Abstract

Effects of wilting rate and fermentation stimulators and inhibitors on protein characteristics of forages typical for organic production were assessed using traditional analytical methods and a gas production in vitro assay. The hypotheses were that the proportion of the crude protein (CP) fraction that was soluble would be lowest, and the protein feed value highest, under rapid wilting and restricted fermentation. The solubility of the CP fraction varied according to treatments and between a first and a second cut, with moderate and high content of clover respectively. It was, however, of minor importance for the protein value, both calculated as amino acids absorbed in the small intestine (AAT(20)) and estimated as effective utilizable crude protein (uCP(04)) by the in vitro assay. In ensiled herbage, AAT(20) was highest in rapidly wilted and restrictedly fermented silages made from a first cut dominated by highly digestible grasses. Silages from the second cut dominated by red clover were far lower in AAT(20). The in vitro assay did not separate silages according to herbage composition or wilting rate, but ranked restrictedly fermented above extensively fermented with regard to protein supply. The assay might still have caught the characteristics that determine the true protein value in vivo.

Keywords

in vitro gas production; red clover; utilizable protein

Published in

Grass and Forage Science
2017, Volume: 72, number: 4, pages: 626-639

SLU Authors

• Vaga, Merko

  • Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences
    

• Hetta, Mårten

  • Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Animal and Dairy Science
Agricultural Science


Publication identifier

DOI: https://doi.org/10.1111/gfs.12271

Permanent link to this page (URI)

https://res.slu.se/id/publ/90504