A comparison of high nitrogen and clover based swards grazed by summer calving cows

Extract

The herbage intake of June/July calving cows in early lactation is limited by a number of factors including the quality of the sward. A typical management strategy is to graze dry cows at a high stocking rate at turnout to maximise the silage area and graze the freshly calved cows on silage aftermaths. A further refinement could be the use of clover rich swards. Winter feeding experiments have demonstrated that animals can eat more and perform better when offered a clover rich silage rather than a conventional silage. The following experiment was carried out to establish whether similar benefits would result from the grazing or clover rich swards.

In a continuous design experiment lasting 12 weeks, sixteen summer calving British Friesian cows (mean calving date 7 June) were allocated to either a perennial ryegrass dominant sward (PRG) or a white clover rich sward (WC) silage aftermath. The target sward height was 7-10 cm measured by swardstick. Additional cows were available on a put and take basis to maintain parity between the sward heights in the two treatments.