Natural and eco-friendly approaches to control aflatoxins in poultry feed

2015 Annual Report for GNE15-113

Project Type: Graduate Student
Funds awarded in 2015: $14,393.00
Projected End Date: 12/31/2016
Grant Recipient: University of Connecticut
Region: Northeast
State: Connecticut
Graduate Student:
Faculty Advisor:
Michael Darre
University of Connecticut
Faculty Advisor:
Dr. Kumar Venkitanarayanan
University of Connecticut

Natural and eco-friendly approaches to control aflatoxins in poultry feed

Summary

The overall objective of this proposal is to investigate the efficacy of two food-grade phytochemicals, namely carvacrol (CR) and trans-cinnamaldehyde (TC), in decreasing aflatoxin (AF) production by Aspergillus spp. in chicken feed and controlling aflatoxicosis in chickens. First, we investigated the inhibitory effect of CR and TC on Aspergillus flavus and Aspergillus parasiticus growth, and AF production during long-term storage in chicken feed. Two hundred gram portions of chicken feed supplemented with CR and TC (0%, 0.4%, 0.8%, and 1.0%) were inoculated with A. flavus (NRRL 3357) or A. parasiticus (NRRL 4123) and stored at 25oC for 3 months. The mold population and AF concentrations in the feed were determined at 0, 1, 2, 3, 4, 8, and 12 weeks of storage. Carvacrol and TC significantly inhibited A. flavus and A. parasiticus growth and AF production in chicken feed during the entire storage period (P < 0.05). All the concentrations of CR and TC decreased AF concentrations in the feed to levels below the FDA regulated limit (20 ppb). However, feed samples with no added CR or TC yielded more than 30 ppb (NRRL 4123 and NRRL 3357) of AF. A second study was conducted to evaluate the efficacy of CR and TC in controlling aflatoxicosis in chickens. One hundred and eighty day-old broiler chicks were fed with AF contaminated feed (~2.5ppm) with or without supplementation of 0.75% CR or TC for 5 weeks. Results revealed that CR and TC supplementation in AF-contaminated feed ameliorated AF-induced adverse effects in chickens. Both CR and TC improved body weight gain of chickens in week 5 compared to chickens fed with AF alone (P < 0.05). In addition, CR and TC supplementation significantly decreased relative liver weight in birds. Results supported our hypothesis that CR and TC supplementation can attenuate AF-induced adverse effects in chickens. However, the experiment needs to be replicated.

Objectives/Performance Targets

       The overall objective of this proposal is to investigate the efficacy of CR and TC in decreasing AF production by molds in chicken feed and controlling aflatoxicosis in chickens. The specific objectives include: (1) To investigate the efficacy of CR and TC in reducing A. flavus and A. parasiticus growth and AF production in chicken feed during long-term storage. (2) To determine the efficacy of in-feed supplementation of CR and TC in reducing aflatoxicosis in chickens (3) To determine the heat stability of CR and TC in chicken feed.

 

       The first objective was accomplished during the period from August through November 2015. The first trial of the in vivo experiment under objective 2 was completed during September to December 2015. The second in vivo experiment will be conducted in spring 2016.

Accomplishments/Milestones

       The project has three components. First, we determined the effect of CR and TC on A. flavus and A. parasiticus growth and AF production in chicken feed during long-term storage. Briefly, the mold population and AF concentrations in the feed were determined at 0, 1, 2, 3, 4, 8, and 12 weeks of storage. Results revealed that CR and TC significantly inhibited A. flavus and A. parasiticus growth and AF production in chicken feed during the entire storage period (P < 0.05).  

 

       Second, we investigated the efficacy of in-feed supplementation of CR and TC in reducing aflatoxicosis in chickens. The first trial of the chicken experiment was completed by December 2015. In this experiment, 180 day-old broiler chicks were randomly allocated to six treatments (n=5): (1) a negative control (no aflatoxin and no compound), (2) CR control (feed supplemented with 0.75% CR), (3) TC control (feed supplemented with 0.75% TC), (4) a positive control (feed contained 2.5 ppm aflatoxin), (5) CR treatment (feed contained 2.5 ppm aflatoxin with 0.75% CR supplementation), (6) TC treatment (feed contained 2.5 ppm aflatoxin with 0.75% TC supplementation). Aflatoxin, CR and TC were supplemented in the feed for 35 days, starting on day 0. In weeks 2, 3, 4, and 5, chicken performance, including body weight gain, feed intake, and feed conversion rate were measured. In addition, the relative weight of liver was determined, and histological analysis of liver was performed. Carvacrol and TC supplementation in AF-contaminated feed reduced AF-induced adverse effects in chickens. Both CR and TC improved body weight gain of chickens in week 5 compared to chickens fed with AF alone (P < 0.05). In addition, CR and TC supplementation significantly decreased relative liver weight in birds. Histology of collected chicken liver samples will be analyzed in spring 2016.

       The third and final component of this project will be determining the heat stability of CR and TC in chicken feed. This objective will be accomplished during the period from March to July 2016.

Impacts and Contributions/Outcomes

       While the project is only partially completed, no outcomes have yet been determined. However, according to the results we obtained from the objective 1 and 2 so far, CR and TC significantly reduced fungus contamination and AF production in chicken feed as well as reduced aflatoxicosis in chickens. These results suggest that these two phytochemicals could potentially be used as feed additives to control aflatoxicosis in chickens, thereby improving the performance of AF-affected chickens, besides improving pre-harvest food safety in chickens.

Collaborators:

Dr. Michael Darre

michael.darre@uconn.edu
Professor
3030 Horsebarn Rd. Ext. 4040
Storrs, CT 06269
Office Phone: 8604861008
Dr. Kumar Venkitanarayanan

kumar.venkitanarayanan@uconn.edu
Professor
University of Connecticut
3636 Horsebarn rd. Ext. 4040
Storrs, CT 06269
Office Phone: 8604864787