Abstract

VILLAREAL GONZALEZ, Jorge Armando et al. Herbage yield and quality of orchard grass (Dactylis glomerata L.), under different grazing frequencies and intensities. Rev. mex. de cienc. pecuarias [online]. 2014, vol.5, n.2, pp.231-245. ISSN 2448-6698.

The aim of this experiment was to study the performance of Orchard grass (Dactylis glomerata L.) based on herbage yield and quality under different grazing management. Three frequencies (2, 3 and 4 wk in spring and summer and 4, 5 and 6 wk in fall) and two grazing intensities (hard: 3 to 5 cm and lax: 6 to 8 cm of residual sward height), in a randomized block design with three replicates, distributed in a 2 x 3 factorial arrangement. Cumulative herbage yield (CHY), net herbage accumulation rate (NHAR), morphological composition and herbage quality were evaluated. The highest CHY and average NHAR were recorded with hard grazing every 4 and 6 wk. The highest seasonal herbage yield (7,844 kg DM ha^-1) and NHAR (107 kg DM ha^-1 d^-1) were observed during summer with hard grazing every 4 wk (P<0.05). There were not statistical differences in herbage yield and NHAR during spring between grazing frequencies. In fall, 5 wk grazing frequency was higher than 4 wk (P<0.05), but it was similar to 6 wk (P>0.05). Across all seasons, hard grazing gave higher forage yield than lax grazing, being different in spring and summer (P<0.05). In overall, total protein and in vitro dry matter digestibility tended to decrease as grazing interval increased, being on average 20 and 65 %, respectively. It was concluded that to obtain the highest herbage yield and quality, orchard grass must be grazed hard every 4 wk in spring-summer and every 5 wk in fall.

Keywords : Dactylis glomerata L.; Grazing; Yield; Net accumulation rate; Nutritive value.