| dc.description.abstract | A total of 194 cows were randomly assigned into one of two treatment groups (Group A and cross over design Group B), with groups balanced for milk yield, days in milk (DIM) and parity. Group A grazed soybean in the first period and pasture in the second, while Group B grazed pasture followed by soybean. The herd was managed with controlled cow traffic and milked by a prototype Robotic Rotary (RR; Automatic Milking Rotary (AMR™), DeLaval, Tumba, Sweden). In controlled cow traffic cows pass one-way gates and automatic drafting gates were they will be recognized and sent to the milking unit or straight to the feeding area if the time since the last milking was less than the minimum milking interval. The trial consisted of two periods of seven days; four habituation days and three trial days. Before the habituation days all the cows had two training days on soybean. Between 0900 and 1500, cows had access to their treatment paddock following milking. Throughout the remainder of the day, treatment groups grazed shared paddocks as a combined herd. Behavioural observations in both treatment paddocks were recorded every 15 minutes starting at 0900 using scan sampling. Behaviours were recorded as: standing idle, lying idle/resting, walking, grazing, standing ruminating, lying ruminating and ‘other’ behaviour. Grazing, lying resting and standing were used for the analysis of cow behaviour. Day, period, cow number, lactation, group, treatment, DIM, yield and the milking interval were also considered in the analyses. A linear mixed model was used to analyze the cow traffic data, while summary statistics were used to describe trends in the behavioural data. Cows tended to graze more in the soybean paddock compared to pasture. They also grazed more during the morning compared to the afternoon. There was a difference in milking interval between cows grazing soybean and grass, where it was shorter when cows grazed soybean, however the difference was not significant. Lactation, DIM and yield had a significant effect on milking interval. Results indicated that grazing soybean did not act as an incentive to increase voluntary cow traffic despite a small difference in milking interval being detected. | |
