The influence of three grazing systems ons ams performance

Pasturing is common practice in The Netherlands and has several advantages. Feeding costs are lower compared to zero-grazing, animal health and welfare benefits from an outdoor period and public opinion toward dairy farming is positively influenced. However dairy farmers increasingly incline to reduce the grazing period in terms of days per year and hours per day. Among them are relatively many farmers with an automatic milking system (AMS). For an efficient use of the AMS and a maximum milk yield per unit they aim to maximize the AMS occupation. Pasturing is believed to increase the peaks and off-peaks in visiting pattern of the AMS. However, pasturing can be organized in many different ways resulting in different cow behaviour and consequently different visiting patterns. This papers aims to investigate the effect of different ways of pasturing on AMS performances. Based on a rotational grazing system, three alternatives were tested: a) Daytime grazing one group (BE); b) Day and night time grazing one group (OT) and c) Day and night time grazing two groups (OG). AMS performance was highest for the BE system and lowest for the OT system. The fact that half of the herd stayed indoor in the OG system could not compensate the loss of daily milk production per AMS. Aiming at optimising AMS occupation to maximise AMS milk yield the BE system is most appropriate. Moreover the other two systems also require a higher labour input to achieve good results. However, if available labour is not limited and if maximum grazing opportunities are positively appraised both OT and OG are possible.