Production and composition of milk by dairy cows fed common vetch or lupin grain as protein supplements to a silage and pasture-based diet in early lactation

Abstract

Milk production and composition were measured for 49 days in early lactation in 40 Holstein-Friesian cows fed 8 kg/day (fresh weight) of 1:1 mixtures of either rolled barley-lupin grain (Lupinus angustifolius L. cv. Gungurru) or barley-common vetch grain (Vicia sativa L. cv. Blanche Fleur). All cows were fed 1 kg/day of a pelleted concentrate containing minerals and vitamins, and wilted perennial ryegrass-subterranean clover pasture silage was available ad libitum with restricted grazing of perennial ryegrass-subterranean clover pasture. Cows ate all of the barley-lupin grain and barley-vetch grain mixtures. Mean daily dry matter intakes of silage (kg/cow.day) were 9.9 and 9.8 for cows fed the barley-lupin grain and barley-vetch grain mixtures respectively. Estimated pasture DM intake was 3.0 kg/cow.day. Mean daily yields of milk (L), fat (kg) and protein (kg) were significantly (P<0.001) greater for cows fed the barley-lupin grain mixture (30.3, 1.30 and 0.92 respectively) than for those fed the barley-vetch grain mixture (27.7, 1.23 and 0.87 respectively). Cows fed the barley-vetch grain mixture gained 0.2 kg/day more liveweight than those fed the barley-lupin grain mixture. Although both common vetch grain and lupin grain were readily eaten by dairy cows, when fed as protein supplements to a high quality silage and pasture-based diet in early lactation, cows fed the vetch grain produced less milk and milk components. This may be related to the greater partitioning of nutrients to liveweight gain rather than to toxicity problems in the cows fed vetch grain.