The application of the n-alkane technique for estimating the composition of diets consumed by equines and cattle feeding on upland vegetation communities

Abstract

The application of n-alkanes as faecal markers to estimate diet composition of equines and cattlewas studied. Twelve mature crossbreed mares (385±47 kg live weight – LW) and six adult non-lactating cows (499±36 kg LW) of Asturiana de los Valles breed were divided in groups of three animals (H1, H2, H3 and H4 in equines and C1 and C2 in cattle) and housed in individual stalls. Animals received a daily total amount of 1.0 kg DM/100 kg LW of different experimental diets composed of herbaceous (Lolium perenne L.) and woody species (Ulex gallii Planchon and heather: Erica spp. and Calluna vulgaris L.). Diet composition varied among treatments: H1 and C1 – L. perenne as sole component; H2 and C2 – L. perenne (0.70) and heather (0.30); H3 – L. perenne (0.70) and U. gallii (0.30); H4 – L. perenne (0.40), heather (0.30) and U. gallii (0.30). Diet composition was estimated from the alkane concentrations (C27, C29, C31 and C33) in diet and faeces by least-squares procedures. Furthermore, the effect of using different sets of alkane.