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Navigate the pitfalls of the transition period

Mike Bettle Published on 12 April 2010

The period three weeks before calving through three weeks after calving is, without doubt, the most critical and stressful six weeks in the lactation cycle of the dairy cow. Navigating the potential pitfalls of this transition period will take you 90 percent of the way toward a successful and, hopefully, profitable lactation.

Preparation and drying-off
Transitioning your dairy cow, however, doesn’t just mean planning her move from the dry cow pen into the lactation string. It involves more long-term planning, which you should begin in the last third of her lactation.

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That’s when a good manager will assess a cow’s body condition. It’s critical that she should not reach dry-off too fat and, almost as critical, she shouldn’t be too thin. Either way, it’s much more efficient to manipulate body condition when a cow is still milking by reducing or increasing feed energy levels.

Losing weight in the dry period is not an option, as it would be both harmful to the cow and calf. Gaining weight while dry, in small increments of up to 1 pound a day, is acceptable but is best avoided. At this stage, the calf is gaining at its greatest rate and you could be running the risk of too large a calf, possible dystocia, and all the associated problems that come from a hard calving.

So now, you’ve gotten your cow to dry-off at a body condition score between 3.25 and 3.75. (1.0 is extremely thin, 5.0 extremely fat.) She is three weeks away from calving. For the previous four or five weeks, she has been on a high-forage, low-grain ration, enjoying a little R & R or rumen recovery, hopefully in spacious surroundings so she could get some exercise and improve her muscle tone. Now comes the challenging part!

Nutrition through freshening
Imagine the metabolic demands that are imposed on the modern dairy cow by her own genetic potential. She transitions from a pregnant, non-lactating animal, to one that can pump out over 100 pounds of high-quality, nutrient-rich milk within a week of birthing a 100-pound calf. That’s dramatic. It takes first-class management practices on your part, at this stage, to prevent her from falling into metabolic disaster.

These management practices involve nutrition, environment and barn design, cow grouping and transfer management, and cow monitoring.

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The most critical influence on your dry cows’ well-being at transition is their dry matter intake (DMI). This, in turn, is influenced by all the above factors. So as the cow transitions toward freshening, her diet needs to be adjusted to take into account she is now only able to consume 1.5 to 1.8 percent of her total bodyweight, down from 1.8 to 2.2 percent earlier in her dry period, and way below her peak lactating goals of around 4 percent. Nutrient density needs to be increased by increasing corn silage, grain and protein levels. These serve to both stimulate rumen development and prepare the rumen bacteria for the coming lactation ration.

As a rule of thumb, I like to keep close-up dry rations in the low 20 percents for starch, protein at 16 percent to provide 1.7 to 1.8 pounds of total protein, an NEl of around 0.70 to 0.74 Mcal/pound and an NDF of between 30 and 33 percent of total DM.

It’s important to keep total potassium levels low in the close-up ration; less than 1.5 percent of DM. I also favor a lower calcium level and these can be achieved by feeding grass hay, where possible. Excess potassium is the enemy of the dry cow. Its alkali properties minimize calcium availability from the bone, and it directly reduces the absorption of magnesium from the ration. These two minerals are critical for good muscle tone. When a cow freshens, there’s a huge draw on body reserves of these two elements. If they’re not readily available, the cow will experience, at best, slow and weakened muscle contractions. At worst, she’ll have a full-blown case of milk fever.

Monitoring energy levels
The fresh cow is always going to be energy-deficient for the first part of her lactation as she rapidly increases milk production and only slowly increases her DMI. Anything that reduces her appetite will exacerbate the problem. She’ll attempt to make up this deficit by mobilizing her body fat reserves. This is normal for the fresh cow.

But if the energy deficit is too large, or the cow was too fat coming into the dry period, she could mobilize fat quicker than the liver can process it. The result is a build-up of ketone bodies in the blood – easily measured by using ketone testing paper in the cow’s urine. Ketosis leads to a cow going off feed and the start of a vicious cycle.

Feed and supplements
Correct presentation of the feed also affects intake. High-quality hays should be provided in fresh cow total mixed rations (TMR). They should be processed into ‘bite-sized’ lengths around 3 inches to cut down on sorting. Add water if the ration is too dry.

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To minimize competition at feeding, allow around 24 to 30 inches of bunk space per cow. Top-quality feed should be available at all times and pushed up regularly. If feeding a TMR, you should feed for a 5 to 10 percent refusal rate per day. Free-choice grass hay is a valid option in the close-up dry cow pen. Free-choice long-stemmed, high-quality alfalfa hay can be fed in the fresh pen, provided the TMR fraction is formulated for all the correct levels of protein, energy, vitamins and minerals. Free-choice hay provides valuable rumen fill for the animal that may not be satisfied by the TMR, especially in winter months.

Vitamin E and selenium levels are very important during transition. They are known to support immune function and can help with cleaning. To increase effectiveness of selenium – which can only be fed at a maximum of 0.3 parts per million (ppm) – more available, organic sources can replace some of the inorganic salt. Vitamin E recommendations can vary from 1500 i.u to 4000 i.u. per day and have been shown to reduce incidence of mastitis.

There are other additives that have merit in the transition ration. Niacin and rumen-protected choline are B-vitamins that can help protect against ketosis and fatty liver, as can ionophores like sodium monensin. If no low-potassium forages are available for the close-up dry cows, ‘anionic’ or acidic additives are available to overcome the alkalinity of potassium, and help to keep calcium free flowing from the bone to the bloodstream. If you have to add an anionic product, make sure you raise the calcium level of the close-up diet to 1.5 percent. Increase the magnesium in these situations, too. It’s always good insurance to ensure that the fresh cow is properly hydrated and there are some excellent proprietary products that provide electrolytes, vitamins and microbials to help stimulate appetites. At the end of the day, something like this might be just what is needed to push your cows away from the precipice of metabolic trouble.

Hydration, cooling and space
Drinking space is also important and you should allow at least 3 inches of trough space per cow. During transition, cows and heifers should ideally be housed separately. If this is not possible, try to have both feed and water available on different sides of the pen so heifers can avoid “boss cows.”

Heat abatement measures in the summer are essential for keeping the transition cow on feed. Install fans over the feed and resting area, and sprinklers over the feed area. Provide electrolytes for the fresh cows either in feed or in solution in the water.

Never stock a transition facility at more than 80 percent of capacity and, if you’re using a bed pack or compost barn, allow up to 300 square feet per animal. If using freestalls, make sure they are built wide enough so a large cow can get in and out without harming herself. Stress should be avoided at all cost! The stress hormone, cortisol, is an immune suppressor and disease is much more prevalent in stressed herds. In an ideal world, have a facility for springing heifers, close-up cows, far-off dry cows and separate fresh cows and fresh heifers. Move animals from pen to pen only once a week, in batches, so as to minimize the stress of the move.

Fresh cows and heifers should be monitored daily while in the fresh pens. Simple observation of a cow’s demeanor after freshening will tell you if she is thriving or not. Body temperatures should not exceed 103.5°F. Check for rumen motility with a stethoscope; contractions should be at the rate of two every minute. Check for ketosis. Check first-test butterfat levels. As a rule of thumb, if your Holsteins average over 5 percent and Jerseys over 6 percent butterfat, you probably have sub-clinical ketosis and need to seriously look at body condition at dry-off or DMI in transition.

Maximizing feed intake
Most importantly, DMI is everything for your transition cow. Keep her eating and she will reward you in abundance. All of the above points are geared toward maximizing feed intake. Remember that 1 pound of dry matter will produce 2.5 pounds of milk, and 1 pound of extra milk at peak will result in 250 pounds of milk through the rest of the lactation. Raise it 4 pounds of milk and you have 1,000 pounds – just for making that extra effort to do everything you can for your transition cows. PD

Mike Bettle is a field nutritionist at the Form-A-Feed and TechMix companies, headquartered in Stewart, Minnesota.

Mike Bettle

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