Abstract:
Fecal samples, evacuated rumen samples, and non-evacuated
rumen samples were compared at different seasons as techniques
for determining diet botanical composition of cattle. The study
was conducted at the New Mexico State University College
Ranch near Las Cruces. Sis rumen-Iistulated steers were used
spring (28 May-7 June), summer (19 July-8 August), fall 1989
(1-17 October), winter (S-28 January) 1990; 4 rumen-fistulated
steers were used during summer (24 July-4 August) 1990.
Sampling techniques differed QQO.05) for the proportion of some
plant species in steer diets at certain seasons. In most cases, these
differences mere observed only for minor forage species.
Similarity (%) between fecal samples, evacuated rumen samples,
and non-evacuated rumen samples varied with season and with
the particular techniques being compared. Similarity was lowest
in fall between fecal samples and evacuated rumen samples
(74%), and highest in summer (1989) between fecal samples and
non-evacuated rumen samples (93%). Differential digestion,
sampling procedures, and observer errors may explain these differences.
For practical purposes, fecal analysis appears to be one
of the best techniques to evaluate diet composition of large herbivores.
