• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1273-1273
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• 2001

The efficiency of the luminal fermentation process influences overall efficiency of luminal production, animal health and reproduction. Ruminant production systems have a significant impact on the global environment, as well. Animal wastes contribute to pollution of the environment as ammonia volatilized to the air and nitrate leached to ground water. Microbial protein synthesis in the rumen satisfies a large proportion of the protein requirements of animals. Quantifying the microbial synthesis is possible by using markers for lumen bacteria and protozoa such as nucleic acids, purine bases, some specific amino acids, or by isotopic $^{15}N,^{32}P,\;and\;^{35}S$ labelled feeds. All those methods require cannulated animals, they are time-consuming and some methods are very expensive as well. Many attempts have been made to find an alternative method for indirect measurement of microbial synthesis in intact animals. The present investigations aimed to assess possibilities of NIRS for prediction of purine nitrogen excretion and ruminal microbial nitrogen synthesis by NIR spectra of urine. Urine samples were collected from 12 growing sheep,6 of them male, and 6- female. The sheep were included in feeding experiment. The ration consisted of sorghum silage and protein supplements -70:30 on dry matter basis. The protein supplements were chosen to differ in protein degradability. The urine samples were collected daily in a vessel containing $60m{\ell}$ 10% sulphuric acid to reduce pH below 3 and diluted with tap water to 4 liters. Samples were stored in plastic bottles and frozen at $-20^{\circ}C$ until chemical and NIRS analysis. The urine samples were analyzed for purine derivates - allantoin, uric acid, xantine and hypoxantine content. Microbial nitrogen synthesis in the lumen was calculated according to Chen and Gomes, 1995. Transmittance urine spectra with sample thickness 1mm were obtained by NIR System 6500 spectrophotometer in the spectral range 1100-2500nm. The calibration was performed using ISI software and PLS regression, respectively. The following statistical results of NIRS calibration for prediction of purine derivatives and microbial protein synthesis were obtained.(Table Omitted). The result of estimation of purine nitrogen excretion and microbial protein synthesis by NIR spectra of urine showed accuracy, adequate for rapid evaluation of microbial protein synthesis for a large number of animals and different diets. The results indicate that the advantages of the NIRS technology can be extended into animal physiological studies. The fast and low cost NIRS analyses could be used with no significant loss of accuracy when microbial protein synthesis in the lumen and the microbial protein flow in the duodenum are to be assessed by NIRS.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.3
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• pp.326-331
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• 2005

A rumen simulated continuous culture (RSCC) system was used to study the influence of supplementation of the three different types of protein sources such as urea, casein and soy protein on rumen microbial synthesis in terms of rumen microbial synchronization. The urea treatment showed the highest pH value. Ammonia nitrogen concentration was rapidly increased after feeding and not significantly different in the urea treatment (13.53 mg/100 ml). Protozoa numbers were not significantly different for soy protein and casein treatment compared to urea treatments during incubation. The average concentration of total VFA (mMol) was not detected with significant difference among treatments, but iso-butyrate production showed the highest for soy protein treatment among treatments (p<0.001). The lowest concentration in total iso-acids (iso-butyrate and iso-valerate) production was observed in urea treatment. The soy protein treatment showed no significantly change in acetate/propionate. The amounts of dry matter (DM) out flow showed no significant difference among treatments. Organic matter (OM) flow was the highest for urea treatments and the lowest for casein treatment (p<0.03). The nitrogen flow for casein treatment was not significantly different from other treatments. The efficiency of microbial protein synthesis in terms of microbial nitrogen (MN) synthesis (g MN/kg ADOM) digested in the rumen was highest for casein treatment (58.53 g MN/kg ADOM) compared to soy protein and urea (p<0.05). This result suggests that rumen ammonia releasing rate may influence on microbial protein synthesis in the rumen.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.181-186
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• 2017

Objective: Leucaena leucocephala (Leucaena) is a perennial tropical legume that can be directly grazed or harvested and offered to ruminants as hay, silage, or fresh. However, Leucaena contain phenolic compounds, which are considered anti-nutritional factors as these may reduce intake, digestibility and thus animal performance. Therefore, the objective of this experiment was to determine effects of Leucaena silage (LS) feeding levels on rumen microbial populations, N-balance and microbial protein synthesis in dairy steers. Methods: Four, rumen fistulated dairy steers with initial weight of $167{\pm}12kg$ were randomly assigned to receive dietary treatments according to a $4{\times}4$ Latin square design. Treatments were as followings: T1 = untreated rice straw (RS; Control), T2 = 70% RS+30% LS, T3 = 40% RS+60% LS, and T4 = 100% LS. Dairy steers were fed rice straw and LS ad libitum and supplemented with concentrate at 0.2% of body weight/d. Results: Results revealed that the rumen microbial population, especially cellulolytic, proteolytic bacteria and fungal zoospores were enhanced in steers that received 60% of LS (p<0.05), whereas the amylolytic bacteria population was not affected by treatments (p>0.05). Protozoal population was linearly decreased with increasing level of LS (p<0.05). Moreover, N-balance and microbial protein synthesis were enhanced by LS feeding (p<0.05) and were the highest in 60% LS group. Conclusion: Based on this study, it could be concluded that replacement of RS with 60% LS significantly improved microbial population and microbial protein synthesis in diary steers.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1689-1697
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• 2013

This study was designed to determine the effect of physical form and urea treatment of rice straw on rumen fermentation, microbial protein synthesis and nutrient digestibility. Four rumen-fistulated dairy steers were randomly assigned according to a 2 (2 factorial arrangement in a 4 (4 Latin square design to receive four dietary treatments. Factor A was roughage source: untreated rice straw (RS) and urea-treated (3%) rice straw (UTRS), and factor B was type of physical form of rice straw: long form rice straw (LFR) and chopped (4 cm) rice straw (CHR). The steers were offered the concentrate at 0.5% body weight (BW) /d and rice straw was fed ad libitum. DM intake and nutrient digestibility were increased (p<0.05) by urea treatment. Ruminal pH were decreased (p<0.05) in UTRS fed group, while ruminal ammonia nitrogen ($NH_3$-N) and blood urea nitrogen (BUN) were increased (p<0.01) by urea treatment. Total volatile fatty acid (VFA) concentrations increased (p<0.01) when steers were fed UTRS. Furthermore, VFA concentrations were not altered by treatments (p>0.05), except propionic acid (C3) was increased (p<0.05) in UTRS fed group. Nitrogen (N) balance was affected by urea treatment (p<0.05). Microbial protein synthesis (MCP) synthesis were greater by UTRS and CHR group (p<0.05). The efficiency of microbial N synthesis was greater for UTRS than for RS (p<0.05). From these results, it can be concluded that using the long form combined with urea treatment of rice straw improved feed intake, digestibility, rumen fermentation and efficiency of microbial N synthesis in crossbred dairy steers.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.3
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• pp.350-353
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• 2005

Effects of sucrose supplement on the pattern of VFA production and microbial protein synthesis in the rumen were examined in sheep consuming basal diet of grass silage (2.5 kg fresh wt/d) that was provided in 24 equal meals each day by an automatic feeder. Four mature wethers were allocated to four experimental treatments in a 4${\times}$4 Latin square design with periods lasting 14 days. The treatments were (1) the basal diet, (2) supplemented with 150 g sucrose and 7.0 g urea, (3) 300 g sucrose and 13 g urea, and (4) 450 g sucrose and 20 g urea given as a continuous intraruminal infusion for 24 h. All infusions were given in 2 litres of aqueous solution per day using a peristaltic pump. The effect of sucrose level on rumen mean pH was significantly linear (p<0.01). There were not significant differences in the concentration of ammonia-N, total VFA and the molar proportions of acetate, propionate and butyrate with the level of sucrose infusion. The molar proportions of isobutyric acid (p<0.05) and isovaleric acid (p<0.001) were significantly reduced when the infused amount of sucrose was increased. The flow of microbial N was linearly (p<0.001) increased with sucrose and urea level. High levels of readily fermentable carbohydrate in a ration reduced the efficiency of microbial protein synthesis in the rumen. It was demonstrated that of the individual fatty acids, only the molar proportion of isovalerate showed a significant negative correlation (R2=$0.3501^{**}$) with the amount of microbial N produced and a significant positive correlation (R2=$0.2735^{**}$) with the efficiency of microbial growth.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.181-188
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• 2006

The objective of this research was to determine the effects of synchronizing the rate of dietary energy and nitrogen release on: ruminal fermentation, microbial protein synthesis, blood urea nitrogen, and nutrient digestibility in beef cattle. Four, two-and-a-half year old Brahman-Thai native crossbred steers were selected for the project. Each steer was fitted with a rumen cannula and proximal duodenal cannula. The steers were then randomly assigned in a $4{\times}4$ Latin square design to receive four dietary treatments. Prior to formulation of the dietary treatments, feed ingredients were analyzed for chemical composition and a nylon bag technique was used to analyze the treatments various ingredients for degradability. The treatments were organized in four levels of a synchrony index (0.39, 0.50, 0.62 and 0.74). The results showed that dry matter digestibility trend to be increased (p<0.06), organic matter and acid detergent fiber digestibility increased linearly (p<0.05), while crude protein and neutral detergent fiber digestibility were not significantly different (p>0.05). Higher concentration and fluctuation of ruminal ammonia and blood urea were observed in the animal that received the lower synchrony index diets. As the levels of the synchrony index increased, the concentrations of ruminal ammonia nitrogen and blood urea nitrogen, at the 4 h post feeding, decreased linearly (p<0.05). Total volatile fatty acid and bacteria populations at the 4 h post feeding increased linearly (p<0.05). Microbial protein synthesis trend to be increase (p<0.08). The results of this research indicate that synchronizing the rate of degradation of dietary energy and nitrogen release improves ruminal fermentation, microbial protein synthesis and feed utilization.

• Animal Bioscience
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• v.36 no.9
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• pp.1384-1392
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• 2023

Objective: Replacing soybean meal (SBM) with cricket (Gryllus bimaculatus) meal pellets (CMP) in concentrate diets was investigated for feed efficiency, ruminal fermentation and microbial protein synthesis in Thai native beef cattle. Methods: Four male beef cattle were randomly assigned to treatments using a 4×4 Latin square design with four levels of SBM replaced by CMP at 0%, 33%, 67%, and 100% in concentrate diets. Results: Results revealed that replacement of SBM with CMP did not affect dry matter (DM) consumption, while digestibilities of crude protein, acid detergent fiber and neutral detergent fiber were significantly enhanced (p<0.05) but did not alter digestibility of DM and organic matter. Increasing levels of CMP up to 100% in concentrate diets increased ruminal ammoniacal nitrogen (NH₃-N) concentrations, blood urea nitrogen, total volatile fatty acids and propionate concentration (p<0.05), whereas production of methane and protozoal populations decreased (p<0.05). Efficiency of microbial nitrogen protein synthesis increased when SBM was replaced with CMP. Conclusion: Substitution of SBM with CMP in the feed concentrate mixture at up to 100% resulted in enhanced nutrient digestibility and rumen fermentation efficiency, with increased volatile fatty acids production, especially propionate and microbial protein synthesis, while decreasing protozoal populations and mitigating rumen methane production in Thai native beef cattle fed a rice straw-based diet.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.398-399
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1439-1444
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• 2002

An objective of this study was to determine the effects of increasing contents of rumen undegradable protein (RUP) from formalin treated soy bean (FSBM) on rumen functions. Four rumen canulated non-lactating cows were randomly allocated to total mixed rations (TMR) containing different proportions of soy bean meal (SBM) and FSBM. Of rumen fermentation characteristics, concentrations of ruminal fluid ammonia and molar proportions of isoacids decreased with increasing contents of RUP in diets (p<0.01). The animals on TMR containing only SBM gained less weight and had smaller rumen volume than those on TMR containing RUP from FSBM (p<0.05). Organic matter and neutral detergent fiber digestibility in sacco were not different (p>0.05). The density of protozoa particularly small Entodinium sp. in ruminal fluid was higher in animal fed TMR containing SBM:FSBM (34:66) and FSBM than those fed TMR containing SBM:FSBM (66:34) and SBM (p<0.01). Total viable count, and net microbial protein synthesis as indicated by purine derivatives in urine increased with increasing contents of RUP from FSBM (p<0.01). It can be concluded that a reduction in net microbial protein synthesis in the rumen with increasing contents of RUP in the diet can be due to the reduction of preformed protein available for microbial growth as well as an increased turnover rate of microbial cells by predatory activity of protozoa.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.11
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• pp.1548-1553
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• 2000

An experiment was conducted to study the nutritional quality of whole crop corn silage ensiled with cage layer manure in sheep. Treatments were designed as a $3{\times}3$ Latin square with 16-day periods. Sheep were allotted in one of three diet-treatments, which were whole crop corn silage (CS), whole crop corn+30% cage layer manure (CLM) silage (based on DM; MS) and rice straw+concentrate (SC) mixed at 8:2 ratio (on DM basis). Silage ensiled with CLM significantly increased (p<0.05) digestibilities of crude protein, NDF and ADF, TDN over the other treatments. Ruminal pH in sheep fed SC was significantly (p<0.05) higher than that of the other diets at 0.5, 1, 2, 4 and 8 h after feeding. Ruminal ammonia nitrogen concentration of the MS treatment was significantly (p<0.05) higher than that of the other treatments at 0, 1, 2 h after feeding. The MS treatment highly increased (p<0.05) feed intake, digestibility of organic matter and crude protein, nitrogen intake and retained nitrogen. The MS treatment highly increased (p<0.05) purine derivative (PD) excretion leading to higher microbial protein synthesis.