Tetany

Grass tetany has become a very real threat over the last week due to a sharp drop in night-time temperatures. Over the weekend, temperatures at night fell to as low as 4°C, increasing the risk of grass tetany in suckler cows. Tetany is caused by a deficiency of magnesium in the blood. Cows have a very poor capability to store magnesium in the blood and therefore must ingest levels of the mineral daily in order to prevent disease.

Grass which has grown rapidly is typically very high-risk as magnesium absorption into the body is significantly reduced. It is for this reason that tetany has been a significant risk after the drought. To compound the problem, however, colder nights can cause an increased level of stress to the suckler cow, thus amplifying the risk.

To avoid grass tetany, an adequate supply of minerals is essential. Minerals can be given through lick buckets, powder minerals and/or in the water supply at drinking troughs. If concerned about uptake, magnesium boluses are a sure way of boosting body levels of the mineral. Roughage such as hay or straw will also help to prevent against tetany, slowing down digestion allowing for more absorption of the mineral into the body.

Finishing cattle

For those finishing cattle, it may be time to consider introducing concentrates to the diet. For those already doing so, the amount of supplementation could be increased. Once again, the main reason for this lies with the onset of colder nights as we approach 1 September. Colder temperatures can have a twofold effect on thrive at this time of the year.

Firstly, animals expend more energy keeping themselves warm as nights get colder. They also become more unsettled, meaning thrive is affected.

The second problem with finishing on grass is the fact that growth slows.

The last thing a finishing animal can afford is to be short on grass. Furthermore, grass quality reduces in colder weather as sugar and digestible fibre levels begin to reduce. The energy content of grazed grass in the autumn is typically only 0.85 UFL/kg DM, much less than that for lush spring grass which is typically 1.05 UFL/kg DM.

With both animal and grass factors considered, now is the time to introduce or increase concentrates in the diet of your finishing animals to ensure performance doesn’t take a setback.

Winter preparations

Just before the farm begins to get busy again with the onset of weaning and housing in the coming months, now is a good time to have a look around the yard and attend to any maintenance or washing that is required. Understandably, most of the attention has been focused towards the fields for the last number of months but perhaps now is a chance to turn back to the yard and sheds and get these jobs done. These tasks are far easier when the yard is empty of stock.