Submitted to: Translational Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2017
Publication Date: 6/23/2017
Citation: Carroll, J.A., Schmidt, T.B., Callaway, T.R., Wilson, J.G., Donaldson, J.R. 2017. Use of a novel oleaginous microorganism as a potential source of lipids in weanling pigs. Translational Animal Science. 1:201-207.

Interpretive Summary: Animal health is one of the primary concerns among livestock producers. It has been estimated that annual losses associated with illnesses among pre-weaning swine account for nearly $329 million in annual losses. The primary causes for these significant losses are due to pathogens (bacterial, viral, or parasitic) and increased energy demands in livestock with low energy reserves during times of stress. In particular, weanling pigs are more susceptible to illness due to reduced energy metabolism, limited energy reserves (i.e adipose tissue), and decreased feed intake, which results in an inefficient immune response. Therefore, a collaborative study was conducted with scientists from the USDA-ARS Livestock Issues Research Unit, Mississippi State University, the USDA-ARS Food and Feed Safety Research Unit, and the University of Nebraska to determine if feeding a novel Enterobacter cloacae strain to newly weaned pigs would increase circulating concentrations of triglycerides and non-esterified fatty acids that could potentially be used as an energy source during this stressful period. To test the hypothesis, weanling pigs were provided novel strains of the Enterobacter cloacae (i.e., JD6301 or JD8715) through oral gavage daily and serum was analyzed every 6 hours throughout the study. An increase in serum triglycerides and non-esterified fatty acids were noted only in pigs provided JD6301 or JD8715. This increase corresponded with alterations in the serum fatty acid profile of these pigs. This is the first study to demonstrate that live bacteria can be provided as a probiotic to increase the availability of energy to animals. Further research is needed to determine if this mechanism of providing additional energy can improve the metabolic response of the animal in the presence of an enteric infection or during stress. This information will be of specific interest to swine nutritionists and veterinarians who are seeking ways to improve the energy status of young pigs during stressful periods such as weaning and during illness.

Technical Abstract: Weanling pigs are exposed to a greater risk of infections due to increased energy demands from the stress of weaning and limited energy reserves. The objective of the current study was to determine if supplementation of oleaginous bacteria could serve as a source of lipids to weanling pigs during this stressful transition. The novel Enterobacter cloacae strain JD6301 was recently determined to produce up to 50% of the cell weight as lipids. Additionally, this strain is able to tolerate conditions encountered within the mammalian gastrointestinal tract, such as bile salts, acidic conditions, and temperatures up to 41 degrees Celsius. In order to determine whether this bacterium could serve as a probiotic that provides an additional source of lipids to livestock, weanling pigs were provided 1x10^9 CFU/kilogram of JD6301 or JD8715 (which is a variant form of this microbe capable of producing extracellular triglycerides) via the oral gavage. Results indicate that providing pigs with either JD6301 or JD8715 significantly increased serum concentrations of triglycerides and non-esterified fatty acids (NEFA) within 72 hours. Enterobacter strains were able to survive within the gastrointestinal tract throughout the duration of the study, suggesting that the increase in lipids was due to the presence of the live microorganisms. Though further research is needed to determine whether the increase in triglycerides and NEFAs is due to specifically to an increase in availability from the bacteria, these results suggest that supplementing weanling pigs with either JD6301 or JD8715 can increase the amount of energy available.