Supplementing young chicks’ diets with probiotics has shown significant benefits in enhancing the presence of beneficial intestinal microorganisms. This finding comes from recent research highlighting alternatives to antimicrobial growth promoters, especially given the concerns about antimicrobial resistance.
Background on Antimicrobial Resistance
Antimicrobial resistance is a growing concern, particularly with the use of antibiotics in livestock feed, which can lead to resistance spreading to other drugs. In light of this, researchers from Penn State University investigated natural feed additives as promising substitutes for antimicrobial growth promoters.
The Study
The study, which will be published in the May edition of Poultry Science, was led by Erika Ganda, an assistant professor specializing in food animal microbiomes. The research team included 320 day-old chicks, which were raised for 21 days in 32 randomly allocated cages. The aim was to understand the effects of a probiotic and a blend of essential oils on the growth and gut health of broilers.
Ganda explained, “With the elimination of antimicrobial growth promoters, we often see an increase in disease and a decrease in growth performance in chicks. Thus, finding antibiotic-free alternatives to enhance intestinal health and growth performance is crucial. Not all natural products are necessarily better than antibiotics, so we aimed to clarify this through our study.”
Experimental Diets
The chicks were divided into four groups, each receiving a different diet:
1. A standard diet
2. A standard diet mixed with the antibiotic bacitracin methylene disalicylate
3. A standard diet with an essential oils blend (including oregano oil, rosemary, and red pepper)
4. A standard diet with the probiotic Bacillus subtilis
Properties of Probiotics and Essential Oils
Probiotics are live microorganisms that, when administered in sufficient quantities, provide health benefits to the host by promoting a diverse range of beneficial bacteria in the digestive tract. Essential oils, derived from plants, possess antioxidant, immune-modulating, and antimicrobial properties and can alter the microbiome.
Methodology
The research team weighed all broiler chickens on the first day and then at the end of each dietary phase on day 10 and day 21. They monitored feed consumption per pen at the end of each growth phase and calculated the daily average bodyweight gain, feed intake, and feed conversion rate (the amount of feed consumed divided by weight gain) for three periods: the starter phase (up to day 10), the grower phase (days 11-21), and the total period (days 1-21).
Findings on Bacterial Strains
Excreta samples were collected daily throughout the experiment, and DNA analysis was performed to identify the bacteria present. Across all nine points in the study, diets supplemented with either the probiotic or the antibiotic significantly altered the relative abundance of bacterial strains compared to the standard diet. In contrast, the essential oils did not affect the microorganisms compared to the standard diet.
Surprising Results
Graduate student Ana Fonseca noted some unexpected outcomes: “We were surprised by the results of the essential oils. We anticipated effects on both the microbiome and the performance side. Although essential oils still hold promise as alternatives to antimicrobial growth promoters, their effectiveness might be influenced by various factors.”
Fonseca added, “Our observation period was just 21 days. Essential oils might show more significant effects as the chicks age and their microbiomes stabilize. This area certainly warrants further research.”
Conclusion
The study underscores the potential of probiotics as beneficial supplements in chick diets, enhancing intestinal health and growth performance. While essential oils showed less impact in this short-term study, their long-term effects and potential as alternatives to antibiotics remain areas of interest for future research. As the poultry industry continues to seek effective, antibiotic-free growth promoters, these findings provide valuable insights into sustainable and health-conscious feeding practices.
