There are numerous metabolic diseases that can affect a cow around calving with many of these the result of not having cows at the optimum body condition score (BCS) – at calving – and also, through incorrect mineral feeding levels during the dry period.
Some of these metabolic diseases include milk fever, retained placenta, and displaced stomachs – which can cause added stress and increased work around calving time.
These diseases, and others, can also have a knock-on effect on a cow’s milk production potential as well her fertility performance.
- Milk fever – €130 per case;
- Left displaced abomasum – €515 per case;
- Grass tetany (clinical) – €632 per case;
- Ketosis – €190 per case;
- Retained placenta – €392 per case;
- Cow death – €2,282 per death.
If each of these problems were encountered during the spring period, for a 100 cow herd, it would equate to a loss of €4,141. This is including direct and indirect costs.
This is a huge cost to the system, which cannot be ignored. However, there is still time to avoid these problems through taking preventative action now.
Body condition score (BCS)
By now, all thin cows – calving in February or early March – should be at a BCS of 3. If not, increase the meal being fed to these cows and ensure they are on ad-lib good-quality silage.
In a study – undertaken by Teagasc – on herds which noted persistent health problems during the spring period; it found that very few of the problem herds were managing BCS in their dry cows correctly.
Over-conditioned cows, in particular, had increased risks of problems. Therefore, if cows are beginning to get too fat (BCS of 3.5 or greater) separate them out and put them on a restricted mix of silage plus straw.
Mineral feeding
Mineral deficiency is responsible for retained placenta, calving difficulty, milk fever, calf deaths and many more metabolic issues.
In another investigation by Teagasc, it found that magnesium (Mg) supplementation levels were too low before calving.
It also found high silage potassium (K) levels were associated with a risk of milk fever – especially if Mg feeding was low.
- Ensure each cow receives at least 25g of Mg added to the diet per day – dry cow minerals need to contain at least 20% Mg for a 120g/head feeding rate;
- Add extra Mg for three weeks per-calving if needed; and,
- Check that silage fed in the two to three weeks before calving has K of less than 2.5%.
It is paramount, by now, that all spring-calving herds are regularly feeding minerals, to cows and heifers, and at the right feeding rate.
Where feed space is limiting, it is advisable to split daily minerals into two offerings and shake on the silage twice daily.
Not only does inadequate mineral supplementation pose a risk to a cow’s metabolic health, it can also cause problems with calf health around birth – resulting in dead or weak calves.