Alternative forages: There has been a fair bit of discussion in the last year surrounding alternative forages, with the jury still very much out on their potential role in Irish grazing systems. There is no doubt that they have potential to increase animal performance, with the issue being poor longevity. At the Teagasc sheep conference on Tuesday night, Professor Paul Kenyon of Massey University, New Zealand, outlined that to enhance longevity of a herb clover sward requires totally different management practices to conventional grass swards.
Paul said crops should never be grazed below 8cm in height as this will reduce the ability of the crop to compete with grass or weeds and result in poor persistency. The optimum grazing height outlined is grazing between 8cm and 16cm, with a crop rested for at least three to four weeks post-grazing or until it has reached at least 16cm. As such, a rotational grazing system is essential, with animals requiring a five to seven-day adjustment period. This means that to obtain the maximum value from the crop, animals must be capable of being retained on it and not coming on and off the crop. Because of this, precise management is required in budgeting the number of animals a crop can sustain.