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Balanced Diets Make More Milk

It’s important to keep a dairy cow’s diet as consistent as possible to ensure good production.

Just as humans need a balanced diet, so do the dairy cows who are producing a nutritious milk product for humans to consume. 

Several factors play a part in the requirements for cows, including body condition, age, and stage of milk production. Hugo Ramirez, Iowa State University Extension dairy specialist, says dairy diets can change many times during a cow’s life. 

“Dairy cows need energy, protein, vitamins, minerals, and microbial requirements, but these requirements change at different stages of their lives,” Ramirez says. 

getting needed nutrients

Most dairy diets are a mixture of forages, grains, and additives. Energy sources are likely from highly digestible forages. Corn is also a source of energy, providing carbohydrates and starches for energy. Right after a cow calves, nutritional needs ramp up with the beginning of milk production. Providing these cows with the proper feedstuff to get the needed nutrients is important, according to Ramirez.

Dry cows can have a bulkier diet since they are not producing milk and only need the energy for the developing calf and to maintain their own weight. Cows are generally dry for the last 50 to 90 days of gestation. 

“Three weeks prior to calving is when we need to be sure cows are getting the proper amount of calcium in their diets,” Ramirez says. “This can be a challenge with the amount of fertilizers that are put on forages in the field.”

In the period shortly before calving, large amounts of calcium are removed from the blood for the production of colostrum. The rapid decrease in calcium can lead to the failure of calcium being absorbed fast enough when lactation begins, which causes milk fever.

Ramirez says to be sure the forages being fed the last three weeks prior to calving include appropriate levels of calcium, phosphorus, magnesium, potassium, sodium, sulfur, and chloride. Preventing milk fever can also limit the long-term effects on a cow’s milk production. 

He also stresses the importance of testing feedstuffs to know the nutrient makeup and consulting a nutritionist to be sure all the proper levels are met for the different stages of the cow’s gestation and lactation, as well as meeting the needs of younger calves and heifers.

“Harvesting equipment can play a big role in having good nutrients. When cutting silage, it’s important for the equipment to be set properly for kernels to be processed correctly and stalks to be cut to the right length,” Ramirez says. “When taking a 32-ounce sample of the silage and spreading it out on a surface, the maximum tolerance should be for two whole kernels of corn total.”

Being proactive in checking silage as it’s cut, he says, can allow equipment adjustments to be made before a problem is seen in the entire harvest. Silage Snap is another source for checking harvesting calibrations. This app is calibrated with the use of a coin and determines the size of the particles present in the sample.

“Corn silage is generally 30% to 40% of a dairy cow’s diet, and changes in quality can greatly affect the diet,” Ramirez says.

weekly check

Producers should work closely with their nutritionist on a weekly basis to be sure cows are being fed the right diet. Adjustments in dry matter are important, as changes can happen quickly with a different area of the silage pit or a different load of hay.

“Keeping the cow’s diet as consistent as possible is important to ensure she continues to produce the most milk possible,” Ramirez says.

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