Nutritive Value of Algae Grown on Sewage2

Abstract
The predominant species of algae grown on sewage were Chlorella spp., Scenedesmus obliquus or S. quadricauda, depending upon the season. In the feeding trials algae had to be pelleted with other feeds to insure consumption and prevent sorting. Algae contained 51% crude protein, which was 73% digestible when fed to cattle and sheep, but only 54% digestible when fed to pigs. The digestible energy content for cattle and sheep was 2.6 kcal./gm. Two feeding trials indicated that algae supplied adequate protein to supplement barley for growing-finishing pigs. Alfalfa-algae pellets resulted in higher gains than alfalfa pellets, when fed to lambs on dry summer range. Although algae grown on sewage are not a high-energy feed because of a high ash content and low digestibility of the nonprotein, nonfat organic matter, it appears to have potential as a livestock feed because of the high content of protein, plus significant amounts of carotene, phosphorus, calcium and trace minerals. Copyright © 1966. American Society of Animal Science . Copyright 1966 by American Society of Animal Science