Open access publications in the SLU publication database

Abstract

The introduction of Automatic Milking Systems (AMS) has created new aspects both in the planning of dairy cowsheds due to the necessity of directing cow traffic, and in general cow management.. The aims of this thesis was to study some of these aspects, such as, the effect of feeding frequency on Waiting Time at the AMS, cowshed facility utilization, and the effects of light Conditioned Reinforcement on the time needed for cows to leave the Automatic Milking Unit (AMU) after a successful milking. In addition, a method to trace cows in a loose housing system and a method to detect cows with deviating locomotion were evaluated. The results of these studies are given in five different papers. In the first experiment it is shown that increasing the forage feeding frequency can substantially reduce the cow waiting time before an AMU. The average waiting time at the AMU when feeding twice per day (08:00 and 16:00 hrs) was 755 sec. When the feeding frequency was increased to six times per day (00:00; 04:00; 08:00; 12:00; 16:00 and 20:00 h, respectively), the waiting time decreased to 351 sec. The Feeding Activity Factor (the factor describing the number of times a cow was observed at the feeding fence 10 min after a forage supply) was also higher and the cowshed facilities in the waiting area (floor and cubicles) were more evenly used . No significant differences were found when comparing the utilization of the facilities in the cowshed, although the feeding fence tended to be more evenly used when 6 feedings per day were given, in comparison to feeding twice daily. To maximise the number of milkings per day per milking stall, the use of the AMU should be as effective as possible, with the time necessary for the cow to enter and leave the AMU as short as possible. In the second study, the effect of a light Conditioned Reinforcement in the form of an acoustic signal followed by either a moving tube rubbing the sides of the cow or a flashing light, was studied on the time needed for cows to leave the unit. It was found that the exit time for primiparous cows decreased by 93-97 sec. For multiparous cows the exit time decreased by 112-168 sec. No negative effect could be found on the time needed for the cows to enter the AMU or on the milking stall visiting pattern. In practise, this meant that 100 and 150 min daily would be available for additional milkings per AMU. In loose housing herds, the tracking of individual cows can provide answers to questions regarding the effect of cowshed layout and managerial practises on behaviour and on health and oestrus status of the animals. In the thesis, a method is described that can automatically track and identify individual cows in a loose house system by optical means. In addition, a method was developed to detect cows with locomotion problems using body weight distribution. While the results were promising for both methods, more studies must be performed before they reach a satisfying level of acceptance.