Forage intake and nutritive value of sheep and goat diets in South-eastern Kenya
Abstract
The forage intake, botanical composition and nutritive value
of diets selected by free-ranging sheep and goats grazing together
in south-eastern Kenya were determined. Forage intake was estimated
using chromium sesquioxide orally administered daily to the
animals. Dietary botanical composition was determined using the
microhistological faecal analysis technique, whereas quality of
simulated diet samples was determined by chemical analysis for
crude protein, neutral detergent fibre, acid detergent fibre,
lignin, total ash and in vitro dry and organic matter
digestibilities.
Dry matter intake in gjday was similar (P > 0.05) for sheep
and goats within a given season, but in terms of metabolic
bodyweight (gjkg WO.7S), it was significantly lower (P < 0.05) for
goats compared to sheep during the dry season. Dry matter intake
averaged 471.3 gjday or 2% of bodyweight and 500.3 gjday or 2.5% of
bodyweight for goats and sheep, respectively. The lowest levels of
intake for both species (1.6% for goats and 2.0% for sheep) were
recorded during the wet season. Overall, sheep consumed 53.0 gjkg
WO·7S while goats had an average intake of 43.6 gjkg WO·7S•
Goats selected diets that were higher (P < 0.05) in crude
protein than did sheep i.e 16. 4% and 13. 5% , respecti vel y when
averaged across the two seasons. Sheep diets had lower (P < 0.05)
levels of lignin during the wet season compared to goats but the
lignin contents for both were the same during the dry season.
Goats, however, selected diets lower in neutral detergent fibre and
acid detergent fibre than did sheep. Goats were found to be better
adapted for survival in this environment than sheep.
In vitro dry matter digestibility of simulated diets were not
different between goats and sheep i.e 56.2% and 55.6%,
respectively. In vitro organic matter digestibility also did not
differ between the two livestock species i.e 55.1% and 56.5% for
goats and sheep, respectively. Digestibility coefficients of the
diets of both animal species were significantly higher (P < 0.05)
for the wet season than the dry season diets.
Goats' diets consisted mainly of browse (> 81%) while those of
sheep comprised mainly grasses (> 77%) during both seasons. Goats
consumed very_little forbs (> 2%) whereas browse was the least
utilized forage category by sheep « 8%). Neither species showed
significant change (P > 0.05) in the proportions of grass, forbs or
browse in their diets with change of season, and no single plant
dominated the diets of either livestock species. Sheep and goats
were therefore complimentary in their feeding in both seasons.
Citation
Ndung'u, J.N(1996). Forage intake and nutritive value of sheep and goat diets in South-eastern KenyaSponsorhip
University of NairobiPublisher
Department of Range Management, University of Nairobi
Description
Msc-Thesis