Milk production and cow behaviour in an automatic milking system with night-time pasture access

摘要

In Scandinavia, pasture for dairy herds with automatic milking (AM) is frequently offered purely for exercise and recreation, rather than as a feed-source. In the present study, cows in an AM-system with 12 hnightly outdoor-access from summer solsticeuntil mid-September were offered either fresh production pasture (treatment P>15 kg dry matter (DM) cow~(-1) nightly, combined with 6 kg DM grass silage daytime) or exercise pasture (treatment E; < 1 kg DM cow~(-1) combined with ad libitum silage allowance day and night). Treatment showed a significant effect on milk yield (P:31.3, E:33.0 kg, P=0.05), and a tendency for milking frequency (P:2.25, E: 2.37 milkings x day~(-1), P=0.06). Group P spent more time outdoors than E, 4.0 and 3.2 h, respectively(P<0.001). Cows in P grazed approximately 2.5 h throughout the season, while E grazed less overall, 0.6 h (P<0.001) and decreased their time spent grazing over the season (1.0 to 0.3 h). In conclusion, night-time pasture is poorly exploited by cows, irrespective of the quantity of both of pasture and silage that are available.