Current Progressive Dairy digital edition

0907 PD: Keep cows eating in the transition period

Elliot Block Published on 31 August 2007

We all want the same things from our dairy cows – high production of quality milk with minimal health problems. During the close-up dry period and the start of lactation, cows go through many changes that present challenges to meeting these goals. The transition period, three weeks prior to and three weeks after calving, is the most sensitive time in the dairy cow lifecycle. During this time, cows freshen, experience nutritional changes and are moved into different pens with different cows, all while producing high volumes of milk.

Prepare the rumen



Stabilizing the rumen to encourage high intake can promote a smooth adjustment for your fresh cows while maximizing profitability for you.

It’s no wonder it’s tough to get fresh cows to eat in the midst of such change. Nutritionally, she is moving from a dry cow diet consisting of high levels of fiber, to the lactating cow diet, with higher starch and energy. This adjustment can have negative effects on the rumen because microbes, which maintain rumen health, do not thrive in low pH levels associated with high-concentration diets.

It’s important to prepare the rumen during close-up for the big nutritional change that is about to occur. One of the most important ways to prime the rumen for a productive lactation is to formulate a specific transitional close-up diet that contains more energy and protein than a far-off diet and to feed this diet for three weeks pre-calving. Besides reformulating protein and energy, lowering the dietary cation-anion difference (DCAD) prepartum is extremely beneficial to cows at this stage of their productive cycle.

DCAD is the measure of positively and negatively charged ions found in the ration, specifically sodium, potassium, chloride and sulfur. Sodium and potassium are cations and are positively charged, while chloride and sulfur (which are anions) carry a negative charge. By adding the charge of the four ions together, you come up with a ration DCAD.

A negative DCAD is important to pre-fresh cows because it allows for the transfer of calcium from bones and the gut to the bloodstream, which reduces the incidence of costly metabolic disorders.


Eating that last bite

According to Ohio State University dairy nutrition specialist Bill Weiss, encouraging dry matter intake (DMI) in the first weeks after calving is the most important nutritional challenge to overcome. Improving DMI during early lactation relates directly back to the lactation curve and peak milk. Peak milk levels, Weiss says, will determine production throughout the entire lactation. Getting a cow to eat even one more bite of feed can be beneficial to milk production and profitability for the rest of her lactation.

Just as a negative DCAD level promoted intake before calving, boosting DCAD balance to a positive level after freshening will do the same. Research completed at the University of Illinois concluded that adding potassium carbonate to fresh cow rations boosted DCAD levels and lead to improved DMI and increased fat-corrected milk and protein production.

Potassium, which is one of the four main ions, is important for DCAD balance and milk production. Since 13 percent of the potassium in a cow’s body is used for milk, it’s no surprise that research done in Texas found a direct link between milk production and the amount of potassium in the cows’ diets. With higher milk production, more potassium is pulled to the milk, lowering the levels in the blood and making it even more important to supplement these high-producing cows.

The source of potassium also can make a difference in its effectiveness. The two most common sources used in rations are potassium carbonate and potassium chloride. Potassium chloride is counter-productive because chloride carries a negative charge and potassium is positively charged. As a result, the two charges cancel each other out, which is not beneficial in raising DCAD balance. Research supports this theory as well. Studies have shown that cows supplemented with potassium carbonate produced 3 pounds more milk per day than those supplemented with potassium chloride.

Another important factor for encouraging high intake is feed quality. Provide high-quality forages and consider feed ingredients that can make the adjustment smoother, recommends Weiss. Although these additives may be too expensive to feed to the whole herd, allocating extra financials on fresh cows can be beneficial.


More than one lactation

Not only must cows eat to be productive during lactation, but they also need to get bred back so they can be profitable in future lactations. Producers are trying to breed cows during the first 100 days, and sound nutrition management plays an important role, says Weiss.

Research at the University of Arizona discovered just how important omega-3 and omega-6 essential fatty acids (EFAs) are for reproductive performance. Researchers found that cows supplemented with feed ingredients rich in omega-3 and omega-6 EFAs generated multiple benefits including:

• 25.4 percent reduction in uterine health disorders

• 81 percent more ovulations by 30 DIM

• 38 percent more estrous cycles in the first 60 DIM

• 21.9 percent more pregnancies when compared to the herd’s historical pregnancy rates

It’s all in the details

Management practices have a direct impact on how fresh cows respond in the milking herd. Attentive producers place priority on fresh cows, paying close attention to them many times every day, which makes all the difference, Weiss says. These cows are usually fed the best forages and feed ingredients. The ration changes, he says, can make a big impact on fresh cows.

Weiss also cites the conscientious manager’s focus on the smaller management details to help make the transition easier for their fresh cows. These managers recognize how sensitive this group of cows is to change, and focus their efforts on:

• Overcrowding

• Stall comfort

• Feed quality

• Disease treatment

• Heat stress

Since cows are extra sensitive during the first months in the milking herd, slight changes in management can cause lowered milk production. Comfort and quality feed can provide what the fresh cow needs to succeed, Weiss added.

During the six-week transition period (three weeks prepartum and three weeks postpartum), your cows are undergoing so many changes. But, as Weiss advised, the key to this group’s success is to get them to eat just one more bite. Achieving the big goal of getting your close-up and fresh cows to improve DMI may be a challenge, but your herd’s “thank-you” will come later in the form of a milk check. PD