• Archives of Pharmacal Research
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• 제28권2호
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• pp.220-226
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• 2005

Temperature and medium composition were changed with the aim of increasing growth and erythropoietin (EPO) production in EPO-producing Chinese hamster ovary (CHO) cells. We used the CHO cell line, IBE, and its derivative, CO5, which over-expresses the first two enzymes of the urea cycle, carbamoyl phosphate synthetase I (CPS I) and ornithine transcar-bamoylase (OTC). When supplements were added to the medium at $33\;^{\circ}C$, the growth of IBE and CO5 cells increased by $27\%\;and;26\%$, respectively and the maximum yield of EPO was increased by $40\%$ in both cell lines. The absolute EPO concentration in the CO5 cells was always $55{\sim}60\%$ higher than in the IBE cells. In addition, when the two cell lines were continuously cultured with supplements at $33\;^{\circ}C$ until their growth rates approached those at $37\;^{\circ}C$, the growth rates of both IBE and CO5 cells increased by $54\%$ and their maximum EPO levels increased by up to $73\%\;and\;56\%$, respectively. Therefore, the growth and EPO expression levels of CO5 cells increased 2.2-fold and 2.6-fold, respectively, compared to those of the IBE cells. These results indicate that adaptation to lower temperature as well as medium supplementation could be important for improving cell growth and EPO production.

• Asian-Australasian Journal of Animal Sciences
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• 제24권6호
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• pp.766-773
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• 2011

The objective of the present study was to examine whether yaks possess any adaptive mechanisms of nitrogen (N) metabolism to survive in the harsh foraging environment of the Qinghai-Tibetan Plateau. A grazing experiment on native alpine meadows was conducted to determine availability of herbage biomass and body weight (BW) change of yaks over the year, followed by two indoor feeding trials to investigate adaptation mechanisms of N metabolism in yaks fed at similar intake level to grazing conditions. Three castrated males of each of three genotypes; yak (Bos grunniens), indigenous cattle (Bos taurus) and their crossbred - cattleyak (Bos taurus male${\times}$Bos grunniens female), were used in the housed trials. Results showed that: i) Monthly herbage biomass production and daily grazing intakes by yaks over the year ranged from 220 to 4,664 kg DM per ha, and 1.90 to 8.50 kg DM, respectively. For about seven months each year, yaks suffer from malnutrition as a result of inadequate pasture conditions; ii) Urinary N excretion and N retention by yaks were significantly affected by feeding level, and yaks had a lower (p<0.05) average daily urinary N excretion (0.39 g/kg $BW^{0.75}$) and a greater (p<0.05) N retention (-0.09 g/kg $BW^{0.75}$) than indigenous cattle (0.47 and -0.16 g/kg $BW^{0.75}$, respectively). Fasting daily urinary N excretion was greater (p<0.05) for indigenous cattle than yaks (353 vs. 248 mg/kg $BW^{0.75}$). Purine derivative N excretion and purine derivative N index (PNI) increased with increasing feeding level, while the value of PNI was greater (p<0.05) for yaks and cattleyak (0.11 and 0.12, respectively) than for indigenous cattle (0.09) during the feeding trials. These results suggest that yaks could rely, in part, on the recycling of N to adapt to the harsh forage environment on the Qinghai-Tibetan Plateau.), were used in the housed trials. Results showed that: i) Monthly herbage biomass production and daily grazing intakes by yaks over the year ranged from 220 to 4,664 kg DM per ha, and 1.90 to 8.50 kg DM, respectively. For about seven months each year, yaks suffer from malnutrition as a result of inadequate pasture conditions; ii) Urinary N excretion and N retention by yaks were significantly affected by feeding level, and yaks had a lower (p<0.05) average daily urinary N excretion (0.39 g/kg $BW^{0.75}$) and a greater (p<0.05) N retention (-0.09 g/kg $BW^{0.75}$) than indigenous cattle (0.47 and -0.16 g/kg $BW^{0.75}$, respectively). Fasting daily urinary N excretion was greater (p<0.05) for indigenous cattle than yaks (353 vs. 248 mg/kg $BW^{0.75}$). Purine derivative N excretion and purine derivative N index (PNI) increased with increasing feeding level, while the value of PNI was greater (p<0.05) for yaks and cattleyak (0.11 and 0.12, respectively) than for indigenous cattle (0.09) during the feeding trials. These results suggest that yaks could rely, in part, on the recycling of N to adapt to the harsh forage environment on the Qinghai-Tibetan Plateau.

• 농약과학회지
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• 제9권2호
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• pp.153-158
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• 2005

광학활성 1-${\alpha}$-methylbenzylphenylurea 유도체의 bensulfuron-methyl, pyribenzoxim에 대한 약해경감효과를 조사하였다. 대부분의 유도체가 담수토양처리시험에서도 제초제 bensulfuron-methyl에 의한 벼의 근부신장 저해에 대하여 높은 약해경감효과를 나타내었다. 특히, S-이성체의 2,3-diCl 치환체와 2-F-4-Me 치환체는 dymuron 보다 4배 높은 약해경감효과를 나타내었으며 두 치환체들은 동시 혼합처리뿐만 아니라 4일 후의 지연처리에서도 bensulfuron-methyl의 약해를 효과적으로 경감하였다. S-이성체의 2-F-4-Me치환체는 벤조산계 제초제 pyribenzoxim에 대해서도 지상부, 근부 모두 95%의 높은 약해경감효과를 나타내었다.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.904-907
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• 1999

The experiment was aimed at studying the effect of ruminal $NH_3-N$ levels on ruminal fermentation, microbial population, urinary purine derivative excretion, digestibility and rice straw intake in swamp buffaloes. Five, 3 to 4 years old, rumen fistulated swamp buffaloes were randomly assigned according to a $5{\times}5$ Latin square design to rceive five different intraruminal infusions of $NH_4HCO_3$ (0, 150, 300, 450 and 600 g/d) on a continuous daily basis. Rice straw as a roughage was offered ad libitum while concentrate was given at 0.8% BW daily. The results were that as levels of $NH_4HCO_3$ increased, ruminal $NH_3-N$ concentrations increased from 7.1 to 34.4 mg%. The highest digestibility and voluntary straw intakes were found at 13.6 to 17.6 mg% ruminal $NH_3-N$ levels; straw intake was highest at 13.6 mg%. Total bacterial and protozoal counts linearly increased as the ruminal $NH_3-N$ increased and were highest at 17.6 mg%. Total urinary purine derivatives and allantoin excretion were highest (44.0, 37.4 mM/d) at 17.6 mg% ruminal $NH_3-N$. Highest total VFAs (115 mM) were obtained a 13.6 mg% ruminal $NH_3-N$ while blood urea nitrogen significantly increased as ruminal $NH_3-N$ increased. The results from this experiment suggest that optimum ruminal $NH_3-N$ in swamp buffaloes is higher than 13.6 mg%, for improving rumen ecology, microbial protein synthesis, digestibility and straw intake.

• Asian-Australasian Journal of Animal Sciences
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• 제30권5호
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• pp.653-659
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• 2017

Objective: This trial was performed to examine the effects of ruminally degradable starch (RDS) levels in total mixed ration (TMR) with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Methods: Eight multiparous Holstein cows (body weight [BW]: $717{\pm}63kg$; days in milk [DIM]: $169{\pm}29$) were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS) or 72.1% ruminally degradable starch (% of total starch, high RDS). Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component. Results: The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR. Conclusion: Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.