Feeding Behavior of Grazing Lambs in a Silvopastoral System during Dry Season in Brazil

The aim of this study was to evaluate the presence of shade on the behavior of grazing lambs during dry season in Jaboticabal, State of São Paulo, Brazil. The climate in Jaboticabal is classified as tropical-Aw, and the dry season starts in June, when this study occurred. Massai grass (Panicum maximum × Panicum infestum) was used as the forage and eucalyptus (Eucalyptus urophylla × Eucalyptus grandis) as the trees. Twenty-four crossbred lambs (23 ± 3.3 kg BW and approximately 90 d old) were blocked by initial BW and assigned into three experimental treatments: Unshaded (UN)= unshaded Massai grass pasture; Moderate Shading (MS)= Massai grass pasture with eucalyptus trees spaced 12 × 2m; Intense Shading (IS)= Massai grass pasture with eucalyptus trees spaced 6 × 2m. Light interception was the criteria for starting grazing period, and the residual pasture height was fixed in 20 cm. Animals were observed over 8 consecutive days in order to assess the grazing activities: feeding (FE), lying ruminating (LR), standing ruminating (SR), lying (LY), standing still (SS), searching for food (SF), and other activities (OA). Previously trained observers recorded the behavioral activities, every 10 minutes, from 0800 to 1700 h. Data were submitted to analysis of variance, using the MIXED procedure of SAS, and the treatments’ means were compared using Tukey test at 5% significance. Animals in UN spent more time on FE (UN = 64%, MS = 54%, IS = 51%, P < 0.0001), with no differences observed between treatments with trees. Time of LR was greater for IS (UN = 23%, MS = 25%, and IS = 32%, P < 0.0001). On the other hand, animals in MS stayed more time on SS (UN = 0.8%, MS = 4%, and IS = 1%, P < 0.0001) and SR (UN = 0.5%, MS = 0.9%, and IS = 0.3%, P = 0.0001), but both activities were similar between UN and IS. The activities LY, SF, and OA did not differ among treatments (P = 0.28, P = 0.61, and P = 0.09, respectively). The silvopastoral system improved the state of welfare of the lambs, shown by the greatest time spent lying ruminating.