• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.3
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• pp.206-212
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• 2013

This study was conducted to investigate the effect of biological membrane transfer modifier, lysophospholipd (LPLs) on the parameters from in vitro rumen simulated fermentation. Commercially available LPLs product (Lipidol$^{TM}$) was supplemented into experimental diets which consisted of orchard grass and concentrate diet (60:40) in different levels (0.1%, 0.3% and 0.5%). Then in vitro rumen simulated fermentation was performed. Although, a declining trend of pH was found in treatments, all pH values were detected in a range relevant to normal rumen fermentation. Gas production, ammonia nitrogen and total VFA production were greatly influenced by the supplementation of LPLs. All parameters were increased along with increased levels of LPLs in diet. As a result, 0.1% of Lipidol$^{TM}$ is recommended based on the determined in vitro rumen fermentative parameters in this study.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.6
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• pp.800-809
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• 2011

The objective of this study was to investigate the effects of different ratios of corn silage (CS): alfalfa hay (AH), and extruded soybeans (ESB) on milk yield, milk composition, blood metabolites, and fatty acids in milk fat and plasma. Ninety multiparous Holstein cows were arranged in a randomized block design experiment which lasted 14 weeks. Treatments were arranged as a $3{\times}3$ factorial with 0%, 5% or 10% ESB (dry matter basis) and three forage treatments: I) 30% CS, 10% AH and 10% Leymus chinense hay (LC); ii) 20% corn silage, 20% alfalfa hay and 10% LC; iii) 10% CS, 30% AH and 10% LC. Cows were allowed to consume a total mixed ration ad libitum. There was no change of dry matter intake when cows were fed the experimental diets. As more AH was added to the diets, milk yield, milk protein content and yield, and trans9, cis11-conjugated linoleic acids (CLA) concentrations in milk fat and plasma increased. When ESB were supplemented to the diets, milk yield, and trans9, cis11-CLA concentration in milk fat and plasma increased. When 10% ESB was added to the diet containing 30% AH the trans9, cis11-CLA content (1.46 g/100 g of total fatty acids) in milk was the highest among all treatments. These results suggests that AH could replace part of a CS diet and be a good forage source of diet for dairy cows to improve milk yield and milk composition. Meanwhile, ESB could be included in the diet with high AH to improve production performance of dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1755-1762
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• 2003

Two experiments were conducted to determine effects of particle size in total mixed ration (TMR) on performance of lactating cows. Three rumen cannulated Holstein cows were used in a $3{\times}3$ Latin square design for the metabolic experiment. The particle size of the diets was determined using the Penn State Particle Size Separator (PSPSS) and weighing the proportion of sample remaining on the top screen (19 mm diameter). The 3 treatments were short, medium or long diets (4.9, 24.2 and 27.8% of sample remaining on the top screen of the PSPSS, respectively). Nine farms in the Edmonton area were surveyed and the farms were placed into groups based on the particle size of the ration fed. The groups were short ${\leq}6%$, medium 7-12% and long ${\geq}13%$ of sample weight remaining on the top screen of the PSPSS. Dry matter intake was greater (p=0.07) for the medium diet than the long diet in the metabolic study and resulted in a higher (p=0.07) efficiency of milk production. On the commercial farms, a significantly (p=0.002) lower milk fat percentage was observed for the long diet compared to the short diet. The results of these studies confirm that forage particle size influences milk composition and milk fat was negatively correlated to TMR particle size.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.1
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• pp.45-51
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• 2013

This study was performed on two groups (10 cows) for primiparous Holstein lactating cows (av. 98 days in milk : DIM) which were divided into low forage diet (LF) and high forage diet (HF) groups based on forage : concentrate ratio (F : C ratio). The F : C ratios of LF and HF groups were 37:63 and 62:38, respectively. Concentrate intake was significantly higher in the LF group than the HF group whereas the HF group showed higher forage intake (12.9 kg) compared to the LF group (7.4 kg) (p<0.05). No significant difference was observed in total feed intake between the HF (20.9 kg) and LF (19.4 kg) group (p>0.05), but the HF group tended to be higher. CP, TDN and NEL intake showed no significant difference between the two groups (p>0.05). Though, there was no significant difference on actual milk between the two groups (26 vs. 23.9 kg/d, p>0.05), the LF group tended to be higher. 4% FCMs of LF and HF groups were 22.8 and 22.3 kg/d, respectively, and showed no significant difference (p>0.05). The HF group was higher in fat content and lower in MUN. C14:0, C16:0 and C16:1n7 of milk fatty acid were significantly higher in the HF group (p<0.05), but there were no differences in other milk fatty acids between the two groups. As a result, increasing high quality forage such as BIRG silage and hay in the diet will not only fulfill nutrient requirements but also reduce milk production.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.313-318
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• 2013

A study was conducted to determine if subacute ruminal acidosis (SARA) induced by feeding high level of non-structural carbohydrates results in increases in lipopolysaccharides (LPS) of peripheral blood in dairy cattle. In this experiment four Holstein steers, two of which having ruminal canulae with indwelling probes placed for measuring long term pH changes, were alloted into two dietary treatments in a cross-over design, where an acidogenic diet (AD) was formulated by including high amount of non-structural carbohydrates (NSC) based on corn silage and corn flake as TMR ingredients. Data for ruminal pH change and plasma LPS concentration were compared against normal diet (ND) which contained grass hay as forage and low NSC ingredients. Feeding AD for more than 14 days to animals brought about a pH change as low as less than 5.8 for more than 4 hours, which made good contrast to ND fed animals. Decreased ruminal pH also had an effect on LPS concentrations which showed significantly higher level for AD compared with ND. Therefore, plasma LPS concentration may be used as an effective indicator to verify acidosis whether it is acute or chronic. Na-bentonite and Propylene glycol, which are frequently included in dairy TMR as additives, helped decrease ruminal pH by buffering and then ultimately alleviates SARA. Therefore, it could also be helpful to lower the occurrence of laminitis which is often caused by increased blood endotoxin (LPS) concentration.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.57-71
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• 2009

Crop-livestock mixed farming systems depend on the efficiency with which nutrients are conserved and recycled. Home-grown forage is used as animal feed and animal excretions are applied to cultivated crop lands as manure. The objective of this study was to develop a mixed farming system model for dairy cattle in Japan. The model consisted of four sub-models: the nutrient requirement model, based on the Japanese Feeding Standards to determine requirements for energy, crude protein, dry matter intake, calcium, phosphorus and vitamin A; the optimum diet formulation model for determining the optimum diets that satisfy nutrient requirements at lowest cost, using linear programming; the herd dynamic model to calculate the numbers of cows in each reproductive cycle; and the whole farm optimization model to evaluate whole farm management from economic and environmental viewpoints and to optimize strategies for the target farm or system. To examine the model' validity, its predictions were compared against best practices for dairy farm management. Sensitivity analyses indicated that higher yielding cows lead to better economic results but higher emvironmental load in dairy cattle systems integrated with forage crop production.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.4
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• pp.379-386
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• 2012

In this study, the in vitro fermentation parameters of whole crop barley (WCBS-TMR) and Italian ryegrass (IRGS-TMR) silage total mixed rations were compared. A rice straw based diet (RSBD), which was a mixture of rice straw and concentrate (60:40), was used as the control. The feeds were incubated in buffered rumen fluid for 3, 6, 9, 12, 24, 48 and 72 hours at $39^{\circ}C$. At the end of each incubation period the following parameters were determined, total gas, pH, ammonia nitrogen ($NH_3$-N), volatile fatty acids (VFA) and then the acetate to propionate ratio (A/P) was calculated. The dietary treatments did not affect (p>0.05) the overall production of $NH_3$-N, gas, total VFA and all the individual VFA, with the exception of n-butyrate (p<0.001). The treatment diets significantly affected the A/P ratio (p<0.01). The control diet resulted in the lowest A/P ratios, followed by WCBS-TMR and lastly IRGS-TMR had the highest ratios. Gas production was not different between treatments, suggesting a probable similar level of digestibility when treatments are fed to animals. It can therefore be concluded from the present study that WCBS and IRGS are of almost an equivalent nutritional value when incubated in a TMR form. WCBS-TMR however resulted in lower A/P ratios than IRGS-TMR, which is indicative of a more energy efficient diet.

• Korean Journal of Agricultural Science
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• v.40 no.2
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• pp.123-129
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• 2013

An experiment was conducted to evaluate the effects of nitrogen supplementation through urea-molasses multinutrient block (UMMB) on the performance of dairy cows fed good quality forage based diets with rice straw as a night feeding. A total of 10 multiparous crossbred dairy cows in their early lactation were grouped into two categories based on their breed, parity, body weight, milk yield, milk fat and protein contents and daily fed a chopped CO-3 grass (Pennisetum purpureum ${\times}$ Pennisetum americanum; hybrid Napier) ad-libitum, 1 kg of dairy cow concentrate feed during the day time and 5 kg of rice straw (dry matter basis) at night as the basal diet (control) for 5 wk. In addition to the basal diet, the treatment group received 300 g of crushed UMMB daily throughout the experimental period. Cows were milked twice daily and the milk yields were recorded. Milk and feed samples were collected weekly for chemical analysis. Supplementation of UMMB had no significant effects (p>0.05) on straw intake, daily milk yield, contents and yields of milk constituents such as milk fat, protein, lactose and solids-non-fat. In addition, milk urea nitrogen content were not affected (p>0.05) by UMMB supplementation. However, numerical increments in all the parameters measured were observed during the study in cows fed diets supplemented with UMMB. It can be concluded that nitrogen supplied through UMMB had no effects on production performances of dairy cows in this study.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.812-818
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• 2009

This study evaluated the effects of live yeast and yeast cell-wall mannan-oligosaccharide supplementation onperformance and nutrient digestibility during early lactation in cows fed a diet based on a mixture of corn silage and alfalfa hay as forage sources. Eight multiparous Holstein dairy cows (average days in milk, 27${\pm}$6) were used in a replicated 4${\times}$4 Latin square design. Diets contained 45% forage and 55% concentrate on a dry matter (DM) basis and treatments were: i) basal diet without additive (Control), ii) basal diet with 32 g/d of mannan-oligosaccharides (MOS), iii) basal diet with $1.2{\times}10^{10}$ colony forming units per day (cfu/d) of live yeast (Saccharomyces cerevisiae CNCM 1-1077; SC), and iv) basal diet with a mixture of MOS (32 g/d) and SC ($1.2{\times}10^{10}$ cfu/d; MOS+SC). Treatments had no effect (p>0.05) on DM intake and yields of milk, 3.5% fat-(FCM) and energy-corrected milk (ECM), and on milk fat percentage, body condition score and blood metabolites. Compared with the Control, only supplementation of SC resulted in numerically higher yields of FCM (41.9 vs. 40.1 kg/d) and ECM (41.8 vs. 40.3 kg/d), and milk fat percentage (3.64 vs. 3.43%). While the MOS diet had no effects on performance compared to the Control, the combination treatment MOS+SC increased milk protein percentage (p<0.05). Also, the MOS supplementation, both alone or in combination with SC, numerically increased milk fat percentage. The SC supplementation increased apparent digestibility of DM and crude protein while the MOS supplementation did not affect digestibility. Concentrations of total volatile fatty acids (VFA) and ruminal pH were similar across treatments. Overall results indicated that supplementation of MOS produced variable and inconsistent effects on rumen metabolism and performance, whereas SC supplementation improved nutrient digestibility and numerically increased FCM and ECM yields, which could not be enhanced by the combined supplementation of MOS+SC. According to our experimental condition, there was no effect of MOS alone or in combination with SC on dairy cow performance.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.1
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• pp.43-48
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• 2010

This study was conducted to compare the chemical composition, dry matter digestibility (DMD), dry matter intake, and utilization of nitrogen and energy of dairy goats (Saanen), when fed on imported timothy hay (IT), mixture grass hay (MG) and native grass hay (NG), respectively. The experimental trials were conducted from April, 2008 to December, 2008 at the environmental controlled barn of Chungnam National University. Twelve dairy goats (Saanen) were selected which had nearly the same body weight (24.2kg, male). The content of crude protein (CP) of MG hay was higher than that of other diets (p<0.05), but the contents of NDF, ADF, cellulose and lignin of IT and NG diet were higher than those of MG diet (p<0.05). The voluntary DM intake of dairy goats fed with herbage from MG diet (30.7/$BW_{kg}$/day) was higher than that of other diets, but no significant difference was observed between that of IT diet and NG diet (p>0.05). The DMD of MG diet (69.8%) was higher than that of NG diet (62.2%) and IT diet (60.8%) (p<0.05), but no significant difference was observed between that of IT diet and NG diet (p>0.05). In nitrogen utilization, the apparently digested N %, retained % and biological value of dairy goats fed with herbage from MG diet were higher and TG diet was lower (p<0.05). In energy utilization, digestible energy and the energy of apparently digested minus urinary losses of MG diet were higher than those of IT diet and NG diet (p<0.05), but no significant difference was found between IT diet and NG diet (p>0.05). Based on the results, the dry matter intake, DMD and utilization of nitrogen and energy of dairy goats of MG were higher than those of IT diet and NG diet (p<0.05), the DMD and biological value (%) of NG diet was higher than that of IT diet (p<0.05).