Seasonal nutrient fluctuation in selected plant species in the Kalahari

Abstract

Seasonal changes in crude protein, phosphorus and calcium contents of five common plant species in the south-western Kalahari were investigated. Three species that are browsed by springbok (Acacia erioloba, Grewia flava and Rhigozum trichotomum) and two grass species (Schmidtia kalahariensis and Stipagrostis obtusa), were included in the study. Browse species had higher crude protein, phosphorus and calcium contents than the grass species, but the fluctuation range was similar to that of the grass species. In general, the crude protein content of the food plant species sampled in the present study was above the level required by African ungulates for maintenance. However, the diet of springbok in the south-western Kalahari appeared to be phosphorus deficient. Crude protein and phosphorus levels in plant food were especially low during the cold-dry season, when the crude protein content of the grass species was at or below that which is required by springbok for sustenance. The phosphorus content was below ruminant requirements in all plant species in all habitats during the cold-dry season. Faecal crude protein and phosphorus percentages higher than that of the selected plant species investigated imply that springbok have the ability to select the most nutrient-rich plant species and plant parts available. The Ca:P ratio of the plant species that were sampled in the present study fell outside the range that is considered to be healthy for ruminants in all instances, with calcium in excess.

Post-Release Monitoring of Diet Profile and Diet Quality of Reintroduced African Buffalo (Syncerus Caffer) in Umfurudzi Park, Zimbabwe

“…Our results show that grass crude protein levels were higher in the wet season compared to the hot dry season, confirming seasonal variation in the levels of crude protein in forage [31,35]. However, we noted no differences in crude protein levels between the wet season and cool dry season, which we attribute to availability and acceptance of palatable nutritious grasses [36].…”

“…The seasonal variation in diversity of species selected by the reintroduced buffalo in Umfurudzi Park has been also observed elsewhere [21,30]. During the wet season, reintroduced buffalos were less selective and utilized a wider spectrum of grass species than in the dry season likely because the nutritive value of grasses generally changes with their morphological development, declining with advancing phenological stage [31]. As the growing stage progresses, i.e.…”

Drivers of diet selection of critically endangered Western Derby eland during the food shortage period within conservation breeding in Senegal

“…Highly diverse herbivore diets, as in the case of WDE in the wild 11 , considered an evolutionary adaptation to varied contents of nutrients accompanied by toxins, imply preferences for and avoidances of particular plant species 12 . Animals might select diets with a higher content of antinutritional or imbalanced compounds as a consequence of selection for nutrients in plants which contain both type of compounds together 13,14 , especially in critical periods of food supply shortage and decrease of nutrient contents below optimal levels 15 .…”