Division of Animal Science
There is growing interest in the animal industry to provide consumers with products that are perceived as healthier.Feeding domestic animals diets rich in omega-3 PUFA is one approach that is currently being investigated and to some extent practiced in the poultry and swine industries.For example, "heart-healthy" eggs enriched with omega-3 PUFA are in the marketplace and are commanding a premium price.My research program is designed to address how dietary PUFA may affect the health of domestic animals as well as the health of humans.
Early in my career, studies were conducted to examine the effect of various dietary fat sources on antibody production and lymphocyte function in layer-type and broiler (meat) chickens.As a result of these studies, we were the first to demonstrate that incorporation of omega-3 fatty acids into poultry rations altered the immune response of both laying hens and broilers.The National Poultry & Egg Board supported a portion of our investigation into the effects of dietary fatty acids on the chicken immune system.These findings were published in three peer-reviewed journal articles in Poultry Science in 1991 and 1992.
The loss of neonatal pigs in the first week of life has a major negative impact on the swine industry.Illness and death from infection is quite common in newborn pigs, in part, because their immune system is not fully functional until they reach several weeks of age. We hypothesized that excessive eicosanoid (e.g., prostaglandin) production by neonatal immune cells contributed to a state of immunosuppression. We further hypothesized that providing neonatal pigs with omega-3 PUFA would reduce eicosanoid biosynthesis, resulting in enhanced immune responsiveness.To test these hypotheses, we had to establish an effective, yet practical means to provide neonatal pigs with omega-3 PUFA. We were first to demonstrate that supplementing a practical late-gestation and lactation diet with fish oil greatly elevates the content of omega-3 PUFA in the sow's serum and milk, as well as, in the serum of nursing pigs.We reported that these changes in tissue fatty acid profiles generally reduced in vitro prostaglandin release by neonatal pig immune cells. Yet, our dietary intervention did not affect primary and secondary antibody responses in these young pigs.
The overall objective of my research program is to better define the influence that dietary fats have on the immune system. This research has involved monogastric domestic animals (i.e., swine and poultry), as well as laboratory animals (i.e., rats and mice). Lines of investigation in my research program have included: (1) defining the interaction between PUFA and vitamin E at the level of the immune system; (2) examining the impact of omega-3 fatty acids on pro-inflammatory cytokine production; (3) exploring the effect of various dietary fats on infectious disease resistance; (4) characterizing the in vivo immune modulatory activity of omega-3 fatty acids using various transgenic and knock-out mouse models. Additionally, Dr. Fritsche, in collaboration with Dr. Michael Petris, is investigating the essential role of intracellular copper trafficking in inflammation and infectious disease resistance.