• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.8
• /
• pp.1205-1212
• /
• 2018

Objective: The aim of this experiment was to evaluate the effects of different dietary ratio of metabolizable glucose (MG) to metabolizable protein (MP) on growth performance, blood metabolites, rumen fermentation parameters and the ruminal microbial community of 8 to 10-month-old heifers. Methods: A total of 24 Holstein heifers weighing an average of 282.90 kg (8 month of age) were randomly assigned to four groups of six. The heifers were fed one of four diets of different dietary MG/MP (0.97, 1.07, 1.13, and 1.26). Results: The results showed that the ratio of MG/MP affected the growth performance, blood metabolites, rumen fermentation parameters and the ruminal microbial community of heifers. The average daily gain of heifers was enhanced by increasing the ratio of MG/MP (p<0.05). The concentration of blood urea nitrogen, cholesterol, and low density lipoprotein cholesterol as well as the concentration of total volatile fatty acid in the rumen fluid of heifers decreased with the improvement in the ratio of dietary MG/MP (p<0.05). However, the relative amount of Ruminococcus albus and Butyrivibrio fibrisolvens in the rumen of heifers was increased significantly (p<0.05) when the dietary MG/MP increased. At the same time, with the improvement in dietary MG/MP, the amount of Fibrobacter succinogenes increased (p = 0.08). Conclusion: A diet with an optimal ratio (1.13) of MG/MP was beneficial for the improvement of growth, rumen fermentation, dietary protein and energy utilization of 8 to 10-month-old dairy heifers in this experiment.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.11
• /
• pp.1557-1562
• /
• 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
• /
• v.14 no.6
• /
• pp.885-893
• /
• 2001

This review summarizes some recent research into ways of improving the productivity of ruminal fermentation by increasing protein flow from the rumen and decreasing the breakdown of protein that results from the action of ruminal microorganisms. Proteinases derived from the plant seem to be of importance to the overall process of proteolysis in grazing animals. Thus, altering the expression of proteinases in grasses may be a way of improving their nutritive value for ruminants. Inhibiting rumen microbial activity in ammonia formation remains an important objective: new ways of inhibiting peptide and amino acid breakdown are described. Rumen protozoa cause much of the bacterial protein turnover which occurs in the rumen. The major impact of defaunation on N recycling in the sheep rumen is described. Alternatively, if the efficiency of microbial protein synthesis can be increased by judicious addition of certain individual amino acids, protein flow from ruminal fermentation may be increased. Proline may be a key amino acid for non-cellulolytic bacteria, while phenylalanine is important for cellulolytic species. Inhibiting rumen wall tissue breakdown appears to be an important mechanism by which the antibiotic, flavomycin, improves N retention in ruminants. A role for Fusobacterium necrophorum seems likely, and alternative methods for its regulation are required, since growth-promoting antibiotics will soon be banned in many countries.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.1
• /
• pp.129-138
• /
• 1999

If rumen bacteria can be manipulated to utilize nutrients (i.e., ammonia and plant cell wall carbohydrates) more completely and efficiently, the need for protein supplementation can be reduced or eliminated and the digestion of fiber in forage or agricultural residue-based diets could be enhanced. However, these approaches require a complete and accurate description of the rumen community, as well as methods for the rapid and accurate detection of microbial density, diversity, phylogeny, and gene expression. Molecular ecology techniques based on small subunit (SSU) rRNA sequences, nucleic acid probes and the polymerase chain reaction (PCR) can potentially provide a complete description of the microbial ecology of the rumen of ruminant animals. The development of these molecular tools will result in greater insights into community structure and activity of gut microbial ecosystems in relation to functional interactions between different bacteria, spatial and temporal relationships between different microorganisms and between microorganisms and reed panicles. Molecular approaches based on SSU rRNA serve to evaluate the presence of specific sequences in the community and provide a link between knowledge obtained from pure cultures and the microbial populations they represent in the rumen. The successful development and application of these methods promises to provide opportunities to link distribution and identity of gastrointestinal microbes in their natural environment with their genetic potential and in situ activities. The use of approaches for assessing pupulation dynamics as well as for assessing community functionality will result in an increased understanding and a complete description of the gastrointestinal communities of production animals fed under different dietary regimes, and lead to new strategies for improving animal growth.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.5
• /
• pp.672-676
• /
• 2003

Effect of a surfactant Tween 80 on the bacterial growth in the rumen was examined on the in vitro pure cultures of Streptococcus bovis, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Prevotella ruminicola, Megasphaera elsidenni, Fibrobacta succinogenes, Ruminanococcus albus and Ruminococcus flavefaciens. Dry matter degradability (DMD), concentrations and compositions of volatile fatty acids (VFA), and the most probable number (MPN) of cellulolytic bacteria and total number of bacteria in the presence of Tween 80 were also examined on the in vitro rumen mixed culture either with barley grain or orchardgrass hay. The growth of S. bovis, S. ruminantium, B. fibrisolvens, P. ruminicola, M. elsidenni and F. succinogenes were significantly higher (p<0.05) at over 0.05% concentrations of Tween 80 than those of the control cultures, while was not changed with R. albus and R. flavefaciens. With rumen mixed culture the DMD of barley grain and orchardgrass hay was significantly higher (p<0.05) at a 0.2% concentration of Tween 80 than the control, being reflected in the significantly higher (p<0.05) VFA production (mmol $g^{-1}$DDM) with orchardgrass hay. The higher (p<0.05) ratio of propionate to acetate at a 0.2% concentration of Tween 80 was also observed with orchardgrass hay, showing a similar trend with barley grain. No changes in the total bacterial number and MPN of cellulolytic bacteria were observed.

• Journal of Life Science
• /
• v.17 no.11
• /
• pp.1555-1561
• /
• 2007

In order to know the effects of scoria, germanium, charcoal, ginger, stevia, and CLA(Conjugated Linoleic Acid) as biologically active materials on pathogenic microbes and rumen anaerobic microbes, the growth rate of pathogens (including Escherichia coli O157, Salmonella paratyphi, Listeria monocytogenes and Staphylococcus aureus) and in vitro lumen microbial growth, gas production, ammonia concentration, carboxymethyl-cellulase (CMCase) activity, and microbial populations were investigated. The growth of pathogenic microbes was inhibited by the supplement of 0.10% ginger. Ginger had powerful antimicrobial properties on all the pathogens used in this experiments. Additionally in the antibacterial assay by paper disc method, we could observe the clear zone of similar area with the positive control(antibiotics) for E. coli as applied with the 10% stevia or the 10% CLA only. The supplements of ginger, stevia and CLA in vitro rumen fermentation inhibited populations of rumen bacteria and protozoa. Particularly supplement of ginger resulted in remarkable reduction of the protozoa population, which means it might serve as a source inhibiting material of methane creation in the rumen.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.10
• /
• pp.1435-1439
• /
• 2005

Bacterio-mineral water (BMW) produced from manure has been known to exert a number of positive effects on animal production and odor control. An experiment was conducted to examine the effects of BMW produced from bio-reacted swine manure on in vitro gas production, cellulose degradation, microbial growth and fibrolytic enzyme activities of mixed rumen microorganisms. The five levels of 0, 0.001, 0.005, 0.01 and 1.0% BMW were supplemented into serum vials containing mixed rumen microorganisms. Incubations were carried out anaerobically at $39^{\circ}C$ without shaking for 0, 12, 24, 48, 72 and 96 h. There were no significant (p>0.05) differences among the treatments for the initial rate of gas production. At 72 h incubation, the gas production tended (p<0.1) to be increased by the 0.01 and 1.0% BMW treatments compared with control and the 0.001% BMW treatment. At the end of incubation (96 h), the sample supplemented with 0.01% BMW was higher (p<0.05) than control (0% BMW) in the gas production. The microbial growth rate was increased by all the BMW treatments, while 0.01% BMW was most effective in stimulating the growth rate. Although the addition of BMW on the filter paper DM degradation was not significantly influenced throughout the incubation period except the 48 h incubation, DM degradation tended to be increased by all BMW treatments compared with control. The addition of both 0.005 and 0.01% BMW highly increased (p<0.05) CMCase activity compared with control after 24 h and 48 h incubation, while at the 72 h incubation the 0.01% BMW addition only significantly increased (p<0.05). After 72 h incubation, the xylanase activity was significantly (p<0.05) increased with the addition of 1.0% BMW compared with the addition of 0.001 and 0.005% BMW, while at the other incubation times, the xylanase activity was not different among the treatments. In conclusion, the 0.01% BMW of supplementation level would be the suitable addition level to stimulate rumen fermentation increasing microbial growth and cellulose degradation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.1
• /
• pp.113-128
• /
• 1999

Protozoa can represent as half of the total rumen microbial biomass. Around 10 genera are generally present on the same time in the rumen. Based on nutritional aspects they can be divided in large entodiniomorphs, small entodiniomorphs and isotrichs. Their feeding behaviour and their enzymatic activities differ considerably. Many comparisons between defaunated and refaunated animals were carried out during the last two decades to explain the global role of protozoa at the ruminal or animal levels. It is now generally considered that a presence of an abundant protozoal population in the rumen has a negative effect on the amino acid (AA) supply to ruminants and contribute to generate more methane but, nevertheless, protozoa must not be considered as parasites. They are useful for numerous reasons. They stabilise rumen pH when animal are fed diets rich in available starch and decrease the redox potential of rumen digesta. Because cellulolytic bacteria are very sensitive to these two parameters, protozoa indirectly stimulate the bacterial cellulolytic activity and supply their own activity to the rumen microbial ecosystem. They could also supply some peptides in the rumen medium which can stimulate the growth of the rumen microbiota, but this aspect has never been considered in the past. Their high contribution to ammonia production has bad consequences on the urinary nitrogen excretion but means also that less dietary soluble nitrogen is necessary when protozoa are present. Changes in the molar percentages of VFA and gases from rumen fermentations are not so large that they could alter significantly the use of energy by animals. The answer of animals to elimination of protozoa (defaunation) depends on the balance between energy and protein needs of animals and the supply of nutrients supplied through the diet. Defaunation is useful in case of diets short in protein nitrogen but not limited in energy supply for animals having high needs of proteins.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.11
• /
• pp.1617-1622
• /
• 2006

Long-term storage of feeds or feedstuffs in high temperature and humid conditions can be difficult because of microbial contamination. Essential oil isolated from industrial waste citrus peel could be used as a preservative because it is likely to have anti-bacterial and anti-fungal activity. Our objective was to determine whether different levels (0.028, 0.056 and 0.112 g/kg) of citrus essential oil (CEO) would provide anti-microbial activity and enhance preservation of animal feed without influencing rumen fermentation. At 0.112 g/kg, CEO inhibited growth of Escherichia coli (ATCC 25922) and Salmonela enteritidis (IFO 3313). Growth of E. coli recovered after 24 h of incubation, but S. enteritidis continued to be inhibited for 72 h. Preservation of antibiotic-free diets for swine was assessed by observing anti-aflatoxin activity. Aflatoxin was detected in control feed samples on days 16 (8 ppb) and 21 (8 ppb) and in anti-fungal agent (AA) treated samples on days 16 (2 ppb) and 21 (4 ppb). However, aflatoxin was not detected in feed samples treated with CEO. Treatment with CEO and AA did not influence ruminal pH, dry matter digestibility (DMD) or organic matter digestibility (OMD) over 48 h of incubation in rumen fluid. Acetate and propionate were slightly higher with CEO treatment (p<0.05), but total concentration of volatile fatty acid (VFA) was not significantly affected by treatment. Ammonia-N concentration was slightly higher for the control treatment (p<0.05). This study showed that treating feed with CEO enhances preservation of animal feed without influencing in vitro rumen fermentation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.4
• /
• pp.530-537
• /
• 2015

The objective of this study was to evaluate the in vitro effects of flavonoid-rich plant extracts (PE) on ruminal fermentation characteristics and methane emission by studying their effectiveness for methanogenesis in the rumen. A fistulated Holstein cow was used as a donor of rumen fluid. The PE (Punica granatum, Betula schmidtii, Ginkgo biloba, Camellia japonica, and Cudrania tricuspidata) known to have high concentrations of flavonoid were added to an in vitro fermentation incubated with rumen fluid. Total gas production and microbial growth with all PE was higher than that of the control at 24 h incubation, while the methane emission was significantly lower (p<0.05) than that of the control. The decrease in methane accumulation relative to the control was 47.6%, 39.6%, 46.7%, 47.9%, and 48.8% for Punica, Betula, Ginkgo, Camellia, and Cudrania treatments, respectively. Ciliate populations were reduced by more than 60% in flavonoid-rich PE treatments. The Fibrobacter succinogenes diversity in all added flavonoid-rich PE was shown to increase, while the Ruminoccocus albus and R. flavefaciens populations in all PE decreased as compared with the control. In particular, the F. succinogenes community with the addition of Birch extract increased to a greater extent than that of others. In conclusion, the results of this study showed that flavonoid-rich PE decreased ruminal methane emission without adversely affecting ruminal fermentation characteristics in vitro in 24 h incubation time, suggesting that the flavonoid-rich PE have potential possibility as bio-active regulator for ruminants.