Robots and Milk Quality

Just like in conventional milking, teats must be clean and dry before cows are milked in robotic milking systems. ( Wyatt Bechtel )

It should come as no surprise that cows are cows, and no matter how they’re milked, the same rules governing cleanliness and hygiene apply.

That lesson was brought home last month at the National Mastitis Council, where Don Anderson, with Quality Milk Management, New Brunswick, Canada, compared milk quality in robot- versus conventionally-milked herds.

The first robotic milking system in North America was installed in Canada in 1999. Since then, about 1,300 Canadian dairy farms have installed Automated Milking System (AMS) technology, or about one in eight Canadian dairy farms.

After nearly 20 years of experience, Anderson says what is true of conventional milking systems is doubly true of AMS milking:

               • Cows must be clean; the margin for error is small.

               • Milking equipment maintenance and analysis are critical.

               • Farmers with AMS must utilize all existing milk quality tools.

At first blush, it appears AMS milk quality is as good as conventionally milked herds. Somatic cell counts (SCCs) are appreciably no different. Conventionally milked Canadian herds are averaging 228,000 cells/mL while Canadian AMS herds average 231,000 cells/mL. The story is much the same when the data is broken down by province, see table.

But there have been some milk quality concerns raised at the provincial level. “[In Ontario], there has been a significant number of high bacteria counts on AMS farms, as well as elevated freezing point and a slightly higher number of (antibiotic) inhibitor infractions,” says Anderson.

In New Brunswick, there were 30 milk quality penalties assessed from January 1 through September 30, 2017. While there are just 31 AMS herds (16%) in the province out of the 193 farms, AMS herds accounted for 43% of the penalties. On the 13 AMS herds penalized, 12 were for bacteria count infractions, standard plate counts and lab pasteurized counts. Only one of the penalties was for an elevated SCC, says Anderson.

Robots retrofitted into existing facilities are having the most problems, while robots placed in new barns have SPCs similar to or less than conventional barns and milking systems. “It is reasonable to assume that new barns were built based on the most up-to-date recommendations for ventilation, stall sizing, bedding and other criteria,” says Anderson.


Average Somatic Cell Count

Province                             Conventional      AMS                     

Atlantic                229,000                              217,000

Ontario                245,000                              249,000

Quebec                218,000                              211,000

West                    220,000                              245,000


Clean and dry

In conventionally milked herds, milkers can adjust their prepping routines to the cleanliness of the cow. If an individual cow comes in dirty, extra time can be taken to ensure teat and teat ends are clean. In AMS herds, the robot has one set milking routine and teat cups get attached regardless of teat cleanliness.

Bedding and maintenance of freestalls is also more challenging in AMS herds because there is never any one time when all stalls are empty. So stall maintenance must be done more frequently to ensure all stalls are bedded, leveled and kept free of manure and soiled bedding. Most AMS herds use alley scrapers, but again, if this is not done frequently, a flood of manure can be built up and cows hooves and legs bathed in manure as they step over the scraper.

In order to optimize robot efficiency, each cow’s “time in the box” is critical. “With AMS, the urges are to minimize udder prep routines, skip one wash cycle and other perceived time saving steps, which are all counterproductive to milk quality and udder health,” Anderson says.

For example, attaching teat cups to wet, undried teats has become standard practice in some AMS herds, he says. And he’s seen more teat end damage in AMS herds if they don’t pay attention to machine and vacuum settings.

At the same, the top AMS herds show that milk quality can be achieved if the farmer pays attention to machine function, manages stalls and routinely maintains the milking robots. In fact, the top AMS herds in New Brunswick routinely out-perform the average of all farms in terms of SCC, SPC and LPC. That shows milk quality isn’t a function of the machine but a function of the person managing the machine, says Anderson.