THE ADAPTATION IN THE FIRST WEEK TO THE AUTOMATIC MILKING SYSTEM INFLUENCES LONG-TERM MILK PERFORMANCE AND BEHAVIOR OF HOLSTEIN COWS

The objective of this study was to evaluate the adaptation of mid-lactating Holstein cows regarding their introduction at the automatic milking system (AMS) and its effect on behaviour and milk performance. From a herd of 400 milking cows, a group of twenty-eight mid-lactating Holstein cows were monitored in the transition from the conventional milking system (twice daily) to the free-traffic automatic milking system. After 37 days from the full transition to the AMS, cows were retrospectively divided into two groups according to the average number of milking visits during the first week of AMS: 1) milking visits < 2 (MV-LOW) and 2) milking visits < 2 (MV-HIGH). Number of milking visits, milk yield, milk quality and rumination and eating time were recorded. In the first week, MV-HIGH cows had an average of milking visits higher compared to the MV-LOW cows (2.44 vs. 1.67 ± 0.06 n°/d, respectively). Starting from the similar milk production in the pre-AMS period, milk yield after the introduction of AMS (from 0 to 37 days) was higher in the MV-HIGH than in the MV-LOW cows (36.91 vs. 30.94 ± 2.11 kg/d, respectively), but with lower fat, protein and lactose percentage. The first week of AMS was characterized by a marked increase in milk yield in the MV-HIGH cows (+30.98 %) and a decrease in the MV-LOW cows (-11.60 %) compared to the pre-AMS. The time spent for eating was also greater in the MV-HIGH compared to the MV-LOW cows. Even though MV-LOW cows increased the milk production over the first week of AMS, these cows had always a lower increase in milk yield compared with the MV-HIGH cows until 37 days of AMS. These results suggest that the adaptability of the cows to the automatic milking system may also depend on the individual behaviour of cows and not only on the environment around them. Therefore, it is necessary to apply new livestock management strategies, when AMS (as a free-traffic system) is going to displace the milking parlour in order to better fine-tune the adaptation of cows (especially for heifers) and also to select cows that respond best to the robotic milking system.