an experiment was conducted to evaluate the effects of dietary crude protein (cp) and lysine levels on performance and nitrogen excretion in broiler chickens. four hundred twenty 7-day old chickens from ross 308 strain were randomly allotted to 6 dietary treatments with 5 replicates of 14 chicks each (7 male and 7 female chicks). the cp levels were 17, 18, and 20 percent and lysine levels were ...

A study was carried out to investigate nitrogen metabolism in response to cecal ligation and colostomy in chickens. We used colostomized plus ceca-ligated chickens fed a low protein diet or a low protein diet supplemented with urea. When both types of diets were fed, nitrogen balance and utilization tended to increase by cecal ligation while total nitrogen excretion tended to decrease. Colostom...

In order to elucidate further the cues for, and the biochemical mechanisms of, the transition to ureogenesis in the gulf toadfish Opsanus beta, experiments on the effects of feeding (i.e. nitrogen loading) were carried out. Baseline nitrogen excretion rates were first measured on solitary toadfish in large water volumes (i.e. unconfined conditions). These nitrogen excretion rates were higher, a...

Roger Gordon is a Professor at Memorial University of Newfoundland. He received his Honours B.Sc. (Zoology) and Ph.D. (Zoology) from the University of Sheffield, England, specializing in the areas of entomology and parasitology. He teaches courses in entomology, parasitology, animal physiology, general zoology, and introductory biology. His research interests include the study of host-parasite ...

Ammonia and urea are the primary forms of nitrogen excretion in teleost fish. There exists, however, a discrepancy between the sum of ammonia plus urea nitrogen and total nitrogen, indicating that 'unknown' nitrogen end products may play an important role in nitrogen metabolism. The current study analysed a wide range of nitrogen end products in both fed and fasted juvenile rainbow trout. Ammon...

deal effectively with the increased density of the pork industry in some areas and the increased public concerns regarding nutrient excretion and odour emissions. Successful management of nitrogen and phosphorus is key for sustainable pork production to address these public concerns. For example, nitrogen excretion in the form of ammonia is a concern because of its impact on the work environmen...

This paper examines the potential to use multiple objective programming to reduce nutrient excretion from dairy cows through incorporation of nutrient excretion functions into a ration formulation framework. In a typical ration formulation model, a ration is formulated to minimize cost while providing sucient nutrients to meet the needs of the animal type being fed. To reduce the nutrient load...

The loss of nitrogen after surgery is said to be related to body size as well as to the magnitude of the metabolic effects of surgery. Urine nitrogen should be 'corrected' for body size before it can be taken as a guide to the severity of surgery in the individual. Twenty-three patients were studied after elective abdominal surgery of moderate severity, when they were having only 3 litres of de...

Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea ...