Skip to Main content Skip to Navigation
Conference papers

The effect of perennial rygrass cultivars and allowance on utilisation, grazing efficiency and milk production

Abstract : The objective of this study was to investigate the effect of four cultivars (AstonEnergy, Delphin, Glenroyal and Tyrella) on sward utilisation, milk production and grazing efficiency of lactating dairy cows at two daily herbage allowances (DHA) during the vegetative growth phase. Four cultivars were compared by offering cows two levels of DHA 15 and 20 kg dry matter (DM) cow-1 day-1 (>4cm), resulting in 8 treatments. Increasing herbage allowance from 15 to 20 kg DM cow-1 day-1 increased milk yield and solids, but reduced sward utilisation with grazing efficiency being unaffected. AstonEnergy had a longer free leaf lamina (P<0.001; + 4.6 cm) but also higher leaf (P<0.001; + 0.14) and lower stem (P<0.01; -0.08) than Glenroyal. This resulted in a higher sward utilisation (P<0.001; +12%) milk yield (P<0.05; +1 kg) and milk solids (P<0.05; +0.1 kg) than Glenroyal. Delphin was most similar to AstonEnergy in sward structure and gave similar sward utilisation and milk production, whereas Tyrella was broadly equivalent to an average of the examined cultivars and also supported an intermediate milk output. Cultivars with longer free-leaf-lamina and higher leaf content were associated with reduced number of grazing bites (P<0.05) and ruminating time (P<0.001).
Document type :
Conference papers
Complete list of metadata

Cited literature [7 references]  Display  Hide  Download
Contributor : Migration Prodinra <>
Submitted on : Tuesday, June 2, 2020 - 9:02:49 PM
Last modification on : Monday, March 22, 2021 - 2:22:08 PM
Long-term archiving on: : Wednesday, December 2, 2020 - 6:45:26 PM


Delaby 2016 EGF_1.pdf
Publisher files allowed on an open archive


  • HAL Id : hal-02738593, version 1
  • PRODINRA : 370448



J. Mcdonagh, T.J. Gilliland, Mary Mcevoy, Luc Delaby, M. O'Donovan. The effect of perennial rygrass cultivars and allowance on utilisation, grazing efficiency and milk production. 26. General meeting of the European Grassland Federation (EGF), Sep 2016, Trondheim, Norway. ⟨hal-02738593⟩



Record views


Files downloads