Tolerance of Broilers to Dietary Supplementation with High Levels of the DHA-Rich Microalga, Aurantiochytrium Limacinum: Effects on Health and Productivity

SIMPLE SUMMARY: Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is considered an essential part of the human diet. Increasing the amount of DHA in commonly consumed foodstuffs can benefit people predisposed to heart problems, depression, and even some forms of cancer. One of the best sources of DHA is oily fish, but the majority of people do not eat fish regularly. By formulating diets for livestock or poultry to include ingredients rich in omega-3 fatty acids, we can increase the omega-3 content of their respective meat and tissues. In this study we fed broilers diets supplemented with increasing amounts of a DHA-rich microalgae to investigate whether it was safe for the birds, in terms of their health and productivity and effective in terms of DHA transfer from feed to meat. The results of the present study showed that feeding the microalgae to chickens had no negative effects on their health in terms of their level of survival or growth. Moreover, we found that supplementing the microalgae resulted in a large increase in the DHA content of meat. This study demonstrated that feeding algae is a safe and effective way to improve the nutritional value of chicken meat. ABSTRACT: It is well established that the docosahexaenoic acid (DHA) content of commonly consumed meats, such as chicken, can be increased through dietary supplementation with DHA-rich ingredients. The purpose of this study was to investigate the tolerance of broilers to dietary supplementation with the unextracted biomass of a DHA-rich microalgae Aurantiochytrium limacinum, so as to ensure its safety, since it is accumulated in broiler meat. Healthy day-old male Ross 308 chicks (n = 1120) were evenly distributed to 32 pens (35 chicks per pen), with pens randomly allocated to one of four dietary treatments, each having eight replicates. The dietary groups included one untreated control and three treatments corresponding to three inclusion levels (0.5, 2.5, and 5.0%) of All-G-Rich(®), with the birds receiving the experimental diets ad libitum during the study (day 0–42). Bird survival, blood parameters, productivity, and breast and thigh DHA content were determined after 42 days of feeding. Supplementation at up to 10 times the intended use level had no negative effects on the mortality, blood parameters or productivity of the birds, while significant increases in the meat DHA content were observed. These results indicate that supplementation with Aurantiochytrium limacinum is a safe and effective way to increase broiler tissue DHA content.