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Signs or symptoms of Vitamin A deficiency
- Growth impairment
- Abnormal skin and mucous membrane changes
- Stillbirth and sterility
- Increased susceptibility to disease
Sources of Vitamin A
- Cod liver oil, whole milk, fishmeal
- Precursor beta carotene, carrots
Function of Vitamin A
- Builds, protects and regenerates the skin and mucous membranes
- Promotes fertility by improving ovulation, implantation and hormonal pregnancy activation
- Regulates growth and differentiation process in the cell metabolism by transfer of 300 previously identified genes (transcription and gene expression)
- Strengthens the immune system
Table 1: Vitamin A requirement per species in International Units (IUs)
| Species | Vitamin A |
|---|---|
| Broiler | 8000 IU |
| Turkey | 10000 - 6000 IU |
| Laying Hen | 8000 IU |
| Sow | 10000 IU |
| Piglet | 10000 IU |
| Fattening pigs | 5000 IU |
| Cow | 100000 IU |
| Calf | 20000 IU |
1 IU is the biological equivalent of 0.3 μg retinol, or of 0.6 μg beta-carotene.
Source: DSM Vitamin Supplementation Guidelines 2016 for animal nutrition
Signs or symptoms of Vitamin E deficiency
- Muscle damage to heart and skeletal muscles
- Fertility disorders
- Changes in the vascular and nervous system
- Impaired immune system
Sources of Vitamin E
- Young green fodder
- Wheat and maize seedlings
- Plant oils
Function of Vitamin E
- Preserves membranes in certain muscles
- Preparation and protection of pregnancy
- Species-specific benefits (less mastitis, better meat quality)
- May protect fatty acids, the building blocks of phospholipid cell membranes
- Regulation of gonadal development and function
- Antioxidant activity in cell metabolism
- May act as antioxidant in living membranes
- Protection against endogenous and exogenous free radicals
Table 2: Vitamin E requirement per species
| Species | Vitamin E |
|---|---|
| Broiler | 150 mg |
| Turkey | 20 - 50 mg |
| Laying Hen | 15 mg |
| Sow | 60 mg |
| Piglet | 60 mg |
| Fattening pigs | 50 mg |
| Cow | 500 mg |
| Calf | 500 mg |
Source: DSM Vitamin Supplementation Guidelines 2016 for animal nutrition
Tip 1: Adjust your Vitamin A and E levels to the requirements
Reduce to high levels in relation to the requirements. Refer to the above tables for Vitamin A and Vitamin E requirements per species. Cutting back a bit will help you to control costs.
Tip 2: Use higher levels of artificial antioxidants to stabilize your feeds
It’s not uncommon to use Vitamin E as a stabilizer for oxidative-sensitive constituents like fats, oils, full fat soja beans, rapeseeds, grains, corn (maize) etc.
Instead, replace Vitamin E with artificial antioxidants that serve the same purpose, such as BHA, BHT, Propyl gallate, or ascorbic acid.
A complete list of antioxidants can be found in the EU Register of Feed Additives in the category of functional feed additives, group 1b, on page 72.
Similarly, consider using more Vitamin C or ascorbic acid in the diets.
Tip 3: Use novel polyphenol products and natural antioxidants to support or spare Vitamin E
Note: this method is not scientifically proven. However, some support the idea of using novel polyphenol products and natural antioxidants in order to achieve a ‘vitamin sparing’ effect.
If you want to pursue this strategy, start by looking at these options:
- Grape kernel products
- Grape extracts
- Rosemary oil
- Resveratrol
Ultimately, Vitamin A and Vitamin E production will likely recover—and hopefully bring relief to feed formulators. These tips may help you during the bridge period. Good luck.