• Asian-Australasian Journal of Animal Sciences
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• v.30 no.11
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• pp.1557-1562
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• 2017

Objective: This study was conducted to investigate the effects of weaning times on the growth performance, rumen fermentation and microbial communities of yellow cattle calves. Methods: Eighteen calves were assigned to a conventional management group that was normally weaned (NW, n = 3) or to early weaned (EW) group where calves were weaned when the feed intake of solid feed (starter) reached 500 g ($EW_{500}$, n = 5), 750 g ($EW_{750}$, n = 5), or 1,000 g ($EW_{1,000}$, n = 5). Results: Compared with NW, the EW treatments increased average daily gain (p<0.05). The calves in $EW_{750}$ had a higher (p<0.05) starter intake than those in $EW_{1,000}$ from wk 9 to the end of the trial. The concentrations of total volatile fatty acids in $EW_{750}$ were greater than in NW and $EW_{1,000}$ (p<0.05). The EW treatments decreased the percentage of acetate (p<0.05). The endogenous enzyme activities of the rumen were increased by EW (p<0.05). EW had no effect on the number of total bacteria (p>0.05), but changes in bacterial composition were found. Conclusion: From the present study, it is inferred that EW is beneficial for rumen fermentation, and weaning when the feed intake of the starter reached 750 g showed much better results.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.1
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• pp.54-62
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• 2018

Objective: Due to the threat of global warming, the livestock industry is increasingly interested in exploring how feed additives may reduce anthropogenic greenhouse gas emissions, especially from ruminants. This study investigated the effect of Rhodophyta supplemented bovine diets on in vitro rumen fermentation and rumen microbial diversity. Methods: Cannulated Holstein cows were used as rumen fluid donors. Rumen fluid:buffer (1:2; 15 mL) solution was incubated for up to 72 h in six treatments: a control (timothy hay only), along with substrates containing 5% extracts from five Rhodophyta species (Grateloupia lanceolata [Okamura] Kawaguchi, Hypnea japonica Tanaka, Pterocladia capillacea [Gmelin] Bornet, Chondria crassicaulis Harvey, or Gelidium amansii [Lam.] Lamouroux). Results: Compared with control, Rhodophyta extracts increased cumulative gas production after 24 and 72 h (p = 0.0297 and p = 0.0047). The extracts reduced methane emission at 12 and 24 h (p<0.05). In particular, real-time polymerase chain reaction analysis indicated that at 24 h, ciliate-associated methanogens, Ruminococcus albus and Ruminococcus flavefaciens decreased at 24 h (p = 0.0002, p<0.0001, and p<0.0001), while Fibrobacter succinogenes (F. succinogenes) increased (p = 0.0004). Additionally, Rhodophyta extracts improved acetate concentration at 12 and 24 h (p = 0.0766 and p = 0.0132), as well as acetate/propionate (A/P) ratio at 6 and 12 h (p = 0.0106 and p = 0.0278). Conclusion: Rhodophyta extracts are a viable additive that can improve ruminant growth performance (higher total gas production, lower A/P ratio) and methane abatement (less ciliateassociated methanogens, Ruminococcus albus and Ruminococcus flavefaciens and more F. succinogenes.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.461-473
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• 2017

Total mixed ration (TMR) including concentrate diet and roughage together have been used for the ruminant animal. Relatively high concentrations of moisture and water soluble carbohydrate are representative feature of TMR. Those moisture and water can also provide a niche for bacterial growth. Therefore, a possible fermentation of TMR induced by micro-organism is generally accepted. The present study hypothesized that different lactic acid bacteria could alter fermentation of TMR and subsequently rumen fermentation. Three lactic acid bacteria, Lactobacillus paracasei (A), L. plantarum (B) and L. parabuchneri (C), were employed and 7 treatments under full factorial design were compared with control without inoculation. TMR for dairy cow was used. Significant alterations by treatments were detected at lactic acid and butyric acid contents in TMR (p<0.05). Treatment AC (mixture of A and C) and BC (mixture of B and C) showed great lactate production. Great butyrate production was found at treatment C. At in vitro rumen fermentation, treatments B, C and AB (mixture of A and B) showed significantly great total gas production (p<0.05). All treatments except treatments B and AB, showed less dry matter digestibility, significantly (p<0.05). Total volatile fatty acid production at treatment AC was significantly greater than others (p<0.05). In individual volatile fatty acid production, treatment AB and AC showed great acetate and propionate productions, significantly (p<0.05). This study investigated correlation between organic acid production in TMR and rumen volatile fatty acid production. And it was found that butyric acid in TMR had significant negative correlation with acetate, propionate, total volatile fatty acid, AP ratio and dry matter digestibility.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1230-1237
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• 2018

Objective: The present study was undertaken to determine an optimal balance between the amount of physically effective neutral detergent fiber (peNDF) to metabolizable glucose (MG) on rumen fermentation, blood metabolites and growth performance of 8 to 10-month-old heifers. Methods: A total of 15 healthy Holstein heifers weighing an average of 256 kg (8 month of age) were randomly assigned to three groups of five. Treatment diets consisted of the following three $peNDF_{8.0}/MG$ levels: 1.46 (Treatment A), 1.74 (Treatment B), and 2.08 (Treatment C). Results: The results showed that the ratio of $peNDF_{8.0}/MG$ affected rumen fermentation, blood metabolites and growth performance of heifers. The average daily gain of heifers tended to decrease as the ratio of $peNDF_{8.0}/MG$ increased (p = 0.07). The concentrations of blood urea nitrogen, triglyceride, and cholesterol increased significantly (p<0.05), while the high-density lipoprotein concentration decreased (p<0.05). After feeding 2 h and 4 h, insulin concentration in Treatment A was greater than Treatment C (p<0.05). Propionate concentration had decreasing trend (p = 0.07); acetate to propionate ratio and non-glucogenic to glucogenic volatile fatty acid (NGR) increased significantly (p<0.05). In addition, the digestibility of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber decreased significantly (p<0.05). Conclusion: The present investigation indicated that dietary $peNDF_{8.0}/MG$ ratio can affect the growth and development, blood metabolites, rumen fermentation and apparent digestibility of heifers, and the optimal dietary $peNDF_{8.0}/MG$ ratio for 8 to 10-month-old heifers in the present study was 1.46.

• Food Science of Animal Resources
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• v.24 no.3
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• pp.303-309
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• 2004

Conjugated linoleic acid (CLA) is currently under intensive investigation due to its health benefits. A great deal of interest has been paid to the possible health-promoting roles of CLA, but there are not many studies available on the mechanism of CLA production by ruminal microorganisms. CLA is produced as an intermediate of the characteristic biohydrogenation process of linoleic acid(LA) in the rumen and its production has direct relationship to numerous environmental factors including particle association, substrate concentration, forage-to-grain ratio, pH, ionopore, bacterial cell density, etc. Some of these factors were known to affect hydrogenating activities of Butyrivibrio fibrisolvens A38 which is an active rumen bacterium in CLA production. Dairy cow is a main source of CLA, and its level could be increased by dietary manipulation changing the physiological environment of rumen bacteria such as B. fibrisolvens A38. Therefore, the effects of various factors on. ruminal biohydrogenation should be carefully considered to optimize not only CLA production, but also other fatty acid metabolism, both of which are directly affecting nutritional quality and functionality of dairy products. In this review, the relationship between various environmental factors and ruminal CLA production is discussed focusing on the CLA production of B. fibrisolvens A38.

• Korean Journal of Veterinary Research
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• v.19 no.2
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• pp.143-147
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• 1979

Eight Holstein cows weighing 419-673kg with 2 to 10 years of age were allocated into two groups, four animals each, to study the effect of feeding urea and urea plus Zeolite on rumen pH and the population of rumen ciliates. Rumen fluid samples were taken after morning feed for 7 times at one hour intervals. Experimental results obtained were as follows; 1. Rumen pH was gradually dropped from 7.272 to 7.163 by 3.01 hour and from 7.18 to 7.07 by 2.87 hour and reached 7.352 and 7.29 at 7 hour after feeding, respectively on urea and urea plus Zeolite feeding group. 2. Total ciliate numbers decreased from 209,540 to 113,755 by 4.311 hour and from 381,430 to 203.125 by 4.406 hour and gradually increased to 151,030 and 265,230 by 7 hour after feeding, respectively on urea and urea plus Zeolite feeding group. 3. Population of ruminal ciliates was not changed and Entodinium simplex was the major ciliate population for both treatments. It was from 81.21 to 89.12% on urea feeding group and from 84.6 to 88.3% of total number of ciliates on urea plus Zeolite feeding group.

• Journal of Animal Science and Technology
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• v.61 no.2
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• pp.98-108
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• 2019

Four Korean native steers ($511{\pm}17.2kg$; $2{\times}2$ replicated crossover design) fitted with duodenal cannulas were used to investigate the influence of oral administration of soluble whey protein (WP; 82.29% crude protein) on ruminal fermentation, gastrointestinal (GI) hormone secretion in the blood, pancreatic ${\alpha}$-amylase activity in the duodenum, and disappearance rate in each segment of the GI tract. Steers were orally fed the basal diet (control; TMR [total mixed ration] 9 kg/d) or the basal diet with enriched WP (400 g/d) for 14 days. The apparent crude protein disappearance rate in the rumen of the WP was higher than in control (p < 0.05). However, no difference between groups was observed in the apparent crude protein disappearance rate in the intestine and the apparent starch disappearance rates in the rumen, GI tract. The level of cholecystokinin, secretin, and ghrelin in serum and pancreatic ${\alpha}$-amylase activity in the duodenum of the WP also did not change. The changes in the level of blood urea nitrogen related to protein metabolism were higher in the WP than in the control (p < 0.05). However, the levels of total protein, lipid, carbohydrate and mineral metabolites did not change. Consequently, we suggest that the oral administration of WP in steers assisted in ruminal fermentation due to the population increase of microbes in the rumen but did not improve the starch digestion rate in the small intestine because GI hormone secretion in the blood and pancreatic ${\alpha}$-amylase activity did not change.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.741-748
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• 2018

This study was conducted to evaluate the nutritional value of total mixed rations (TMR) containing rice grain in an in vitro rumen fermentation system. Three types of grains (corn, wheat, and rice), timothy, and soybean meal (SBM) were used to prepare the experimental TMR: Corn TMR, Wheat TMR, and Rice TMR. The rumen fermentation characteristics of all the experimental TMRs were evaluated by an in vitro anaerobic system using rumen fluid for 24 and 48 h. The digestibility of the nutrients (dry matter [DM], crude protein [CP], and neutral detergent fiber [NDF]), pH, ammonia ($NH_3-N$), and volatile fatty acids (VFA) were determined. Rice TMR showed a higher DM digestibility than that of the Corn TMR at 48 h (p < 0.05). In all treatments, the CP digestibility was more than 80% at 48 h, but no significant differences were observed among the treatments. The NDF digestibility tended to be the lowest in the Wheat TMR (p = 0.06), and the pH tended to be the lowest in the Rice TMR (p = 0.09) among the treatments for the 48 h incubation. The Wheat TMR had the highest $NH_3-N$ concentration among the treatments (p < 0.01). Rice TMR had a lowest total VFA concentration among the treatments (p = 0.05) at 24 h, but no significant differences were observed at 48 h. Based on this in vitro result, it was considered that a rice grain has the potential to replace conventional grain ingredients when the TMR was formulated.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.1
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• pp.72-81
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• 2019

Objective: To determine the effect of gut pH and rumen microbial fermentation on glycerol encapsulated in alginate and alginate-chitosan polymers. Methods: Glycerol was encapsulated at 2.5%, 5%, 7.5%, or 10% (w/w) with sodium alginate (A) and alginate-chitosan (AC) polymers. Surface morphology and chemical modifications of the beads were evaluated using scanning electron microscopy and Fourier transform infrared (FTIR) spectra. Encapsulation efficiency was determined at the 5% glycerol inclusion level in two experiments. In experiment 1, 0.5 g of alginate-glycerol (AG) and alginate-chitosan glycerol (ACG) beads were incubated for 2 h at $39^{\circ}C$ in pH 2 buffer followed by 24 h in pH 8 buffer to simulate gastric and intestinal conditions, respectively. In experiment 2, 0.5 g of AG and ACG beads were incubated in pH 6 buffer at $39^{\circ}C$ for 8 h to simulate rumen conditions. All incubations were replicated four times. Free glycerol content was determined using a spectrophotometer and used to assess loading capacity and encapsulation efficiency. An in vitro experiment with mixed cultures of rumen microbes was conducted to determine effect of encapsulation on microbial fermentation. Data were analyzed according to a complete block design using the MIXED procedure of SAS (SAS Institute, Cary, NC, USA). Results: For AG and ACG, loading capacity and efficiency were 64.7%, 74.7%, 70.3%, and 78.1%, respectively. Based on the FTIR spectra and scanning electron microscopy, ACG treatment demonstrated more intense and stronger ionic bonds. At pH 6, 36.1% and 29.7% of glycerol was released from AG and ACG, respectively. At pH 2 minimal glycerol was released but pH 8 resulted in 95.7% and 93.9% of glycerol released from AG and ACG, respectively. In vitro microbial data show reduced (p<0.05) fermentation of encapsulated glycerol after 24 h of incubation. Conclusion: The AC polymer provided greater protection in acidic pH with a gradual release of intact glycerol when exposed to an alkaline pH.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8
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• pp.1153-1160
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• 2019

Objective: The objective of this study was to investigate the effect of bamboo grass (Tiliacora triandra, Diels) pellet (Bamboo-Cass) supplementation on feed intake, nutrient digestibility, rumen microbial population and methane production in Thai native beef cattle. Methods: Four Thai native beef cattle bulls ($190{\pm}2kg$) were randomly allotted to four respective dietary treatments in a $4{\times}4$ Latin square design. Treatments were the varying levels of Bamboo-Cass supplementation at 0, 50, 100, and 150 g/head/d, respectively. Rice straw was fed ad libitum and the concentrate offered at 0.5% of body weight. Results: Under this experiment, the findings revealed that acetate and butyrate production were decreased (p<0.05), propionate increased (p<0.05), whilst ruminal $NH_3-N$ concentration was decreased (p<0.05) by supplementation of Bamboo-Cass at 150 g/head/d. Moreover, rice straw intake, and microbial population were linearly increased (p<0.05), while methane production was decreased (p<0.05). Conclusion: The results from the present study indicate that supplementation of Bamboo-Cass at 150 g/head/d significantly enhanced feed intake, decreased protozoa and increased bacterial population, rumen fermentation efficiency while decreased methane production. Therefore, Bamboo-Cass as a supplement is promising as a rumen enhancer in beef cattle fed on rice straw.