Effects of perennial ryegrass variety and ploidy on voluntary dry matter intake and in vivo digestibility in sheep

• Published in: Livestock science 2020-10, Vol.240, p.104164, Article 104164
• Main Authors: Garry, B., McGovern, F.M., Boland, T.M., Baumont, R., Lewis, E., O'Donovan, M.
• Format: Article
• Language: English
• Subjects: In vivo digestibility; Life Sciences; Perennial ryegrass variety; Vegetal Biology; Voluntary feed intake
• ISSN: 1871-1413; 1878-0490
• DOI: 10.1016/j.livsci.2020.104164

•Regardless of heading date time, of year significantly affects the digestibility of perennial ryegrass varieties.•As time of year progresses the intake and digestibility of tetraploid varieties increases over and above diploid varieties.•Perennial ryegrass varieties should be evaluated independently for dry matter intake and digestibility potential as variations in their chemical composition vary and significantly impact the traits in question. Two tetraploid varieties, Astonenergy and Delphin, and two diploid varieties of perennial ryegrass (Lolium perenne), Tyrella and Glenroyal, were evaluated for voluntary dry matter intake (VDMI) and in vivo organic matter digestibility (OMD) using Texel wether sheep housed in digestibility stalls. The structural profile and leaf, stem, dead proportions of the sward were also measured. The experiment was repeated on three occasions (Time Stage (TS)): May/June 2013 (TS1), August/September 2013 (TS2) and September/October 2014 (TS3). Data from both years were analysed separately. There was no variety effect on VDMI during TS1 (1481 ± 44.4 g/day), TS2 (1621 ± 41.7 g/day) or TS3 (1223 ± 86 g/day). There was a significant interaction between TS and variety for OMD (P