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Milk Fever and Milk Quality

Milk fever is a metabolic problem of fresh cows, but its effects reach well past the cow that goes down. Cows that struggle after calving are more likely to face other health trouble, and that can show up in the bulk tank.

What milk fever is

Milk fever, also called hypocalcemia, happens when a cow cannot move enough calcium from her body into her blood to keep up with the sudden demand of early milk production. Calcium is needed for muscles to work, including the muscles that move the cow, support the heart and close the teat end. When blood calcium drops too low, the cow gets weak.

It is most common around calving, and older cows are generally at greater risk than first-calf heifers. Some cows show obvious signs, while others have a milder, hidden form that is easy to miss but still hurts health and production.

Signs to watch for

Early signs can be subtle. A fresh cow may be nervous, stand stiffly, shiver, or eat less than expected. As the problem advances she may stagger, have trouble rising, and eventually go down and lose the ability to get up. Her ears and legs may feel cool to the touch.

Treat any fresh cow that goes down as an emergency and call your veterinarian. Do not try to guess the cause, because other problems can look similar, and treatment decisions belong to the vet.

• Unsteady or stiff movement soon after calving
• Reduced appetite and a dull or anxious look
• Cow lying down and unable to rise
• Cold ears or a drop in overall alertness
• Slow or weak rumen activity

How it connects to milk quality

A cow weakened by low calcium has muscles that work poorly, and that includes the sphincter that keeps the teat end closed. A teat that stays open longer is an easier path for bacteria into the udder. Cows that are down and lying in poor conditions face even more exposure.

Milk fever is also linked in herd health discussions with other fresh cow problems such as retained placenta, displaced abomasum and metritis. Cows with several problems at once are more likely to be treated, and treated animals mean more records, more withdrawal times and more risk to the milk supply if something is missed.

Preventing milk fever with your nutritionist

Prevention is mostly about the dry cow diet in the weeks before calving. Mineral balance in that diet changes how well a cow adjusts to the sudden calcium demand of milk. The details are specific to your forages and your herd, so this is where your nutritionist earns their fee.

Ask your nutritionist to review the dry cow ration, forage mineral content and mineral supplements, and to explain what monitoring they recommend. Do not change dry cow rations on your own, since well-meant changes can create other problems.

• Have forages tested and share results with your nutritionist
• Keep dry cow feeding consistent and well mixed
• Make sure every cow can reach feed and water
• Ask whether urine or blood checks fit your system
• Keep close-up cows comfortable and low stress

Record keeping for fresh cow problems

Keep a fresh cow record that notes calving date, ease of calving, any cow that was slow to eat, and every health event and treatment. Over a year the pattern shows whether problems cluster in certain months, certain pens or certain rations.

Any treatment given under veterinary direction needs a written entry with the date, the cow, the person who made the decision and the withdrawal times. Follow label or veterinary withdrawal times for milk and meat exactly. Mark treated cows clearly so no one ships their milk by mistake.

Handling a down cow safely

A cow that cannot rise needs a clean, dry and well-bedded place while she waits for the vet. Handle her gently, keep other animals away, and avoid dragging or forcing her. Moving a down cow can injure both her and the people helping, so follow manufacturer guidance for any lifting equipment and use extension and OSHA safety recommendations for working around large animals.

Always plan for help before you try to move her, and do not stand where a thrashing cow can hit you.

What to ask your vet and nutritionist

At your next herd health visit, bring the fresh cow record and ask what level of milk fever and related disease is reasonable for your herd. Ask whether your dry period length, pen setup and feed bunk space need changes, and whether any fresh cow monitoring routine would help you catch problems early.

Keep the answers in writing and review them together at the next visit.

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