Source :
Animal Feed Science and Technology
Descriptors :
Tal and FS-5 sorghum , Ensiling , Digestibility , Sheep , Sorghum composition
Abstract :
Changes in the response of short (Tal) and tall (FS-5) types of
forage sorghum varieties to irrigation level during summer and
subsequent fall growth were measured with respect to crop yield,
assimilate partitioning, chemical composition and digestibility. The
digestibility by sheep of silages made from Tal or FS-5 plants grown
for summer and fall harvests was also investigated. During summer
cycle, FS-5 plants attained maximal height of 3.2m and stem
diameter of 2–2.1 cm, whereas the upper height of Tal plants was
lower (1.7–1.8 m, P<0.05), and their stems were thinner (diameter
of 1.7 cm, P<0.05). Within each genotype, plants morphology
and chemical composition were not affected by irrigation from 180
to 250mm. Dry matter (DM) yields of the summer plants ranged
from 25.3 to 30.1 t DM/ha and was not affected by genotype or irrigation
level. Yield of the fall harvests attained to lower levels of
12.5–14.6 t DM/ha. Crude protein (CP) content was higher in Tal
than in FS-5 biomass. During the ensilage process, differences in
composition that were found in the green forages, disappeared
in the two genotypes, resulting in similar in vitro DM digestibility
(0.59–0.61) for both growth cycles. During ensilage most of the
soluble carbohydrates and in the case of Tal also part of the solubilized
hemicelluloses were converted mainly into lactate, acetate
and ethanol, resulting in similar and low pH values (3.7–4.0). High DM recovery during ensilage was found in all the genotypes. Voluntary
intake by sheep of DM and NDF from diets based on the fall
silages was higher than that of the summer silages however, there
was no difference in forage intake between the two genotypes. In
vivo DM digestibility by sheep was similar (0.61–0.64) in the two
genotypes irrespective of the growth season, and reflected their
similarity in NDF (0.51–0.55) and cellulose (0.61–0.64) digestibility.
The main difference between genotypes was observed in CP intake
and digestibility thatwere higher (P<0.05) in Tal than in FS-5 silages
grown in both cycles.
Title of Article :
Characteristics of tall versus short-type varieties of forage sorghum grown under two irrigation levels, for summer and subsequent fall harvests, and digestibility by sheep of their silages
Author/Authors :
Yosef, E. , Carmi, A. , Nikbachat, M. , Zenou, A. , Umiel, N. , Miron, J.
Author/Authors - جزئيات :
