Grazing and browsing times of goats with three levels of herbage allowance

Goats have been reported to browse and graze in different proportions durin g the year varying with the quantity and quality of available forage. Never theless, the proportions of these behaviors when the standing crop of bush and herbaceous forage is kept constant in availability (dry matter/ha) and varied in height (canopy) has been largely ignored. In this experiment thre e adjacent mixed irrigated pastures of grass (Cenchrus ciliaris) and shrub (Leucaena leucocephala) were used. Grass height was maintained at 27, 14 an d 7 cm for treatments I, II and III, respectively, while the height of bush es (6666 plants/ha) were all kept at 150 cm. Dry matter availability was es timated on a weekly basis. Six 2-month-old Saanen female goats were placed in the three pastures (two goats per pasture) every morning from 0700 to 08 00. One person observed each treatment (pasture), registering the time that each animal spent browsing, grazing and engaged in other activities. Every week, pairs of animals were assigned to a different treatment. By the end of the experiment (21 weeks), each pair of goats, had been observed for 7 w eeks in each treatment. Across treatments goats grazed 63%, browsed 32% and were engaged in other activities for 3% of their time. The time spent brow sing declined (P < 0.05) while time spent grazing increased (P < 0.05) as g rass height increased. Other behaviors, remained constant. It is concluded that height of the grazing strata can influence time goats spend grazing an d browsing when accessibility to browse is held constant. (C) 1999 Elsevier Science B.V. All rights reserved.