To Enhance Early Lactation, Minimize Change, Monitor Key Factors in Dry and Fresh Cows

 

The time immediately before and after a cow gives birth is an extremely stressful one. The cow is going through significant biological and hormonal changes. Then, there are the social and physical changes of being moved from distant pens or pasture to calving pens. She has a whole new environment and routine to acclimate to: she’s going to be a milking cow again. 

 

So, the name of the game, according to Noah Litherland, Ph.D., Assistant Professor of Dairy Cattle Nutrition at the University of Minnesota, is to minimize changes in her routine.

 

“Cows are really creatures of habit, and dairy operations can be pretty intense,” he offered. “We move pregnant cows to far-off dry period pens, then to close-in pens, followed by calving pens and fresh pens. It’s stressful, not unlike it is for students in a new school who have to figure out where classrooms are, where to sit and where to eat lunch.”

 

So, Litherland says it’s important to provide as much comfort and continuity as possible—and to think about ways to reduce sources of stress, such as heat, changes in routine and crowding. 

 

Further, it’s critical to monitor several key factors to make sure the cow maintains her health and her body condition score during the transition period. 

 

One of those factors is the dry matter intake and feeding behaviors during the dry period. These factors are crucial in setting the stage for a smooth transition to calving and lactation. Litherland recommends keeping dry matter intake at about 28 pounds per cow per day and feeding dry cows a high forage, moderate energy diet so that they are still eating several hours a day.

 

“If we expect her to eat four hours a day during lactation, we can’t make that change overnight,” Litherland said. “So, we need to put together new diets that are very high in forage and wheat straw during the dry period. Those are high bulk and take a long time to eat, so cows get used to being at the feed bunk. If you can achieve a dry matter intake of 28-32 pounds per cow per day while they are dry, it positions them well to make the transition to lactation.”

 

He added that some dairy producers try to minimize feed costs and labor by feeding dry cows every other day, a practice he discourages. 

 

But dry matter considerations alone are not enough. Proper balancing and nutrient content are also important for dry cows. Litherland advises producers to keep cows in positive, but not excessive, energy balance. 

 

“If you over-feed energy, it tends to drive down dry matter intake and causes cows to tend toward obesity,” he explained. “Preventing overconsumption of energy during the dry period is one of the biggest challenges, because cows are bred to make milk, so their drive is to eat to make milk. So, you have to formulate the diet to allow for ad libitum intake and allow the bulk in the forage to fill a cow’s rumen; that forces her to stop eating and prevents overconsumption of energy. Forages like wheat straw or grass hay dilute the energy density of the diet.”

 

For fresh cows, Litherland says optimizing forage digestibility is essential to assure that protein and energy are adequate, adding that supplemental fat might be necessary initially to increase the energy density of their diets and avoid ruminal acidosis situations that occur when excessive starch is fed.

 

“You want to avoid excessive mobilization of amino acids out of the muscle or fatty acids from adipose, so you must build the diet to meet the fresh cow’s nutrient needs and minimize her draw upon her reserve,” he stated.

 

Failure to meet those nutritional needs at a time when the fresh cow has so much going on can compromise her immune system and make her more susceptible to such things as ketosis, fatty liver, mastitis and uterine infections, he added. 

 

Graduating the cows from the fresh pen into the high producing group is a judgment call, Litherland said, but the decision should be based on observation and facts. 

 

“Is she eating enough dry matter? Has she had several consecutive days with the same rectal temperatures? Is her uterine health and mammary health good? If so,” Litherland said ”she can graduate to the high producing pen, and we can focus on other fresh cows.”

 

 

The importance of monitoring and recordkeeping cannot be over-emphasized when it comes to evaluating the quality of a transition cow program. Litherland suggests producers evaluate the ratio of fat to protein (percent fat ÷ percent protein) in the milk of fresh cows to make sure the fat content isn’t too high. A fat-to-protein ratio of 1.4 or less at first DHIA test is desirable. If the fresh cow is producing milk with higher ratios than that, it is likely she is mobilizing too much of her body fat—dipping into her reserves, which puts her at risk for ketosis, which decreases intake.

 

Another number that can be used to assess the transition program is somatic cell count. If cows’ first tests after calving reflect an SCC greater than 200,000 cells per ml, that indicates cows are calving with some mammary health issues that need to be addressed. So, Litherland suggests looking back into the dry period to see if teats were sealed properly, preventive antibiotics were used, dry pens were clean and dry, or if she had previous problems with high SCCs. Also, look at sanitary conditions after the cow freshened.

 

“If cows are healthy and teat ends are kept clean, producers should be able to reach their SCC goals,” he declared.

 

Also analyze the volume/weight of first test milk (within the first 30 days of lactation) to evaluate the progress of each cow. If she—and perhaps others in her group—are producing significantly less than the rest of the herd, you have to look for reasons why –  such as dietary deficiencies, immune challenges, ketosis, fatty liver disease and ruminal acidosis.

 

Culling percentage is another way to measure the effectiveness of transition programs.

 

“What is the culling rate for cows less than 30 days in milk?” Litherland queried. “If it is less than 5 percent, you’re doing a fantastic job. If its’ more than 5 percent, what is going on to make you remove cows? Break it down by cows that are 30 days in milk, then 60 days. Dig into records and look at patterns about why cows are leaving the herd. Look back into the dry period to prevent this from happening in the future,” he suggested.

 

The calving interval is another good indicator of a successful transition program. If cows are calving in 12 months since their previous calf was born, Litherland says that is “really, really good and indicates that cows are returning to positive energy balance in good time after calving, and that cows are cycling and conceiving. If your transition program is broken, your calving interval will be longer than 12 months and herd average days in milk will increase, resulting in reduced dairy efficiency.”

 

And, lastly, the dry matter intake is also a good indicator of a sound transition program. Again, he recommends an average of 28 to 32 pounds of dry matter per cow per day. “We’ve done multiple studies, and they all come back the same. If the cow is not getting 28 pounds in, something is not quite right.”

 

When asked about the biggest mistakes producers make, Litherland said he had posed that very question to producers in his area. Here are the mistakes—and advice—they offered:

 

• Not observing cows. You don’t have to be a big producer, Litherland said, but you must have a fresh cow pen so that you can physically observe them every day. One producer put a wireless video camera in the barn so he could keep a better eye on the cows.

 

• Short dry periods (less than 30 days). Don’t do it. The cow needs vacation time, so Litherland recommends giving them close to two months off to let their mammary glands die and regenerate and get a new cascade of hormones…all the things required for good lactation.

 

• Avoid high potassium forages (> 2-2.5 percent potassium), which can cause hypocalcemia or milk fever after calving.

 

 

• Continually evaluate energy density of the dry diet.

 

 

Tips for Reducing Stress in Freshening Cows and Developing a Sound Transition Program