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Dietary preference and grazing behaviour of male hoggets (6-8 months old) grazed on Cenchrus ciliaris pasture were continuously monitored from 08:30-17:30h at weekly intervals from December to March. Population distribution (%) and preference index of Cenchrus ciliaris and Crotalaria burhia forb and dead litter were 21.11, 2.01; 6.31, 8.41 and 9.32, 1.60 respectively. Daily rhythmic periodicity in grazing pattern of hoggets was observed with two major periods of active grazing at 08:30-12:50 and 14:20-17:30. Increase in environmental temperature from December (20.6 degrees C) to March (31.2 degrees C) resulted in a decrease (P < 0.05) in the length of the grazing period from 8.36 to 7.40 h and an increase in the length of the resting period from 24 to 80 minutes. The study revealed that Crotalaria burhia needed to be protected in bush cleaning operations owing to its preference by sheep during summer. Furthermore, grazing periods of animals should be increased during the dry season in order to achieve optimal production. (C) 1997 Elsevier Science B.V.