The transition period, extending from approximately three weeks prior to calving to about 40 days after calving, includes the time frame during which the overwhelming majority of dairy cow diseases occur.
If you can’t measure it, you can’t manage it
Because management of the transition cow is critical to dairy cow health, it is critical to have good measures of fresh cow health. Health records would appear to be the obvious monitor. However, the experiences of many skilled people in many places have shown that farm health records are too inconsistent between farms to be comparable. Even on a single farm, there is a problem with the low frequency of specific cases.
For example, if a herd has four displaced abomasums (DAs) in 100 calvings one month and eight DAs in 100 the next month, most would conclude the DA rate has gotten pretty bad, but a statistical analysis shows we can only be 60 percent certain the increased numbers were not simply due to random chance.
Transition cow index
The transition cow index (TCI) uses the information from the prior lactation of each individual to predict her expected performance in the transition period of the next lactation. Cows with health problems that occur prior to the first DHIA test date will usually have negative TCI scores, while cows that start off better than average will have positive TCI scores. From a limited data set, the following diseases are associated with these TCI scores:
•metritis -540 pounds
•ketosis -2,463 pounds
•lame -2,835 pounds
•displaced abomasums -3,823 pounds
Benchmarking herd transition cow management
Using the herd average TCI values, individual dairies can benchmark their herds and fresh cow management programs against industry standards and monitor the effects of transition management programs in their own herd.
Fresh cow health is more than rations and vaccines
Herd average TCI is the net result of both the preventive programs that reduce the proportion of cows that get sick and the diagnostic and treatment programs that handle sick cows. When fresh cow problems become substantial, most people focus on changes to the dry cow and fresh cow rations and review the herd vaccination programs. While the rations and vaccines are certainly important, there are many other factors of equal or greater importance that are commonly overlooked.
Traditional fresh cow disease prevention practices
Dry cow antibiotic mastitis infusions and vaccination for infectious diseases have become standard practices in the modern dairy industry to improve the health of fresh cows. The introduction and widespread acceptance of Orbeseal® dry cow treatment has also been proven to be effective in reducing new mastitis infections through the dry period.
Transition cow nutrition
There are many strongly held opinions about dry cow nutrition, but few have been proven to significantly affect fresh cow health. For example, optimal energy, protein and mineral levels in dry cow and prefresh rations remain controversial. Some research suggests consistency of intake through the close-up period is more important than maximal dry matter intake (DMI) for fresh cow performance. Yet in spite of the uncertainty of the nutritional standards, our industry usually turns to the nutritionist first when fresh cow health problems arise. The remainder of this discussion will focus on other factors to consider.
Pen moves during the transition period
Research has shown that during the first two to three days after new cows are introduced to another group, the number of dominance interactions is increased about three times and physical conflicts about eight times. Milk production is reduced, and presumably individual feed intake is also reduced. In our clinical investigations, we have observed resolutions of herd ketosis problems by both reducing the number of pen changes and by changing the timing of planned pen moves.
Dairy managers should try to bring cows from the dry lot into the high group with a maximum of four intermediate moves:
3. non-saleable milk
It appears that it would be preferable to reduce this to three intermediate pens and move cows directly from the calving pen into the post-fresh pen, separating colostrum from the milk line on an individual cow basis. Situations with two-stage prefresh pens appear to be very detrimental to fresh cow health.
Clinical data also suggests pen moves in the period from nine until three days before calving put those cows at substantially greater risk of ketosis, displaced abomasums and being culled prior to 60 days in milk, compared to moves within 48 hours of calving.
Bedded surfaces of stalls or packs
Research in England shows the calving event is associated with subsolar hemorrhages in the hooves of heifers, similar to the hemorrhages seen in laminitis. Those researchers have recommended the use of bedded straw packs just before and after calving.
Research done by our group in Wisconsin has shown that even slightly lame cows show dramatic increases in stall standing time on mattress stalls but do not increase standing time in sand stalls. The difference may be due to the ability of the lame cow to immerse the sore hoof deep into sand, spreading the weight across a much greater surface area, while the weight gets concentrated onto a much smaller and probably inflamed surface area when getting up and down on mattresses. In a survey underway by our group, it appears sand-based stalls are associated with higher herd TCI averages.
Sick cows separated from colostrum cows
It is currently very common to find sick cows on treatment mixed with fresh cows still yielding colostrum in a “non-saleable milk” pen. While convenient, the practice places the stressed fresh cow with a reduced immune capacity into an environment where sick cows are shedding pathogens at high rates. It is commonly recognized these pens put fresh cows at great risk of new mastitis cases.
A field study in Washington showed dairies with these mixed pens were nine times as likely to experience an outbreak of clinical salmonellosis. It is a high-risk practice that needs to be changed.
Cow avoidance and fear of people
Dairy cows are put in close proximity with people on a frequent basis. Fear of people in milking parlors could inhibit milk letdown and put them at risk of injury. Systems have been developed to classify cows and herds for their relative comfort with people. Avoidance scores are commonly used for this purpose, where cows are approached by a stranger in a specific way and are graded according to how close the person can approach and if the cow will tolerate touch. Tolerance of close contact has been associated with increased milk production in several scientific studies in Australia and New Zealand grazing systems.
For fresh cows, fear of people could have a significant effect on health management issues. Cows fearful of people may mask clinical signs of illness. If the cow is in fright, herdsmen and veterinarians may be unable or reluctant to examine the cow as fully or carefully as they might wish. Fear may increase stress hormones and render the cow less able to resist infections.
Fear of people is usually learned while the animal is young. If flighty behavior is a problem on a dairy, efforts should be made to identify the people who interact with the calves, heifers and cows in ways such that the cows learn to fear them, and those people should be removed from contact with the cattle. If the fear is learned at a custom heifer-rearing facility, another grower should be located.
Disease screening and treatment protocols
As herds have become larger, screening procedures have been developed to more efficiently identify cows that should be examined carefully for disease. Treatment protocols based upon clinical signs like fever, ketone-positive urine, smell, etc., rather than a diagnosis have been widely adopted. Successful disease screening and treatment programs require handling facilities that enable workers to succeed and workers who are competent in recognizing basic disease problems and performing basic treatment practices.
Screening of fresh cows for abnormalities requires convenient restraint facilities. The most effective system appears to be self-locking stanchions that can hold all animals in the pen. The most successful systems have fresh mixed ration, topped with some flakes of very palatable hay in front of the self-locks when the fresh cows return from milking. A pen with three rows of stalls and self-locks usually means that all cows cannot be locked at once, compromising the system from the start.
Pens that require herdsmen to identify suspect cows while loose in the group and move her to other locations for restraint usually do not work well. The workers are “punished” for acting on their suspicions of illness, which usually results in delayed recognition of problems. In some cases, fresh cows are screened for problems in palpation rails in central traffic lanes. This approach generally provides only modest restraint, limited access to the cows for examination and the workers are frequently pressured to clear the cows so that another group can pass, rushing the screening and treatment processes.
When cows must be moved from a pen to a sick pen or elsewhere, it is important to provide simple traffic lanes. Facilities that require cows to move through other pens usually present so many difficulties that appropriate management is discouraged.
Herdsmen must be given adequate time to perform high-quality observation, screening and treatments. In my observations, the most successful programs are seen where the herdsman follows the fresh cows into the parlor, observes udder fill and behavior, but does not milk, then observes fresh cow appetites when they return from milking to fresh flakes of hay at lockups. Following those observations, a line of cows can be examined more fully.
The most successful programs place the herdsmen in convenient and frequent contact with the fresh pen and sick pen. Ideal facilities have a record and medication room adjacent to these pens, preferably elevated slightly with windows, so individual cows can be observed from the room while the herdsman is completing records or performing other office tasks in the room.
There is an established management principle to delegate every task to the lowest-paid person who can competently perform the task. While the principle is sound, application of the principle requires management must be able to measure competence. It is my opinion that health care on too many dairies has been delegated to a level of marginal or inadequate competence, but the absence of an objective monitoring tool has left managers without tools to adequately measure competence.
While I am not an unbiased observer, it is my opinion the standard treatment protocols should be reviewed by the herd veterinarian on a regular, periodic basis. Based upon detailed evaluations of standard protocols on more than 70 large dairies, it is common to find inappropriate and ineffective treatments and dosages in routine use.
Even if well designed, virtually all protocols are subject to “drift” and change inadvertently over time for many reasons. Protocols should be reviewed by the herd veterinarian, and the drug purchases should be reconciled with the plan to make sure the drugs being purchased are the same as the drugs in the protocols.
In addition, the veterinarian should work with the herdsman to screen the fresh cows and examine the selected sick cows on a regular, periodic basis. Too often, veterinarians are only asked to evaluate chronic problem cows after all treatment efforts have failed. These are lose-lose cases, as the veterinarian appears to be ineffective to the owner or herdsman and the herdsman or owner appear to be negligent to the veterinarian. Given the opportunity to work with the herdsman, the veterinarian can observe the methods in place, improve some practices and correct others, improving the quality of the work and the health care of the cows.
Many factors influence the behavior and performance of our cows. The development of the transition cow index is an objective monitor that should help us identify the factors that are truly effective in improving the quality of fresh cow care. PD
—From 2006 Professional Dairy Producers of Wisconsin Annual Business Conference Proceedings