Correlations between milking characteristics and behavior of cows milked in robotic systems|Correlações entre características de ordenhabilidade e comportamento de vacas ordenhadas em sistemas robotizados

The objective of this study was to analyze the correlation between milking characteristics and the behavior of cows in automatic milking systems. Data were collected between September 2019 and March 2020 from two commercial dairy herds located in Minas Gerais, Brazil, which use an automatic milking system (AMSTM, DeLaval, Tumba, Sweden). The dataset comprised 68,896 observations from 542 primiparous and multiparous cows of Holstein and crossbred (Holstein × Jersey) breeds. Daily milking characteristics, including milk flow rate (FR), time spent in the milking box (BT), and milking efficiency (ME), were recorded, along with behavioral traits such as milking handling time (HT), incomplete milkings (IM), and kicks. To assess the relationships between these traits, a bivariate correlation analysis was performed using Pearson’s correlation coefficient, executed with the statistical software SPSS version 22. The results revealed moderate negative correlations between FR and BT, ME and HT, and BT and ME. Conversely, a strong positive correlation was observed between FR and ME. A high positive correlation was identified between BT and HT, a moderate positive correlation between ME and milk yield, and a weak positive correlation between HT and IM (P<0.01). No significant correlation was found between milking frequency and kicks or incomplete milkings.