Blue-green algae blooms may be toxic to cattle

Source: Saskatchewan Agriculture and Food

The spring runoff from melting snow recharges dugouts and other surface water bodies with much needed water, while at the same time bringing nutrients to the soil. With the warm weather of summer, these soil nutrients can act as the perfect food for algae growth.

The appearance of algae on surface waters such as dugouts, dams, sloughs, and lakes should be treated by livestock producers as an indicator that conditions may be right for the growth of potentially toxic blue-green algae, also known as Cyanobacteria.

“Cyanobacteria are capable of producing toxins, which in high concentrations can actually kill livestock and companion animals,” warned Bob Klemmer, a Beef-Forage Specialist with Saskatchewan Agriculture and Food.

“Commonly called blue-green algae, these organisms are quite often mistaken for true algae. However, they are, in fact, a type of bacteria called Cyanobacteria.”

Several factors increase the risk of toxic blooms to livestock. In addition to spring run-off or heavy summer rains, which wash soil nutrients into surface water bodies, direct watering of livestock introduces nutrients from urine and feces into the drinking area. Extended periods of hot weather increase the temperature of nutrient-rich surface waters during summer. As well, if blue-green algae is present, wind can cause the bloom to concentrate on one side of the water body.

“The combination of readily available nutrients and warm weather provides the optimum conditions for both algae and Cyanobacteria growth,” Klemmer explained.

“When Cyanobacteria are predominant, there is a higher degree of risk for livestock. Many animal deaths that occur each year are due to toxins released from the Cyanobacteria when the bloom dies off.”

But Klemmer says there are several management practices which can reduce the risk of algae and Cyanobacteria growth.

“Installing remote watering systems and restricting livestock from direct access to the body of water is one method of prevention,” he stated. “Properly designed aeration systems can also reduce the levels of nutrients available for algae and Cyanobacteria growth.”

Producers are able to find more information on the appropriate sizing and design of aeration systems through the water quality publication website maintained by the Prairie Farm Rehabilitation Administration (PFRA) at www.agr.gc.ca/pfra/water/quality_e.htm.

Planting forage buffer strips along water runs and around dugouts, streams, sloughs, and dams will help to reduce the amount of soil nutrients entering these water bodies and helps to clarify the water.

Producers are encouraged to monitor algae and Cyanobacteria growth, and to be prepared with alternate fresh water sources during times of higher risk.

However, Klemmer says that the best approach to reducing the risk of Cyanobacteria poisoning is to learn how to recognize it. Cyanobacteria, unlike true algae, are single celled organisms, and do not typically stick together. “Using this habit of growth, producers are able to identify Cyanobacteria by running their hand with fingers slightly open through the bloom,” he stated.

“Cyanobacteria will largely flow through their fingers, or individually stick, whereas algae will clump together and not flow through.” Be sure to wash your hands with soap and water after doing this.

Klemmer points out that some Cyanobacteria will also form a thick, pea-soup-like appearance, while others look like a shimmering blue-green sheen across the surface of the water.

Algae and Cyanobacteria blooms cause off tastes and smells in water bodies, as well. This side effect may cause a reduction in livestock water intake and poor cattle performance.

There are several treatment products containing copper sulfate that can be used to control algae and Cyanobacteria blooms in dugouts and smaller water bodies. The PFRA fact sheet “Copper Treatments for Dugouts” lists the products available, the amounts of product necessary for given water volumes, and the methods of treatment. This fact sheet can be found at www.agr.gc.ca/pfra/water/copper_e.htm.

For more information, contact:
Bob Klemmer, Beef-Forage Specialist
Saskatchewan Agriculture and Food
Phone: (306) 848-2380