Economics and feed value of integrating duckweed production with a swine operation

The large production of livestock on the Southern High Plains each year results in needs to handle manure and wastewater. The beef and swine Industries are incorporating manure waste management plans to ensure a stable environment. Aquatic plants have been used for many years as an integral part of wastewater treatment. One aquatic plant, duckweed, is providing high removal rates of nutrients and potential pollutants. Studies have reported crude protein in duckweed as high as 45%. The high crude protein values offer possibilities of incorporation into animal feeding operations.

In the formulation of swine rations, protein or more specifically amino acids are critical to growth and performance. The aquatic plant duckweed has similar crude protein levels and contains essential amino acids like lysine, threonine, and tryptophan that needed in swine rations. Experiment 1 utilized sixty-four nursery pigs in a feeding trial to determine the effects of replacing soybean meal with duckweed as the crude protein supplement. The data from the 21-day growth trial indicated there was a significant increase (P<0.05) in average daily gains between the 40% and 60% replacement of soybean meal with duckweed treatments and the control treatment with no differences (P>0.10) in feed efficiency. Pigs fed duckweed treatments had a long-term effect on weight gain as indicated by higher (P<0.025) final slaughter weights.