Comportamento de ovinos em capim-tanzânia sob lotação rotativa com quatro níveis de suplementação concentrada

Abstract

The sheep behavior over 24 hours in Tanzania grass irrigated pastures under four supplementation levels (0.0; 0.6; 1.2 and 1.8% LW) was evaluated in this work. A complete randomized design with six replicates (sheep) was used. The percentage of total time under shade, grazing, ruminating, in "other activities", in idleness, the number of supplement/salt ingestions, defecations, urinations, water ingestion and bite rate were estimated, splitting the day in eight periods of three hours (from 5 to 8 a.m.; 8 to 11 a.m.; 11 a.m to 2 p.m; 2 to 5 p.m.; 5 to 8 p.m.; 8 to 11 p.m.; 11 p.m. to 2 a.m.; 2 to 5 a.m). The highest grazing time occurred in animals without supplementation and decreased gradually and increased back again in the supplementation level of 1.8% LW. The rumination time was higher in the supplementation level of 0.6% LW, mainly in the periods from 2 a.m. to 5 p.m and from 5 p.m to 8 p.m. The idleness time was higher in the supplementation level of 1.2% LW. Water ingestion increased up to time the supplementation level of 1.2% LW and was concentrated in the period from 11 a.m to 2 p.m. The urination and defecation frequency was higher in the supplementation level of 1.8% LW. The gradual increase of bite rate up to the supplementation level of 1.2% LW, in the periods from 11 p.m to 8 p.m, with posterior decrease, suggests an additive effect of the supplement on the grass until such level, and a substitutive effect beyond this level. The total time under shade was concentrated in the periods from 8 a.m. to 2 p.m and decreased with the supplementation level up to 1.2% LW. The supplementation level affected the sheep behavior under grazing, where the supplementation level of 1.2% LW presented optimization of the ingestive capacity of the grazing sheep. The highest supplementation levels compromised the ingestive behavior, suggesting that changes on ration formulation in such levels should be implemented. © 2009 Sociedade Brasileira de Zootecnia.