In the next fifty years, the world’s population will continue to expand, as will its need for basic supplies such as food and energy. Eleanore O’Neil ’15, an animal science major, researches the diets of commercial chickens in the lab of Prof. Xin Gen Lei, animal science, to combat these important global issues.
Algae fuel is a type of renewable biofuel. According to the United States Department of Energy, to make fuel from algae, first, large amounts of algae are grown. Once enough algae is grown, fuel precursors, such as carbohydrates, are extracted from the algae. These compounds will later be processed into usable fuel.
However, once the fuel-producing compounds are extracted, algae fuel producers are left with the unusable parts of the algae. This large amount of residual biomass is not useful to fuel production, but it still contains nutritional content.
Many chickens that are raised for either meat or egg production live predominantly on diets of corn and soybeans. Algae can be used to supplement these diets. Supplementing algae into chicken diets, according to O’Neil, produces chicken meat which is healthier than that of chickens only raised on traditional diets that lack algae.
According to O’Neil, algae-fed chickens are considered healthier because their meat contains heightened levels of omega-3 fatty acids as compared to omega-6 fatty acids. Omega-3 fatty acids, commonly found in plant and marine oils, are important in our metabolism and, according to the Mayo Clinic, have many health benefits, including a lowered risk of heart attacks. Omega-3 fatty acids are also the reason many call fish a healthy alternative to other meats.
O’Neil said she found the optimal level of algae in chickens’ diets through a six-week trial using five groups of broiler chickens. One group was fed a traditional diet of corn and soybeans, the other four groups were given two, four, eight, and 16 percent algae supplements in their diets, respectively.
“You can’t completely switch [the chickens] over to algae — there just aren’t enough nutrients or energy there to have a completely algae diet,” O’Neil said.
Broiler chickens, which are bred for fast growth, were then monitored for growth, feed intake and water consumption throughout the six weeks. A few birds in each group, O’Neil said, were euthanized at three and six weeks old in order to look at blood components, omega-3 fatty acid levels, and organ weights.
O’Neil said her final results found that the optimal level of algae inclusion in chicken diets is about eight to 10 percent, depending on the type of algae. Higher amounts of algae in the diet, although not fatal to the chickens, did cause reduced growth rates, making such a diet not ideal for large-scale chicken production, according to O’Neil.
Although omega-3 fatty acids are healthy, higher levels of these compounds can cause meat to spoil faster. This is because unsaturated fatty acids are susceptible to oxidation. O’Neil is currently studying the effect of supplementing chicken diets with antioxidants, such as vitamin E, to promote the shelf-life of meat. According to O’Neil, antioxidants also improve meat quality and increase the amount of omega-3 fatty acids deposited in the meat.
In the future, the Lei lab also plans to continue this research by testing the taste of chicken meat when chickens are fed algae. According to O’Neil, they will do this by partnering up with another lab outside Cornell as there are additional health laws to follow when working foods for human consumption to ensure safety. Others in the Lei lab are researching algal supplement effects on egg-laying as opposed to meat-producing chickens for similar purposes, O’Neil said.
Correction: A previous version of this article stated that O’Neil is a food science major. She is majoring in animal science.
Photo: Courtesy of Eleanore O’Neil Green grub | Eleanore O’Neil ’15 studied how chickens respond to a diet with algae.
View original article at: Peer Review: Eleanore O’Neil ’15 Raises Chickens on Energy-Efficient Feed