he global demand for consumable proteins is increasing, which is sequentially increasing the demand for high quality animal feedstocks. Algae have the potential to increase the quality of animal feed by acting as a nutritional supplement that is high in desirable protein and other nutrients. However, further evaluation of algae as a nutritional supplement must be conducted as different algal strains have different nutritional characteristics.
Here at the West Central Research and Outreach Center (WCROC), we recently completed an experiment to evaluate the efficacy of dried algae meal in diets for nursery pigs. Basically, the algae meal we fed to pigs resulted from biomass after pretreatment for other purposes.
We had two primary objectives in the experiment. First, we wanted to know if the algae feed would act as a pre-biotic in the gut of newly weaned pigs. A pre-biotic is a compound that provides necessary nutrients to support the growth of beneficial bacteria in the gut. Our thought was that some portions of the algae might help newly weaned pigs transition from the milk diet they consumed while nursing to the dry diet provided to them after weaning.
The diet to test this objective included only 1% algae meal. We monitored health of the pigs and growth performance. In addition, we collected content samples from the pigs’ intestines, stomach, and digestive tract. These data and samples would tell us how well the pigs adapted to their new diet after weaning.
Our second objective was to determine if the algae provided adequate nutrients to support normal growth of nursery pigs. Maybe the algae are just another source of nutrients for pig growth just like corn, milk products, soybean meal, and other common swine feedstuffs. To test this idea, we included 5, 10, or 20% algae meal in diets based on corn and soybean meal. We monitored growth rate, feed intake, and efficiency of weight gain for the pigs over a 6-week period.
What did we learn? Pigs seemed to readily consume diets containing 1, 5, or 10% algae meal with no problems. The highest level of algae meal (20%) seemed to be less desirable to pigs. It appeared that this diet was very “sticky” and would cake on the feeders. We suspect the pigs experienced an undesirable texture of this diet that reduced their feed intake.
The study just concluded, so we still need to evaluate the samples collected to determine if algae meal acted as a pre-biotic. We will continue our experiments to look for ways to capture nutrients from algae and other sources that will improve the sustainability of pork production.