Portuguese 
Spanish 
Case registered in the Midwest affected high-performance animals, was associated with the bacterium Clostridium perfringens type A, and raised an alert about starch-rich diet, specific vaccination, and sanitary management in confinements
More than a thousand Nellore cattle died in November 2025 in a confinement in the Brazilian Midwest, after an outbreak of enterotoxemia associated with the bacterium Clostridium perfringens type A. The case affected an operation with about 20,000 animals and exposed risks related to diet, vaccination, and sanitary management in the intensive system.
Outbreak affected Nellore cattle in advanced fattening stage
The episode occurred on a farm with approximately 20,000 confined cattle, mostly composed of Nellore breed animals.
The animals were between 30 and 60 days on feed, with good body condition and high productive performance.
-
Researchers Turn Discarded Mango Pits into Hydrogel That Absorbs 400% of Its Weight in Water, Offering Agricultural Solution for Droughts and Waste Reuse
-
Flower strips in Brazilian farms become pest control strategy, attracting predator insects and reducing the need for chemical pesticides.
-
Yara acquires Texas ammonia plant for $1.3 billion, boosting global fertilizer competition with 1.3 million tons annual capacity
-
At 35, Lawyer Leaves Corporate Career to Turn 1-Hectare Farm into Organic Supplier for Schools in Southern Brazil
According to the technical analysis released by veterinarian Enrico Ortolani, at Scot Consultoria, the cattle had an average gain of over 1.7 kg per day.
The most affected were precisely the so-called “feed champions,” animals with higher consumption and better weight gain.
The deaths began in small batches and quickly advanced in the following days. The animals were found dead in the morning, usually lying on their side with severe abdominal distension.
During necropsies, technicians identified severe lesions in the small intestine, internal hemorrhages, excess gas, and intestinal necrosis. The condition was compatible with bacterial enterotoxemia.
Nellore cattle were affected by fast-acting bacteria
The diagnosis pointed to the presence of Clostridium perfringens type A, a bacterium capable of causing rapid death with practically no prior clinical signs. This characteristic made it difficult to react before the loss of the animals.
The technical investigation indicated that the outbreak occurred after a change in the nutritional formulation of the diet. The starch percentage in the feed had been raised to 49% of the dry matter.
This increase occurred mainly due to the greater use of energy concentrate based on ground corn, cornmeal. The combination favored the rapid multiplication of the bacterium in the animals’ intestines.
With more rapidly fermentable carbohydrates available, there was intense toxin production in a few hours. In practice, the animals that consumed the most feed were more exposed to the problem.
Diet and vaccination appear as central points of the alert
The case drew attention not only for the number of deaths but also for the technical factors involved. The analysis pointed out two recurring elements in similar outbreaks: excess starch in highly energetic diets and failures in vaccination protection.
According to the technical material, other similar cases have already been recorded in Brazilian confinements.
They are also associated with more concentrated diets and the lack of specific coverage against Clostridium perfringens type A.
A highlighted point is that many commercial vaccines offer protection against types C and D of the bacteria. However, not all cover type A, responsible for the outbreak recorded in the Midwest.
In intensive systems, this difference can have a significant impact. When thousands of animals receive a similar diet, a failure in nutritional or sanitary balance can cause losses on a large scale.
Measures adopted reduced mortality in confinement
After the confirmation of the enterotoxemia outbreak, the adopted protocol included two immediate measures. The first was the reduction of starch in the diet, which went from 49% to 40%.
The second was emergency vaccination against Clostridium perfringens type A. After these actions, mortality dropped rapidly, according to the technical analysis.
The episode reinforces the importance of aligning productive performance, nutritional formulation, and sanitary protocols. In large-scale confinements, more energetic diets can accelerate weight gain but also require rigorous preventive control.
The death of more than a thousand Nellore cattle shows how technical adjustments within the intensive system can have direct effects on productive safety.
The case became an alert for operations seeking high performance with large volumes of animals.
This article was prepared based on information from the technical analysis released by veterinarian Enrico Ortolani at Scot Consultoria, with data, numbers, and statements preserved as per the consulted material.
