Vitamin C Questions from the Field

By Michael Edmonds, V.P., Swine and Poultry Nutrition

With the recent addition of Vitamin C to our NexGen starter programs, there have been questions from the field that we will address in this Nutrition Notes article.

  1. In the trial with health-challenged pigs, what was the Vitamin D level at day -21 (birth), day 0 (weaning), day 11, and day 34 (post trial)?

    Vitamin C

    ANSWER: We did not measure the pigs’ Vitamin D level at birth. We chose littermate pairs of gilts for assignment to the treatments for blood sampling in order to try and minimize variation, and had 8 pigs per treatment to try and observe differences. Notice the increase in Vitamin D levels at Day 11 from added Vitamin C with 24,25 Hydroxy being almost significant (P < .09) so the added Vitamin C “did move” the numbers and thus increased Vitamin D at Day 11. This is a key finding during a period that is especially critical to a stressed pig. At day 34, we observed no differences between treatments on Vitamin D metabolites, even though there was still a huge effect in performance with added Vitamin C in these health-challenged pigs. So, under “normal” conditions, pigs may be able to make enough Vitamin C; but during times of increased stress it may be important to fortify diets during the first 10 days post-weaning in order to improve performance and Vitamin D levels.

  2. Was the trial carried out any further to see if the pigs without the added Vitamin C would have compensatory gain responses?
    ANSWER: No, we did not follow the pigs after the nursery trial. With pigs under these health challenges, we were glad to find that the stabilized Vitamin C resulted in marked improvements in performance and economics during the period tested. Thus, we do not want to rely on “any possible compensatory responses” had we not discovered the benefits of added Vitamin C. Other work indicates that a “compensatory” response in “control” animals is probably unlikely (, see Case #1).
  3. How did we determine the level of Vitamin C? What happens if a higher concentration was used or could we get by with less? Did we only test one level?
    ANSWER: We worked with Dr. Jon Bergstrom of DSM and he recommended we use 300 ppm of their stabilized Vitamin C during the first 10 days post-weaning. Using 300 ppm of Vitamin C would be sufficient during this critical post-weaning period. After the first 10 days, we then used 150 ppm of added Vitamin C until the trial was concluded at Day 34. So we believe that using 300 ppm then reducing to 150 ppm (for those who want to feed it longer in the nursery) is a very good program to follow.
  4. There are sow units that use oral Vitamin D at birth. Do they still need to do this?
    ANSWER: By all means, if your program works for you do not change. For those operations that use both the oral Vitamin D and a water-soluble Vitamin D product, we would recommend to continue that procedure along with the added Vitamin C in the early starter stages with our new NexGen® program. In our research with added Vitamin C, we observed that overall net return was improved by 9 and 73 cents per pig for healthy and health-challenged pigs, respectively. To feed the Vitamin C levels we recommend with the patented stable form (Rovimix ® Stay-C® 35), it would cost around 2 cents per pig for the first 10 days post-weaning. Given the challenges of keeping pigs healthy, we believe that utilizing the low cost of all of the above programs is a good procedure to follow.
  5. What is the level of Vitamin D in the NexGen® starter products?
    ANSWER: The NexGen starter programs are well fortified, including Vitamin D at over 8 times the NRC level, with multiple sources.
  6. What will the Kent Nutrition Group and DSM do with these research findings?
    ANSWER: Vitamin C has many functions in the body, so to find that it offers a huge benefit in health-challenged pigs and that it helped in enhancing higher levels of Vitamin D metabolites is significant. This is the first study in pigs to show this response. We decided to partner with DSM and write the Feedstuffs article since no one has ever evaluated or observed both performance and increased Vitamin D levels at Day 11 post-weaning in health-challenged pigs. Based on our findings, we have added Vitamin C to our NexGen 5-10 Complete (2025); NexGen 8-13 Complete (2030); NexGen 12-17 Complete (2040); NexGen 17-25 Complete (2050); and NexGen 12-17 Mixer (2047). It is certainly conceivable that other feed companies may consider supplementing Vitamin C to help their own customers. In addition, these data will be presented in a “scientific format” by Dr. Jon Bergstrom1 of DSM at the Midwest Animal Science Meetings in March of 2014.
  7. With such significant responses to added Vitamin C in health-challenged pigs, what other research has the Kent Nutrition Group conducted with natural additives, and what were the results?
    ANSWER: “Additives” that give a return on investment are difficult to find. For example, we have conducted 32 trials with 58 products involving natural compounds in the last 12 years in grow-finish pigs and only 22% of these trials have ever shown even a small response. Over 50% of the combinations that have provided a response have been products involving the Kent Nutrition Group and Grain Processing Company.
  8. Why own a Product Development Center in Muscatine, Iowa?
    ANSWER: One of the key ways of developing new products is to have a facility to evaluate ideas. Finding that Vitamin C can significantly improve net return at Day 10, Day 20, and Day 34 in our studies is very meaningful to the swine producers that we serve and the reason that the Kent Nutrition Group still owns and believes in the Kent Product Development Center.

1Dr. Jon Bergstrom is a senior swine technical support manager for DSM Nutritional Products in North America.