5.2 Alternative Systems for Assessing the Nitrogen Value of Feeds for Ruminants

Autor: B. R. Howarth, D.E. Beever, J.L. Black, G.J. Faichney
Rok vydání: 1982
Předmět:
Zdroj: BSAP Occasional Publication. 6:107-118
ISSN: 2053-5953
0263-967X
DOI: 10.1017/s0263967x00030469
Popis: Systems suitable for evaluating the nitrogen status of feeds for ruminants must consider (i) the requirements of the animal's tissues for nitrogenous substances, (ii) the amount and nature of the nitrogenous substances absorbed by the animal and (iii) the efficiency with which absorbed nitrogen is used for various body functions. Such systems must also include aspects of energy utilization because, in ruminants, both the tissue needs for nitrogen and the flow of protein to the intestines are affected by energy availability. Several systems which attempt to include all three considerations in more or less detail have recently been proposed (Burroughs, Nelson and Mertens, 1975; Satter and Roffler, 1975, 1977; Kaufmann, 1977; Jarrige, Journet and Vérité, 1978; Fox, Sniffen, Van Soest and Robinson, 1979; Agricultural Research Council (ARC), 1980; Chalupa, 1980).
Databáze: OpenAIRE