Chlorella sp.: Lipid extracted algae utilization of algae biodiesel co-products as an alternative protein feed in animal production

In order to explore some of the potential uses of algae co-products for animal nutrition, a project was designed to determine the effects of the lipid-extracted algal meal as a component of finishing rations for ruminant and monogastric livestock. The main project consisted of two studies that were conducted at the Colorado State University Agriculture Research, Development, and Education Center (ARDEC) facilities. Both studies were conducted for 28 days, with 8 animals per treatment. Both studies had similar diet nutritional profile to a diet of a traditional commercial finishing facility.;The first study used crossbred wethers (n = 40; initial BW = 45.3 kg +/- 3.5) in a randomized complete block design to evaluate the effects of titrated concentrations of algal meal as a protein supplement on live performance, live health status and carcass characteristics. Wethers were randomly assigned to one of the 5 treatments and blocked by time that they began the trial (ten animals per block). Treatments included: 1.) a control diet with soybean meal and rice meal as protein supplementation sources (CON); 2.) 5% of algae meal on a DM basis (5%AM); 3.) 10% of algae meal on a DM basis (10%AM); 4.) 15% of algae meal on a DM basis (15%AM); and 5.) 20% of algae meal on a DM (20%AM); All diets were formulated to be isocaloric and isonitrogenous.;Research results suggest that feeding up to 20% of algae co-product meal as a replacement protein source to finishing wethers is feasible with limited impact on performance and carcass characteristics as compared to the standard protein sources that have been used by the industry. Further research may be necessary to determine the response of different levels of supplementation of algal meal for sheep, effects on animals in a different physiological stage or effects on other ruminants in the finishing diet on performance and carcass merit.;The second study used crossbred barrows (n = 40; initial BW = 42.3 kg +/- 3.4) in a randomized complete block design to evaluate the effect of different levels of protein supplementation on live performance, live health status and carcass characteristics. Barrows were blocked by time of start on treatments and randomly assigned to one of the 5 treatments. Treatments included: 1.) a control diet with soybean meal as protein supplementation sources (CON); 2.) 5% of algae meal on a DM basis (5% AM); 3.) 10% of algae meal on a DM basis (10% AM); 4.) 15% of algae meal on a DM (15% AM); and 5.) 20% of algae meal on a DM basis (20% AM); All diets were formulated to be isocaloric and isonitrogenous. All pigs were fed a typical high concentrate dried whole corn based finishing diet once daily in individual pens at to the Colorado State University Agricultural Research, Development and Education Center (ARDEC). Pigs were individually weighed on d -1, 0, 21, and 28. On d 21, pigs were transported to the ARDEC metabolism facility for the metabolic phase of the study. A lumbar spinal tumor was discovered in one of the animals fed the 15% AM treatment and it had to be removed from the study and euthanized. On day 28, barrows were transported to a commercial abattoir for harvest. Initial and final BW, average daily gain (ADG) for feedlot period, ADG for metabolism period, and gain:feed were significantly different (P ≤ 0.01) across treatments, with greater performance values encountered in the CON group and lesser values in the 5%, 10%, 15% and 20% AM. Furthermore, hot carcass weight, unribbed carcass weight, ham, loin, belly, butt, shoulder, feet, total parts, carcass length, ham circumference, and lion eye area were also decreased (P < 0.01) as the concentration of AM in the ration increased above %% of the ration DM. Last rib fat, last lumbar vertebrae fat, first rib fat, belly thickness, 10th rib fat, LE L, LE a*, LE b*, marbling score and color score were similar ( P ≥ 0.17) across treatments. These data suggest that feeding up to 20% of algae co-product meal to finishing pigs has a negative impact on performance and carcass characteristics as compared to the standard protein sources that have been used by the industry. Further research may be necessary to determine the response of different levels of supplementation of algal meal for pigs and other monogastric species, effects on animals in a different physiological stage and maximal tolerable levels of algae co-product supplementation.