Sulphur (S) - cattle
Definition
Sulphur (S) is an essential mineral for both plants and animals. It is a key component of sulphur-containing amino acids such as methionine and cysteine, which are vital for protein synthesis. In ruminants, sulphur plays a crucial role in the production of microbial protein within the rumen.
Importance
Sulphur is not only important for protein formation but also forms part of:
- B vitamins such as thiamine and biotin
- The hormone insulin
Adequate sulphur intake supports rumen microbial activity, feed efficiency, and overall animal health.
Sulphur requirements (CVB, 2016)
| Category | g/kg dry matter |
| Young cattle from 4 months | 1.5 |
| Young cattle from 9 months | 1.5 |
| Young cattle from 16 months | 1.5 |
| Dry 8-3 wks to calving | 1.5 |
| Dry 3-0 wks to calving | 1.5 |
| Lactating (20 kg) | 2.0 |
| Lactating (40 kg) | 2.0 |
Sulphur deficiency
A deficiency in sulphur can lead to:
- Reduced feed intake and milk production (due to impaired rumen microbial activity)
- Dull hair coat
- Excessive salivation
- Moist eyes
Sulphur excess
Sulphur toxicity can occur relatively easily:
- Symptoms may appear at 3–4 g/kg dry matter
- CVB (2005) sets a chronic toxicity limit at 4 g/kg dry matter
Effects of excess sulphur
- Acute excess (sulphite form): Nervous system disorders, intestinal inflammation, blindness, muscle twitching, diarrhoea, dehydration, lung and kidney damage, bleeding
- Sulphate form: Less severe; mainly causes osmotic diarrhoea
- Chronic excess: May lead to copper deficiency
Key considerations
- Monitor sulphur levels in the ration to avoid both deficiency and toxicity.
- Balance sulphur intake with other minerals, especially copper.
- Consider feed composition and fertilisation practices that influence sulphur content.
