Tree shade efects on water intake and weight gains of grazing sheeps

Abstract

The effect of the shade proyected by Acacia caven (Mol.) Mol on the intake of water and liveweight of Suffolk sheep on an annual pasture of mediterranean climate was evaluated. The trial was conducted under two conditions in a one-ha fíeld where tree species had been eliminated, and in another field where a density of 59 A. caven trees per hectare was maintained. Mean height of trees was 3.5 m, mean canopy diameter 4.8 m, and height to foliage 1.1 m. In both conditions there were portable drinking troughs with ad lib water availabity. Six ewes and ane ram were kept in each field. Water intake was measured from January to March 1996. The intake by animals which had access to the shade was significantly inferior (P < 0.05) since in the control period it did not exceed 7.5 1 per animal daily. Conversely, the ewes with no access to shade consumed 11.3 per animal daily during the three control months, that is a 33 per cent of grater intake. Beside, during the mating season the mean liveweight increased 11 kg/animal in the former treatment and 5.3 kg/animal in the latter, a difference of 103.3% (P < 0.05).