Evaluation of maize and forage sorghum silages using Boran steers
Abstract
Digestion and feeding trials were conducted to evaluate maize
and forage sorghum silages in terms of chemical composition,
digestibility and animal performance. A digestion trial, using
six steers was conducted and treatments were: (1) maize silage;
(2) forage sorghum silage. Feed intake and water intake were
measured. A feeding trial using 27 Boran steers was conducted.
The treatments wer •'.:(1) maize silage; (2) forage sorghum silage.
Twelve steers were allocated to treatment one while the re~t were
allocated to treatment two. Feed intake and weight gains were
measured. Feed, weighback, faeces and urine samples were chemically
analysed using methods by AOAC (1975) and Van Soest (1963). Feed
intake and digestibility coefficients data were subjected to
analysis of variance. Student ItI test was used to compare the
means of feed chemical composition and animal performance.
Dry matter content (30.65%; 34.75%)) Crude protein (7.16%;
6.99%), Ether extract (4.47%; 3.86%), Ash (9.78%; 9.23%) and gross
energy in Kcal/g (OM) (4.07; 4.16) were not different (P <.05) in
maize and forage sorghum silages respectively. The fibrous
components were lower (P <.01) in maize silage than in forage
sorghum silage, i.e. Crude fibre (29.25%; 38.05%), Cell wall
content (54.49%; 68.99%), Acid detergent fibre (37.52%; 48.65%)
and Acid detergent lignin (3.88%; 5.95%) respectively. Silage
juice for pH determination was squeezed out using cheese cloth.
The pH in maize and forage sorghum silages were 4.04 and 4.21
respectively.
Maize silage was higher (P< .05) in diqes t tb ilit ies of
dry matter and energy than forage sorghum silage. Digestibilities
of crude fibre, cell wall content and acid detergent fibre were
higher (P < .01) in maize silage thani n forage so rghurnsilage.
The lower digestibility of forage sorghum silage may have been due to
its higher lignin content. Crude protein digestibility for
maize (34.17%) and fr~age sorghum silage (28.17%) were not
different (P < .05).
Whole grain kernels were isolated from the silages as fed and
also from faeces samples. Maize silage grain kernels were more
digestible than fora~2 sorghum silage whole grain kernels.
In the digestion trial, forage sorghum dry matter intake
{69.76 g/W·75) was higher (P <.05) than for maize silage (60.20
g/W·75). The difference in dry matter intake may have been due
to difference i'n dry matter content of the silages. In the feeding
trial the dry matter intake for maize silage (79.37 g/t.J'75)and
for forage sorghum silage (82.17 g/W·75) were not different (P <.05).
The average dry matter intake vias higher i,nthe feeding trial than
in the digestion trial. This may have been due to group feeding
effect in the feeding trial. Confinement in the digestion trial
may also have caused stress .'•h.i.ch may have 1owered the feed intake,
Steers on forage sorghum silage had higher (P <.05) weight
gains than those on maize silage. The steers used in the t riat
were brought from range areas and they were in poor condition.
Their poor condition prior to the trial period and inexposure
to silage feeding may have contributed to their performance.
On average maize and forage sorghum silage maintained the
weight of the steers.
Citation
Master of Science in Animal SciencePublisher
University of Nairobi Department of animal production