Effect of the presence of shade in sheep grazing areas. 2. Animal activity

In order to evaluate the activities done by grazing sheep, in the presence or absence of artificial shade, 24 West African ewes of 18,73 [+ or -] 2,36 kg of average live weight were used, separated into two treatments: T1: without shade (NS) and T2: with shade (WS). The shade was provided by a canopy of synthetic mesh (70% shade) in paddocks with Cynodon nlemfuensis. The ambient temperature (AT in[degrees]C), relative humidity (RH in%) and solar radiation (SR in W/[m.sup.2]) were measured; and the temperature and humidity index (THI) was calculated. On three days per week (Tuesday, Wednesday and Thursday) observations of the animals were carried out, from 9:00 to 9:30 h and from 13:00 to 13:30 h, during the four weeks of the trial. The activities done by the ewes were recorded: "grazing", "walking", "standing", "ruminating", "defecating", "drinking water" and "urinating". The average AT was 29,8[degrees]C in the paddock with artificial shade and 29,4[degrees]C in NS; while RH was higher in WS (62%) than in NS (51%) SR was higher in NS (556,6 W/[m.sup.2]) than in WS (0 W/[m.sup.2]). The THI was higher in WS (79,2) than in NS (77,6). The most frequent activity was grazing, which turned out to be higher (p < 0,01) in NS than in WS (71,0 and 65,2%, respectively). Other less relevant activities were: walking, defecating, urinating, standing, ruminating and drinking water. To conclude, the behavior was affected by climate variables, and the activities were more frequent in treatment NS than in WS. Keywords: behavior, relative humidity, solar radiation, temperature.