As more producers take the automatic-milking-system route, it makes sense to breed cows that better suit this technology. One breeding organisation is highlighting genetics that are better suited to robotic milking.
TEXT INGE VAN DRIE
An increasing number of herds are switching to robotic milking, and CRV’s Gert-Jan van den Bosch says producers are looking to breed cows that are better suited to automatic systems.
“Labour is scarce and expensive – those are just two reasons why more producers are opting for robots. And we are also seeing more automatic milking systems being used on larger dairy units, as well as those that also graze.”
Making maximum use of the milking robot is key to the success of these set ups. And Mr van den Bosch says that to help producers who have automatic systems with their breeding decisions, CRV now offers bulls branded with a special icon to mark them out as good sires for producing robot-capable daughters. “This means that producers can look at our sire lists and recognise robot-suitable bulls at a glance.”
Table 1 comprises a list of sires suitable for robotic milking that are available in the UK. “If producers want to make maximum use of their robots, it is smart to use bulls with the icon for robot suitability,” adds Mr van den Bosch.
Teat length and teat placement are two criteria CRV looks for when determining whether a bull breeds daughters that are easy to milk automatically. “Short teats increase the chance that the teat cups will fall off,” explains Mr van den Bosch. “And if rear teats are too close together, the milking robot can sometimes have difficulty connecting the milking cluster.”
CRV also takes into account the breeding value of locomotion when selecting robot-suitable sires. “In order to be able to visit the robot regularly, the cow must be able to walk properly. If not, she will visit the milking robot less often.”
Milking speed is a fourth point of attention. “The daughters of bulls that score low for milking speed will milk more slowly,” explains Mr van den Bosch. “A cow with a low milking speed will ‘occupy’ the robot for longer and, as a result, the capacity of the milking robot is reduced, and less milk is produced per robot.” CRV uses milking-robot data to calculate the breeding value for milking speed. These data come from more than 1,400 dairy units using Lely milking robots, with participating producers giving their permission to share this information.
“By using milking-robot data to formulate the breeding value, we are able to use information from more animals,” explains CRV’s Gerben de Jong. “And thanks to this extra information, we can calculate more accurate breeding values.” Finally, CRV also takes the new udder-balance breeding value into account when selecting sires best suited to breeding cows that will be robotically milked. “Udder balance indicates the difference in depth between the fore and rear udder of a cow,” explains Mr van den Bosch. “A positive udder balance, which is a score higher than 100, indicates that the rear of the udder is shallower than the front. Conversely, with a negative udder balance, with a score lower than 100, the fore udder is shallower than the rear.
“By using this breeding value, producers can breed cows with the desired udder balance for easy milking through a robotic system.”
Udder balance: extreme postive (right) or negative (left) scores are undesirable
As with milking speed, CRV uses milking-robot data when calculating the udder-balance breeding value. “Robots use teat coordinates when connecting the milking cups. These represent the distance of the teats from the floor, the robotic arm and an imaginary centerline across the udder. CRV calculates the udderbalance breeding value based on the latter,” adds Mr van den Bosch.
Even for producers who are only just considering switching to robotic milking, it can already be useful to select bulls with the icon for robot suitability “They could begin to adjust their breeding goals and select sires that score well for robot compatibility,” he says. “It will take a while before that next generation is milking, so it would be a smart move to add these values to the herd’s breeding criteria.”
And if producers choose to continue to milk their herd conventionally this isn’t a problem either. “It’s always good to select sires for traits such as milking speed, teat length, teat placement, and udder balance,” adds Mr van den Bosch.
Robot breeding values
CRV also publishes breeding values for robot efficiency, milking-robot interval and milking-robot habituation. CRV calculates these values based on milking-robot data from thousands of dairy units. The robot-efficiency breeding value provides insight into kilogrammes of milk produced in robot-time minutes. Daughters of sires with a high robot efficiency produce more milk per minute of time spent in the robot. In a herd with average robot efficiency, the cows produce 1.76kg of milk per minute in the robot. If this producer begins using sires with a breeding value of 108 for robot efficiency, the daughters will produce an average of 1.94kg of milk per robot minute, or an additional 0.18 kg of milk per minute.
With a total available robot time of 20 hours per day, that equates to an additional 215kg of milk per day, and more than 78,000kg of milk per year. A herd with an average milk production of 30kg per day can milk an additional seven cows. The milk-robot-interval breeding value provides information about the time between two successful milkings. The higher the breeding value, the more often cows will visit the robot and the less often a producer has to collect these cows and guide them to be milked.
The milking-robot-habituation breeding value indicates how quickly heifers get used to being milked through the robot. A breeding value greater than 100 indicates that a sire’s daughters reach their mature milking interval earlier as heifers.