In voluntary milking systems (VMS), cows access the milking robot at times of their choosing, typically 2-4 times per 24 hours. Research shows that cows on AMS farms have more flexible resting patterns, lower cortisol (when systems are working well), and show behavioural indicators of lower chronic stress compared to conventional parlour milking on some farms. Cows with access to outdoor grazing on AMS farms show particularly good welfare indicators.
Modern AMS units monitor udder health continuously — milk yield, conductivity, colour, and SCC per quarter can be assessed at every milking. This high-frequency monitoring enables early detection of mastitis. However, the absence of a human milker at each milking means clinical signs may be missed if automated alerts are not responded to promptly. Farmer and system management discipline is essential.
A proportion of cows in AMS herds fail to present voluntarily for milking and must be fetched. Fetching is stressful and labour-intensive. High proportions requiring fetching may indicate: poor flow (traffic) design, social bullying at robot entry, pain or lameness, poor robot location relative to feed and lying areas, or inadequate training for fresh cows. Fetching rate is a key AMS welfare and management indicator.
Fresh cows must learn to use the AMS robot, which requires a training period and additional supervision. Freshly calved cows with mastitis, metabolic disease, or lameness may struggle to use robots independently. Good transition management and swift identification of cows needing assistance is critical.
AMS systems create opportunities for improved lameness detection through gait analysis software and automatic lameness scoring. However, lame cows may be reluctant to travel to robots, resulting in reduced milking frequency and worsened condition. Robot placement close to lying areas and feed reduces the distance lame cows must travel.