CONTENIDO Y PATRÓN DE ALCANOS EN FORRAJERAS NATIVAS DEL NE DE MENDOZA, ARGENTINA

ALLEGRETTI L; EGEA V; BAKKER M L; PAEZ S; SARTOR C; GRILLI D

Mendoza

Jornada; XXVI Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2008

Sociedad de Biología de Cuyo

Estimates of intake and diet composition to understand the foraging behaviour of Criollo goats in the rangelands of NE Mendoza are required but scarce. The n-alkanes present in forages may be used as markers to estimate diet composition. The objective of this preliminary study was to analyse the content and pattern of n-alkanes in some native forage species, to evaluate its potential to estimate diet composition in goats. Six species: Prosopis flexuosa (PF), Capparis atamisquea (CA), Atriplex lampa (AL), Mimosa ephedroides (ME), Bulnesia retama (BR), Tricomaria usillo (TU) were collected in March 2007, plant parts (current season´s leaves, stems or fruits) were analysed for odd n-alkane (C23 to C35) content (mg.kgDM-1) by capillary GC, and the pattern of n-alkanes (% of each in total) was calculated. The patterns of n-alkanes had some contrasts among species and plant parts. More abundant n-alkanes in all species were C27, C29, C31 and C33; but C29 was high in ME fruits (72%), PF stems (70%) and leaves (61%) and TU leaves (61%), stems (54%) and fruits (52%), C31 in BR stems and fruits (74%) and ME stems (54%), and C33 in CA leaves and stems (68%). CA had also a comparatively high proportion of C35 (8%), which is a rare finding in forages. AL had C27, C29 and C33 accounting for ca. 25-30% of total each. A comparatively high proportion of the even n-alkane C28 (to confirm) in PF would allow the use of this compound as an extra marker to separate this species from others.