• Asian-Australasian Journal of Animal Sciences
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• v.29 no.8
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• pp.1111-1119
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• 2016

Mao seed is a by-product of the wine and juice industry, which could be used in animal nutrition. The current study was designed to determine the effect of supplementation of mao (Antidesma thwaitesianum Muell. Arg.) seed meal (MOSM) containing condensed tannins (CT) on rumen fermentation, nitrogen (N) utilization and microbial protein synthesis in goats. Four crossbred (Thai Native${\times}$Anglo Nubian) goats with initial body weight (BW) $20{\pm}2kg$ were randomly assigned to a $4{\times}4$ Latin square design. The four dietary treatments were MOSM supplementation at 0%, 0.8%, 1.6%, and 2.4% of total dry matter (DM) intake, respectively. During the experimental periods, all goats were fed a diet containing roughage to concentrate ratio of 60:40 at 3.0% BW/d and pangola grass hay was used as a roughage source. Results showed that supplementation with MOSM did not affect feed intake, nutrient intakes and apparent nutrient digestibility (p>0.05). In addition, ruminal pH and ammonia nitrogen ($NH_3$-N) were not influenced by MOSM supplementation, whilst blood urea nitrogen was decreased quadraticly (p<0.05) in goats supplemented with MOSM at 2.4% of total DM intake. Propionate was increased linearly with MOSM supplementation, whereas acetate and butyrate were remained the same. Moreover, estimated ruminal methane ($CH_4$) was decreased linearly (p<0.05) when goats were fed with MOSM at 1.6% and 2.4% of total DM intake. Numbers of bacteria and protozoa were similar among treatments (p>0.05). There were linear decreases in urinary N (p<0.01) and total N excretion (p<0.01) by MOSM supplementation. Furthermore, N retention was increased linearly (p<0.05) when goats were fed with MOSM supplementation at 1.6% and 2.4% of total DM intake. Microbial protein synthesis were not significantly different among treatments (p>0.05). From the current study, it can be concluded that supplementation of MOSM at 1.6% to 2.4% of total DM intake can be used to modify ruminal fermentation, especially propionate and N utilization in goats, without affecting the nutrient digestibility, microbial populations and microbial protein synthesis.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.397-403
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• 2008

Nikkomycins are a group of peptidyl nucleoside antibiotics with potent fungicidal, insecticidal, and acaricidal activities. sanN was cloned from the partial genomic library of Streptomyces ansochromogenes 7100. Gene disruption and complementation analysis demonstrated that sanN is essential for nikkomycin biosynthesis in S. ansochromogenes. Primer extension assay indicated that sanN is transcribed from two promoters (sanN-P1 and sanN-P2), and sanN-P2 plays a more important role in nikkomycin biosynthesis. Purified recombinant SanN acts as a dehydrogenase to convert benzoate-CoA to benzaldehyde in a random-order mechanism in vitro, with respective $K_{cat}/K_m$$ values of $3.8mM^{-1}s^{-1}\;and\;12.0mM^{-1}s^{-1}$ toward benzoate-CoA and NADH, suggesting that SanN catalyzes the formation of picolinaldehyde during biosynthesis of nikkomycin X and Z components in the wild-type stain. These data would facilitate us to understand the biosynthetic pathway of nikkomycins and to consider the combinatorial synthesis of novel antibiotic derivatives.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1455-1461
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• 2010

Three rumen-cannulated Holstein steers were fed three diets, each with a different synchrony index (SI) (LS: 0.77, MS: 0.81, and HS: 0.83), in order to examine the effect of diet on rumen fermentation, nitrogen balance, and microbial protein synthesis. Synchrony index was calculated based on the carbohydrate and crude protein fractions of each ingredient and their degradation rates. Feeding the steers diets with different SIs did not influence dry matter, crude protein, NDF, or ADF digestibility. The concentrations of total and individual VFA in the rumens of steers that were fed the two higher-SI diets were higher than in those fed the low-SI diet (p<0.05), but there was no significant difference between the two higher-SI diets. One hour after feeding, steers on the LS diet had lower ruminal pHs than did those fed the MS or HS diets (p<0.05), and animals on the LS diet generally showed higher ruminal $NH_3$-N levels than did animals on the other diets, with the 4-h post-feeding difference being significant (p<0.05). Steers receiving the LS diet excreted more nitrogen (N) in their urine than did those on the two higher-SI diets (p<0.05), and the total N excretion of those on the LS diet was also higher (p<0.05). Microbial N levels calculated from the concentration of urinary purine derivatives were generally higher when the SI was higher, with the highest microbial protein synthesis being produced by steers on the HS diet (p<0.05). In conclusion, in the current study, ingestion of a synchronous diet by Holstein steers improved microbial protein synthesis and VFA production and decreased total N output.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.6
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• pp.661-672
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• 1998

Two experiments were conducted to examine the effects of a range of concentrations of ruminal fluid ammonia ($NH_3$-N) on forage digestibility, microbial growth efficiency and the mix of microbial species. Urea was either continuously infused directly into the rumen of sheep fed 33.3 glh of oaten chaff (Exp. I) or sprayed onto the oaten chaff (750 g/d) given once daily (Exp. 2). Concentrations of $NH_3$-N increased with incremental addition of urea (p < 0.01). Volatile fatty acids (VFA) concentrations and 24 h in sacco organic matter digestibility in the rumen were higher when supplemental urea was given (p < 0.01). The (C2 + C4) : C3 VFA ratio was lower (p < 0.05) when $NH_3$-N was above 200 mgN/I. The fungal sporangia appearing on oat leaf blades were significantly higher when urea was supplemented, indicating that $NH_3$-N was a growthlimiting nutrient for fungi at levels of $NH_3$-N below 30 mgN/l. The density of protozoa was highest when $NH_3$-N concentrations were adjusted to 30 mgN/I for continuously fed ($4.4{\times}10^5/ml$) and to 168 mgN/1 for once daily feeding ($2.9{\times}10^5/ml$). Thereafter increasing concentrations of $NH_3$-N, were associated with a concomitant decline in protozoal densities. At the concentration of $NH_3$-N above 200 mgN/l, the density of protozoa was similar to the density of protozoa in ruminal fluid of the control sheep ($1.8{\times}10^5/ml$). The efficiency of net microbial protein synthesis in the rumen calculated from purine excretion was 17-47% higher when the level of $NH_3$-N was above 200 mgN/1. The possibilities are that 1) there is less bacterial cell lysis in the rumen because of the concomitant decrease in the protozoal pool and/or 2) microbial growth per se in the rumen is more efficient with increasing $NH_3$-N concentrations.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.8
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• pp.1084-1093
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• 2000

An in vitro gas production system was used to investigate the influence of various substrate mixtures on a natural mix of rumen microbes by measurement of fermentation end-products. The treatments were combinations of cassava (15.0, 30.0 and 45.0%) with different roughage sources (ruzi grass, rice straw or urea treated rice straw). Microbial biomass, net $^{15}N$ incorporation into cells, volatile fatty acid production, gas volume and rate of gas production increased linearly with increasing levels of cassava inclusion. There was also an effect of roughage source, with rice straw being associated with the lowest values for most parameters whilst similar values were obtained for ruzi grass and urea treated rice straw. The results suggest that microbial growth and fermentation rate increase as a function of readily available carbohydrate in the substrate mixture. A strong linear relationship between $^{15}N$ enrichment, total volatile fatty acid production and gas production kinetics support the suggestion of the use of the in vitro gas production system as a tool for screening feedstuffs as an initial stage of feed evaluation.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.3
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• pp.209-216
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• 1998

The paper presented here is aimed at increasing knowledge on purine metabolism in ruminants and hence the quantification of microbial cells entering the small intestine from urinaη excretion of purine derivatives. Nucleic acid metabolisms of micro-organisms in the rumen, digestion and absorption of nucleic acids entering the intestines, metabolisms of absorbed and endogenous purines involving de novo synthesis of nucleic acids in the ruminants host, and the relationship between absorbed and excreted purines are reviewed. Principal concerns about an amount of purine derivatives excreted in urine in relation to a change in purine-N: total-N ratios in rumen microbes that leave the rumen are discussed. The use of urinary excretion of purine derivatives as an indicator of the amount of microbial biomass leaving the rumen has to be done with some caution since it may be impossible to get a representative sample of microbes entering the intestine and thus yield estimates are relative rather than absolute.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.6
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• pp.820-826
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• 2013

The objective of this study was to determine the effect of rain tree pod meal with palm oil supplementation on feed intake, digestibility, microbial protein synthesis and microbial populations in dairy cows. Four, multiparous early-lactation Holstein-Friesian crossbred (75%) lactating dairy cows with an initial body weight (BW) of $405{\pm}40$ kg and $36{\pm}8$ DIM were randomly assigned to receive dietary treatments according to a $4{\times}4$ Latin square design. The four dietary treatments were un-supplementation (control), supplementation with rain tree pod meal (RPM) at 60 g/kg, supplementation with palm oil (PO) at 20 g/kg, and supplementation with RPM at 60 g/kg and PO at 20 g/kg (RPO), of total dry matter intake. The cows were offered concentrates, at a ratio of concentrate to milk production of 1:2, and chopped 30 g/kg of urea treated rice straw was fed ad libitum. The RPM contained condensed tannins and crude saponins at 88 and 141 g/kg of DM, respectively. It was found that supplementation with RPM and/or PO to dairy cows diets did not show negative effects on feed intake and ruminal pH and BUN at any times of sampling (p>0.05). However, RPM supplementation resulted in lower crude protein digestibility, $NH_3$-N concentration and number of proteolytic bacteria. It resulted in greater allantoin absorption and microbial crude protein (p<0.05). In addition, dairy cows showed a higher efficiency of microbial N supply (EMNS) in both RPM and RPO treatments. Moreover, NDF digestibility and cellulolytic bacteria numbers were highest in RPO supplementation (p<0.05) while, supplementation with RPM and/or PO decreased the protozoa population in dairy cows. Based on this study, supplementation with RPM and/or PO in diets could improve fiber digestibility, microbial protein synthesis in terms of quantity and efficiency and microbial populations in dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.75-81
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• 2007

The object of this study was to determine the influence of supplementation of concentrate containing high levels of cassava chip on rumen ecology, microbial protein and digestibility of nutrients. Four, rumen fistulated crossbred beef steers with initial body weight of 400${\pm}$10 kg were randomly assigned according to a 4${\times}$4 Latin square design. The dietary treatments were concentrate cassava chip based offering at 0, 1, 2 and 3% BW with urea-treated rice straw fed ad libitum. It was found that ruminal pH was significantly decreased with increase of concentrate. Volatile fatty acids (VFA) concentration in the rumen was significantly different among treatments. In addition, a molar proportion of propionate was higher in supplemented groups at 2 and 3% BW (p<0.05), leading to significantly decreased acetate:propionate ratio. Furthermore, microbial N supply was significantly improved and was highest at 2% BW supplementation. The efficiency of rumen microbial-N synthesis based on organic matter (OM) truly digested in the rumen was highest in level of concentrate supplementation at 2% BW (80% of cassava chip in diets). Moreover, bacterial populations such as amylolytic bacteria was linearly increased, while cellulolytic bacteria was linearly decreased (p<0.01) when cattle received concentrate supplementation in all levels. The total protozoal counts were significantly increased, while fungal zoospores were dramatically decreased in cattle receiving increased levels of concentrate. In conclusion, cassava chip can be use as energy source at 80% in concentrate and supplementation of concentrate at 2% BW with urea-treated rice straw as roughage could improve rumen fermentation efficiency in beef cattle.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.686-696
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• 2003

Ethyl (coumarin-4-oxy)acetate 1 was prepared through the reaction of 4-hydroxycoumarin with ethyl bromoacetate. Compound 1 was allowed to react with hydrazine hydrate to produce coumarin-4-oxyacetic hydrazide 2. The synthesis of N-(arylidene and alkylidene)-coumarin-4-oxyacetic hydrazones 3-20 was performed. The preparation of 2-substituted-3-[(coumarin-4-oxy) acetamido]thiazolidinones 21-26 and 2-[(coumarin-4-oxy )methyl]-4-acetyl-5-substituted-$\Delta^2$-1,3,4-oxadiazolines 27-33 was performed by the reaction of the hydrazones 3, 4, 7, 9, 12, 14 with mercaptoacetic acid and the hydrazones 3, 4, 5, 7, 12, 15, 16 with acetic anhydride, respectively. The antiviral activities, cytotoxicities and structure-activity relationship (SAR) towards different microorganisms of the prepared compounds were studied.

• 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.