Recent research at the University of Wisconsin has affirmed the importance of supplementing dietary Vitamin D for enhancing productivity and bone development of pigs. Vitamin D is needed for the efficient absorption and metabolism of calcium and phosphorus and is required for normal bone growth.

A Vitamin D deficiency in young pigs can result in rickets, stiffness, lameness, and general unthriftiness. In mature animals, broken bones may result if vitamin D is deficient. 

Researchers at Kansas State University are evaluating supplemental Vitamin D requirements in commercially-raised pigs. “Supplementing with calcium and phosphorus is not as effective without adequate amounts of Vitamin D,” says Steve Dritz, DVM, Kansas State University. “If Vitamin D is not supplemented in swine diets at adequate levels, that will be a problem.”

Current Vitamin D feeding recommendations of Kansas State are between 6 and 8 times the National Research Council (NRC) recommended levels. Feeding these higher levels is not a significant cost, according to Dritz. “The cost of Vitamin D consumed in a pig’s lifetime is pennies.”

However, feeding greater than 10 to 20 times NRC recommended levels for extended periods can lead to toxicity. Also, high dietary levels of Vitamin D can reduce feed intake. Therefore, caution should be practiced when feeding higher dietary levels of Vitamin D.

When formulating diets, care must be taken in supplying adequate levels of Vitamin D, which are typically supplied in vitamin/trace mineral combination premixes. “The vitamins may not retain potency as long when mixed in with trace minerals, but if product is rotated frequently and kept fresh, it’s probably not a big deal," Dritz says. However, from a stability standpoint, producers may consider keeping the vitamin premix and trace mineral premix separate.

Dritz recommends the additional steps to eliminate premix errors to help ensure that Vitamin D levels, as well as other nutrients present in premixes, are supplied in adequate amounts in swine diets:

  • Develop clear premix specifications and use reputable premix suppliers.
  • Verify nutrient levels supplied by reviewing premix production batch sheets.
  • Keep vitamin premix separate from trace mineral premixes and ensure proper product rotation
  • Consider testing of premix to verify nutrient levels present
  • Eliminate hand-adding of nutrients at mixing
  • Evaluate feed mixer function to ensure mixing efficiency