Selenium (Se) - cattle
Definition
Selenium (Se) is an essential trace element required in very small amounts in the bodies of animals.
Despite its minimal quantity, selenium plays a critical role in several biological processes. It is involved in the production of enzymes that neutralise peroxides and free radicals, protecting cell membranes from oxidative damage.
Selenium also contributes to iodine metabolism, which is vital for thyroid function.
Importance in cattle nutrition
Selenium is indispensable for maintaining animal health and productivity. Its functions include:
- Antioxidant Protection: Through enzymes such as glutathione peroxidase, selenium helps prevent oxidative stress.
- Hormonal Regulation: Supports iodine metabolism, influencing thyroid hormone activity.
- Immune Function: Enhances resistance to infections and promotes overall health.
Selenium requirements (CVB, 2016)
The daily selenium requirement varies by age and production stage:
| Category | Per day/per animal | per kg/DM |
| Young cattle from 4 months | 0.40 mg | 0.10 mg |
| Young cattle from 9 months | 0.62 mg | 0.11 mg |
| Young cattle from 16 months | 0.87 mg | 0.12 mg |
| Dry 8-3 weeks to calving | 1.44 mg | 0.13 mg |
| Dry 3-0 weeks to calving | 1.44 mg | 0.13 mg |
| Lactating (20 kg) | 2.72 mg | 0.15 mg |
| Lactating (40 kg) | 4.22 mg | 0.18 mg |
Selenium deficiency in animals
A lack of selenium can lead to:
- Muscle disorders (stiffness, tremors)
- Reduced immunity and higher infection risk
- Hormonal imbalances
- Reproductive issues such as reduced fertility and stillbirths
Selenium excess in animals
Excess selenium can cause similar symptoms to deficiency, with additional severe effects such as:
- Respiratory problems
- Blindness
- Heart failure
Interactions with other nutrients
Sulphur and iron can negatively affect selenium absorption due to their displacing effect. Regular soil and feed analysis helps anticipate and manage these interactions, ensuring optimal selenium levels in the ration.
