2.1. Animals
Three adult malewild ruminants of each species; Thomson's gazelle
(Gazella thomsonii), Grant's gazelle (Gazella grantii), Oryx (Oryx beisa)
and wildebeest (Conochaetes taurinus) and four adult male domestic
ruminants of each species; Turkana goat (Capra hircus), fat-tailed sheep
(Ovis aries) and Zebu cattle (Bos indicus) were used in this study. The
wildebeest were over 1.5 years of age when captured, and remained in
captivity for a minimum of six months before being used in these
experiments. The Thomson's gazelle, Grant's gazelle and Oryx were
captured when they were only a few months of age and bottle-fed on
cow'smilk untilweaned. These speciesweremaintained in captivity for
a minimum of 1 year before the beginning of experimental studies. The
Turkana goats, fat-tailed sheep and Zebu steers were purchased from
pastoral nomadic tribesmen in the Northern Rift Valley Province of
Kenya. The adultweights of the animalswere;Grant's gazelle: 20–30 kg;
Oryx: 75–110 kg; Turkana goat: 15–30 kg; Fat-tailed sheep: 18–25 kg;
Zebu cattle: 250–320 kg; Thomson's gazelle: 11–15 kg;wildebeest: 130–
180 kg. The experimental studies on the animalswere carried out under
controlled laboratory conditions, in accordance with guidelines set
forth by the American Physiological Society (2002). The animals were
grouped into three groups: The Arid non-domestic (Grant's gazelle and
Oryx), Arid domestic (Turkana goat and Fat-tailed and Zebu cattle) and
the Non-arid (Thompson's gazelle and wildebeest).