Labelling of corn as forage for ruminants using isotope ¹⁵N

Abstract

In vitro and in vivo testing for ruminant feed efficiency can be done by utilizing the stable isotope Nitrogen-15 (15N) as a tracer. Feed can be traced by labeling the forage using isotope 15N. Feed crops are labeled using an isotope 15N-enriched fertilizer. The critical thing to note is to know the content of isotopes 15N in the part of forage feed plants that have been labeled. This research aims to know the effect of urea fertilizer on the percent of atom excess 15N on corn. Corn are labeled using urea enriched with isotopes 15N in the form of urea fertilizer (10% excess atom 15N) with different doses (0-200% recommended urea dose). As a control used corn plants given urea fertilizer is not labeled 15N. The results showed that corn forage feed was successfully labeled and correlated with the dose of fertilizer. The range of atom excess 15N was 4.28 – 6.99% in corn forage. Biomass production showed no significant difference between the dose of fertilization and control, but neither protein content. Based on data, the corn forage can be used for further testing.