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

•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.