• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.102-115
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• 2001

Through out the last few decades, processing methods for ingredients of feed grains, such as grinding, flaking, extrusion, soaking, cracking etc., have been adopted in order to improve the nutrient digestibility in ruminants. Among feed grains, processing methods for whole corns have been the most frequently studied since corns are utilized as the thumb ingredients in formulating feeds. In these days, flaking of whole corns is the most incessantly used in formulation feeds, resulting in enhancing the performance of ruminants. Recently formulating non-forage feed for beef cattle, especially Holsteins, without processing whole corns is carrying out through various feed companies with expectations of whole corns acting like forages. However, it can not be ruled out that whole corns might possibly result in decreasing the productivity due to the depression of nutrient utilizations. Therefore, one must reevaluate the non-forage feeds as well as makes an effort to develop the rational and effective methodology in processing whole corns with the consideration of rumen eco-system.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.851-858
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• 2002

This study was conducted to determine effects of whole (intact), coarsely-ground (4 mm), finely-ground (1 mm), steam-flaked and steam-flaked-ground (1 mm) corns on in vitro and in situ DM digestibilities and also in vitro fermentation characteristics. After 48 h incubation, in vitro dry matter digestibilities of whole, steam-flaked, coarsely-ground, steam-flaked-ground, and finely-ground corns were 6.79, 61.68, 76.48, 85.72 and 90.31%, respectively. Steam-flaked-ground corn showed the highest digestibility until 24 h incubation (p<0.01). After 48 h incubation, pH of whole corn decreased with a small range. However the values of pH of other media significantly decreased (p<0.01). The gas productions of finely-ground and steam-flaked-ground corns were higher than those of the other corns (p<0.01). After 24 h incubation, $NH_3$-N concentration of finely-ground and steam-flaked-ground corns increased rapidly. Total VFA was the highest in finely-ground corn, followed by steam-flaked-ground, steam-flaked, coarsely-ground and whole corns. Incorporating steam-flaked corn resulted in the highest propionate concentration (p<0.01) and the lowest acetate : propionate value (p<0.05). Finely-ground corn showed the highest in situ DM digestibility throughout the incubation period (p<0.01), followed by coarsely-ground, steam-flaked and whole corns, respectively. Overall, DM of whole corn was merely digested in vitro as well as in situ.

• Journal of Life Science
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• v.19 no.1
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• pp.65-74
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• 2009

The objective of this study was to examine the effects of steam flaking treatment of corn grains imported from USA and India on in vitro gas production, microbial growth and contents of aflatoxin $B_1$ and ochratoxin A. Each treatment was composed of total 4 treatments including (1) USCW (US com-whole type), (2) USCF (US corn-flaked type), (3) IDCW (India corn-whole type) and (4) IDCF (India orn-flaked type) with 4 replications $\times$ 6 incubation times (3, 6, 9, 12, 18 and 24 hr). Mycotoxin (aflatoxin $B_1$ & ochratoxin A) contents in test corns tended to increase gradually with increasing logistics periods from the harbor, hopper, silo to processing line. The contents of aflatoxin $B_1$ in India corn (IDCW) and US corn (USCW) were 11.71 and 1.78 ppb, respectively when measured at the hopper. After steam flaking, both contents of aflatoxin $B_1$ in USCW and IDCW were 0.00 ppb. It means that Aspergillus flavus could be decreased by steam flaking. However, this trend was not observed in ochratoxin content. The gas production rate of USA corns (USCW & USCF) was significantly (p<0.05) higher than India corns (IDCW & IDCF), and that of steam flaked corns (USCF & IDCF) was higher $1.5{\sim}2%$ than whole corns (USCW & IDCW) after 3 hr incubation in in vitro experiment. pH value was optimally maintained for microbial growth during whole incubation times with the value of 6.05 to 6.54, and was not significantly different between treatments, but USCF was somewhat lower than other treatments. pH value decreased following 12 hr of incubation but gas production increased rapidly during the same period. In addition, in vitro microbial growth rates also increased with up to 18 hr of incubation period, thereafter experienced a decrease with extended incubation time. In conclusion, US corn was superior to India corn by origin based on the results of in vitro and mycotoxin contents. And steam flaking process of imported corns tended to decrease mycotoxin contents such as aflatoxin $B_1$ and ochratoxin A as well as improve in vitro gas production and microbial growth rates.

• Journal of Animal Science and Technology
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• v.45 no.3
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• pp.421-432
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• 2003

The objective of this study was to examine the effects of processing methods of corn grains on protein and starch degradability in the rumen by three ruminally cannulated dry Holstein cows. The corns for these experiments were untreated; whole corn L(density; 660 g/$\ell$), whole corn H(density; 740 g/$\ell$), and treated by four different types: Ground corn, 3.8 mm, 2.8 mm, and 1.5 mm flaked corn. The results obtained were summarized as follows: For 48 hrs, the protein degradabilities were high in order, ground corn, 1.5 mm, 2.8 mm, and 3.8 mm flaked corn(82.6, 76.5, 64.5, and 33.9%, respectively). Flaked corn grains were degraded lower than ground corn. However, as increasing the processing degree of flaking, the protein degradabilities, from 4 hrs to 48 hrs, were increased. The starch degradabilities on 48 hrs were higher in 1.5 and 2.8 mm flaked corns, ground corn, 3.8 mm flaked corn(99.1, 91.5, 89.5, and 68.9%, respectively) than whole corn L(32.0%) and whole corn H(20.5%)(P<0.05). By increasing the processing degree of flaking, the protein degradabilty between 2.8 mm and 3.8 mm was increased significantly from 68.9% to 91.5%, however, that of 1.5 mm flaked corn, processed thinner, tended to be increased slightly, but was not significantly different. From 12 hrs to 24 hrs, whole corn L was degraded little more than whole corn H in starch, was not significantly different. However, after 48 hr incubation in the rumen, whole corn L was degraded more 50% than whole corn H(P<0.05). The value of degradation parameter “a” of protein was lower in all flaked corns than in ground corn. In contrast, the value of degradation parameter “a” of starch was significantly higher in all flaked corns than in ground corn(P<0.05). It seemed that by flaking the corn grains, starch particles were gelatinized, and then, starch was degraded more rapidly, while protein was degraded more slowly. Referring to these kinds of physical characteristics of grain sources in ruminal degradabilities, it is possible to synchronize the fermentation of nitrogen and carbohydrate sources, in formulating the cattle diets.

• Journal of Animal Science and Technology
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• v.45 no.3
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• pp.433-442
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• 2003

The objective of these studies were to examine the effects of processing methods of corn grains on in vitro dry matter digestability and in sacco degradability in the rumen by three ruminally cannulated dry Holstein cows. The corns for these experiments were untreated; whole corn L(density; 660 g/$\ell$), whole corn H(density; 740 g/$\ell$), and treated by four different types: Ground corn, 3.8 mm, 2.8 mm, and 1.5 mm flaked corns. The results obtained were summarized as follows: The DM degradabilities, after 48 hr incubation by in sacco method, were the highest(94.4, 88.0 and 87.0%, respectively) in 1.5 mm flaked corn, ground corn, and 2.8 mm flaked corn. The 3.8 mm flaked corn was degraded significantly lower than these. Until 12 hr incubation, whole corn L tended to be degraded little more than whole corn H, was not significantly different. However, after 24 hr incubation, the significant differences between whole corn L and whole corn H were shown(P<0.05). The DM digestabilities by in vitro digestion were the highest for 1.5 mm flaked corn and ground corn(92.3 and 91.2%, respectively)(P<0.05), followed by 2.8 mm and 3.8 mm flaked corn(83.9 and 83.4%, respectively), tended to be similar to those by in sacco method. Whole corn L was digested twice more rapidly than whole corn H. Summarizing the experimental data, compared with unprocessed corns, the flaked corns were significantly increased in the degradabilities of dry matter in the rumen. In addition, as increasing the flaking degree of corn, the degradabilities of dry matter were significantly improved. Referring to these kinds of physical characteristics of grain sources in the ruminal degradabilities, it is believed to be possible to optimize the environment of the fermentation in the rumen.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.132-141
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• 2001

This study was conducted to determine effects of whole and processed corns on attachment characteristics of rumen microbes in Hanwoo. Whole corn(WC) was processed into four different types; ground corn(GC), cracked corn(CC), flaked corn(FC), and soaked corn(SC). After each processed corns was incubated in the rumen of Hanwoo for 12 h and 24 h, attachment characteristics of rumen microbes and morphological changes of feed substrates was examined by utilizing scanning electron microscopy(SEM). In this study, the treatment group of GC and CC showed the highest in the attachment of rumen microbes. On the other hand, microbial attachments to the starch particle of WC and SC were hardly detected. However, with the increase of incubation time the surface of WC and SC was covered by many microbes, resulting in enhancing the surface degradation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.3
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• pp.178-184
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• 1992

Five varieties of silage corn were cultivated to compare the growth characteristics and productivity. Corn varieties were Pioneer 3144(P 3144), 3160(P 3160), 3282(P 3282), 3352(P 3352) and Suweon 19 (S 19). The corns were seeded on May 2 and harvested on August 15, and measured the plant height, leaf length, leaf width, stem diameter, and yields of fresh and dry matter. The results obtained were as follows: 1. Plant height of P 3352 and P 3144 grown about 280cm throughout the experimental period was the tallest(P<.Ol), and those of P 3160, P 3282 and Suweon 19 ranged from 246.3 to 256.0 cm. 2. Leaf length is the longest in P 3352 and the shortest in P 3282(97.63cm vs 84.17cm), and there was significant(P<.Ol) difference between corn varieties. 3. Stem diameter was the longest in P 3144 and the shortest(P<.Ol) in P 3352(3.28cm vs 2.66cm). 4. P 3144, P 3282 and P 3352 had the greatest(P<.Ol) fresh matter yields per 10a in leaf, stem, and ear and whole plant, respectively. 5. Dry matter yield of P 3282 was the greatest(P<.Ol) in stem(1,080.6 kg/lOa) and leaf(304.5 kg/lOa), and that of P 3352 was the greatest in ear(864.1 kg/lOa) and whole plant yield(2,021 kg/lOa). 6. Ratios of respective part of corn to total dry matter were ranged from 12.7 to 17.8 76 for leaf, 44.5 to 66.9% for stem and husks, and 16.9 to 42.8 % for ear, and the highest in P 3160, P 3160 and P 3352, respectively. Consequently, P 3352, P 3144 and P 3282 shown high productivity in dry matter yield could be recommended as a reliable corn varieties for silage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.425-431
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• 2006

In order to investigate the effects of ethylene on the seed development of three corn types (dent, sweet, and super sweet corns), aminoethoxyvinyl glycine (AVG) and silver thiosulfate (STS) and ethephon (2-chloroethylphosphonic acid, CEPA) were applied either on whole plants or shanks of ears at 9 and 21 days after silking. Ethylene production of developing super sweet corn seeds was much higher than those of sweet and dent corns. The cavity in the endosperm tissues of the super sweet corn started earlier and endosperm was collapsed more severely compared to those of sweet and dent corns. Ethylene production seemed to be related to the death of endosperm cells to form a cavity. Application of AVG and STS reduced ethylene production and delayed cavity formation in endosperm of super sweet corn seeds, while CEPA increased ethylene production and enhanced the time of cavity formation. AVG and STS increased 100-seed weight, while CEPA decreased.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.116-131
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• 2001

Experiments were conducted to determine effects of whole and processed corns on in situ disappearance rates of nutrients in the rumen and in vitro degradability of dry matter by rumen microorganisms. Whole corn(WC) was processed into four different types; ground corn(GC), cracked corn(CC), flaked corn(FC), and soaked corn(SC). In the in situ experiment, the rate of ruminal DM disappearance after 48 hour incubation was highest in GC(76.1%) and lowest in WC and SC(12% ; P<0.01). The rate of ruminal CP disappearance after 48 hour incubation was highest in GC and CC(48 and 38%, respectively; P<0.01). The rate of ruminal OM disappearance after 48 hour incubation was highest in GC(76.14%) and lowest in WC and SC(11.82 and 12.26%, respectively; P<0.01). In the in vitro experiment, the two-stage incubation technique was used to measure digestibilities of whole and processed corns. The digestibility of DM was higher in GC, CC and FC(86.95, 85.84 and 82.29%, respectively) than in WC(15.36%; P<0.01).

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.3
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• pp.185-192
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• 1992

This experiment was conducted to compare the productivity of five silage corn varieties. Corn varieties were Pioneer 3144(P 3144), 3160(P 3160), 3282(P 3282), 3352(P 3352) and Suweon 19(S 19) and were seeded on May 2 and harvested on August 15. Ratios of stalk, leaf and ear, chemical composition and yields of nutrients were investigated in respective corn part. Experimental design was accepted by Latin square arrangement with five replicates and each plot had twenty two plants. The results obtained were as follows: 1. Crude portein, crude ash and nitrogen free extract(NFE) contents of whole plant ranged from 6.32 to 7.18%, 5.16 to 7.43% and 52.62 to 57.90%, respectively, and there were no significant(P>.Ol) differences between varieties. Crude protein and NFE content were the highest in ear between corn parts. 2. Crude fiber conent of whole plant ranged from 18.98 % to 24.01 %, and was the highest in suweon 19 and the lowest in P 3352(P<.01). Crude fiber content was the highest in stem and the lowest in ear, However, crude fat content(2.03-3.66 %) vice versa. 3. Yields of organic matter, crude protein, crude fat, NFE and TDN per 10a were the greatest(P< .01) in P 3282, however crude fiber yield was the highest(P<.Ol) in P 3352. 4. Ratios of different part to total dry matter yield ranged from 12.7 %(P 3352) to 17.8 %(P 3160) for leaf, 44.5(P 3352) to 66.9 %(P 3160) for stem and husks, and 16.9 %(P 3282) to 42.8 %(P 3352) for ear, and there were significant differences between corn varieties(P<.Ol). Consequently, P 3352 has the greatest nutrient yields, particularly by ear, and P 3282 has a great nutrient yield by stem. This result suggested that could be appear a better character of silage corn by hybridization of this two corn varieties.