Farm Ireland

Sunday 17 December 2017

Dealing with fevers, supplements and calmag

Frequently asked questions about dry cow feeding.

Q What type of supplement should I feed with silage if cows are in poor condition?

A Energy is needed for body condition gain, not protein. Rolled barley will suffice. Avoid high calcium supplements.

Q I am having problems with sub-clinical milk fever. Will additional magnesium help?

A Yes, additional magnesium may help alleviate the problem. The target magnesium intake in this situation is 22-25g of magnesium per day.

If cows are getting a standard pre-calver supplying 15g of magnesium, the additional 10g of magnesium can be supplied by feeding 20g of calmag or 30g of sweetened calmag.

Q Does calmag have calcium in it?

A No. Calcined magnesite is a source of magnesium, not calcium. Calcined is simply the process it undergoes to reduce it to a powder.

Also Read

Q Are boluses adequate for the dry cow?

A Boluses will supply some trace elements but none of the vitamins or major elements, such as phosphorus and magnesium. If boluses are being used for dry cows, it's important to get magnesium in through another source and possibly phosphorus if the phosphorus content of the silage is low.

Q I am feeding kale for the first time this year. What do I need to look out for?

A The key management considerations for feeding kale include:

1. Unless you have an accurate way of estimating yield, it is trial and error in allocation. Start off with a small allocation and build the allocation gradually over at least one week.

2. Feed at least 20pc of the dry matter intake as grass silage or straw, this equates to half a round bale per day to 40 cows.

3. Strip-graze Brassicas.

4. Crop breaks should be long and narrow rather than short and wide.

5. Ensure that fencing is very secure as poisoning can occur if animals overgraze or gorge on the crop.

6. Feed a good quality mineral with a high level of iodine and copper.

7. The crop should be grazed out before flowering, since flowering brassica crops are poisonous. Aim for the final grazing of the crop before mid-March.

Irish Independent