New Research From North Carolina State University Shows That Targeted Pre-Farrow Calcium- and Vitamin-Based Supplementation Can Significantly Reduce Rectal Prolapse in Sows.

By Mark Knauer

Sow prolapses have continued to plague pig farmers for 10-plus years. Yet few management techniques have been reported to mitigate their occurrence with consistency.

New data from North Carolina State Swine Extension supports the concept that sow prolapse is a genotype × environment interaction.

Maternal line genetics has progressed rapidly with the addition of genomic selection. Yet many components of a sow gestation diet have not changed substantially over the past 20 years.

Sows (n=569) within two 3,600- sow commercial farms (from two different production systems) were randomly assigned to one of two pre-farrow treatments.

Treatment females were top-dressed daily with a supplement containing 50 grams of dicalcium phosphate and extra vitamins (equivalent to doubling the vitamin premix) from day 109 or 110 of gestation until farrowing.

Control sows did not receive any extra supplementation. Total calcium and phosphorus levels in the control diets appeared representative of the industry (0.85% total calcium and 0.57% total phosphorus).

Results are shown in Figure 1, where fewer (P=0.03) sows receiving the top-dress prolapsed during lactation when compared to Control sows. The difference between the Treatment and the Control females was largely explained by a smaller (P<0.01) number of rectal prolapses in the sows that were top-dressed.

Nutrition has previously been implicated in the occurrence of prolapse across various species.

In sheep, injections of vitamins A, D, and E were reported to reduce the incidence of vaginal prolapse in breeding ewes (Allott et al., 2020).

Similarly, a systematic review in humans found that pelvic organ prolapse was associated with lower serum vitamin D (25-OH-D3) levels (Kurniawati et al., 2023).

In buffalo, researchers have reported lower serum calcium and phosphorus levels in prolapsed females compared to healthy counterparts (Ahmed et al., 2005; Akhtar et al., 2008).

Collectively, these studies suggest that calcium and/or phosphorus metabolism are key components of the prolapse etiology.

Our results are further supported by a genomic study investigating the genetic architecture of the sow prolapse condition.

Bhatia et al. (2023) set out to confirm the association between genetics and sow prolapse while also identifying genomic regions and candidate genes associated with the disorder. The authors reported that genes on several chromosomes (1, 3, 7, 10, 12, and 14) were associated with sow prolapse.

Candidate genes associated with sow prolapse included genes related to bone mineral density, bone strength, calcium homeostasis, and calcium blood levels, amongst other biological processes.

Hence, the fact that we reduced the incidence of sow prolapse by feeding more calcium, phosphorus and vitamin D seems plausible.

Going forward, our current study perhaps lays the blueprint for reducing or eliminating rectal prolapses in sows.

Yet vaginal and uterine prolapses are generally more costly than rectal prolapses. Therefore, continued work is needed to identify cost-effective management solutions that mitigate vaginal and uterine prolapses.

We would like to thank the North Carolina production systems and DSM-Firmenich for their continued support. Questions can be directed via email to Mark Knauer at mtknauer@gmail.com.

References

Akhtar, M. S., Lodhi, L. A., Ahmad, I., Qureshi, Z. I., & Muhammad, G. (2008). Serum concentrations of calcium, phosphorus and magnesium in pregnant Nili-Ravi buffaloes with or without vaginal prolapse in irrigated and rain fed areas of Punjab, Pakistan. Pakistan Veterinary Journal, 28(3).

Allott, B. S., Dittmer, K. E., Kenyon, A. G., & Elder, P. A. (2020). Preliminary investigation of the effect of treating sheep during pregnancy with a vitamin A, D, E formulation on the incidence of vaginal prolapse. New Zealand veterinary journal, 68(3), 193-197.

Ahmed, S., Ahmad, I., Lodhi, L. A., Ahmad N. & Samad, H. A. (2005). Clinical, haematological and serum macro mineral contents in buffaloes with genital prolapse. Pakistan Veterinary Journal, 25(4).

Bhatia, V., Stevens, T., Derks, M. F., Dunkelberger, J., Knol, E. F., Ross, J. W., & Dekkers, J. C. (2023). Identification of the genetic basis of sow pelvic organ prolapse. Frontiers in Genetics, 14, 1154713.

Kurniawati, E. M., Rahmawati, N. A., & Widyasari, A. (2023). Differences between 25-hydroxyvitamin D levels in patients with pelvic organ prolapse and non-pelvic organ prolapse: A systematic review. Journal of Obstetrics and Gynaecology Canada, 45(12), 102198.

Mark Knauer
North Carolina State University

Mark Knauer was born and raised on a pure-line pig and cattle operation in southern Wisconsin. He received his B.S. in agriculture education and M.S. in animal breeding at Iowa State University. Following his time at ISU, Mark completed his PhD in animal breeding and genetics at North Carolina State University. Dr. Knauer currently is currently a swine extension specialist at North Carolina State University where he focuses on genetics and production management.