Determinants of wet season landscape and forage selectivity by cattle on farm Kiamsab West 364, central Namibia
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Date
2025
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University of Namibia
Abstract
Forage shortages are increasing in frequency and severity, affecting livestock farmers
in Namibia. Cattle grazing preferences are well documented in various ecosystems but
remain unknown in patchy, arid environments. This study investigated the
determinants of forage and landscape selectivity by cattle during the wet season at
Farm Kiamsab West, Central Namibia. Transects were demarcated on crests (n = 12,
72 plots) and slopes (n = 13, 78 plots) based on where cattle had been observed grazing,
grazing signs, and accessibility. In each plot, species were identified to species level,
grazing status was recorded, cover was visually estimated, and above-ground biomass
was collected. Forage selectivity was determined with Jacob's Selectivity Index (JSI).
Percentage slope, elevation, species richness, species diversity (H'), cover, and
biomass were explanatory variables in the Canonical Correspondence Analysis (CCA)
to identify landscape selection determinants. The Chi-Square Test of Association
revealed that cattle exhibit selective foraging behaviour (χ² = 17.416, df = 2, p = 0.001).
The JSI demonstrated that cattle selected grasses such as Eragrostis nindensis,
Anthephora pubescens and forbs Cleome suffruticosa, and Tribulus terrestris. Forage
selectivity is linked with plants’ nutritional value, palatability, and availability in the
landscape. The CCA showed that explanatory variables explained 36.7% of the
observed variation in landscape-type selection. The overall test of all canonical axes
(F = 1.4, p = 0.002) was significant, with elevation (F = 1.9, p = 0.004), species
richness (F = 1.6, p = 0.014), and slope (F = 1.6, p = 0.02) significantly influencing
landscape-type selection. These determinants influence forage accessibility,
availability and determine the balance of costs and benefits for selecting a landscape
type, guiding cattle to forage where benefits outweigh effort. These findings inform
targeted rangeland management strategies to promote preferred species, emphasizing
ii
the importance of prioritizing richness, elevation and slope in managing mountainous
rangelands
Description
A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Science in Environmental Science
Keywords
Foraging behaviour, Species richness, Elevation, Percentage slope, Crests, Slopes, Namibia, University of Namibia