Abstract

Four farmlets were established at a stocking rate of 4.41 Friesian cows per hectare to compare rolled maize grain, maize silage and a nutritionally balanced ration as supplementary feeds for grazing dairy cows, for three complete seasons. Supplements were offered whenever it was estimated the herds were eating less than 15 kg DM/cow/day or were leaving a post-grazing residual herbage mass of less than 1800 kg DM/ha. Offering 1.3 to 1.5t DM/cow/year of supplement increased net herbage accumulation from 18.3 to 19.2 t DM/ha, however, this did not result in higher annual herbage intake. The use of rolled maize grain, maize silage, and balanced ration supplements increased production from 1188 kg milksolids (MS)/ha to 1763, 1602, and 1769 (±69.6) kg MS/ha/year, with responses of 98, 77, and 99 g MS/kg DM, respectively. The magnitude of the response to the supplementary feed was directly proportional to the increase in metabolisable energy supplied by the supplement. Full lactation responses to supplementary feeds were two fold greater than those measured in short term feeding trials. Responses of 7.5g MS/MJME can be expected over the complete lactation when supplements are offered to dairy cows grazing restricted pasture.

JW, Penno, JM McGrath, KA MacDonald, M Coulter, and JAS Lancaster

Proceedings of the New Zealand Society of Animal Production, Volume 59, , 188-191, 1999