• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.3
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• pp.169-174
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• 1991

For simple estimation of pasture production and nutritive value in relation to height of orchardgrass (Ductylis glomumtu L.), the experiment was carried out in a pasture mixture dominated by orchardgrass. The samples of grasses were harvested at the heights of about 30, 40, 50, 70 and 90 cm at the first harvest under different percentage of 100 (grass coverage): 0 (bareland), 80 : 20, 60 : 40, 40 : 60 and 20 : 80, respectively. As the height of orchardgrass was increased, fresh and dry matter (DM) yield were significantly increased. The regression equation between DM yield (Y) and height (X) was Y=ll. 5390 X- 146.60 (r=O. 9414 * * ). Also the higher bareland, the lower pasture production was observed. As the plant height at the first harvest was increased, the contents of crude (C) protein, C. fat, C. ash and relative feed value were markedly decreased. On the other hand, the contents of C. fiber, NFE, NDF. ADF, cellulose and lignin were significantly increased, respectively. The higher height, the lower DM digestibility was found. The equation between digestibility (Y) and height (X) was Y=- 0.2193 X+ 80.99 (r = - 0.9862**). Considering DM yield, digestibility and crude protein, the optimum height of orchardgrass at the first harvest was 59 to 67crn for better pasture production and nutritive value.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.769-775
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• 2008

This study was on the relative net income (RNI) for 18,286 Iranian Holstein cows from 799 herds, with first freshening between 1991 and 2000. Two kinds of production system, which differed mainly in milk pricing system and feed cost, were considered. Four different models adopted from the literature were examined to find the optimum model. They differed by the cost of rearing and growth after first calving and they needed different amounts of economic data at the farm level. Results showed that four measures of RNI were highly correlated (>0.96) and could be used equally to measure lifetime profitability of cows. Therefore, in herds without a regular system for recording economic and management data, use of the simplest model is recommended. Multiple regression analysis revealed that RNI was affected by age at first freshening, milk yield and days of productive life (DPL), regardless of production system, and a similar breeding goal could be defined for the two systems. Multiple regression analysis of RNI showed that in order to obtain an unbiased estimate of economic value for DPL, the per day milk yield, not total lifetime milk yield, should be included in the regression model along with DPL. Regression analysis suggested that it is possible to predict RNI using information on age at first freshening along with the length of first lactation and per day milk yield with a coefficient of determination ranging from 0.44 to 0.47.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.233-238
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• 2006

This study was conducted to evaluate growth characteristics, yield and feed value of newly bred domestic silage corn hybrids compared to foreign imported corn hybrid. Days to silking were $78{\sim}86$ days and longer than that of P3394 (Control). Kwangpyeongok, Cheonganok, and Cheongsaok were resistant to lodging. Such trait of stay-green of Kwanganok, Kwangpyeongok, Cheonganok, Cheongsaok, and Suwon159 was not different from that of P3394. Duruok, Kwangpyeongok, and Suwon159 were more resistant to Bipolaris maydis (southern corn leaf blight) than P3394. All of the silage corn hybrids were resistant to Exserohilum turcicum (northern corn leaf blight) and Smut. Ear ratios to total dry matter (%) of Cheonganok was similar to P3394. Ear lengths of domestic hybrids were similar or longer than that of P3394. Dry matter yield of domestic hybrids except Suwon19 and Jangdaok were similar to that of P3394. Total digestible nutrient (TDN) yields, Duruok, Kwangpyeongok, Cheonganok, and Cheongsaok were similar to P3394, but Kwanganok, Suwon19, Jangdaok and Suwon159 were lower than P3394. Acid detergent fiber(ADF), Suwon19 was lowest among all hybrids, and all hybrids except Suwon19 had values ranging from 44.7 to 49.0%, similarly with P3394. Neutral detergent fiber (NDF) values of the hybrids were similar to that of P3394, and ranged from 68.1 to 72.8%, except for Duruok which was lowest. Relative feed values (RFV) of Duruok, Kwangpyeongok, Cheonganok, Jangdaok, and Suwon159 had values ranging from 71.0 to 75.7 and were not significantly different from P3394. ADF was significantly negatively correlated with number of days to silking, number of days to maturity, and fresh matter yield, but was significantly positively correlated with resistance to corn borer. RFV showed a significantly positive correlations with no. of days to maturity and fresh matter yield, but significantly negative correlation with resistance to European corn borer. Therefore, indices for evaluation of feed value as well as production were important to select corn hybrids for silage. It is concluded that domestic hybrids tested in this study have high feed value as well as high production similar to those of imported corn hybrid.

• Journal of Animal Science and Technology
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• v.57 no.7
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• pp.26.1-26.5
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• 2015

Background: Rice bran is a by-product of the rice-milling process, which remains largely underutilized; however, efficient processing treatments may improve its feeding value for chickens. This is of great economic and environmental importance, as this can lower the production costs, and offer an opportunity for valorization of a low-quality agricultural by-product, to a high-value feed source. Methods: This experiment was conducted to study the effect of extruded rice bran on performance and phosphorous (P) bioavailability in broiler chickens. In a completely randomized design, 200 seven-day-old broilers (Cobb 500) were allotted to five treatments with five replicates per treatment and 8 chicks per replicate, and fed with their respective diet during the starter (8 to 21 days) and grower (22 to 42 days) periods. Diets were a basal corn-soybean based diet (T1), or diets containing 20 % rice bran (T2), 30 % rice bran (T3), 20 % extruded rice bran (T4), or 30 % extruded rice bran (T5). Results: Birds feeding on T4 and T5 diets had a higher body weight gain and lower feed-to-gain ratio compared to those feeding on T2 and T3 diets (p < 0.05). Birds receiving diets containing extruded rice bran had higher total P availability and tibia ash content, as compared with those receiving diets containing un-extruded rice bran (p < 0.05). Relative weight of the pancreas was higher in birds receiving T2 and T3 diets. Conclusions: The results confirmed the beneficial effect of extrusion treatment of rice bran on performance and P availability in broilers. Up to 30 % extruded rice bran may be included in the broiler diet without apparent adverse effects on the performance.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1098-1113
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• 2021

Maturation process of alfalfa (Medicago sativa L.) could be prevented by the reduction of lignin content in terms of conventional breeding or transgenic technology. Alfalfa could exhibit higher leaf/stem ratio, with a concern of yield loss. The objective of this study was to compare forage yield and nutritive value of low lignin alfalfa and two reference varieties subjecting to two harvest intervals and three seeding rates. The experimental design was a randomized complete block in a split-split plot arrangement with four replicates, where harvest intervals (28-day and 35-day) were assigned to whole plots, seeding rates were subplots, and varieties were sub-subplots. The weighted mean nutritive value was applied to two production years of 2016 and 2017. Hi-Gest 360 (low lignin alfalfa) provided similar yield potential and increased nutritive value compared to two reference varieties. Over a two-year production period, alfalfa harvested at every 28-day interval provided more economic returns than those at 35-day interval. For the seeding year and first production year, five cuts made by the 28-day interval produced more yield than four cuts by the 35-day interval. Due to limited rainfall in May 2017, a sharp drop of the first cutting overturned the advantage of the five-cut system. Shorter intervals between harvests generally increased crude protein (CP) concentrations. The differences of relative feed value (RFV) between two harvest intervals tended to be great during the first and second cuttings. Overall, harvest interval had a large effect on nutritive value and a more significant effect on alfalfa dry matter yield than variety selection. Seeding rate did not affect alfalfa yield and nutritive value.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.934-938
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• 2000

Built-up edge affects the surface integrity of the machined surface and tool wear. Tool geometry and cutting conditions are very important factors to remove BUE. In this paper, we optimized the geometry of the metal slitting saw .1nd cutting conditions to remove BUE by the experiment. In general, the metal slitting saw is plain milling cutter with thickness less of a 3/16 inch. This is used for cutting workpiece where high dimensional accuracy and surface finish are necessary. The experiment was planned with Taguchi method that is based on the orthogonal array of design factors(coating, rake angle, number of tooth, cutting speed, feed rate). Response table was made by the value of the surface roughness, the optimized tool geometry and cutting conditions through response table could be determined. In addition. the relative effect of factors were identified by the variance analysis. filially. coating and cutting speed turned out important factors.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.1-8
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• 2022

In order to manufacture feed suitable for consumer use and provide feed value information, we analyzed the feed components of the four main forage rice varieties by plant parts harvested 30 days after heading. The contents of the six feed ingredients were significantly different (p<0.05) among harvested parts. In the panicle, the crude protein (CP) (6.97%) and lignin (3.11%) were the highest, while the crude ash (CA) and neutral detergent fiber (NDF) contents were significantly lower, resulting in a total digestible nutrient (TDN) content of 77.29%, which is higher than that of the stem (64.82%) and leaf blade and sheath (LBS) (63.57%) (p<0.05). In contrast, the content of crude fat (CF) did not differ significantly among parts (p<0.05). In panicles from 'Jonong', 'Nokyang' and 'Yeongwoo', the TDN content of each cultivar was 78.48-79.07%, with no significant difference among the varieties. In 'Mogwoo' (Mw), the CP content was 8.70%, which was much higher than that of other varieties (p<0.05). In particular, the Mw TDN content was slightly lower in the panicle (72.95%) but higher in the stem (75.37%) and LBS (66.49%) than in the other varieties. The CA, NDF, acid detergent fiber (ADF), and lignin contents were also very low compared to other varieties; therefore, the feed value of the stem and LBS was excellent. In addition, the total dry matter weight (DMW) was 123 g per hill, which was much higher than 82-105 g per hill for other varieties. The distribution of DMW by part was LBS (56.9 g), stem (36.8 g), and panicle (29.3 g), and because the parts, except the panicles, were much higher than the 43-57% of other varieties (grain straw ratio: 76%), rice straw is advantageous in terms of quantity and feed value when used as forage on farms. The relative feed value (RFV) of the four cultivars ranged from 86.79-403.74 across all parts, and hay of grade 3 or higher with an RFV of 100 or more increased with delayed heading in both stems and LBS. This is due to the accumulation of starch into grains during ripening, which supports the observation that the RFV of the early flowering 'Jonong' and 'Nokyang' panicles increased.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.694-699
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• 2009

The present study was conducted to evaluate the effect of chilled drinking water on the productivity of laying hens under constant high ambient temperature. A total of seventy-two, 123-day-old Hy-line brown layers was divided into two equal groups. The first group (UDWG) was given unchilled water ($23.0{\pm}2.5^{\circ}C$) as a control, and the second group (CDWG) was given chilled water ($16.0{\pm}0.5^{\circ}C$). The laying hens were kept at $30^{\circ}C$ constant temperature with 50% relative humidity and were exposed to 17 h of light per day. Feed intake, egg production, egg quality (egg weight, shell weight, shell thickness, egg color, yolk color, and Haugh unit), and blood samples were collected and analyzed. The results showed that the feed intake of CDWG laying hens was significantly higher (11.64%) than the UDWG counterparts (p<0.01). Egg production of CDWG was also significantly higher (11.27%) than the UDWG counterparts (p<0.001). Furthermore, we observed that the CDWG laying hens had significantly higher (11.72%) levels (p<0.10) of blood calcium, with a corresponding value of 21.92 mg/dl compared to the UDWG hens (19.62 mg/dl). The higher calcium concentration in the CDWG animals may contribute to increased egg production. The CDWG laying hens also contained higher (12.53%) phosphorus concentrations in blood compared to the UDWG (4.22 mg/dl vs. 3.75 mg/dl), although not statistically different (p>0.10). Egg weight and egg quality were not affected by chilled drinking water. In conclusion, providing chilled drinking for laying hens under high ambient temperature improved feed intake and egg production.

• Membrane Journal
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• v.8 no.2
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• pp.94-101
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• 1998

The oil separation is effectively performed from the oil containing alkaline cleaner solution by using a backflushed ultrafiltration system, where hollow fibers commercially made by polyacrylonitrile copolymer are bundled. Backflushing to reduce membrane fouling during crossflow ultrafiltration is investigated. Experimental observations allow us to understand the behavior of permeate flux according to the relative operating conditions, and determine the optimum condition of normal operation and backflushing. The maximum improvement of net permeate flux owing to backflushing was found to be about 23 % with the condition of 10 min/40 sec for the cycle of normal/backflushing operations. Note that, however, the maintenance of stable permeate flux is lost as the duration of normal operation is increased. The permeate flux depends on both the backflushing pressure and the feed flow rate. It is obvious that there is a critical velocity of feed flow, in which permeate flux is practically independent of backflushing pressure. Above this critical value, the permeate flux is proportional to an appropriate power of the backflushing pressure, $\Delta P_{back}^n$, where exponent n is enhanced with increasing feed velocity.

• Animal Bioscience
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• v.35 no.8
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• pp.1205-1214
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• 2022

Objective: Spent ginger is a byproduct of juice extraction from the rhizome of ginger (Zingiber officinale). Despite its nutritional value, it is difficult to preserve or further process and thus is often wasted. This study uses spent ginger as a substrate for fermentation and cultivates spent ginger yeast cultures (SGYCs) that are then added to the feed of laying hens. The effects of SGYCs on production performance, egg quality, serum composition, and intestinal microbiota of laying hens were investigated. Methods: Eighty 60-week-old Hy-Line Brown hens were separated into 5 experimental groups with 4 replicates per group (4 hens per cage, 4 cages per replicate). The control group was fed a basal diet while experimental groups were also given SGYCs at the levels of 5, 10, 20, and 40 g/kg for 6 weeks. Results: The addition of SGYCs significantly increased the laying rate and nutrient digestibility, decreased feed conversion ratio, and enhanced the color of egg yolks (p<0.05). No changes were observed in activity levels of alanine aminotransferase and aspartate aminotransferase in the serum (p>0.05), but the activities of superoxide dismutase, glutathione peroxidase, and peroxidase all significantly increased, and contents of malondialdehyde were significantly reduced (p<0.05). In addition, changes in the relative abundance of Firmicutes and Bacteroidetes might be the main factor contributing to the significant increase in the apparent digestibility of crude protein and crude fat in laying hens (p<0.05). Conclusion: The current evidence shows that dietary supplementation of SGYCs to the feed of laying hens can improve laying rates, enhance antioxidative defenses, and influence dominant intestinal bacteria.