Prevention and treatment of milk fever (2024)

Treating hypocalcemia

Milk fever cases should be treated with 500 milliliters of 23 percent calcium gluconate IV and followed by the administration of two oral calcium bolus given 12 hours apart. It is important to emphasize that oral calcium bolus should not be administered if cows do not respond to the calcium IV treatment.

In milk fever cows, failing to rise after treatment with IV calcium is a signal that normal muscular function has not been reestablished.Cows may choke on the calcium bolus if treatment is givenwhile they are still down. A veterinarian should be consulted and further treatment should be evaluated when milk fever cows do not respond to IV administration of calcium.

Do NOT give calcium IV to cows with no signs of milk fever

Contrary to the milk fever cases, supplementation with IV calcium to dairy cows with subclinical hypocalcemia is not recommended.

Giving acalciumIV to dairy cows with subclinical hypocalcemia can resultin a long term decrease in blood calcium concentration. Researchers found thatblood calcium concentration reachedlevels even lower than their baseline six hours after treatment. Moreover, blood calcium concentration remained lower than the levels measured in cows that did not receive any IV calcium.

Minimize the risk

Since dairy cows with subclinical hypocalcemia do not show clinical signs, and cow-side measurements of blood calcium concentrations are very expensive, subclinical hypocalcemia is rarely diagnosed in commercial farms. Despite that, giving two oral calcium bolus (first bolus immediately after calving and second bolus 12 hours later) to lame and high producing cows (two or more lactations) can minimize the risk of developingmilk fever.

Giving calcium bolus to this group of cows (approximately 51 percent of the animals in an average dairy in the United States) can result in a return on investment of 180 percent ($1.80 of return for each $1.00 invested).

NO

• Give 500 mL of 23% calcium gluconate IV
• Follow with 2 oral calcium bolus
  • 1st bolus when cow stands up again
  • 2nd bolus 12 hours later

YES

• DO NOT give calcium IV
• Give 2 oral calcium bolus
  • 1st bolus immediately after calving
  • 2nd bolus 12 hours later

Lowering blood pH can prevent hypocalcemia

There is avariety of different nutritional strategiesto prevent hypocalcemia. Feeding low potassium diets or forages during the pre-fresh period can result in a change in the dietary cation-anion difference (DCAD), which will, in turn, cause an acid-formingresponse in dairy cows. This response is essential to improve the cow’s ability to mobilize calcium from the bones and to absorb dietary calcium from the small intestines.

However, the changes resulting from the use of low potassium diets and forages may not be enough to lowerblood pH. So the use of anionic salts isrecommended to further decrease the blood pH in order to improve calcium metabolism.

These adaptations are essential to support the cow’s elevated calcium demands for colostrum and milk production around calving. The use of low potassium diets in association with mineral anionic supplement during the pre-fresh period has effectively contributed to the decrease inhypocalcemia in dairy farms across the United States.

When feeding anionic salts during the pre-fresh period, it is extremely important to monitor if the mineral supplements are working. The easiest method for monitoring the effectiveness of the DCAD diet is by measuring urine pH in prepartum dairy cows that have been consuming anionic salts for at least two days. Urine pH of cows consuming DCAD diets should be within the 6.0 to 6.5 range.