Calf or grass - What would the cow choose?

The growing interest for keeping dairy cows with their calves for an extended period after calving is putting pressure on the scientific community to investigate the effects of cow-calf contact systems on the animals ' welfare. The main aims of this study were to investigate the dairy cows ' motivation for accessing their calves over a fresh pasture, and to evaluate if their motivation decreased with increasing calf age. Twenty-two Swedish Red and Swedish Holstein cow-calf pairs were enrolled at calving. The dams were housed in a robotic barn with free access to outdoor pasture, where the calves were kept during pasture season. The behaviours of the dams were recorded on three separate test days occurring every two weeks, starting when the calves were on average 10 weeks old. During test days, the calves were confined to a heavily grazed area, while the dams had free access both to the calf area and to an adjacent fresh pasture. Which of the areas the dams entered first upon returning outdoors from the barn, and what behaviours they performed in which area were registered using 10-min scan sampling during 8 h per day. The dams spent more time outdoors on Test day I (76.8 +/- 3.09%; LSMeans +/- SEM) compared to Day II (60.9 +/- 3.86%; P=0.006), while Day III (66.8 +/- 4.38%) did not differ from Day I (P=0.15) or Day II (P=0.55). On Test day II, they chose the calf area 54 +/- 10.05% of the times they returned to pasture, which was significantly more often than during Day I (18.2 +/- 4.96%; P=0.01), while no difference was found between Day III (37.1 +/- 9.86%) and Day I (P=0.17) or Day II (P=0.5). There was no effect of breed on total time spent outdoors, but Holstein dams tended to spend more outdoor time in the calf area (36.4 +/- 5.28%) than Swedish Red dams (24.2 +/- 3.95%; P=0.09). Upon returning outdoors, Holstein dams also chose the calf area over fresh pasture more often (46.0 +/- 7.19%) than did Swedish Red dams (25.2 +/- 6.21%; P=0.05). Primiparous cows tended to choose the calf area over fresh pasture more often (46.9 +/- 6.11%) than multiparous cows (24.5 +/- 7.25%; P=0.06). Exploratory analyses suggest that the effects of test day were more affected by the ambient weather than by the age of the calves. The study results provide some further information about factors influencing maternal motivation to reunite with their calves on pasture. However, further research is needed so that cow-calf contact systems can be designed to enable good welfare.