What causes ketosis in dairy cows?

Ketosis develops when cows cannot consume enough energy after calving to meet milk production demands, causing excessive body fat mobilisation and elevated ketone bodies.

When does ketosis usually occur?

Most cases occur during the first two to six weeks after calving when energy demand is highest.

How is ketosis diagnosed?

Ketosis can be diagnosed using blood, milk or urine ketone tests together with clinical signs and veterinary assessment.

Can ketosis be prevented?

Good transition management, maintaining appetite, appropriate body condition, balanced mineral supplementation and consistent energy intake all help reduce ketosis risk.

When should I call my veterinarian?

Contact your veterinarian if multiple cows develop ketosis, cows stop eating, show nervous signs, become recumbent or fail to respond to treatment.

Ill Thrift

At a glance

Ill‑thrift describes cows that fail to grow, put on condition or maintain weight as expected. It is a production and welfare issue that usually reflects an ongoing problem in nutrition, parasite load, chronic disease, poor feed quality or management gaps.

The first step is to treat it as a herd or mob issue: map where affected cows are grazing or which feeds they have received, then run basic checks on nutrition, parasites, disease and minerals. Fixing ill thrift is usually a stepwise process of elimination and targeted intervention rather than a single quick fix.

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Symptoms

Progressive weight loss, failure to gain weight
Dull, rough coat
Poor body condition
Scours
Decreased milk production
Decreased overall performance
Weakness or lethargy

What you might notice on-farm

Progressive weight loss or failure to gain condition over weeks
Dull, rough or poor coat quality and poor skin condition
Scours or intermittently loose faeces in groups of animals
Reduced milk yield and declining production from affected cows
Lethargy, weakness or lower activity and reduced grazing time
Variable response to increased feed, some cows do not eat more when offered better feed

What good looks like

Steady or improving condition score across the mob, matching seasonal and feed expectations
Good coat condition and normal faecal consistency for the system
Predictable production and fertility profiles with few chronically poor performers
Rapid improvement in condition after removing the limiting factor (parasite control, better feed, treatment)

Follow these quick checklists

What to do today

Walk the herd and record which cows are affected, where they are grazing and what supplements they have had recently and map any clusters.
Check feed quality visually at the feed face, silage face and in any supplement bins for mould, heating or contamination and remove suspect feed.
Look at faecal consistency and coat condition. Note any scouring or signs of parasites (tail area soiling).
Ensure clean water access and minimise competition at feed troughs; small things reduce intake quickly.

What to do this week

Weigh or body condition score a representative sample to quantify the problem and track progress.
Do a basic parasite control check: scour faecal egg counts on younger stock or cows if scours are present and review drenching history.
Get a feed test on suspect conserved feeds and calculate likely energy and protein intake versus requirement.
Isolate and monitor any very thin or lame cows for targeted treatment or further investigation.

During early lactation

Check fresh cows closely: ill‑thrift can show early if cows calved thin or have periparturient disease.
Treat clinical conditions promptly and ensure treated cows get extra supportive feed or shelter.
Review transition and close‑up feeding, underfeeding or uneven intake in the lead‑up often shows as ill‑thrift after calving.

Issues, likely causes and where to start

Ill‑thrift is usually multi‑factorial. Below are common scenarios, likely causes and practical starting checks.

Scours and poor condition in young stock or cows

Likely causes

Gastrointestinal parasites or coccidiosis in young stock
Feed changes or poor quality supplements causing loose faeces and malabsorption
Infectious causes, such as Johne’s in adult cows in some herds

Start with

Do faecal egg counts and consider targeted drenching where counts are high, review your drench rotation and resistance risks.
Test suspect feeds for spoilage or toxins.
Investigate adult chronic wasting diseases with your vet if young cow groups are clear and adults are affected.

Poor condition persists despite good pasture and supplements

Likely causes

Chronic worm burdens, liver fluke or internal parasites reducing feed efficiency
Mineral or vitamin deficiencies limiting appetite or metabolism (e.g. copper, selenium, cobalt)
Dental problems, jaw or mouth injuries, or lameness reducing intake

Start with

Do a clinical check of teeth, mouth and feet in a sample of affected cows.
Run blood tests for key trace minerals and metabolic indicators with your vet or adviser.
Consider strategic parasite testing and a review of pasture contamination.

If clusters are tied to a particular feed or paddock

Likely causes

Poor silage, heating or mould leading to reduced palatability and possible mycotoxin exposure
Toxic plant ingestion or plant secondary metabolites in certain paddocks
Low availability of high‑quality grazing in that area (overgrazed, muddy, pugged)

Start with

Remove the suspect feed or move cows off the paddock. Replace with clean, palatable feed and monitor recovery.
Sample suspect conserved feeds for lab testing and inspect pasture for toxic plants.
Improve stand‑off, trough access or fencing to remove environmental stressors.

If two or more issues present (e.g. poor fertility and ill thrift)

Likely causes

Chronic subclinical disease, such as Johne’s, chronic mastitis, or ongoing parasite pressure
Long‑term mineral deficits or repeated exposure to low‑level toxins

Start with

Do herd screening tests recommended by your vet for chronic infectious diseases.
Run a nutrition audit: feed tests, pasture quality, mineral delivery and actual intakes.

When to call the vet

Call your vet if:

You have multiple thin cows that do not respond to simple management changes within 7–10 days
You suspect chronic infectious disease (Johne’s), sudden cluster abortions, or unexplained deaths
You need help with diagnostic testing, such as blood mineral panels, faecal egg counts, feed toxicology or necropsy of a dead animal

Early veterinary involvement speeds diagnosis and helps avoid wasted time and money on inappropriate treatments.

How minerals fit in

Minerals are rarely the sole cause of ill thrift, but they often play a supporting role. Poor trace mineral status can reduce appetite, impair immune function and limit recovery from parasites or disease.

How minerals help

Selenium, copper and cobalt influence appetite, growth and immune response; cobalt is key for rumen microbial function and energy metabolism.
Magnesium and calcium are important for appetite and neuromuscular function; imbalances can reduce grazing behaviour.
Iodine and selenium support thyroid and metabolic health, which affects condition and coat quality.

Practical mineral checks

Don’t assume free‑choice access equals intake. Monitor who is eating and consider in‑feed or in‑shed delivery for at‑risk groups.
Test blood or liver for trace minerals where ill‑thrift is persistent and unexplained. Work with your vet or adviser to interpret results.
Use bespoke blends when conserved feeds or crops alter mineral ratios significantly.

If you would like to know more about the importance of mineral bioavailability and how it can be the difference on your farm, read this article.

FAQs

How long before I should expect to see improvement after fixing a cause?

It depends on the cause. For parasites or poor‑quality feed, visible improvement can appear in 7–14 days. Chronic disease or mineral recovery may take weeks to months.

Can a single cow with ill thrift indicate a herd problem?

One cow can be an individual issue, but multiple cases or a pattern is usually a system problem. Always map where affected cows graze and what they were fed.

Should I drench all cows if I find high faecal egg counts?

Targeted drenching based on counts and age groups is a better practice. Blanket drenching risks resistance. Discuss a plan with your adviser.

Can poor teeth cause ill‑thrift in adult cows?

Yes. Dental wear, broken teeth or mouth injuries reduce grazing efficiency. Examine the mouths of chronic poor performers.

When is culling the best option?

Culling is a practical choice for chronic non‑responders once diagnostics and targeted interventions have been tried. Work through options with your vet and consider production, fertility and welfare.