Cattle fed algae

Cattle fed the algae product at the 5% level had significantly greater average daily gains and finished weight, lower feed intake and better feed-per-gain compared with control cattle. (John Maday)

J dropcapohn Maday writes in Drovers.com that, as algae emerges as a commercial source for omega-3 fatty acids for human and animal foods, the process for extracting those fatty acids — leaving the byproduct condensed algal residue solubles (CARS) — could replace some grain in cattle feedlot rations.

With the CARS product becoming available from processing facilities in Nebraska this year, University of Nebraska researchers conducted a trial to evaluate its potential as animal feed. The CARS product researchers used in this trial, at 41.7% dry matter, contained high levels of crude protein (29.3%) and neutral detergent fiber at 34.6%. The product also was relatively high in sulfur and sodium, which the researchers note could limit levels of inclusion in cattle diets.

In this trial, the researchers substituted CARS for dry-rolled corn at 0, 2.5, 5 and 7.5% of the total ration, and monitored each group of cattle through the finishing period. They found that cattle fed CARS at the 5% level had significantly greater average daily gains and finished weight, lower feed intake and better feed-per-gain compared with control cattle receiving no CARS. At the 7.5% level, daily gains and finished weights declined along with feed intake.

The researchers found no adverse effects on cattle health, and concluded CARS is a safe feed ingredient for cattle. More research will be needed to determine optimum feeding rates and cost-effectiveness, and to evaluate effects on beef characteristics.

The full 2019 Beef Cattle Report is available online from the University of Nebraska.

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