Sign up & Download
Sign in

Nitrogen budgets and losses in livestock systems

by Oene Oenema
International Congress Series ()

Abstract

Livestock farming systems encompass (i) grazing, (ii) mixed, and (iii) land-less systems. These systems convert crop protein into animal protein with an efficiency ranging from 5% to 45%, depending on animal type, system and management. The nitrogen (N) in the remaining fraction (55-95%) is in urine and dung, and is conducive to N losses. This paper reviews N input-output budgets and N losses in livestock farming systems. Systems differ in N inputs, outputs and budgets. Generally, N inputs and N losses increase in the order grazing systems < mixed systems < land-less systems. The estimated global amount of manure N ranges between 75 and 138 Tg N/year. Cattle (56-60%), sheep (12%) and pigs (6%) have the largest share in manure N production. Roughly 40-50% of manure N is collected in barns, stables and paddocks, and only half of this amount is recycled to cropland. Gaseous N losses from manure N are estimated at 45-75 Tg/year. There are opportunities for decreasing N losses and improving animal feed conversion efficiency by improving the composition of the animal feed and the genetic production potential of the herd. A major challenge lies in improving manure management. © 2006 Elsevier B.V. All rights reserved.

Cite this document (BETA)

Page 1
hidden
Page 2
hidden

Readership Statistics

30 Readers on Mendeley
by Discipline
 
 
 
by Academic Status
 
23% Ph.D. Student
 
23% Student (Master)
 
13% Assistant Professor
by Country
 
7% United Kingdom
 
3% Chile
 
3% Kenya

Sign up today - FREE

Mendeley saves you time finding and organizing research. Learn more

  • All your research in one place
  • Add and import papers easily
  • Access it anywhere, anytime

Start using Mendeley in seconds!

Already have an account? Sign in