Mineral level warning follows wet winter

Poor mineral levels in grass following one of the wettest winters on record could result in livestock deficiencies and production losses, say experts.

Testing fresh grass will indicate how well minerals are being taken up by the crop, suggests Lisa Hambly, head of grassland and forage agronomy at Mole Valley Farmers. Soil tests should also be considered, she adds.

This could be a broad-spectrum test or an animal health soil test. “If you know your soil has an underlying issue of over or under supply, you can take action to prevent any problems.”

Slurry analysis

“Having studied a lot of slurry analyses, you can see a massive difference with what is coming through the diet. If something appears in the slurry but does not show up in the soil analysis, it is being fed in the diet.

“Oversupply can be just as important as undersupply. Minerals that can’t be stored will just come out of the back end. Phosphorous is a prime example of this, which becomes a pollutant you have paid for.”

Alison Bond, technical services manager for Nettex and Rumenco, says land flooded for any length of time during the winter could see its mineral content affected – with knock-on effects for grass quality and livestock.

Compaction

These can interfere with the availability of other minerals and impact the availability of other major elements such as calcium, magnesium and phosphorous. Iron levels can also increase where there is compaction.

“This can prevent other minerals from being available to the animal. Areas known for high levels of molybdenum could see exacerbated levels caused by the overwinter conditions. For cattle close to calving, those levels are extremely important.”

Magnesium levels can also be diluted by fast-growing grass, says Dr Bond. “If that grass is also relatively low dry matter, so it’s moving through the rumen quite quickly, the animal won’t be able to take up all the available magnesium.

Physical signs

“Blood tests can demonstrate in the short term what is going on in that animal before any physical signs are picked up. They can help understand how available some of those elements are in grass.”

Mineral supplementation options include free access in blocks or buckets and inclusion in compound feeds or through individual boluses. Bespoke minerals can be formulated where a mineral audit has been conducted.

“What an animal needs today might be very different from what it needs in six months, depending on what you are trying to do with those animals. It’s about looking at supply versus what they actually need.”

Signs of livestock mineral deficiency

1. Reduced performance
2. Poor fertility
3. Twitching and nervousness
4. White muscle disease