Botanical Composition of Goat Diets in Thinned and Cleared Deciduous Woodland in Northeastern Brazil

Abstract

Clearing and thinning of caatinga vegetation in northeastern Brazil are viewed as methods of optimizing forage and wood production. Our study compared the botanical composition of goat diets relative to forage availability in undisturbed, cleared and 2 levels of thinned (25% and 55% canopy cover) stands of tropical woodland. Clearing and thinning of caatinga vegetation resulted in higher amounts of available forage through the wet season and up to the time of leaf fall. At the end of the growing season, available herbaceous biomass was generally 7 to 8 times higher on the treated pastures than on the control; biomass of available browse was about 4 times greater. After leaf fall, total available forage was similar for all 4 treatments but about 90% of the available forage on the control was leaf litter. Diet composition differed among the treatments only in February and May; at this time, goats on the treated pastures were selecting higher amounts of herbaceous vegetation than those on the control pastures. Even though browse availability was high throughout the wet season on the treated pastures, herbaceous vegetation was the primary dietary constituent. Only during the mid to late dry season, when herbaceous vegetation was dead and leafistem ratios were low, was browse consistently selected at high levels. We concluded that clearing and thinning increases the amount and diversity of available forage; thereby, improving foraging conditions. Moreover, production of herbaceous vegetation declines towards control levels only at some canopy cover higher than 55%.

Forage production and small ruminant grazing responses in Mediterranean shrublands as influenced by the reduction of shrub cover

“…Reduction of the woody component resulted in an increase of the standing herbaceous vegetation. This was expected and demonstrated in similar previous studies (Kirmse et al, 1987b;Schacht and Malechek, 1990;Papanastasis and Liacos, 1991).…”

Use of paired plots and multivariate analysis for the determination of goat grazing preference

“…Goats have been domesticated worldwide, including areas with harsh environmental conditions. Studies in various parts of the world have shown their grazing selectivity (Malechek & Leinweber 1972;Provenza & Malechek 1984;Schacht & Malechek 1990). It is known that goat browsing results in changes of plant species composition; some species decline, whereas those avoided by goats increase (Riggs & Urness 1989).…”

Preference Indices for Forage Species Grazed by Spanish Goats on a Semiarid Shrubland in México

“…The goats are opportunistic foragers and can maintain a high quality diet under diverse conditions (Schacht and Malechek, 1990;Elamirez et al, 199Oa). As a result goats have acquired a reputation for survivability on harsh, degraded rangelands (Devendra, 1978).…”