• Asian-Australasian Journal of Animal Sciences
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• 제27권5호
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• pp.658-666
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• 2014

This study aimed to evaluate urea excretion, nitrogen balance and microbial protein synthesis in lactating goats fed with diets containing different protein sources in the concentrate (soybean meal, cottonseed meal, aerial part of cassava hay and leucaena hay). Four Alpine goats whose mean body weight was $42.6{\pm}6.1kg$ at the beginning of the experiment, a mean lactation period of $94.0{\pm}9.0days$ and a production of $1.7{\pm}0.4kg$ of milk were distributed in a $4{\times}4$ Latin square with four periods of 15 days. Diets were formulated to be isonitrogenous, containing 103.0 g/kg of CP, 400 g/kg of Tifton 85 hay and 600 g/kg of concentrate. Diet containing cottonseed meal provided (p<0.05) increased excretion of urea and urea nitrogen in the urine (g/d and mg/kg of BW) when compared with leucaena hay. The diets affected the concentrations of urea nitrogen in plasma (p<0.05) and excretion of urea nitrogen in milk, being that soybean meal and cottonseed meal showed (p<0.05) higher than the average aerial part of the cassava hay. The use of diets with cottonseed meal as protein source in the concentrate in feeding of lactating goats provides greater nitrogen excretion in urine and negative nitrogen balance, while the concentrate with leucaena hay as a source of protein, provides greater ruminal microbial protein synthesis.

• Asian-Australasian Journal of Animal Sciences
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• 제19권6호
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• pp.857-864
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• 2006

The aim of this study was to apply the Cornell net carbohydrate and protein system (CNCPS) in subtropical Taiwan. This was done by means of 3 trials, viz, in situ, lactation and metabolic trials, the latter using the urinary purine derivatives (UPD) to estimate the ruminal microbial yield. Dietary treatments were formulated according to different nutrient requirement systems including, (1) a control NRC78 group on NRC (1978), (2) a NRC88 group on NRC (1988), and (3) a CNCPS group on Cornell Net carbohydrate and protein system model. Results from the lactation trial showed that DM intake (DMI) was higher (p<0.05) in the NRC78 than the other treatment groups. The treatments did not significantly influence milk yield, but milk yield after covariance adjustment for DMI was higher in the CNCPS group (p<0.05). The FCM, milk fat content and yield were greater in both the NRC78 and the NRC88 group over the CNCPS group (p<0.05). The treatments did not significantly influence the DMI adjusted FCM. The solid-non-fat and milk protein contents were higher in the CNCPS group (p<0.05) with or without DMI covariance adjustment. Lactating efficiency was higher in the CNCPS group (p<0.05) compared to the other groups. The significantly lowest milk urea-N (MUN) with better protein utilization efficiency in the CNCPS group (p<0.05) suggested that less N would be excreted into the environment. Cows in the CNCPS group excreted significantly more and the NRC88 group significantly less urinary purine derivatives (UPD) implying that more ruminal microbial protein was synthesized in the CNCPS over the NRC88 group. The CNCPS could become the most useful tool in predicting the trends in milk yield, microbial yield and MUN.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1416-1423
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• 2016

This study was designed to investigate the effect of grape pomace powder (GPP), mangosteen peel powder (MPP) and monensin on feed intake, nutrients digestibility, microorganisms, rumen fermentation characteristic, microbial protein synthesis and nitrogen balance in dairy steers. Four, rumen fistulated dairy steers with initial body weight (BW) of $220{\pm}15kg$ were randomly assigned according to a $4{\times}4$ Latin square design to receive four treatments. The treatments were as follows: T1 = control, T2 = supplementation with monensin at 33 mg/kg diet, T3 = supplementation with GPP at 2% of dry matter intake, and T4 = supplementation with MPP at 30 g/kg diet. The steers were offered the concentrate diet at 0.2% BW and 3% urea treated rice straw (UTRS) was fed ad libitum. It was found that GPP supplemented group had higher UTRS intake and nutrient digestibility in terms of neutral detergent fiber and acid detergent fiber than those in control group (p<0.05). Ammonia nitrogen ($NH_3-N$) and blood urea-nitrogen concentration were higher in monensin, GPP and MPP supplemented groups (p<0.05). Total volatile fatty acids and propionate in the GPP group were higher than those in the control group (p<0.05) while acetate concentration, and acetate to propionate ratio were decreased (p<0.01) when steers were supplemented with GPP, monensin, and MPP, respectively. Moreover, protozoal populations in GPP, MPP, and monensin supplementation were significantly lower than those in the control group (p<0.05), while cellulolytic bacterial population was significantly higher in the control group (p<0.05). Nitrogen retention, microbial crude protein and efficiency of microbial nitrogen synthesis were found significantly higher in steers that received GPP (p<0.05). Based on this study it could be concluded that the GPP has potential as an alternative feed supplement in concentrate diets which can result in improved rumen fermentation efficiency, digestibility and microbial protein synthesis in steers fed on treated rice straw.

• Asian-Australasian Journal of Animal Sciences
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• 제20권10호
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• pp.1567-1574
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• 2007

A study was carried out to study the response of total purine derivatives (PD) excretion in urine to determine microbial N (MN) supply at four fixed levels of feed intake (namely 95, 80, 60 and 40% of voluntary intake). The crossbred (CB) calves were allocated according to a $4{\times}4$ Latin Square Design and fed wheat straw and concentrate (1:1). The rate of PD excretion (mmol/d) as a linear function of feed intake was 15.85/kg DMI and 20.12/kg DOMI. Based on the endogenous and PD excretion rates obtained in this study, a relationship between daily urinary PD excretion (Y, mmol) and daily microbial protein supply (X, mmol) was developed for crossbred calves as Y = 0.83X+0.296 kg $W^{0.75}$. The derived microbial N values using this equation differed (p<0.001) among the 4 groups and was the highest in L-95 followed by L-80, L-60 and L-40. The relationship between urinary nitrogen loss (Y, g/d) and DOMI (X, kg/d) was established as: Y = 6.038X+21.753 ($r^2$ = 0.663, p<0.01). When urinary excretion of PD (Y, mmol/d) was plotted against intake of DM and DOM (X, kg/d), the equations obtained were: Y = 7.1711X+8.674 ($r^2$ = 0.889, p<0.01) and Y = 12.434X+7.683 ($r^2$ = 0.896, p<0.01), respectively. The proportional contribution of allantoin and uric acid to total PD remained stable irrespective of level of feed intake. Similarly, urinary excretion of creatinine did not differ (p>0.05) between animals fed at different levels. The MN supply was the highest to animals at intake levels L-95, and decreased linearly with corresponding decrease in feed intake. However, the MN supply when expressed per kg DOMI remained statistically (p>0.05) similar irrespective of level of intake. The results revealed that the excretion of urinary purine derivatives were positively correlated with the level of feed intake as well as rumen microbial supply and thus it could be a good indicator for measuring the microbial protein supply and nutritional status of animals.

• Asian-Australasian Journal of Animal Sciences
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• 제19권3호
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• pp.368-375
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• 2006

Four rumen-fistulated dairy steers were randomly assigned according to a $4{\times}4$ Latin square design to investigate effects of supplementation levels of sodium dl-malate in concentrates on rumen ecology, ruminal fermentation, nitrogen balance, feed intake and digestibility of nutrients and ruminal microbial protein synthesis. The dietary treatments were cassava concentrate-based, containing sodium dl-malate supplementation at 0, 9, 18 and 27 g/hd/d with urea-treated rice straw (UTS) fed ad libitum. The experiment was conducted for four periods, each period lasting 21 days. Ruminal pH increased with incremental addition of malate (p<0.05). Additionally, molar proportions of propionate were higher in supplemented groups and was highest at 18 g/hd/d of malate supplement (p<0.05). Microbial protein synthesis tended to be higher in dairy steers receiving sodium dl-malate supplements and also was the highest at 18 g/hd/d. Variable bacterial populations, such as amylolytic, proteolytic and cellulolytic species were increased (p<0.05). Furthermore, protozoal populations were decreased significantly (p<0.05), while fungal zoospores were dramatically increased in dairy steers receiving sodium dl-malate supplement (p<0.05). These results suggested that supplementation of concentrate containing a high level of cassava chip at 18 g/hd/d with UTS in dairy steers could improve rumen fermentation efficiency and rumen microbial protein synthesis.

• Journal of Microbiology
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• 제44권4호
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• pp.369-374
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• 2006

To investigate the mechanism of salt tolerance of gram-positive moderately halophilic bacteria, two-dimensional gel electrophoresis (2-D PAGE) was employed to achieve high resolution maps of proteins of Halobacillus dabanensis $D-8^T$. Approximately 700 spots of proteins were identified from these 2-D PAGE maps. The majority of these proteins had molecular weights between 17.5 and 66 kDa, and most of them were distributed between the isoelectric points (pI) 4.0 and 5.9. Some protein spots were distributed in the more acidic region of the 2-D gel (pI <4.0). This pattern indicated that a number of proteins in the strain $D-8^T$ are acidic. To understand the adaptation mechanisms of moderately halophilic bacteria in response to sudden environmental changes, differential protein profiles of this strain were investigated by 2-D PAGE and $Imagemaster^{TM}$ 2D Platinum software after the cells were subjected to salt shock of 1 to 25% salinity for 5 and 50 min. Analysis showed 59 proteins with an altered level of expression as the result of the exposure to salt shock. Eighteen proteins had increased expression, S proteins were induced, and the expression of 33 proteins was down-regulated. Eight of the up-regulated proteins were identified using MALDI-TOF/MS and MASCOT, and were similar to proteins involved in signal transduction, proteins participating in energy metabolism pathways and proteins involved in stress.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.349-350
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.398-399
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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• pp.364-370
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• 1997

Four local cattle were ($145{\pm}9.7kg$) used in a $4{\times}4$ Latin square design to study the effect of different levels of rumen degradable protein (RDP) in straw based ration on purine derivatives excretion and microbial N supply in cattle. The four rations were formulated at the same amount of energy but varying RDP approximately 50 (U0), 75 (U1), 100 (U2) and 150 (U3) percent levels of RDP requirement for maintenance. They were fed ranged from 101 to 304 g RDP/d. Apparent digestibility of all nutrients increased significantly (p < 0.01) in cattle fed ration U2 than other rations. Rumen $NH_3-N$ concentration increased from 43 to 130 mg/l in response of RDP intake. Purine derivatives excretion increased significantly (p < 0.01) with incremental level of 203 g RDP/d (U2) intake and positively correlated (r=0.69, p < 0.01, n=16) with amount of RDP intake. The rates of rumen microbial N supply were 16.8, 27.2, 39.1 and 32.9 g/d for rations U0, U1, U2 and U3 respectively. Efficiency of microbial N supply (EMNS) per kg of DOMR were 19.0, 25.3, 33.0, and 28.6 g and per MJ of ME. Intake were 0.62, 1.00, 1.44 and 1.21 g for U0, U1, U2 and U3 respectively and highest results were obtained in cattle fed U2 ration. Results of this study suggest that PD excretion and EMNS were increased as incremental level of RDP intake (U2) in local cattle.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.34-45
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• 2012

A thermophilic Bacillus stearothermophilus F1 produces an extremely thermostable serine protease. The F1 protease sequence was used to predict its three-dimensional (3D) structure to provide better insights into the relationship between the protein structure and biological function and to identify opportunities for protein engineering. The final model was evaluated to ensure its accuracy using three independent methods: Procheck, Verify3D, and Errat. The predicted 3D structure of F1 protease was compared with the crystal structure of serine proteases from mesophilic bacteria and archaea, and led to the identification of features that were related to protein stabilization. Higher thermostability correlated with an increased number of residues that were involved in ion pairs or networks of ion pairs. Therefore, the mutants W200R and D58S were designed using site-directed mutagenesis to investigate F1 protease stability. The effects of addition and disruption of ion pair networks on the activity and various stabilities of mutant F1 proteases were compared with those of the wild-type F1 protease.