Resumen

ESPINOZA, Freddy; HERNANDEZ, Rafael Alejo  y  FOLACHE, Luis. Ethology of double purpose heifers in a silvopastoral system during the dry season in a tropical savanna. Zootecnia Trop. [online]. 2008, vol.26, n.4, pp.429-437. ISSN 0798-7269.

In order to evaluate the behaviour of double purpose heifers in a tropical dry forest during the dry season, it was carried out a study during the dry season in the municipality of San José de Guaribe at North of Guárico state, Venezuela. Treatments were G: Grazing of star grass, Cynodon nlemfuensis, GRA: Grazing of C. nlemfuensis with restricted access to forest, and GFA: Grazing of C. nlemfuensis with free access to the forest. A grazing pressure of 6 kg DM/100 kg LW was used. Seven heifers in G, six in GRA, and 10 in GFA were used in paddocks of 0.5, 0.5 and 3 ha, respectively. The evaluation was made during three days following the activities of the animals: grazing, ruminating, intake of fallen leaves, water drinking, browsing, resting, defecating, and urinating. A design of blocks at random was used, where each animal represented a repetition (three/treatment). The data were analyzed through descriptive statistic. The distribution of the grazing time tended to be different, being higher for G with a total of 53%; whereas in GRA and GFA it varied between 41 and 43%. Animals tended to ruminate prostrated during the nocturnal hours with average of 20%. During the day when the animals entered to the forest, the intake of fallen leaves was the most important activity (9%). Grazing of the animals in G and GRA was around sunrise, whereas in GFA was the intake of fallen leaves. A greater diversity of cycles of grazing was obtained in G. It is concluded that the introduction or use of other consumable plant components by the animals, besides to increase the availability and consumption of dry matter during the dry season, modify the ethology.

Palabras clave : grazing; ruminating; intake of fallen leaves; water drink; browsing; resting; defecating; urinating.

        · resumen en Español     · texto en Español     · Español ( pdf )