How Does Bovine Ketosis Affect Milk Production? Understand the Causes and Symptoms to Prevent It!

Ketosis in cows is a silent yet serious challenge for livestock producers. This metabolic disorder alters milk composition, reduces milk yield, and can even result in long-term reproductive problems—ultimately increasing production costs. While mild cases of ketosis disease in cattle may resolve on their own, the recovery process is often slow, impacting dairy productivity and farmer income. Early detection and treatment are crucial when cow ketosis symptoms appear. Proactive prevention measures are also key to minimizing clinical ketosis cases on the farm.

What Is Ketosis in Cows? Understanding Clinical and Subclinical Symptoms

Ketosis in dairy cows typically occurs during early lactation due to inadequate dry matter intake or imbalanced nutrition, resulting in low blood glucose. When glucose is insufficient, cows mobilize body fat as an alternative energy source, leading to excessive production of ketone bodies. This elevates ketone levels in bodily fluids and tissues. Ketosis can be categorized as either clinical or subclinical. In either case, accurate measurement of ketone concentrations is vital for assessing herd-level prevalence, improving overall cow health, and boosting milk production.

Clinical Ketosis

Since the 1990s, ketosis disease in cattle has been among the most impactful metabolic disorders in U.S. dairy herds. Clinical cases are often accompanied by digestive or neurological symptoms.

Subclinical Ketosis

Subclinical ketosis refers to elevated ketone levels in blood, urine, or milk without visible symptoms.

Economic Impact of Cow Ketosis on Taiwan’s Livestock Industry

A single case of subclinical ketosis can result in a financial loss of around USD 78 (approximately NTD 2,600). For a farm with 100 lactating cows and a 40% subclinical ketosis rate, the annual economic loss can reach USD 3,120 (about NTD 100,000). Considering Taiwan’s estimated 50,000 lactating cows, the national annual economic impact could range between NTD 40 to 50 million.

Three Types of Ketosis in Cows: Causes and Symptoms

Ketosis in dairy cows generally falls into three categories, each with distinct causes and clinical signs. A farm's ability to recognize and manage cow ketosis symptoms largely depends on the farmer’s knowledge of herd management and disease prevention during early lactation.

Type I Ketosis

Also known as spontaneous or underfeeding ketosis, Type I ketosis typically occurs 3 to 6 weeks postpartum and is the most common form during early lactation. Cows usually appear healthy initially—with normal appetite and milk yield—but as lactation progresses, they may enter a negative energy balance and develop chronic hypoglycemia. This type is often observed in traditionally fed herds and becomes more pronounced as milk production peaks. With proper treatment, cows with Type I ketosis generally recover well.

Type II Ketosis

Type II ketosis commonly affects overweight cows after calving and is often linked to poor management during the transition period. Stressors like overcrowding before parturition, frequent regrouping, and overfeeding postpartum can trigger this condition. Overweight first-calving cows are particularly vulnerable and may also experience calving difficulties, retained placenta, or uterine infections. Unlike Type I, Type II ketosis may involve hyperglycemia, even though ketone levels might be lower.

Type III Ketosis

Also called butyric acid silage ketosis, Type III ketosis is typically associated with feeding silage high in butyric acid—especially when corn is harvested prematurely or lacks soluble carbohydrates. Imbalanced diets rich in protein and carbohydrates can lead to excessive production of acetate and butyrate, which are converted into large amounts of ketone bodies in the rumen lining, eventually causing ketosis in cows.

Comparison Table: Three Types of Cow Ketosis

Three Key Testing Methods to Prevent Ketosis in Cows

Cow ketosis symptoms can be detected by measuring ketone levels in blood, urine, or milk. Clinical ketosis is diagnosed when ketone body concentrations exceed 30mg/dL in blood, 84mg/dL in urine, or 10mg/dL in milk.

Blood Testing

The main ketone bodies include acetone, acetoacetic acid (AAA), and beta-hydroxybutyric acid (BHB). Commercial blood glucose and ketone meters offer precise measurement of BHB in cow blood and are regarded as the gold standard for diagnosing ketosis.

Urine Testing

Urine testing mainly detects acetoacetic acid and serves as a quick on-site screening tool. Studies show ketone levels in urine may exceed those in blood among cows with ketosis. However, urine reflects accumulated ketone excretion rather than real-time metabolism and is not a replacement for blood testing. A positive urine test suggests potential ketosis risk, but a negative result doesn't rule out subclinical ketosis. For accuracy, combine with blood BHB testing.

Milk Testing

Milk ketone levels are roughly half those found in blood, with a BHB threshold of 100–200 µmol/L. While 200 µmol/L is insufficient to diagnose individual cases, milk testing helps evaluate herd-wide ketosis risks.

Why is Blood Testing the Most Accurate Method for Ketosis?
Blood testing is considered the most accurate for detecting ketosis because ketone levels differ significantly across blood, urine, and milk. Milk contains about half the ketones found in blood, while urine levels can range from 2 to 20 times higher. Measuring BHB in blood ensures precise results, and BHB is highly stable in blood, making it the gold standard. A typical threshold is 14.4mg/dL.

How to Use a Cow Ketone Meter? Insights from GL Biotech Experts

The SANcheck Cow Ketone (BHB)/Glucose Dual Monitoring System from GL Biotech uses electrochemical technology to deliver fast and accurate ketone readings. Once the sample touches the test strip, it’s drawn into the reaction zone, where BHB levels are measured through electrochemical response. This system works with both capillary and venous blood, delivering results in just 10 seconds. With a detection range of 0.58–46.48mg/dL, it supports comprehensive cow health monitoring throughout various lactation stages. Here's how to use the meter:

1. Prepare Materials: You'll need the SANcheck dual meter, SANcheck BHB and glucose test strips, lancing device, and lancets.

2. Power On: Insert a test strip into the meter. If using a strip from a container, close the lid promptly to avoid moisture exposure. The device powers on automatically.

3. Code Verification: Confirm the code on the screen matches the test strip packaging. A blood drop symbol indicates the meter is ready.

4. Sample Application: Gently touch the strip tip to the blood sample. The sample will automatically be drawn in.

5. View Results: After the countdown, glucose levels appear on screen. If inactive for 3 minutes, the meter shuts off automatically.

〈Recommendation：SANcheck Cow Ketone (BHB)/Glucose Dual Monitoring System〉

Conclusion

With proper ration formulation, optimal nutrition, and regular monitoring of protein, fat, and ketone levels in milk, dairy producers can detect both clinical and subclinical ketosis early. This minimizes production loss, reduces treatment costs, and enhances overall profitability. The SANcheck meter from GL Biotech features powerful data management, storing up to 200 ketone and 800 glucose results. It also calculates 7-, 14-, 30-, 60-, and 90-day averages—empowering farmers with comprehensive cow health insights. Safeguard your herd’s health by staying ahead of ketosis in cows. Contact us now to track changes and improve cow welfare and milk quality.
〈More Info: How to Use a Ketone Meter Correctly? A Deep Dive into Ketone Testing〉
〈More Info: [Glucose Meters and Test Strips: Full Guide] Manage Your Blood Sugar at Home〉

References:
〈參考資料：酮症造成台灣荷蘭牛的經濟損失（請看下方“相關照片”資訊欄）〉
〈參考資料：控制乳牛酮症的要點〉
〈參考資料：乳牛酮體檢測及應用－國立中興大學獸醫學系（PDF檔）〉