Effects of harvesting red clover/ryegrass at different stage of maturity on forage yield and quality

Total nitrogen concentrations and digestibility of perennial ryegrass (Lolium perenne; PRG) and red clover (Trifolium pratense; RC) decline with increasing maturity. However, whilst harvest date is negatively correlated with silage digestibility, it is positively correlated with herbage yield. Currently, there is a lack of information on the ideal cutting stage for mixtures of red clover grown in combination with ryegrass. An experiment was conducted to examine the effects of increasing harvest date on growth stage, dry matter yield, species ratio, forage composition and digestibility of red clover (cv. AberClaret) and perennial ryegrass (cv. AberMagic) grown as a mixed sward. First cut silage was harvested at weekly intervals on 5 occasions from early May to early June, and second cut silage was harvested at weekly intervals on 5 occasions from mid-June to mid-July. Forage nitrogen, neutral detergent fibre and digestible organic matter in the dry matter concentrations were affected by harvest date in both cuts and were significantly correlated with the growth stages of both PRG and RC. Overall, the growth stage of RC was a better indicator of sward forage quality than growth stage of PRG especially in the second silage cut