True or false. Once cows graduate the fresh-cow pen, it is smooth sailing ahead?
The answer is “it depends.” While cows that graduate with “A” grades tend to milk well, get bred back and remain in the herd, those that graduate with a marginal grade often end up leaving before 60 days in milk. When cows move into the lactating pen, they tend to become “invisible” unless they become ill or get culled.
The long-fresh cow is not something normally tracked on farm, says David Rhoda, veterinarian in
Use the following steps to learn how to identify at-risk cows.
The graduation exam
The goal is to build a process to identify and manage the cows that still have needs when they leave the fresh-cow program. A casual look at the cows does not reveal who the non-achievers are, explains Rhoda. It takes a review of their medical history, visual assessment and production history, combined with a physical exam, to try and develop an understanding of why these cows are not achieving their potential.
1. Medical history first 21 days in milk
Create a list of cows that have had a health event during the first 21 days in milk, and those that have delivered twins or had a dystocia birth. Creating this list does two things for you; it starts to identify potential at-risk cows and starts collating individual-cow information into a herd monitor of fresh-cow problems.
2. Visual assessments
Several visual assessments are needed. The goal of each is to help judge if a cow is ready for lactation.
Start by looking at udder fill. This is a good substitute if daily milk weights are not available. (Milk production and milk tests will be discussed in a later step.) Does her udder look full or does it appear slack before she enters the parlor? A cow that is 21 days in milk should have a well-filled, tight udder as she enters the parlor.
Next, look at the cow’s eating pattern. Does she go up to the bunk when feed is delivered or pushed up? Does she dig right in, or push the feed around with her nose and sort through it? Does she wait for other cows to finish before she approaches the bunk? All of these factors tell you a little about the individual cow, says Mike Hutjens, dairy nutritionist at the
Next, look at each cow’s appearance. Does her hair coat look shiny or dull? Are her ears perked up or drooping down? Are her eyes bright and alert? Is her nose clean and wet or dirty? Does she appear alert or lethargic?
The final visual assessment is body-condition score, which helps reveal the cow’s energy balance. Cows that are thin have lost excessive weight and most likely have a negative energy balance, whereas cows that are over-conditioned are often not milking as expected, and the energy that is not converted to milk is stored as fat. As a general guideline, weight loss should be limited to less than 120 pounds from freshening to 60 days in milk. That equates to a maximum drop of 1.0 in a cow’s body-condition score, says Hutjens. Keep the following guidelines in mind:
At freshening, aim for a body-condition score of between 3.0 and 4.0.
At one month post-calving, the body-condition score should lie somewhere between 2.5 and 3.2.
3. Examine milk tests
Milkfat, the milkfat-to-milk-protein ratio and milk urea nitrogen tests can help assess how the fresh-cow group is doing.
Let’s start with the milkfat test. When cows in the fresh-cow group have a milkfat test greater than 4.0, it indicates that they are mobilizing fat off their backs, and research shows they also have an increased risk for reduced conception rates, says Mark Kirkpatrick, technical services veterinarian for Pfizer Animal Health in Kuna, Idaho. Kirkpatrick uses DairyComp 305 to look at first test day data on newly fresh cows within the last 30 days. This, he says, allows him to monitor the percentage of cows above that 4.0 threshold.
Another monitor is to examine a whole-herd histogram of milkfat vs. days in milk broken out in 30-day intervals. Compare cows in the first 30 days against cows in the 30-60 day group. If there is more than one full-point difference between the two groups, it can indicate possible excess fat mobilization, weight loss and a high probability of ketosis in the fresh-cow area. It also indicates that further examination of the dry, transition and fresh pens is warranted.
The milkfat-to-milk-protein ratio at first test day should also be considered. Generally, ratios in excess of 1.4 fat-to-protein indicate potential problems, such as subclinical ketosis and displaced abomasums. Individual ratios greater than 1.4 should not be used as the primary criteria to identify specific problem cows, but taken as a group the ratio can be very informative, explains Kirkpatrick. Consider testing for ketosis if more than 40 percent of the group has a ratio above 1.4.
The milk urea nitrogen test can be used to help evaluate protein, fermentable carbohydrates and rumen performance. According to Hutjens, values under 7 and over 16 indicate problems. Values less than 7 often indicate a lack of nitrogen for optimal rumen microbial growth. And, when MUN values are too high, it can lead to reduced fertility, higher feed cost, and increased energy cost to the cow.
4. Milk-production records
You can use daily milk weights, monthly DHIA test data or whatever milk-production records you have available. Dairies should set a minimum threshold for expected production for first calf-heifers and for multiparous cows. This threshold will be used to identify individual cows that perform below expectations.
This information will then be combined with the cow’s production pattern to assess how she is doing.
“We are not just seeking the low-producing cow on a given day, but those that do not follow the expected pattern of increasing production during early lactation,” explains Rhoda. With good records, you can tell if a cow’s production is increasing, flat-lined or decreasing.
An easy way to check a cow’s progress is to subtract first test day milk production from the second test day milk production. If the number is zero or a negative value, production is flat-lined or declining. If the value is positive, her production is increasing and following the normal tendency of the lactation curve.
Generally, after calving, a healthy cow will increase milk production by about 10 percent per day until peak. A flat-line indicates that cows are not working toward a peak. And, cows with declining milk production are probably developing a medical condition. Cows that are flat-lined or declining in milk production should receive further review to identify medical conditions that may be interfering with their production.
5. Cows to monitor
Many of the cows evaluated — including some from your list in step 1 — will graduate into the lactating herd with high grades. Others that fail one or more of the above categories should be considered “at risk,” and therefore monitored longer. And some of the cows now on your list were probably added after the assessments revealed that they were struggling.
Rhoda has developed the following terminology for tracking these cows — “non-achiever,” “watch-cow,” and “will-cow.”
The non-achiever has flat-lined milk production, or is below the herd threshold.
The watch-cow is a diagnostically difficult cow that probably has a medical condition which has not totally surfaced yet, so she needs to be watched short-term.
The will-cow is a cow that in your gut you believe will probably leave before 60 days in milk.
All of the cows that make your list for continued monitoring can enter the lactating string. They will need to be re-checked and observed on a regular basis, preferably weekly. The goal is to keep track of them so that you can catch any developing problems early and identify what caused them to fail. The information learned from these individual cows can be used to identify herd patterns which can then be used to make management changes that may minimize the problem in the future.
More training online
Dairy Herd Management has teamed up with Validus, our distance-learning provider, to create an in-depth training program on how to identify at-risk cows. In this online training course, David Rhoda, veterinarian in