• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.237-244
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• 2015

Four ruminally cannulated Holstein steers (BW $401.0{\pm}2.22kg$) fed TMR containing low protein (CP 9.63 %) as a basal diet were used to investigate the effects of cornell net carbohydrates and protein system (CNCPS) fraction enriched protein feeds on rumen fermentation and blood metabolites. The steers used in a $4{\times}4$ Latin square design consumed TMR only (control), TMR with rapeseed meal (AB1), TMR with soybean meal (B2) and TMR with perilla meal (B3C), respectively. The protein feeds were substituted for 30 % crude protein of TMR intake. For measuring ruminal pH, ammonia-N and volatile fatty acids (VFA), ruminal digesta was sampled through ruminal cannula at 1 h-interval after the afternoon feeding. Blood was sampled via the jugular vein after the ruminal digesta sampling. Different CNCPS fraction-enriched proteins did not affect (p>0.05) ruminal pH except B3C being numerically low compared with the other groups. Ammonia-N and VFA were not significantly different among the experimental groups. Numerically low ammonia-N appeared in the steers fed rapeseed meal even though it contained high soluble N composition (A and B1 fractions). The discrepancy is unclear; however this may be related to low protein level in the diet and/or low DM intake. Blood metabolites were not significantly affected by the protein substitution except for blood urea nitrogen that was significantly (p<0.05) increased.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.1
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• pp.58-68
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• 2015

Requirements to control the large decrease in serum calcium (Ca) due to parturition and to increase the feed intake soon after parturition have been well accepted in dairy cows. This study was aimed to investigate the feed intake affected by serum Ca concentration with difructose anhydride (DFA) III supplement in dairy cows soon after parturition. Fourteen transition Holstein cows were divided into DFA and control (CONT) groups within 1 to 5 parity variations in each group. Measurement schedule for an individual cow was from 14 d before parturition to 7 d following parturition. The cows in DFA group were supplied 0.2 kg/head/d of DFA III feed containing 40 g of pure DFA III while the cows in CONT group received no DFA III. Other feeding procedures were the same for all cows in both groups. At parturition (d 0), serum Ca concentration sharply declined in both groups (p<0.05). Time interval for recovery from decreased serum Ca to its normal range (>9.0 mg/dL) tended to be faster in DFA group (12 h) than in the CONT group (48 h), but the differences were not significant. Active ruminal contraction was observed in DFA group at following parturition of d 1 (p<0.05), d 3 (p<0.05), and d 5 (p<0.01). Dry matter (DM) intake did not differ between the groups. However, positive correlations were observed between serum Ca concentration and ruminal contraction (p<0.001), and between ruminal contraction and DM intake (p<0.001) during following parturition. According to multiple regression analysis ($R^2$ = 0.824, p<0.001), the DM intake was positively affected by serum Ca concentration and ruminal contraction. These results suggest that feed intake soon after parturition in dairy cows can be increased by improvement of serum Ca concentration and active ruminal contraction, but DFA III supplementation in this study did not improve the lower serum Ca concentration due to parturition.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.523-528
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• 2013

This study investigates the effects of three branched-chain amino acids (BCAA; valine, leucine, and isoleucine) on the in vitro ruminal fermentation of wheat straw using batch cultures of mixed ruminal microorganisms. BCAA were added to the buffered ruminal fluid at a concentration of 0, 2, 4, 7, or 10 mmol/L. After 72 h of anaerobic incubation, pH, volatile fatty acids (VFA), and ammonia nitrogen ($NH_3$-N) in the ruminal fluid were determined. Dry matter (DM) and neutral detergent fiber (NDF) degradability were calculated after determining the DM and NDF in the original material and in the residue after incubation. The addition of valine, leucine, or isoleucine increased the total VFA yields ($p{\leq}0.001$). However, the total VFA yields did not increase with the increase of BCAA supplement level. Total branched-chain VFA yields linearly increased as the supplemental amount of BCAA increased (p<0.001). The molar proportions of acetate and propionate decreased, whereas that of butyrate increased with the addition of valine and isoleucine (p<0.05). Moreover, the proportions of propionate and butyrate decreased (p<0.01) with the addition of leucine. Meanwhile, the molar proportions of isobutyrate were increased and linearly decreased (p<0.001) by valine and leucine, respectively. The addition of leucine or isoleucine resulted in a linear (p<0.001) increase in the molar proportions of isovalerate. The degradability of NDF achieved the maximum when valine or isoleucine was added at 2 mmol/L. The results suggest that low concentrations of BCAA (2 mmol/L) allow more efficient regulation of ruminal fermentation in vitro, as indicated by higher VFA yield and NDF degradability. Therefore, the optimum initial dose of BCAA for in vitro ruminal fermentation is 2 mmol/L.

• Korean Journal of Agricultural Science
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• v.26 no.2
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• pp.25-32
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• 1999

An in vitro study was conducted to examine the effects of the addition of activated charcoal (AC) on the ruminal fermentation characteristics, nutrient disappearance, and ruminal gas production. AC was added at the levels of 0.00, 0.25, and 0.50 % to each of the four types of diets (roughage/concentrate ratio : 8/2, 6/4, 4/6 and 2/8), respectively. Although not significant, ruminal pH tended to increase by adding AC, and as the concentrate level increased, ruminal pH decreased (P<0.05). Acetate concentration and acetate/propionate molar ratio tended to decrease in AC diets. but molar % of propionate tended to increase by the addition of AC. Ruminal degradation of dry matter, crude protein, NDF, ADF, and hemicellulose in AC diets tended to increase than in non-AC diet, however, no tendency in ruminal degradation of crude fat was observed. As the concentrate level increased, rumunal degradation of dry matter and nutrients in AC diets increased significantly(P<0.05). Ruminal gas production tended to decrease in the 0.50 % AC diets, however, it tended to increase in high roughage diets. Although there appeared some beneficial effects in adding AC to ruminant diets in this study, more works should be done with AC before we can make clear conclusion on the use of AC in the ruminant diets.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.200-207
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• 2007

In vitro rumen incubation studies were conducted to determine effects of initial pH on bacterial attachment and fiber digestion. Ruminal fluid pH was adjusted to 5.7, 6.2 and 6.7, and three major fibrolytic bacteria attached to rice straw in the mixed culture were quantified with real-time PCR. The numbers of attached and unattached Fibrobacter succinogenes, Ruminococcus flavefaciens and Ruminocococcus albus were lower (p<0.05) at initial pH of 5.7 without significant difference between those at higher initial pH. Lowering incubation media pH to 5.7 also increased bacterial numbers detached from substrate regardless of bacterial species. Dry matter digestibility, gas accumulation and total VFA production were pH-dependent. Unlike bacterial attachment, maintaining an initial pH of 6.7 increased digestion over initial pH of 6.2. After 48 h in vitro rumen fermentation, average increases in DM digestion, gas accumulation, and total VFA production at initial pH of 6.2 and 6.7 were 2.8 and 4.4, 2.0 and 3.0, and 1.2 and 1.6 times those at initial pH of 5.7, respectively. The lag time to reach above 2% DM digestibility at low initial pH was taken more times (8 h) than at high and middle initial pH (4 h). Current data clearly indicate that ruminal pH is one of the important determinants of fiber digestion, which is modulated via the effect on bacterial attachment to fiber substrates.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.9
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• pp.1288-1295
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• 2015

In experiment 1, eighty crossbred steers ($239{\pm}15kg$) were used in a 229-d experiment to evaluate the effects of increasing levels of enzymatically hydrolyzed yeast (EHY) cell wall in diets on growth performance feedlot cattle during periods of elevated ambient temperature. Treatments consisted of steam-flaked corn-based diets supplemented to provide 0, 1, 2, or 3 g EHY/hd/d. There were no effects on growth performance during the initial 139-d period. However, from d 139 to harvest, when 24-h temperature humidity index averaged 80, EHY increased dry matter intake (DMI) (linear effect, p<0.01) and average daily gain (ADG) (linear effect, p = 0.01). There were no treatment effects (p>0.10) on carcass characteristics. In experiment 2, four Holstein steers ($292{\pm}5kg$) with cannulas in the rumen and proximal duodenum were used in a $4{\times}4$ Latin Square design experiment to evaluate treatments effects on characteristics of ruminal and total tract digestion in steers. There were no treatment effects (p>0.10) on ruminal pH, total volatile fatty acid, molar proportions of acetate, butyrate, or estimated methane production. Supplemental EHY decreased ruminal molar proportion of acetate (p = 0.08), increased molar proportion of propionate (p = 0.09), and decreased acetate:propionate molar ratio (p = 0.07) and estimated ruminal methane production (p = 0.09). It is concluded that supplemental EHY may enhance DMI and ADG of feedlot steers during periods of high ambient temperature. Supplemental EHY may also enhance ruminal fiber digestion and decrease ruminal acetate:propionate molar ratios in feedlot steers fed steam-flaked corn-based finishing diets.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1399-1406
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• 2000

A continuous culture study was conducted to determine the impact of ruminal degradable soy protein (S-RDP) level and dilution rate (D) on growth of ruminal non-structural carbohydrate-fermenting microbes. Corn starch, urea and isolated soy protein (ISP) were used to formulate three diets with S-RDP levels of 0, 35 and 70% of total dietary CP. Two Ds were 0.03 and $0.06h^{-1}$ of the fermenter volume in a single-effluent continuous culture system. As S-RDP levels increased, digestibilities of dietary dry matter (DM), organic matter (OM) and crude protein (CP) linearly (p=0.001) decreased, whereas digestion of dietary starch linearly (p=0.001) increased. Increasing D from 0.03 to $0.06h^{-1}$ resulted in decreased digestibilities of dietary DM and OM, but had no effect on digestibilities of dietary starch (p=0.77) and CP (p=0.103). Fermenter pH, the concentration of volatile fatty acids (VFA) and daily VFA production were unaffected (p=0.159-0.517) by S-RDP levels. Molar percentages of acetate, propionate and butyrate were greatly affected by S-RDP levels (p=0.016-0.091), but unaffected by D (p=0.331-0.442). With increasing S-RDP levels and D, daily bacterial counts, daily microbial N production (DMNP) and microbial efficiency (MOEFF; grams of microbial N produced per kilogram of OM truly digested) were enhanced (p=0.001). The increased microbial efficiency with increasing S-RDP levels is probably the result of peptides or amino acids that served as a stimulus for optimal protein synthesis. The quantity of ruminal degradable protein from soy proteins required for optimum protein synthesis of non-structural carbohydrate-fermenting microbes appears to be equivalent to 9.5% of dietary fermented OM.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.816-824
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• 2005

The effects of the nonionic surfactant Tween 80 and a mixture of fibrolytic enzymes on total tract digestion, in situ disappearance (ISD) and ruminal fermentation characteristics of orchardgrass hay and barley grain were investigated in a 4${\times}$4 Latin square experiment with 4 non-lactating Holstein cows and 4 diets in 4 periods. Cows were offered a total mixed ration of 50% rolled barley grain and 50% orchardgrass hay treated with either 1) water (control), 2) 0.2% (vol/wt) Tween 80, 3) 0.2% (vol/wt) hydrolytic enzyme, or 4) 0.2% hydrolytic enzyme plus 0.2% Tween 80. Total tract digestibility coefficients of DM, nitrogen, NDF and ADF were not affected (p>0.05) by dietary treatment. Compared to the control, the rate of ISD of DM from orchardgrass hay was faster (p<0.05) in cows receiving diets treated with the enzyme alone or with enzyme plus Tween 80 (0.06/h vs. 0.076 and 0.069/h). The rate of digestion was lower (p<0.05) as compared to control when barley grain was treated with these additives. Ruminal fluid pH and concentrations of total VFA, acetate, isobutyrate and butyrate were not affected (p>0.05) by treatments. Cows that consumed diets treated with enzyme plus Tween 80 had higher (p<0.05) ruminal concentrations of propionate and isovalerate, and lower (p<0.05) acetate:propionate ratios. Compared to the control, microbial protein synthesis tended (p = 0.13) to increase with the addition of enzyme to the diet while nonammonia nitrogen flow to the duodenum increased (p<0.05) with both enzyme and Tween 80 treatments. The study indicated that fibrolytic enzymes alone or in combination with Tween 80 could enhance ISD of orchardgrass hay and ruminal concentrations of propionate, valerate and iso-valerate, but do not affect total tract digestibility.

• Animal Bioscience
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• v.35 no.2
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• pp.184-195
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• 2022

Objective: In this study we aimed to evaluate the effect of dietary live yeast supplementation on ruminal pH pattern, fermentation characteristics and associated bacteria in beef cattle. Methods: This work comprised of in vitro and in vivo experiments. In vitro fermentation was conducted by incubating 0%, 0.05%, 0.075%, 0.1%, 0.125%, and 0.15% active dried yeast (Saccharomyces cerevisiae, ADY) with total mixed ration substrate to determine its dose effect. According to in vitro results, 0.1% ADY inclusion level was assigned in in vivo study for continuously monitoring ruminal fermentation characteristics and microbes. Six ruminally cannulated steers were randomly assigned to 2 treatments (Control and ADY supplementation) as two-period crossover design (30-day). Blood samples were harvested before-feeding and rumen fluid was sampled at 0, 3, 6, 9, and 12 h post-feeding on 30 d. Results: After 24 h in vitro fermentation, pH and gas production were increased at 0.1% ADY where ammonia nitrogen and microbial crude protein also displayed lowest and peak values, respectively. Acetate, butyrate and total volatile fatty acids concentrations heightened with increasing ADY doses and plateaued at high levels, while acetate to propionate ratio was decreased accordingly. In in vivo study, ruminal pH was increased with ADY supplementation that also elevated acetate and propionate. Conversely, ADY reduced lactate level by dampening Streptococcus bovis and inducing greater Selenomonas ruminantium and Megasphaera elsdenii populations involved in lactate utilization. The serum urea nitrogen decreased, whereas glucose, albumin and total protein concentrations were increased with ADY supplementation. Conclusion: The results demonstrated dietary ADY improved ruminal fermentation dose-dependently. The ruminal lactate reduction through modification of lactate metabolic bacteria could be an important reason for rumen pH stabilization induced by ADY. ADY supplementation offered a complementary probiotics strategy in improving gluconeogenesis and nitrogen metabolism of beef cattle, potentially resulted from optimized rumen pH and fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1743-1748
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• 2003

The effect of pH on the fermentation characteristics and the formation of cis-9, trans-11 conjugated linoleic acid (CLA) and trans-11 octadecenoic acid by mixed ruminal bacteria was examined in vitro when incubated with linseed or rapeseed. Concentrate (1%, w/v) with ground linseed (0.6%, w/v) or rapeseed (0.5%, w/v) was added to 600 ml mixed solution of strained rumen fluid with artificial saliva (1:1, v/v), and was incubated anaerobically for 12 h at $39^{\circ}C$. The pH of culture solution was maintained at level close to 4.5, 5.3, 6.1 and 6.9 with 30% $H_2SO_4$ or 30% NaOH solution. pH increment resulted in increases of ammonia and total volatile fatty acid (VFA) concentration in culture solutions containing both oilseeds. Fermentation did not proceeded at pH 4.5. Molar proportion of acetate decreased but that of propionate increased as pH increased when incubated with oilseeds. While the hydrogenating process was very slow at the pH range of 4.5 to 5.3, rapid hydrogenation was found from the culture solutions of pH 6.1 and 6.9 when incubated with linseed or rapeseed. As pH in culture solution of linseed or rapeseed increases proportions of oleic acid (cis-9 $C_{18:1}$) and trans-11 octadecenoic acid increased but those of linoleic acid and linolenic acid decreased. The CLA proportion increased with pH in culture solution containing rapeseed but CLA was mostly not detected from the incubation of linseed.