Translator Disclaimer
5 March 2015 Grazing defoliation and nutritive value of Setaria pumila and Digitaria sanguinalis in Lolium perenne-based swards
K. N. Tozer, C. A. Cameron, L. Matthews
Author Affiliations +
Abstract

Setaria pumila and Digitaria sanguinalis are undesirable, C4 annual grass species in intensively managed temperate and subtropical dairy pastures. A comparative, small-plot study was established in Lolium perenne-based dairy pastures to determine the extent to which these species are grazed and how this relates to changes in their nutritive value over summer–early autumn. Setaria pumila was taller than D. sanguinalis before grazing (16–24 and 10–17 cm, respectively) and was grazed to lower post-grazing height and less post-grazing groundcover than D. sanguinalis: height 4.1 and 4.7 cm, cover 67 and 83%, respectively, averaged over January–March (summer–early autumn). Nutritive quality was similar for both species (with metabolisable energy values for December–March averaging 11.1, 10.0, 8.5 and 9.0 MJ kg DM–1) and is unlikely to be a key determinant of differences in grazing defoliation. In addition, post-grazing cover and post-grazing height for both annual grasses increased over the grazing season and were associated with declining nutritive value of both species. The nutritive value of L. perenne was higher than that of both S. pumila and D. sanguinalis and it did not decline over the grazing season (December–March: 11.3, 11.5, 9.3 and 11.4 MJ kg DM–1). Although S. pumila and D. sanguinalis were grazed in all months, they readily produced new panicles between grazings. Given this, these annual grasses are likely to spread in Lolium perenne-based dairy pastures unless interventions are used.

© CSIRO 2015
K. N. Tozer, C. A. Cameron, and L. Matthews "Grazing defoliation and nutritive value of Setaria pumila and Digitaria sanguinalis in Lolium perenne-based swards," Crop and Pasture Science 66(2), 184-191, (5 March 2015). https://doi.org/10.1071/CP14079
Received: 14 March 2014; Accepted: 1 October 2014; Published: 5 March 2015
JOURNAL ARTICLE
8 PAGES


Share
SHARE
KEYWORDS
grazing defoliation
nutritive quality
pasture performance
pasture productivity
summer grass
yellow bristle grass
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top