25-Hydroxyvitamin D₃ (25-OH-D₃) is gaining increasing attention in animal nutrition due to its superior absorption and efficacy compared to traditional Vitamin D₃. As synthetic biology advances its production and formulation, it is essential to understand its benefits, applications, and global guidelines for effective use.

Why is 25-OH-D₃ Absorbed More Efficiently?

Unlike fat-soluble Vitamin D₃, which depends on bile salts and intact intestinal mechanisms for absorption, 25-OH-D₃ is a hydroxylated form readily absorbed directly by small intestinal cells. This bypass allows for higher and more consistent bioavailability, particularly valuable in livestock with compromised fat digestion [1].

Stability and Bioavailability: Biosynthetic vs. Chemical 25-OH-D₃

Both biosynthetic and chemically synthesized 25-OH-D₃ are often formulated using microencapsulation, enhancing their stability against heat, acid-base conditions, and storage challenges. The intestinal absorption depends primarily on product purity and concentration, rather than the synthesis method [2].

Recommended Supplementation Levels

Internationally recognized nutritional guidelines and research support the following supplementation ranges:

• Swine: 1,500–3,000 IU/kg Vitamin D₃ plus 50 μg/kg 25-OH-D₃
• Poultry (layers and breeders): 1,500–3,000 IU/kg Vitamin D₃ plus approximately 62.5 μg/kg 25-OH-D₃ [3]

The optimal Vitamin D₃ level within these ranges may vary depending on the animal’s growth or production stage. For swine, requirements can differ between piglets, growers, and sows; for poultry, adjustments are often made between early laying, peak production, and late laying phases to align with bone mineralization and reproductive demands [3][4].

Key Benefits Across Animal Types

Layers:

• Enhanced bone mineral reserves reduce fracture risk in late laying phases
• Increased eggshell thickness and reduced breakage
• Extended peak egg production period [5]

Broilers:

• Improved bone strength, reducing leg disorders
• Increased growth rates and feed efficiency
• Higher breast meat yield [6]

Breeders:

• Higher hatchable egg percentage and embryo viability
• Improved chick quality and innate immunity [7]

Evaluation Metrics in Trials

To assess 25-OH-D₃ efficacy, focus on:

• Egg production and shell quality in layers
• Growth performance, bone strength, and meat yield in broilers
• Hatchability, chick quality, and breeder fertility rates in breeders

A Global Perspective on Regulations and Use

While local regulatory frameworks differ, internationally recognized bodies such as the NRC (National Research Council) provide extensive guidance on Vitamin D metabolites in animal feed. Supplement users should always consult current regulations in their regions, as well as rely on validated scientific literature to optimize inclusion rates and ensure compliance [3][4].

Disclaimer: This article compiles information from publicly available research and is intended for informational purposes only. It does not constitute veterinary advice or prescription. Individual results may vary based on genetics, management, and environment.

References:

[1] Bar, A., et al. (2010). “Vitamin D metabolism and requirements in poultry: physiological and production considerations.” Poultry Science, 89(4), 805–813.

[2] Glatzle, J., et al. (2017). “Stability and bioavailability of encapsulated vitamins in animal feed.” Animal Feed Science and Technology, 225, 1–10.

[3] National Research Council. (2012). Nutrient Requirements of Swine, 11th ed.

[4] National Research Council. (1994). Nutrient Requirements of Poultry, 9th ed.

[5] Fleming, R.H., et al. (2006). “Bone strength and eggshell quality in laying hens supplemented with 25-hydroxycholecalciferol.” British Poultry Science, 47(5), 570–576.

[6] Driver, J.P., et al. (2005). “Effect of dietary 25-hydroxycholecalciferol on broiler performance.” Journal of Applied Poultry Research, 14(4), 623–629.

[7] Saunders-Blades, J.L., et al. (2009). “Effect of 25-hydroxyvitamin D₃ on reproduction and hatchability in broiler breeders.” Poultry Science, 88(9), 1903–1908.