Sward structure management for a maximum short-term intake rate in annual ryegrass.

This study tested the hypothesis that different sward structures, which were constructed by varying the pre- and post-grazing sward heights of annual ryegrass pasture ( Lolium multiflorum Lam.) in southern Brazil, affect the short-term intake rate ( STIR) by dairy cows. Treatments consisted of four sward-management strategies defined by a combination of two pre- (25 and 15 cm) and two post-grazing sward heights (10 and 5 cm): 15-05, 15-10, 25-05 and 25-10. A completely randomized block design with four replicates was used for the experimental design. The STIR was determined by the double-weighing technique. Jaw movements were evaluated using automatic recorders ( IGER Behaviour Recorder). The results showed that treatment 25-10 allowed the animals to collect more herbage with a greater bite mass and thus resulted in a greater STIR. Treatments in which sward height was reduced to 10 cm generally favoured the ingestion process than treatments with a post-grazing sward height of 5 cm. [ABSTRACT FROM AUTHOR]