View this email in your browser

IN THIS ISSUE

Is Vitamin C a Key Piece to the Sow Survival Puzzle?

Mark Knauer

Department of Animal Science, North Carolina State University, Raleigh 

Image courtesy of Suzanne Leonard.

Swine geneticists have designed a sow that emulates a race car. She is sleek and lean and she has incredible piglet output. Yet, is our race car receiving high-performance fuel, or is she getting something that resembles 2-cycle fuel-something you may use to power your weed whacker or your leaf blower? With implementation of genomic selection, geneticists have been able to change the sow faster than ever. Yet, the nutritional requirements of this highly efficient female have changed and sow nutrition research takes time and funding. Hence, we may be looking at a genotype × environment interaction scenario where we have created a high-performing sow but are seeing engine troubles due to low-quality fuel.

In 2007, the late Dr. Mahan discussed potential nutritional strategies to enhance sow livability. He showed concentrations of antioxidants, specifically vitamins C and E, are reduced in late gestation. Once a sow’s antioxidant status is lowered, it could affect the responses of her tissues and perhaps even lead to death.

North Carolina State University Study

Therefore, a pilot study was designed (Knauer, 2023) to evaluate late gestation supplementation of vitamins C and E on sow survivability. Sows (n=466), housed in stalls at a commercial sow farm in eastern North Carolina, were randomly allocated to either receive 35 g of a top-dress containing vitamins C and E or no top-dress in the diet (Control). The 35 g top-dress contained 1.05 g of vitamin C (from STAY-C®35), 500 IU of vitamin E (from ROVIMIX®E50), and ground corn as a carrier. Vitamins C and E were top-dressed twice per week, from day 87 of gestation until farrowing. The farm’s gestation and lactation diets were formulated to contain no vitamin C and 66 IU/kg of vitamin E.

Sow survival was evaluated from day 95 of gestation through day 30 post-farrow. Mortality codes recorded by farm technicians included sudden death, lameness, prolapse and farrowing difficulty. Sow survival traits were analyzed using a Chi-square analysis.  

Of the 466 sows, 29 (6.2%) died or were euthanized between day 95 of gestation and 30 days post-farrow. Sows supplemented with vitamins C and E tended (P=0.11) to have lower incidences of sudden death and prolapse when compared to Control sows (Figure 1, 6.0 vs. 3.0%). Vitamin C and E supplementation tended (P=0.08) to reduce the number of sows that died at or before farrowing (Figure 2). Hence, results suggest that supplementation of vitamins C and E in late gestation may be a strategy to enhance sow livability.

Figure 1. Incidences of sudden death and prolapse of commercial sows supplemented with vitamins C and E in late gestation or not supplemented (Control).

Figure 2. More commercial sows supplemented with vitamins C and E in late gestation lived, prior to farrowing, than sows not supplemented (Control).

Underlying Biology

Oxidative Stress

Oxidative stress can be explained as an imbalance of free radicals and antioxidants in an animal that leads to cellular damage. Cellular damage can then lead to a variety of diseases.

Mahan et al. (2007) proposed oxidative stress as a potential cause of sudden death in sows. Vitamin supplementation needs are highest during periods of stress (Lauridsen, 2019). Furthermore, farrowing can be a stressful event in a sow’s life. Hence, enhancing the supplementation of certain vitamins in late gestation may be a strategy to improve sow health and survival at farrowing.

Anemia

Anemia can be characterized as a problem of not having enough healthy red blood cells or hemoglobin. Multiple forms of anemia exist. For example, anemia can result from a lack of iron in the body, yet anemia can also develop from the deficiency of certain vitamins.

Recent data suggests U.S. sow herds may have problems with sow anemia. Castevens et al. (2020) reported that 49.7% of sows evaluated in the U.S. were anemic. McClellan et al. (2024) found sow hemoglobin concentration had a moderate correlation with farrowing duration. Their data showed that sows with < 10 g/dL of hemoglobin had substantially longer farrowing durations than sows with > 10 g/dL (571 vs. 285 minutes). Harshman et al. (2023) reported non-prolapsed sows had substantially greater blood iron levels than prolapsed sows (3.76 vs. 2.77 ppm). These studies suggest that sow anemia near farrowing is associated with farrowing complications and sow mortality.

Enhanced vitamin supplementation may be part of the strategy to enhance sow hemoglobin concentration. Aznar et al. (2024) reported that vitamin C supplementation from day 76 to farrowing enhanced sow hemoglobin levels when compared to control-fed sows. In humans, it is well known that vitamin C enhances the adsorption of non-heme iron (Lane and Richardson, 2014). Hence, nutritional strategies to enhance sow hemoglobin concentration may likely include vitamin C supplementation.

We would like to thank our producer partners, DSM, and DSM scientists Dr. Jon Bergstrom and Dr. Sara Hough for their continued support. Questions can be directed to Mark Knauer @ mtknauer@ncsu.edu.

References

Castevens, K., Ferreira, J. B., Gillespie, T., Olsen, C., Nielsen, J. P., & Almond, G. 2020. Assessment of hemoglobin concentration in relation to sow reproductive stage and parity. Journal of Swine Health and Production, 28(5), 254-257.

Harshman, J. A., Carter, S. D., Daniels, C. S., Coble, K., & Madson, D. 2023. 196 Serum Trace Minerals and Tumor Necrosis Factor Alpha Concentrations in Prolapsed and Non-Prolapsed Sows. Journal of Animal Science, 101(Supplement_2), 242-242.

Knauer, M. 2023. PSIV-2 Impact of Vitamins C and E on Sow Mortality and Stillborn Rate. Journal of Animal Science, 101(Supplement_2), 352-353.

Lane, D. J., & Richardson, D. R. 2014. The active role of vitamin C in mammalian iron metabolism: much more than just enhanced iron absorption!. Free radical biology and medicine, 75, 69-83.

Lauridsen, C. 2019. From oxidative stress to inflammation: redox balance and immune system. Poultry science, 98(10), 4240-4246.

Mahan, D.C., J.C. Peters, and G.M. Hill. 2007. Are antioxidants associated with pig and sow mortalities? Midwest Swine Nutrition Conference. pp. 13-21 Indiana Farm Bureau.

Indianapolis, IN.

McClellan, K. A., Sheffield, S. L., & Levesque, C. L. 2024. The impact of hemoglobin concentration on farrowing duration in sows. Translational Animal Science, 8, txae158.

Sosnowska, A., Kawęcka, M., Jacyno, E., Kołodziej-Skalska, A., Kamyczek, M., & Matysiak, B. 2011. Effect of dietary vitamins E and C supplementation on performance of sows and piglets. Acta Agriculturae Scandinavica, Section A-Animal Science, 61(4), 196-203.

Yeast-based Postbiotics Enhance Intestinal Health in Nursery Pigs Challenged with F18⁺ Escherichia coli

Enterotoxigenic Escherichia coli (ETEC) is an ever-present intestinal pathogen and is a common cause of post-weaning diarrhea in pigs, contributing to reduced growth and increased mortality. Given restrictions on the use of in-feed antibiotics, pig producers are seeking effective alternatives to enhance intestinal health, thereby reducing the need for antibiotic use to manage enteric pathogens. This study evaluated the efficacy of a yeast-based postbiotic in mitigating the negative effects of ETEC infection on intestinal health of growth performance of nursery pigs¹.

Materials and Methods

Thirty-six pigs were weaned at 21 d of age. Pigs were housed individually with free access to feed and water throughout the 28-d trial. Pigs were fed 3 dietary treatments, including 1) NC, control diet; 2) PC, control diet + ETEC challenge; 3) SYP, control diet with a Saccharomyces yeast postbiotic included at 175 g/ton of feed + ETEC challenge. Challenged pigs were orally inoculated with ETEC on d 7 of the study. Body weight, feed intake, and fecal score were recorded throughout the study. At the conclusion of the study, pigs were humanely euthanized to collect intestinal tissues for evaluation of intestinal health markers.

Key Findings

Pigs in the PC group showed reduced growth performance and increased incidence of diarrhea when compared with the NC group, confirming the efficacy of the ETEC challenge. Pigs receiving the SYP treatment showed a decreased incidence of diarrhea compared with the PC group.

Figure 1. Incidence of severe diarrhea across dietary treatments in nursery pigs. Severe diarrhea was considered to be a fecal score of 5 for 2 or more consecutive days.

Pigs in the SYP group had reduced relative gene expression of Toll-like receptor 4 (TLR4), a key mediator of intestinal inflammation and decreased concentrations of protein carbonyl, a product of oxidative stress, compared with the PC group. Conversely, expression of mTOR, a kinase involved in cellular growth and repair, was increased in the SYP group when compared with the PC group.

Analysis of the mucosa-associated microbiota revealed that ETEC challenge in the PC group increased the relative abundance of gram-negative bacteria that are generally regarded as harmful. In contrast, the SYP group had a decreased proportion of gram-negative bacteria and an increase in beneficial gram-positive bacteria, indicating the positive influence of yeast-based postbiotics on the mucosa-associated microbiota under challenge conditions.

Figure 2. Relative abundance of the jejunal mucosa-associated microbiota at the genus level in nursery pigs fed diets supplements with a Saccharomyces yeast postbiotic, grouped by proportion of gram-positive to gram-negative bacteria.

Conclusions

Collectively, these findings demonstrate that dietary supplementation with a yeast-based postbiotic could reduce inflammation, promote intestinal health, and positively modulate the mucosa-associated microbiota in nursery pigs challenged with ETEC. The reduced incidence of diarrhea and improved intestinal health suggest that yeast-based postbiotics may serve as a promising alternative to antibiotics in the diets of nursery pigs.

For further details, you can access the full study here.

¹Gormley, A. R., Duarte, M. E., Deng, Z., & Kim, S. W. (2024). Saccharomyces yeast postbiotics mitigate mucosal damages from F18+ Escherichia coli challenges by positively balancing the mucosal microbiota in the jejunum of young pigs. Animal Microbiome, 6, Article 73. https://doi.org/10.1186/s42523-024-00363-y.

Upcoming Events

2025 ASAS-CSAS Annual Meeting

July 6th - 10th

Diplomat Beach Resort in Hollywood, FL

PQA Advisor Training

August 1st

Raleigh, NC

Contact Mark Knauer at mtknauer@ncsu.edu to register.

Carolina Feed Industry Association Summer Meeting

August 19th - 21st

Lumina at Wrightsville Beach, NC

If you did not receive this newsletter directly in your inbox and would like to in the future, please join our mailing list by completing this form

Stay Connected

To stop receiving our promotional email, unsubscribe now
NC State College of Agriculture and Life Sciences
Campus Box 7601
NC State University Campus
Raleigh, NC 27695-7601
United States