Revista Brasileira de Zootecnia
On-line version ISSN 1806-9290
MONTAGNER, Denise Baptaglin et al. Sward structural characteristics and ingestive behaviour of beef heifers in a Pearl Millet pasture. R. Bras. Zootec. [online]. 2009, vol.38, n.9, pp. 1668-1674. ISSN 1806-9290. http://dx.doi.org/10.1590/S1516-35982009000900005.
Ingestive behaviour of beef heifers and sward structural characteristics of Pearl Millet (Pennisetum americanum (L.) Leeke) were evaluated. The experiment was carried out in a randomized complete design following a repeated measure arrangement (three experimental periods) with three replications of two leaf blade masses (600 and 1,000 kg/ha DM), which were maintained using continuous grazing with variable stocking rate. The variables measured were sward height, herbage mass, leaf blade and stem bulk density in sward vertical strata (sward structural characteristics), grazing, idling, rumination time and bite rate of heifers (ingestive behaviour). Bite rate was modified by pasture management and was lower when the leaf blade mass was 1,000 kg/ha DM. The daily grazing, rumination and idling time of beef heifers were similar for both leaf blade masses. Structural variation of the sward, during the experimental period, altered the grazing, rumination and idling time of heifers, and affected the bite rate. In Southern Brazil, the beef heifers concentrate their grazing activities in the 12 p.m. to 6:00 p.m. period, decreasing the grazing between 12 a.m. and 6:00 a.m., even in the hottest season of the year.
Keywords : bite rate; grazing time; leaf blade bulk density; Pennisetum americanum; rumination time.