Urea metabolism was studied with nitrogen-starved cells of Chlorella vulgaris Beijerinck var. viridis (Chodat), a green alga which apparently lacks urease. Incorporation of radioactivity from urea-(14)C into the alcohol-soluble fraction was virtually eliminated in cell suspensions flushed with 10% CO(2) in air. This same result was obtained when expected acceptors of urea carbon were replenishe...

the aim of this study was to evaluate the effects of balancing low protein diets for methionine and lysine on performance of early lactation holstein cows under hot environmental temperature. twenty one multiparous holstein cows in early lactation were allocated to three experimental rations including, 1) high protein ration with 17.5% cp, 2) medium protein ration with 16% cp and 12 g/d rumen p...

Nitrogenous waste excretion in resting dogfish occurred largely (>90 %) as urea-nitrogen (urea-N) efflux across the gills, with a very small urea efflux via the kidney. Ammonia excretion, almost entirely at the gills, accounted for less than 3 % of total nitrogen excretion. Given the extremely high blood urea levels (approximately 640 mmol-N l-1) 'retained' for osmoregulation, and blood ammonia...

to evaluate the effects of plant growth promoting rhizobacteria (pgpr) such as azotobacter chroococcum, azospirillum lipoferom and brasilence and pseudomonas fluorescens and nitrogen fertilizer from urea source on yield and yield components of maize (zea mays l.) double cross hybrids (dc 370), a field experiment was carried out in a factorial experiment (5*3) in rcbd with 4 replications. bacter...

The requirements of non-lactating non-pregnant ewes for digestible nitrogen for maintaining nitrogen or weight equilibrium were studied using soybean meal or urea as the sources of supplemental nitrogen. From the nitrogen balance data, assuming nitrogen losses of .05 g N/kg -73, the digestible nitrogen requirement for maintaining nitrogen equilibrium was. 195 -+ .0237 and .188 + .0099 g N/kg.73...

Twenty-four multiparous Holstein cows were used in six 4×4 Latin squares with 28day periods to determine inclusion rates for wet corn gluten feed (WCGF) in diets for lactating dairy cows. Cows were housed in a tie-stall barn and fed diets to meet or exceed NRC (1989) nutrient requirements. Experimental treatments were 1) control, 2) WCGF constituting 20%, 3) WCGF constituting 27.5%, and 4) WCGF...

In this study, the effects of nitrogen fertilizer and plant growth regulator (ethephon) application on leaf chlorophyl, stem height and diameter, stalk yield, total sugar and bioethanol of sweet sorghum were determined. Four nitrogen treatments 0, 100, 200 and 300 Kg Urea ha-1 and four ethephon concentrations 0, 800, 1000, and 1200 ppm were applied on sweet sorghum in a split plot on randomized...

In mammals, urea is the predominant end-product of nitrogen metabolism and plays a central role in the urinary-concentrating mechanism. Urea accumulation in the renal medulla is critical to the ability of the kidney to concentrate urine to an osmolality greater than systemic plasma. Regulation of urea excretion and accumulation in the renal medulla depends on the functional state of specialized...

The dietary lysine requirement of adult sows nursing 10 pigs was estimated by using plasma urea nitrogen (PUN) concentration as a rapid response criterion. A preliminary experiment indicated that a 3-d feeding time is required to re-equilibrate PUN concentrations after a change in the dietary concentration of lysine. In the main experiment, 12 sows (BW = 219 +/- 5 kg; parity = 4.5 +/- .3; ultra...