EFFECTS OF HERBAGE AND BUSH LEVEL ON DIET SELECTION AND NUTRIENT INTAKE OF CATTLE IN A COMMIPHORA SAVANNA

Effects of season, available herbage, and bush level on dietary compos ition and preference, plus dietary crude protein, digestible organic m atter, and forage intake were determined for cattle in a Commiphora sa vanna of south-central Kenya. Grass dominated the diet selected at all bush and herbage levels. However, browse levels in the diet increased when grass consumption declined, particularly at low herbage levels ( < 500 kg/ha) and during the dry-wet transition period. Principal grass es in the diet included Chloris roxburghiana, Cymbopogon pospochilii a nd Digitaria macroblephara, while Hermania alhiensis was the dominant browse in diets. Season strongly affected dietary crude protein (CP) a nd energy intakes but had little effect on in vitro digestible organic matter. Dry season CP intake was below maintenance levels due to low forage CP. However, low herbage levels during the dry season were asso ciated with below-maintenance energy intake and reduced forage digesti bility, while normal herbage levels were associated with energy intake s above maintenance and higher forage digestibility. Although CP and e nergy concentrations were relatively high during the dry-wet transitio n period, CP and energy intakes were at or below maintenance, respecti vely, due to depressed forage intake. Apparently, green herbage scarci ty and inefficient browse harvestability restricted intake during the dry-wet transition season.