BACKGROUND The 1985 FAO/WHO/UNU requirement for leucine is too low according to tracer-derived estimates of leucine oxidation and balance in adults from developed regions. OBJECTIVE The leucine requirement in populations in developing countries was assessed with use of the 24-h tracer balance method and on the basis of nitrogen balances. DESIGN Twenty healthy Indian men were studied during ...

The paper presents a new mathematical model of anaerobic digestion based on mass balances of organic dry matter (oDM) and nitrogen. The model was used for simulation of two agriculture biogas plants. The results of simulation in respect of biogas and methane yield, concentrations of ammonium nitrogen and dry matter (DM) in digested sludge, showed a satisfying compliance with measurements. Based...

Purified diets were offered to sheep ad libitum in two experiments. Urea was the main source of nitrogen, while energy was supplied as cellulose (20 to 72% ), starch (0 to 32% ) , or sucrose (0 to 35%) . The data indicated that (a) cellulose could serve as a suitable sole source of energy for rumen microbial synthesis, and (b) diets composed largely of cellulose, urea, and minerals could mainta...

A pilot-scale modified Orbal oxidation ditch with internal recycle of the nitrified liquor was developed to significantly enhance total nitrogen (TN) removal through simultaneous nitrification/denitrification (SND) coupled with pre-denitrification under the aerated-anoxic condition. Long-term operational results showed that the highest TN removal efficiency was achieved at very low dissolved ox...

Dairy farms comprise a complex landscape of groundwater pollution sources. The objective of our work is to develop a method to quantify nitrate leaching to shallow groundwater from different management units at dairy farms. Total nitrate loads are determined by the sequential calibration of a sub-regional scale and a farm-scale three-dimensional groundwater flow and transport model using observ...