A comparison of the establishment, productivity, and feed quality of four cocksfoot (Dactylis glomerata L.) and four brome (Bromus spp.) cultivars, under leaf stage based defoliation management

Abstract

A glasshouse study was undertaken to investigate the differences in rate of establishment, productivity, feed quality, and response to defoliation frequency between new and old cultivars within the brome (Bromus spp.) and cocksfoot (Dactylis glomerata L.) genera. Three of the more recent brome (Bareno, Gala, and Exceltas) and cocksfoot (Tekapo, Megatas, and Uplands) cultivars were compared with Matua and Kara, the most widely sown and utilised brome and cocksfoot dairy pasture cultivars, respectively. The improvements resulting from breeding and selection within the cocksfoot genera included faster seedling emergence and tiller production during establishment, higher tiller density once established, lower acid detergent fibre (ADF), higher crude protein (CP), and higher metabolisable energy (ME) concentrations. The newer cocksfoot cultivars had lower leaf and tiller dry matter (DM) yields than Kara, with little variation in ME levels between cultivars. The improvements resulting from breeding and selection within the brome genera, measured in this study, included faster seedling emergence, lower ADF, and higher CP concentrations. The higher fibre levels for Matua did not translate into a lower ME concentration; in fact, the energy content in Matua and Gala was higher than for all remaining cultivars. There were further similarities between Matua and Gala, the high water-soluble carbohydrate levels, leaf, and tiller DM yields of these cultivars, reflecting a strong regrowth response to defoliation. Further research in the field is required to confirm the observed variation within and between cocksfoot and brome cultivars, and to quantify the potential benefits of using the new v. the original cultivars.