Avian and Poultry Biology Reviews 14 (2), 2003
Bioavailability of Phosphorus in Poultry Manure
K. H. Nahm*
Feed and Nutrition Laboratory, College of Natural Resources, Taegu University, Gyong San, 712-714, South Korea
ABSTRACT
Phosphorus (P) is a critical nutrient for both animals and plants. P is provided in the diet to poultry as a natural constituent of ingredients and by inorganic salts as supplemental materials. It has been suggested that the Pin poultry manure may be apotential source of soil and water hypermineralization. Almost all strategies to control P inputs are based on total P (TP) although most of the P (80^90%) in the runoff is in the soluble form, which is the form of most available for algae uptake. Bioavailable P may be changed from TP to bioavailable P (BAP) and grouped into soluble P (SP) or dissolved P (DP) or dissolved reactive P (DRP), total particulate P (PP) and sediment P (SEP). Particulate P is transported into bioavailable PP (BPP). Poultry manures contain significant amountof P composed of inorganic and organic P,which are changed from inorganic P to dissolved inorganic P and from organic P to dissolved organic P when they are in the soluble forms of the runoff. Most of the P in all manures and composts is inorganic (60^90% of TP) with smaller amounts of organic and residual forms. Water extractable P in poultry manure may be used to estimate the potential for land-applied poultry manures or composts to enrich leachate and surface runoff.The Redfield ratio can be used for obtaining reasonable standards for total P concentration. The proper Redfield ratio for N to Pis about15 to16:1when receiving water to the water lab is acceptable. The Redfield ratio of poultry manure is generally two or less. Manure analysis is needed to control the positive and negative long-term effects of manure use in order to minimize P loss into receiving waters.
Keywords: BPP, DP, DRP, P, Redfield ratio, SEP, SP, TP, water contamination
Biosynthesis and Biological Actions of Neurosteroids in the Avian Brain
Kazuyoshi Tsutsui*, Masahiro Matsunaga and Kazuyoshi Ukena
Laboratory of Brain Science, Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739 - 8521
and Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Tokyo 150 - 0002, Japan
ABSTRACT
Peripheral steroid hormones cross the blood-brain barriers, due to their chemically lipid solubility, and act on braint issues through intracellular receptor-mediated mechanisms that regulate several important brain neuronal functions. Therefore, the brain is considered to be a target site of peripheral steroids. In contrast to this classic concept, new findings have shown that the brain itself also synthesizes steroids de novo from cholesterol through mechanisms at least partly independent of peripheral steroidogenic glands. The pioneering discovery of Baulieu and his colleagues, using rodents, has opened the door to a new research field. In contrast to mammalian studies, little has been known regarding de novo steroidogenesis in the brain of nonmammalian vertebrates. We have therefore looked for steroids formed from cholesterol in the brain of birds. A series of our studies over the past decade has demonstrated that the avian brain itself can synthesize steroids de novo. Independently, Schlinger's laboratory has also contributed to this exciting area of research. Thus, the formation of several steroids from cholesterol in the brain is now known to occur in birds as well as other vertebrates. Such steroids synthesized de novo in vertebrate brains are called neurosteroids. Neurosteroids may act on neuronal tissues through genomic and nongenomic actions to regulate several important neuronal functions. This paper summarizes the advances made in our understanding of biosynthesis of neurosteroids in the avian brain. This paper also describes what is currently known about biological actions of neurosteroids.
Keywords: neurosteroids, steroidogenic enzymes, biosynthesis, genomic action, nongenomic action, brain
Hazard Analysis Critical Control Point System and its Impact on the Meat and Poultry Industry
J. deGraft-Hanson
Division of Animal and Veterinary Sciences, West Virginia University, P.O. Box 6108, Morgantown, WVA. 26506-6108, USA
ABSTRACT
The Hazard Analysis Critical Control Point (HACCP) program is the result of the United States Department of Agriculture's (USDA's) Food Safety Inspection Service (FSIS) Final Pathogen Rule to meat and poultry producers and processors to use in their production and processing plants and establishments in order to reduce biological, chemical and physical contamination of meat and poultry to make the products safer for the public. This article examines the impact on the meat and poultry industry of the HACCP program, in terms of cost and time.
Keywords: pathogens, meat and poultry industry, contamination