• Asian-Australasian Journal of Animal Sciences
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• v.26 no.3
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• pp.349-357
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• 2013

The aim of this study was to evaluate the efficiency of supplements containing different energy sources in relation to mineral supplementation of steers grazing guineagrass (Panicum maximum cv Tanz$\hat{a}$nia) pasture, during the dry season. The experimental design was a randomized block with three treatments and four replications. The treatments consisted of a mineral supplementation and two other supplements, one based on corn seed and the other based on soybean hulls, and provided at 0.8% of body weight. Forty-eight, 12 month-old crossbred steers with an average initial body weight of 267 kg, were assigned to twelve paddocks (1,125 ha) of guineagrass. The animals that were fed with soybean hulls and corn seed presented a greater average daily gain (0.982 and 0.937) when compared with the mineral supplementation. Soybean hulls can be used as a satisfactory food source, replacing corn as an energy source in the supplementation of beef cattle without compromising animal performance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.55-58
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• 2000

Germination of sweet and super sweet corn is lower than normal corn due to the higher sugar and lower starch contents of kernels. Sweet corn seeds are easily deteriorated in the field under the unfavorable condition, therefore it is important to identify the optimal harvesting time for seed production. This trial was conducted to investigate the responses of germination percentage of shrunken-2(sh2), brittle(bt), sugary(su), and sugary enhancer(se) hybrids in relation to harvesting dates. Eight hybrids of four different gene sweet corns were harvested at 15, 20, 25, 30, 35, 40, 45, and 50 days after silking(DAS). Germination test was performed using paper towel method. Mean germination percentages across eight hybrids showed the highest value at 45 DAS. There were significant differences among genes and within gene for germination. Shrunken-2 hybrid Mecca was higher than su hybrids for germination, indicating that sh2 would not be poorer than su Late harvesting beyond the optimal harvesting date might not be desirable because of more lodging and ear rots. Theoretical optimal harvesting date estimated from the regression equation was 40.9 DAS, however, practical date for harvesting would be a few days later than the estimated date if seedling vigor might be considered. Kernel dry weight per ear showed similar response to germination. Regression equation showed the highest kernel dry weight at 40.7 DAS. Significant correlations between kernel dry weight and germination were observed, impling that kernel dry matter accumulation would be an important factor for germination.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.108-115
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• 2002

The effects of long-term fertilization on soil properties and nutrient availability are not well documented for cassava cultivation in Vietnam. In 1990, a field research plots were established with 12 treatments to test the effect of different rates of nitrogen (N), phosphorus (P) and potassium (K) on soil properties in Acrisols at Thai Nguyen University in Northern Vietnam. In 1999, composite soil samples (0 to 20cm depth) were collected from eight selected plots for measurements of nutrient supply rates by ion exchange membrane probes and for growing corn and canola in a growth chamber with and without added lime. Generally, long-term nitrogen (N) fertilization increased available N supply rates but decreased available potassium (K) and magnesium (Mg). Long-term phosphorus(P) applications increased canola N, calcium (Ca) and Mg uptake. Canola P uptake increased with increased P rates only when lime was added. Long-term K applications increased canola N, K, Ca, Mg uptake but only significantly increased corn N uptake. Liming significantly increased uptake of N, P, K, Ca, Mg and S for both corn and canola. However, N $H_{4-}$N, K and Mg soil supply rates were reduced when lime was added, due to competition between Ca from the added lime and other nutrients.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.212-217
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• 2010

A new waxy corn hybrid 'Daedukchal 1' was developed from single cross between CNU 504 and CNU 2396 at Chungnam National University in 2007. Inbred CNU 504 used as a seed parent and inbred CNU 2396 as a pollen parent were collected throughout domestic regions. Tasseling date of this hybrid was seven days later than that of check hybrid, 'Chalok 1'. 'Daedukchal 1' was 19.7 cm in ear length and 4.5 cm in ear diameter. On yield trial, ear length of this hybrid was increased 29.7% compared with a check hybrid, 'Chalok 1'. 'Daedukchal 1' had white kernels and good eating quality due to high sugar content and thinner pericarp. The ratio of kernel set length/ear length was similar to 'Chalok 1'. It is moderately resistant to southern leaf blight and northern leaf blight but susceptible to corn borer. The yields of 'Daedukchal 1' in fresh ear weight and in number of fresh ear were 16% and 8%, respectively, higher than those of a check hybrid in regional yield trials for two years. Seed production for this hybrid was better because of the consistency of tasseling dates.

• Journal of Animal Science and Technology
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• v.65 no.6
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• pp.1254-1269
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• 2023

This study aims to predict the change in corn share according to the grazing of 20 gestational sows in a mature corn field by taking images with a camera-equipped unmanned air vehicle (UAV). Deep learning based on convolutional neural networks (CNNs) has been verified for its performance in various areas. It has also demonstrated high recognition accuracy and detection time in agricultural applications such as pest and disease diagnosis and prediction. A large amount of data is required to train CNNs effectively. Still, since UAVs capture only a limited number of images, we propose a data augmentation method that can effectively increase data. And most occupancy prediction predicts occupancy by designing a CNN-based object detector for an image and counting the number of recognized objects or calculating the number of pixels occupied by an object. These methods require complex occupancy rate calculations; the accuracy depends on whether the object features of interest are visible in the image. However, in this study, CNN is not approached as a corn object detection and classification problem but as a function approximation and regression problem so that the occupancy rate of corn objects in an image can be represented as the CNN output. The proposed method effectively estimates occupancy for a limited number of cornfield photos, shows excellent prediction accuracy, and confirms the potential and scalability of deep learning.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1215-1221
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• 2007

Three Holstein steers fitted with ruminal and duodenal cannulae were fed grass silage-based diets supplemented with potato pulp silage as a substitute for rolled corn at levels of 0%, 50% and 100% on a DM basis in a $3{\times}3$ Latin square design to investigate the effect of potato pulp silage on nitrogen (N) utilization in ruminants. Organic matter (OM) intake, and rumen and total tract digestibilities did not differ among treatment diets. Rumen and post-rumen starch digestibilities were similar among treatments, although starch intake decreased (p<0.01) with potato pulp supplementation. There were no significant differences (p>0.05) in ruminal N utilization and non-ammonia N supply to the duodenum of steers fed grass silage supplemented with potato pulp silage as a substitute for rolled corn. There were no treatment differences (p>0.05) in rumen pH, volatile fatty acid (VFA) concentration or the molar percentages of acetate and propionate. The ammonia-N concentration in rumen fluid tended to decrease (p<0.1) when rolled corn was substituted with potato pulp silage. Ether extract intake and post-ruminal digestibility significantly (p<0.01) decreased in steers fed diets containing potato pulp silage. Concentrations of total cholesterol and phospholipids in serum markedly decreased (p<0.01) with potato pulp silage supplementation without adversely affecting liver function. These data suggested that potato pulp silage has a similar value as rolled corn as an energy source for rumen microorganisms.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.8
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• pp.1124-1130
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• 2014

The objective of this study was to determine the responses in the digestibility of dry matter (DM) and amino acid (AA) composition of ileal endogenous flow (IEF) of pigs (initial body weight, $69.1{\pm}6.46$ kg) fed N-free diets (NFD) formulated with different ratios of corn starch to dextrose. Fifteen pigs fitted with a T-cannula at the distal ileum were fed 5 diets according to a triplicated $5{\times}2$ incomplete Latin-square design. Each period consisted of a 5-d adjustment period and 2 d of ileal digesta collection for 12 h on each of d 6 and 7 and between each period, there was a 5-d recovery period to avoid abnormal weight loss. The ratios of corn starch to dextrose investigated were 0:879, 293:586, 586:293, 779:100, and 879:0 for diet numbers 1, 2, 3, 4 and 5, respectively, and chromic oxide (5 g/kg) was used as an indigestible index. Ileal DM digestibility was greater in Diet 1 than that in Diet 4 (89.5% vs 87.3%, p<0.01) but they were not different from Diet 2, 3, or 5. The IEF for most of indispensable AA were not different among diets with the exception of Met, in which a lack of corn starch or dextrose gave lower (p = 0.028) IEF of Met than diets containing corn starch and dextrose. Likewise, the dispensable AA and total AA in the IEF did not differ among diets. The respective IEF of AA (mg/kg of dry matter intake) in pigs fed Diets 1, 2, 3, 4, or 5 were 301, 434, 377, 477,or 365 for Lys, 61, 89, 71, 87, or 61 for Met, and 477, 590, 472, 520, or 436 for Thr. Proline was the most abundant AA in the IEF followed by Gly, Glu, and Asp and together accounted for approximately 50% of the total ileal AA flows of pigs fed NFD. In conclusion, the variation in proportion of corn starch and dextrose in a NFD does not largely affect estimates of IEF of N and AA for growing-finishing pigs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.91-106
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• 2013

Exserohilum turcicum is considered serious destructive disease of maize (Zea mays L.) in North Korea. This study aimed to understand genetic inheritance and combining ability of newly bred lines of maize tolerant to E. turcicum by diallel crosses. Three diallel sets for two different ecological regions and one agronomic trait; eastern (E), northern (N) and stay green (SG) involving 29 inbred lines were tested in eight locations of 2000 and 2001. E. turcicum infections were under natural conditions, respectively. Lines used were selected for high yield potential in test crosses with good agronomic traits and tolerance to biotic and abiotic stresses. Selection for race specific high resistance to biotic stresses was avoided to select quantitatively inherited genes. Host plant responses to E. turcicum were rated on a scale of 1 (highly tolerant) to 9 (highly susceptible). Highly significant variations were recorded in all trials. General combining ability (GCA) mean square was roughly twice that of specific combining ability (SCA). The genotype (G) by environment (E) interaction was highly significant. The overall results of genetic studies in three diallel sets show that genetic control for inbred tolerance to E. turcicum is polygenic and quantitatively inherited. New inbreds; E-3, N-1 and SG-4 confer better tolerance to E. turcicum than the widely used inbreds; Mo17, and B73. Proper use of genetic information from this study shall increase of corn production under high E. turcicum infection in the Far Eastern Regions of Korea and China.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.19-24
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• 2004

Effect of polyphenolic compounds from green tea leaves and surfactant micelles on lipid oxidation in corn oil-in-water emulsion (O/W) wag determined. Concentrations of polyphenolic compound and surfactant in continuous phase of O/W were measured. Particle size of O/W with 17 mM Brij 700 and 5% corn oil increased with increasing concentration of polyphenolic compound (100-200 ppm). Concentration of surfactant in the continuous phase was lower than that of control. Lipid oxidation rates, as determined by the formation of lipid hydroperoxides and headspace hexanal, in O/W emulsions containing polyphenolic compounds decreased with increasing concentration of polyphenolic compounds (100-200 ppm). Inhibition of hydroperoxide and headspace hexanal produced via lipid oxidation by polyphenolic compounds in O/W was BHT>procyanidin B3-3-O-gallate>(+)-gallocatechin >(+)-catechin.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.115-122
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• 1993

A study was conducted to compare the effect of feeding commercial formula ration and corn-soybean meal based rations on growth performance, feed conversion ratio, mortality percentage, dressing percentage, carcass composition and economics of raising broiler chicks at commercial farms. 3000 day old broiler chicks were randomly divided into 4 groups with 3 replicates of 250 birds in each. Four iso-nitrogenous and isocaloric rations (A, B, C and D) were prepared and randomly allotted to each group. Ration A was a commercial broiler ration whereas ration B had the same formula with the exception that all the animal protein sources were replaced with soybean meal (SBM). Ration C was based on only corn and SBM. Ration D contained corn, SBM and 25% fullfat soybean (FFSB). The birds were given the experimental rations starter from day 1 to 28 and finisher from 29 to 49. The results indicated that the birds fed on corn-soybean meal based rations gained significantly figher weights showed better feed conversion ratio, gave higher dressing percentage with better carcass composition, lower mortality and higher net profits as compared to those fed on commercial ration. The replacement of animal protein sources in commercial ration with SBM (ration B) although did not show any significant differences in the performance of birds as compared to ration A, a little improvement was visible indicating that SBM can be used as a good substitute of animal protein sources. Similarly the replacement of SBM with FFSB up to a level of 25% did not affect the broiler performance as compared to only SBM.