The nutritional ecology of Coke's hartebeest (Alcelaphus buselaphus cokei) in Kenya.
One male Coke's hartebeest (Alcelaphus buselaphus cokei) weighing 108 kg was used in a digestibility trial. Chopped medium-quality hay with 36.5% crude fibre (CF) gave organic matter digestibility (OMD) 56.0%. A different batch of hay with 39.1% CF gave mean OMD 58.4% in 2 sheep, which were losing weight and eating much less than the hartebeest in relation to metabolic weight. In each of January, April, July and September 1972, 6 adult hartebeest were shot in the Athi Plains, Kenya. They were weighed, air-dry rumen contents were measured, and in rumen contents plant parts were analysed, the food eaten being mainly grasses. Vegetation was sampled by clipping at the same times. OMD in vitro and gross energy of grass leaf, sheath and stem were estimated. OMD of grass leaf, sheath and stem ranged from 42 to 45, 33 to 44 and 17 to 37% and was lowest in the dry season in September. The crude protein (CP) contents ranged from 3.4 to 6.2, 3.2 to 6.3 and 2.1 to 2.9%. The daily DM intakes (DMI) were estimated from the formula DMI = g DM in rumen/overall retention time of DM in hours X 24. Assumed retention time was based on previous work (see NAR/B 48, 2470) and were corrected for the differing proportions of plant parts. DMI estimated in this way was used to calculate intakes of digestible CP, metabolizable energy (ME) and total digestible nutrients. The protein content of the diet selected was from 48%, decreasing to 5%, greater than that of the sward, the advantage by selective grazing falling as the dry season advanced. The hartebeest seemed to have a low water and energy requirement. ME and CP intakes fell below estimated maintenance requirements in September, when the animals could no longer gain much advantage from selective grazing.