients of determination in cross validation ($R^2{_{cv}}$) and the lowest standard error of cross validation (SECV). Results of this study revealed that the NIRS method could be used to predict chemical constituents accurately (correlation coefficient of cross validation, $R^2{_{cv}}$, ranging from 0.77 to 0.91). The best mathematical treatment for moisture and crude protein (CP) was first-order derivatives (1, 16, 16, and 1, 4, 4), whereas the best mathematical treatment for neutral detergent fiber (NDF) and acid detergent fiber (ADF) was 2, 16, 16. The calibration models for fermentation parameters had lower predictive accuracy than chemical constituents. However, pH and lactic acids were predicted with considerable accuracy ($R^2{_{cv}}$ 0.74 to 0.77). The best mathematical treatment for them was 1, 8, 8 and 2, 16, 16, respectively. Results of this experiment demonstrate that it is possible to use NIRS method to predict the chemical composition and fermentation quality of fresh corn silages as a routine analysis method for feeding value evaluation to give advice to farmers.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.2
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• pp.94-99
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• 2013

Yanganok, a new single cross variety, was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2012. This hybrid, which has a high yield of grain was produced by crossing two inbred lines, KS164 and KS163. KS164 is the seed parent and KS163 is the pollen parent of Yanganok. It is a yellow-orange intermediate maize hybrid (Zea mays L.). After a preliminary yield trial and advanced yield trial of Yanganok (Suwon180) in Suwon for 2 years, a regional yield trial was carried out for its growth characteristics, and yields were determined at 4 different locations from 2009 to 2012, with the exception of 2010. It was named 'Yanganok'. The silking date of Yanganok is 2 days earlier than that of the check hybrid, Kwangpyeongok. Plant height of Yanganok is similar to Kwangpyeongok, but its ear height ratio is higher than that of Kwangpyeongok. It has resistance to lodging. Stay-green features of Yanganok are similar to those of Kwangpyeongok. The ear ratio of Yanganok is similar to Kwangpyeongok. It has moderate resistance to southern leaf blight (Bipolaris maydis) and strong resistance to northern leaf blight (Exserohilum turcicum). It has moderate resistance to black streaked dwarf virus (BSDV), ear lot and corn borer. The dry matter yield of Yanganok, 17.45 ton/ha, was similar to that of Kwangpyeongok. The total digestible nutrients (TDN) yield of Yanganok, 11.96 ton/ha, was similar to that of Kwangpyeongok. The grain yield of Yanganok, 8.32 ton/ha was similar to that of Jangdaok. Seed production of Yanganok went well due to a good match during crossing between the seed parent, KS164, and the pollen parent, KS163, in Yeongwol, and F1 seed yield was 1.79 ton/ha. Yanganok would be a suitable cultivar to all plain areas in the Korean peninsula.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.203-208
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• 2012

Pyeongangok, a new single cross variety, is an yellow dent maize hybrid (Zea mays L.) developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2011. This hybrid, which has a high yield of grain and dry matter, was produced by crossing two inbred lines, KS160 and KS155. KS160 is the seed parent and KS155 is the pollen parent of Pyeongangok. Silking date of Pyeongangok is 2 days earlier than that of check hybrid, Jangdaok, and equal to that of another check hybrid, Kwangpyeongok. Plant height of Pyeongangok is longer than that of Jangdaok and similar to that of Kwangpyeongok. Ear numbers per 100 plants of Pyeongangok is more than that of Jangdaok. Ear length of Pyeongangok is shorter than that of Jangdaok. 100 seeds weight of Pyeongangok is lighter than that of Jangdaok. Ear rate of Pyeongangok is lower than that of Kwangpyeongok. Stay-green of Pyeonganok is not greatly different with that of Kwangpyeongok. It has moderately resistance to southern corn leaf blight (Bipolaris maydis), black streaked dwarf virus (BSDV) and corn borer. It has strong resistance to northern corn leaf blight (Exserohilum turcicum). It has resistance to lodging. Pyeongangok was evaluated for the yields of grain and dry matter at four locations from 2009 to 2011. The yield of Pyeongangok in grain was 7.66 ton/ha. The yield of Pyeongangok in dry matter was 19.80 ton/ha. The yield of Pyeongangok in total digestible nutrient (TDN) was 13.32 ton/ha. Seed production of Pyeongangok has gone well due to a good match during crossing between the seed parent, KS160, and the pollen parent, KS155, in Yeongwol.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.3
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• pp.369-378
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• 2018

Objective: The impact of forage feeding strategy on growth performance, ruminal fermentation and nutrient digestibility in post-weaning calves was investigated. Methods: Forty-five female Holstein calves (body weight [BW] = $79.79{\pm}0.38kg$) were enrolled in the 35-d study at one week after weaning and randomly assigned to one of three dietary treatments. All diets were fed as total mixed ration containing 60% (dry matter [DM] basis) of basal starter feed and 40% (DM basis) of forage, but varied in composition of forage source including i) alfalfa (40% DM, AH); ii) alfalfa hay (26.7% DM)+oat hay (13.3% DM; OH); iii) alfalfa hay (26.7% DM)+corn silage (13.3% DM; WS). Results: Dry matter intake was not different among treatment groups (p>0.05). However, BW (p<0.05) and average daily gain (p<0.05) of calves fed AH and OH were greater than WS-fed calves, whereas heart girth was greater in OH-fed calves than those fed AH and WS (p<0.05). Ruminal fermentation parameters including proportion of butyric acid, acetated-to-propionate ratio, concentration of total volatile fatty acid, protozoal protein, bacterial protein, and microbial protein in rumen were the highest in OH (p<0.05) and the lowest in WS. Compared with the AH and WS, feeding oat hay to postweaning calves increased crude protein digestibility (p<0.05), and decreased duration of diarrhea (p<0.05) and fecal index (p<0.05). Conclusion: Our results suggested that partially replacing alfalfa hay with oat hay improved ruminal fermentation, nitrogen utilization, and reduced incidence of diarrhea in post-weaning dairy calves.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.55-61
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• 1984

A Korean local maize line, MET, which has multi-ears and tillers has been proved as a potential source for silage production. However, no fundamental genetic nature for the line has been investigated. Therefore, this study was done to find genetic information on the multi-earing and -tillering habits of MET line. MET line and a hybrid. (Mo 17 ${\times}$ B68), with monoculm and single ear per plant were used for production of F$_1$(F$\_$1-12/ and F$\_$1-21/), F$\_$2-12/, F$\_$2-21/, BC$\_$1-12/ and BC$\_$1-21/ generations. From the comparison of reciprocal crosses, it was found that the tillering and earing habits of the MET line are controlled by cytoplasmic factors. The tiller and ear numbers, and barren ears were all characters associated with the MET cytoplasm. The cytoplasmic effect of MET on tiller and ear numb en was not evident in F$_1$ generation, probably because of suppressing effect of heterosis on appearance of tillers or ears. Genetic parameters for the gene action for both tiller and ear number also indicated a lack of mono- or digenic-chromosomal gene effects. The heritability (broad) was very low for both characters. Therefore, it is strongly concluded that the tillering and earing characters of MET line are due to cytoplasmic reasons.