Grazing Capacity Estimation: why include biomass estimates from arable lands

Abstract

Forage for ruminants in the dry season were assessed and matched with feed requirements in three villages in Zimbabwe, namely; Chiweshe, Makande and Mudzimu. Stocking rates were compared with grazing capacity to determine grazing intensities. Grazing capacities were estimated with or without crop residues to assess the importance of crop residues in livestock feeding during the dry season. 333,742, 5,320 tonnes of forage DM were estimated from crop yield in arable lands from Chiweshe, Makande and Mudzimu, representing 19.2, 31.8 and 81.3% respectively of total available forage DM produced in the villages. Including crop residues in the estimation of grazing capacity, all three villages were understocked. However, without the contribution of crop residues, the grazing intensities changed. Grazing capacities for Chiweshe, Makande and Mudzimu declined from 2.8 to 4.9, 1.5 to 2.8 and 1.1 to 8.2 ha/LU representing a reduction of 44, 46 and 87% respectively, making all three villages overstocked. Results obtained revealed that in areas with intensive crop production, crop residues assume great importance in decreasing the level of feed deficit in the dry season. When the contribution of crop residues is taken into account in grazing capacity estimates, the level of grazing intensity is not as high as is normally depicted.