CERZOS   05458
CENTRO DE RECURSOS NATURALES RENOVABLES DE LA ZONA SEMIARIDA
Unidad Ejecutora - UE
artículos
Título:
Preferences for Italian ryegrass (Lolium multiflorum L.) and barley (Hordeum vulgare L.) herbage as choices.
Autor/es:
CATANESE, F; DISTEL, R; ARZADUN, M
Revista:
GRASS AND FORAGE SCIENCE (PRINT)
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2009 vol. 64 p. 304 - 309
ISSN:
0142-5242
Resumen:
Partial preference for feeds in ruminants is a well documented phenomenon although their explanation
can be elusive. The hypothesis was tested that sheep offered herbage of two annual grass species differing in
chemical composition free-choice would select a diet that would maximize the nutritive value of the diet compared
with sheep offered each herbage separately through a greater nutrient balance and synchronization of nutrient
release for efficient ruminal microbial function. Fifteen male lambs were placed into metabolic cages, and
randomly assigned to three treatments (n = 5): Italian ryegrass fresh herbage (treatment R), barley fresh herbage
(treatment B) or free-choice Italian ryegrass and barley fresh herbage (treatment RB). Both herbages had
similar crude protein concentrations but Italian ryegrass herbage had higher concentration of water-soluble
carbohydrates and lower concentration of fibre than barley herbage. Lambs were exposed to the treatments
for 15 d. Lambs on treatment RB showed a partial preference of 0.82 (s.e. 0.031) for Italian ryegrass. Lambs
on treatment RB had higher intakes of digestible dry matter and higher values for nitrogen retention than
lambs on treatment B although similar to that of lambs on treatment R. The results for the dietary choices were not
always consistent with maximizing the nutritive value of the diet. Other explanations, such as lambs needed to
sample and track the nutritive value of dietary options or there was the development of transient food aversions,
were also possible.