THE IMPACT OF DAYS IN MILK ON ROBOTIC MILKING

According to Dairy Records Management System (DRMS), US herds average 177 days in milk (DIM). Average DIM depends on when cows become pregnant. The sooner cows get pregnant, the lower the average days in milk will be. The lowest herd in the DRMS dataset averaged 123 DIM. The majority of herds are between 158 and 196 DIM. Days in milk are even more important in robotic milking.

Average DIM is a snapshot of the current reproductive status of the herd. Here’s another way to look at it. How much of the herd is over 200 DIM? Try to keep less than 35% of the herd over 200 DIM. Here are some challenges associated with long lactations, and some ways to avoid them.

Challenges with Long Lactations

Late lactation cows make less milk and are less motivated to come to the robot. Poorly filled udders are more difficult for robots to attach, resulting in more failed milkings and longer milking duration. Milk access is very flexible, allowing cows to be milked according to yield or interval. It is still very difficult to keep the yield per milking higher than 25 pounds for a cow that is 400 DIM and producing 45 pounds per day. In a free flow barn, it is difficult to motivate that 45-pound cow to come to the robot because her nutrient requirements are more than met at the bunk. Late lactation cows just get in the way. They are not motivated to move. They take up space in cross alleys, at waterers, and if front of smart gates and robots, so cows that need to be milked don’t have access.

Strategies to Avoid Long Lactations

Getting cows pregnant by 130 DIM, for a herd average of 177 DIM depends on 3 things. First, the voluntary waiting period, or when you start. Second, the insemination rate,

or after you start how many of the heats are detected and followed with insemination. Third, the conception rate, or how many of the inseminated cows become pregnant.

The DRMS average voluntary waiting period is 60 days and the longest is 90. When 1st service conception is low, it is tempting to delay the first breeding in order to achieve higher conception rates. Resolving metabolic problems at transition can improve conception rates without delaying first breeding. Someone said, “You don’t have to be great to start, but you have to start to be great.” If you have cows that are not inseminated by 100 DIM, you have to start.

The DRMS average is 62% of heats observed. If a cow is found open at herd check, either a heat was missed or an embryo was lost. Through 40 years in the industry, I have met 2 or 3 managers who were able to find 62% of heats using visual observation alone. The rest of us need synchronization programs or activity systems, or a combination of the 2.

The DRMS average conception rate for all services is 39%. Low conception is the most difficult reproductive problem to resolve because there are so many variables. We already mentioned metabolic problems at freshening and poor heat detection. It’s easy to point fingers at semen quality and technician efficiency, but those are less likely to be the problem. Work with your veterinarian, AI specialist, and Cow Corner to drill down to specific groups of cows and signs of heat.

Cow Corner can help set up breeding protocols and monitor results. I can help you dig for more details in your herd management software. And I can help your team to develop a plan and execute it.