Further Comparisons Between a Rigid Rotational Wye College' System and Other Systems of Grazing for Milk Production

In two 20‐week grazing experiments, a rigid rotational system of grazing termed the ‘Wye College’ system was compared with a flexible paddock‐grazing system in 1972 and with strip grazing and set‐stocking in 1973. Eight spring calved Ayrshire cows were used on each treatment at a stocking rate of 5 cows/ha (2 cows/ac). The mean daily milk yields per cow were 17·7 and 17·0 kg(39·0 and 37·5 Ib) on the Wye College and the paddock systems, respectively, in 1972; and 17·9, 17·7 and 16·4 kg (39·4, 38·9 and 36·2 Ib) on the Wye College, strip, and set‐stocking systems in 1973. The average annual output of milk varied from 11,500 kg/ha (1030 gal/ac) on the set‐stocking system to 12,500 kg ha (1120 gal/ac) on the Wye College system, but none of the differences was significant. The most rapid decline in daily milk yield occurred on the set‐stocking system in August and September as the amount of available herbage declined. This system requires further investigation. It is concluded that the Wye College system, with its rigid and pre‐determined grazing cycle was as effective as either a one‐day paddock or a daily strip‐grazing system in producing high yields of milk.