Submitted to: Advances in Pork Production
Publication Type: Proceedings
Publication Acceptance Date: November 15, 2002
Publication Date: January 15, 2003
Citation: CARROLL, J.A. CAN SUBTHERAPEUTIC LEVELS OF ANTIBIOTICS BE ELIMINATED FROM SWINE DIETS?. ADVANCES IN PORK PRODUCTION. 2003. V. 14. P. 151-157. Technical Abstract: The use of subtherapeutic levels of antibiotics in animal production to enhance growth and performance (i.e., antibiotic growth promoter, AGP), and the possible link to the further emergence of antibiotic-resistant bacterial strains has developed into a global issue. The use of AGPs in animals and the potential link to antibiotic-resistant bacterial strains which could possibly affect human health has become a topic of discussion for conversations across the United States. Unfortunately, a lack of scientific evidence has not abated public concerns, and has not prevented the effort to ban the use of AGPs. While the future of AGP use in animal agriculture hangs in the balance, efforts are underway to identify non-antibiotic alternatives to AGPs. The available propaganda on the use of various compounds to prevent disease and infection, or to stimulate immune function grows on a daily basis. One particular class of compounds, immune system modulators, has received considerable attention, and has been the subject of many scientific studies in the area of animal agriculture. The primary immunologically-active compounds which have been investigated include antibodies, cytokines and nutritional supplements such as spray-dried plasma (SDP) and fish oil. While scientific studies on each of these have provided promising results, the focus of this report will be on the use of SDP in swine production. The majority of available research data support an immunologically-protective effect of SDP. Research in our laboratory suggests that the enhanced performance of pigs consuming SDP may be the result of the pigs being more immunologically naïve than pigs consuming diets with no SDP. We speculate that the increased immune and stress responses noted in pigs fed SDP are related to the lack of immunological priming. Feeding SDP is thought to have a protective effect in the pig, such that the immunoglobulins present in SDP bind to and prevent attachment of pathogens to the intestine. Preventing pathogen attachment in the intestine would limit activation of the immune system, resulting in an animal which would not be fully immunocompetent, and would therefore have a greater immune response to an endotoxin challenge. Research in other laboratories also indicates that SDP provides immunological protection to the pig, which may prevent immune system activation, thus allowing nutrients to be diverted towards growth. Finally, the intent of this report is neither to support nor oppose the use of AGPs in swine diets, but rather to provide scientific data on a possible alternative which has repeatedly been demonstrated to enhance growth and performance in weaned pigs.