
%0 Journal Article
%A Faichney, GJ 
%A Tagari, H 
%A Teleki, E 
%A Boston, RC 
%T Nitrogen transactions in the rumen of sheep given a barley straw diet supplemented with untreated or formaldehyde-treated sunflower seed meal
%J Australian Journal of Agricultural Research
%D 1994/09/01
%V 45
%N 6
%P 1203-1214
%K 15N-ammonia;15N-urea;14C-urea;bacteria;protozoa;turnover time;N recycling
%R https://doi.org/10.1071/AR9941203
%U https://www.publish.csiro.au/paper/AR9941203 
%X The effect of formaldehyde treatment of the sunflower seed meal in a barley straw based diet on rumen N transactions was studied in two fistulated crossbred sheep using 15N-ammonia and 15N- and 14C-urea. Treatment decreased organic matter and N digestibility to a small extent, but substantially decreased urine N excretion so that N retention increased. Treatment resulted in decreases in ammonia and urea synthesis which were reflected in reduced rumen ammonia and plasma urea levels; the net flow of N from the rumen ammonia pool to the plasma urea pool was reduced by 50%. 56-65% of the bacterial N was derived from ammonia. The contribution of bacterial N to N in the protozoal fraction decreased from 45 to 40% in the first sheep, but increased from 35 to 39% in the second; as a consequence, there was a very close relationship (r2 = 0.95) between this parameter and rumen ammonia recycling. Treatment decreased protozoal turnover time in the first sheep, but increased it in the second sheep; this effect may have been due to an increase in lysis of protozoa in the first sheep and a decrease in lysis in the second. Solutes mixed throughout the rumen in from half to one hour. 
