• The metabolism of excess dietary protein results in high plasma urea nitrogen (PUN) concentrations • High PUN concentrations (and ammonia to a lesser extent) are associated with decreased fertility in lactating dairy cows • High PUN concentrations probably affect fertility via direct toxic effects on the oocyte and embryo, alterations in the uterine environment and decreased progesterone secr...

Data of 42 balance measurements from dry and lactating Holstein cows and blood and urine samples from 24 Japanese Black cows were collected to evaluate the potential for predicting urinary nitrogen (N) excretion from plasma urea nitrogen (PUN). Similar positive correlations were obtained between N intake and apparent N absorption in dry and lactating cows. The regression equations of N intake o...

in this paper we define the removable cycle that, if $im$ is a class of graphs, $gin im$, the cycle $c$ in $g$ is called removable if $g-e(c)in im$. the removable cycles in eulerian graphs have been studied. we characterize eulerian graphs which contain two edge-disjoint removable cycles, and the necessary and sufficient conditions for eulerian graph to have removable cycles h...