Effect of dietary sophorolipids on growth performance and gastrointestinal functionality of chickens infected with Eimeria maxima

Authors: PARK, INKYUNG - US Department Of Agriculture (USDA); OH, SUNGTAEK - Johns Hopkins University; GOO, DOYUN - US Department Of Agriculture (USDA); CELI, PIETRO - University Of Melbourne; Lillehoj, Hyun

Submitted to: Animal Feed Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2022
Publication Date: 5/2/2022
Citation: Park, I., Oh, S., Goo, D., Celi, P., Lillehoj, H.S. 2022. Effect of dietary sophorolipids on growth performance and gastrointestinal functionality of chickens infected with Eimeria maxima. Animal Feed Science and Technology. https://doi.org/10.1016/j.psj.2022.101944.
DOI: https://doi.org/10.1016/j.psj.2022.101944

Interpretive Summary: Naturally occurring cell wall component of common yeast, sopholipids (SLs) have been commercially available as feed additives. In this paper, ARS scientists and their collaborators evaluated SLs for their antimicrobial activity against Eimeria, intestinal parasites which cause coccidiosis affecting poultry industry more than $ 13 billion globally. A detailed understanding of how SLs could serve as antibiotic alternative feed additive in poultry will facilitate developing antibiotic approaches to reduce losses due to diseases like coccidiosis. The results showed that dietary supplementation of newly hatched chickens supplemented with SLs and infected with E. maxima showed lesser gut damage and better growth. Furthermore, there were additional benefits due to the ability of SLs to reduce parasites and such benefits included reduced cytokine release during pro-inflammatory responses, and enhanced gut health. Overall, dietary SL supplementation maintains growth performance, positively modulates intestinal immune responses, and maintains the intestinal barrier integrity of young broiler chickens during coccidiosis challenge infection. These results demonstrate the potential for using SLs as an alternative to antibiotics for commercial poultry production.

Technical Abstract: Two experiments were conducted to evaluate the effects of dietary sophorolipids (SLs) supplementation as antibiotic alternatives for increased growth and gut heath of chickens infected with E. maxima. In experiment 1, 336 (0 day-old) male broilers were used. The chickens were weighed and randomly allocated to the following six treatments groups with 7 chickens/cage and 8 cages/treatment: control group that received a basal diet (CON), negative control group that received a basal diet and was challenged with E. maxima (NC), CON+C18:1 lactonic diacetyled SL (SL1), CON+C18:1 deacetyled SL (SL2), CON+C18:1 monoacetyled SL (SL3), and CON+C18:1 diacetyled SL (SL4). Each SL (200 mg/kg feed) was added to the corresponding treatment group. In experiment 2, 588 (0 day-old) male broilers were used. The chickens were randomly allocated to the following experimental groups with 10 or 11 chickens/cage and 8 cages/treatment: CON (basal diet), negative control (NC), CON+monensin at 90 mg/kg feed, CON+SL1 at 200 mg/kg feed (SL1 200), CON+SL1 at 500 mg/kg feed (SL1 500), CON+SL4 at 200 mg/kg feed (SL4 200), and CON+SL4 at 500 mg/kg of feed (SL4 500). The chickens and feed were weighed at 0, 7, 14, 20 and 22 d to determine growth performance. In both experiments, all chickens except the CON group were orally infected with E. maxima (10,000 oocysts/chicken) at day 14. One chicken per cage was euthanized at day 20 to sample jejunal tissue to measure lesion scores, cytokines, and tight junction (TJ) proteins. Excreta samples were collected daily between day 20 and 22 to measure oocyst numbers. Data were analyzed using Mixed Model (PROC MIXED) in SAS. In experiment 1, SLs did not affect the growth of broiler chickens, but SL4 decreased (P < 0.05) the lesion score and oocyst number compared to NC chickens. In terms of cytokines and TJ protein gene expression, SLs increased (P < 0.05) IL1ß, IL6, IL17F, IL4, IL13, occludin and ZO1 levels compared to NC chickens. In Experiment 2, monensin increased (P < 0.05) body weight, and decreased (P < 0.05) the lesion score and oocyst number compared to the NC group. SL4 500 increased (P < 0.05) average daily gain and feed conversion ratio but decreased (P < 0.05) lesion score and fecal oocyst number. SL4 decreased (P < 0.05) IL6, IL17F, TNFSF15, IL2, and IL10 levels but increased (P < 0.05) occluding and ZO1 levels. Overall, dietary SL supplementation, especially SL4, improved growth and gastrointestinal functionality of young broiler chickens, demonstrating significant potential as an antibiotic alternative.