Identification of nutritional status,emphasizing minerals,in northwestern zaire

Abstract

A study was conducted in northwestern Zaire during the beginning of the dry season (December 1994) at a specific ranch to determine the crude protein (CP), in vitro organic matter digestibility (IVOMD), and mineral content of the principal pasture forages. This region is located in Zaire at 4°36'N latitude and 20°28'E longitude. Average rainfall is 1695 mm a year and mean monthly temperature is 25.5°C. Soils are red lateritic clays. Thirty forage samples were collected at 2‐, 3‐, and 4‐week regrowths of Imperata cylindrica and Savanna Stylosanthes (excluding 2‐week age) from low and high elevation grazing areas. Eighteen soil samples and a mineral supplement fed to cattle (primarily N'dama breeding) were collected for analysis. There were decreases (PO.05) in IVOMD as plants matured and deficiencies of protein, sodium (Na), phosphorus (P), magnesium (Mg), and copper (Cu) at 4 weeks of regrowth. The mineral mixture fed to cattle provided less than 1% of the requirements for the deficient minerals. This study suggests the need for provision of a suitable free‐choice mineral supplement.