Urinary urea N (UUN) is the principal nitrogen (N) source controlling emissions of ammonia (NH) and nitrous oxide (NO) from dairy manure. The objectives of this study were (i) to study the integrative nature of dietary crude protein (CP) management, secretion of milk urea N (MUN), excretion of UUN, and N emissions from dairy production systems; (ii) to evaluate how associative changes in dietar...

The objectives of this study were to assess the relationship between urinary nitrogen excretion (UN, g/d) and milk urea nitrogen concentration (MUN, mg/dl) and whether the types of carbohydrates fed interacts with the dietary CP and the breed (size) of cows to affect this relationship. Eight multiparous cows (four Holstein and four Jersey) were fed four different diets in a 2 × 2 factorial arra...

Background: Inclusion of urea and calcium oxide (CaO) during sugarcane ensilage has been hypothesized to improve dairy cow performance. Objective: To evaluate the use as additives preserve silage quality determine whether they performance metabolic efficiency. Methods: Four diets were used: without additive (SS), with 10 g/kg (SU), 5 + CaO (SUC), (SC). Eight crossbred cows at approximately 100 ...

21 Three levels of metabolizable protein supply (108, 98–95 and 85 g PDIE kg DM) (PDIE: protein digested in the small intestine when rumen-fermentable energy is limiting) in the diet and three levels of difference between rumen-degradable 21 energy and N (PDIE 2 PDIN 5 0, 10 and 20 g kg DM) (PDIN: protein digested in the small intestine when rumenfermentable nitrogen is limiting) were used in t...

to examine the effects of different sources of rumen-degradable carbohydrates on rumen fermentation, nitrogen metabolism and performance of holstein dairy cows, four lactating holstein cows fitted with rumen cannulae in a 4×4 latin square with four diets and four 28 day periods each, were employed. experimental diets contained different levels of pure sucrose and corn starch in which sucrose wa...

Milk urea nitrogen (MUN) and blood are correlated with balance excretion; however, there is also a genetic component to MUN concentrations that could be associated differences in transport. It was hypothesized portion of the variation among cows caused by gastrointestinal kidney clearance rates. Eight lactating varying while fed common diet were infused [15N15N]urea determine N entry rate (UER)...

The objectives of this study were to evaluate the potential for using blood urea N concentration to predict urinary N excretion rate, and to develop a mathematical model to estimate important variables of N utilization for several different species of farm animals and for rats. Treatment means (n = 251) from 41 research publications were used to develop mathematical relationships. There was a s...