Shropshire Farming Talk: Get your dry cow system right this Winter

This is the period where the cow lays down the building blocks for the coming lactation, minimising metabolic disease. 

Implementing a system to reduce negative energy balance and maximise post-calving dry matter intakes can be very profitable.

Poor feeding and management during the transition period can result in a host of problems around calving such as dystocia (difficult calving), retained placenta, milk fever (hypocalcaemia), lameness, rapid weight loss and ketosis. 

Many of these issues are related, as one may lead to the manifestation of other conditions, often as a result of reduced feed intake.

Feed intake tends to decline as calving approaches and does not peak until about 10 to 12 weeks after calving. 

This is the opposite of cow requirements as nutrient demands increase in the latter stages of pregnancy, and cows achieve peak milk yields about 6 to 8 weeks after calving. 

Any calving or metabolic issues can be the final insult resulting in downer cows and the consequent effects.

For example, when a cow experiences a case of milk fever, she is then far more likely to experience ketosis (negative energy balance), displaced abomasum (twisted stomach), retained cleansings and even higher cell counts. 

The same can also be said for sub-clinical milk fever which by its nature, is very difficult to see and treat but can have a similar effect and so must not be ignored.

Milk fever is considered the gateway disease, and the above symptoms should also focus attention towards milk fever prevention.

So, what are the key points to focus on? 

1. Body condition score – The ideal calving condition score is 3 – 3.25, calving thinner will reduce lactation and peak yield, calving overweight will reduce early dry matter intakes and increase chances of milk fever and ketosis. For cows calving overweight, have post-calving drenches available for the inevitable issues. 

2. Nutrition – High dry matter intakes will help to keep the rumen expanded and drive intakes post-calving, but high energy intakes will drive dangerous weight gain. Therefore, forage should be clean, fresh and palatable but low in energy, that’s where chopped straw can be a useful tool. If straw is used however, it must be chopped to approx 2cm to enable intakes of 3-5kg. 

3. Minerals – Potassium is generally high in green forage (grass, grass silage and hay) but low in cereal silage. Higher potassium in dry cow diets will increase milk fevers due to its relationship with magnesium and calcium. Reducing potassium should be the first job, after this feed magnesium through magnesium chloride flakes and/or dry cow minerals as this will counteract the potassium in the diet, DCAB products may also be required. 

4. Monitor and react – Speak to your feed advisor as soon as symptoms show, small changes can have big effects. For example, a change of silage could shift the potassium levels, if retained cleansings increase this can be a sign of sub-clinical milk fever so increasing magnesium can help. Low colostrum levels could be lower starch in the close up group or an impact of milk fever. Reacting to such symptoms could pay dividends through lactation

by Adam Clay, NWF Technical Director