The n-alkane profile of some native and cultivated forages in Canada

Abstract

Frage samples were collected from swards growing in Carberry, Manitoba, Brandon, Manitoba, Saskatoon, Saskatchewan, and St. John’s, Newfoundland, and the alkane concentrations were determined by gas chromatography. Considerable differences were observed in almost all odd-numbered alkanes and in their total content between species. The odd-numbered alkanes were always present in high concentrations compared to the even-chain alkanes in both native and cultivated species. Of the cultivated grasses, the fescues had very high concentrations of CN31 among the odd-chain alkanes, while the legumes tended to have higher concentrations of C29 than C31 or C33. The low concentrations of odd-chain alkanes (< 50 mg kg-1 DM) in little bluestem, indiangrass, reed canarygrass, orchardgrass, timothy and Russian wildrye forages could bias intake calculations of these forages when the double alkane technique is used. Differences between location and cultivar were observed for C29 in timothy and C31 in meadow bromegrass (P < 0.05). There were no effects of location and cultivar on n-alkane concentrations for orchardgrass (P > 0.05). Key words: n-alkanes, forage species, cultivar, location