Effect of the presence of shade in sheep grazing areas. 1. Selection of forage species

In order to evaluate the effect of shade on the selection of forage species by grazing sheep, a trial was conducted at the Experimental Sheep Unit, Animal Production Institute, School of Agronomy, Central University of Venezuela. Twenty four West African ewe lambs were used (18,73 ± 2,36 kg), randomly distributed in two treatments: T1: no shade (NS) and T2: shade (S). The shade was provided by a canopy of synthetic mesh (70 % shade) placed at a height of 2 m for a 36-m2 covered area, over enclosed pastures (0,13 ha) sown with Cynodon nlemfuensis. The plant species were identified and the height, cover and biomass production were measured. The grazing animals were observed (15 min/animal) with binoculars in two time periods: 9:30 a.m. to 10:00 a.m. and 1:00 p.m. to 1:30 p.m., and the intake per species and consumed plant part were recorded. Twenty seven species belonging to 14 families were identified. The variables plant height and cover differed per treatment (p ≤ 0.05), and biomass production was affected by treatment, sampling and stratum (p ≤ 0.05). The species with the highest selection percentage by the animals was C. nlemfuensis (95 %). Leaf intake was higher during the morning period (96 %) than the afternoon period (71 %). It is concluded that artificial shade influenced the forage species selection by the ewe lambs.