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Livestock at Risk from Summer Algae Blooms

Jul 03, 2025
By Farms.com

Hot Weather Raises Chances of Toxic Cyanobacteria Exposure

Summer’s hot and dry weather can lead to the development of harmful cyanobacteria, also known as blue-green algae, in water sources used by livestock.

These blooms often occur in stagnant ponds with high nutrient levels, especially nitrogen and phosphorus from manure and fertilizers.

Cyanobacteria can produce dangerous neurotoxins and liver toxins. Symptoms in animals range from weakness and trembling to respiratory distress and death.

Often, animals are found dead before symptoms are seen. “The hot, dry conditions projected for July are perfect for the production of cyanobacteria,” says Miranda Meehan, a livestock environmental stewardship specialist.

To reduce exposure, farmers are encouraged to test water sources following NDSU guidelines. Gloves should be worn when collecting samples to avoid human exposure.

Samples should include surface and subsurface water and be kept cool (not frozen) before being sent to a diagnostic lab.

Veterinarian Jake Galbreath advises producers to act quickly if poisoning is suspected. “A veterinarian can determine which samples would be appropriate for each situation,” says Galbreath.

Farmers can reduce cyanobacteria risks by following these steps -

  • Apply nutrients at proper rates and times.

  • Use buffer strips to limit runoff.

  • Avoid direct livestock access to ponds.

  • Pump water from deeper areas or alternative sources during hot spells.

Management practices like erosion control and strategic grazing also help reduce nutrient loads in water bodies.

Cyanobacteria are a serious summer concern, but with proactive water management and testing, the threat to livestock health can be greatly reduced.

For water testing and nutrient management resources, farmers are encouraged to contact local agricultural extension offices or visit NDSU's water quality page.


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What Happens When Pigs Adapt to High Soybean Meal Diets? - Gustavo Lima

Video: What Happens When Pigs Adapt to High Soybean Meal Diets? - Gustavo Lima



In this special rerun episode of The Swine Nutrition Blackbelt Podcast, Gustavo Lima, PhD candidate in Animal Science at Iowa State University, discusses how grow-finish pigs respond to high soybean meal diets. He explains the initial drop in feed intake, changes in backfat, later adaptation, energy efficiency, amino acid utilization, and the rise in nitrogen excretion at higher inclusion levels. Listen now on all major platforms!

Click here to read the full research article: https://academic.oup.com/jas/article/...

“Once they got adapted to the diet, they can handle higher levels of inclusion of soybean meal.”

Meet the guest: Gustavo Lima / gustavo-lima-a9867127 is a PhD candidate in Animal Science at Iowa State University whose work focuses on swine nutrition, ingredient characterization, energy metabolism, caloric efficiency, and applied data analysis. With more than 15 years of experience in swine production across Latin America, Gustavo also brings expertise in environmental control, performance evaluation, barn ventilation, and grow-finish housing. Learn more from Gustavo Lima on The Swine Nutrition Blackbelt Podcast, available on all major platforms.