Synergistic effects of phytochemicals and disinfectants in mitigating experimental coccidiosis in broiler chickens and its impact on growth performance and gut health

Introduction

The global human population is estimated to reach 9.6 billion by 2050. During this period, broiler chicken production is expected to grow by 121% to meet the increasing demand for animal protein (Mottet & Tempio, 2017) [19] . However, poultry health and nutrition face significant challenges, particularly due to the increased incidence of enteric diseases such as coccidiosis and necrotic enteritis, which impair nutrient absorption and digestion (Fathima et al., 2022) [10] . These conditions result in poor feed conversion efficiency, higher mortality rates, and increased condemnation at processing plants. Ensuring food safety and security for the expanding human population requires effective control and prevention of enteric infections. Coccidiosis, caused by Eimeria spp., is a major parasitic disease affecting poultry, leading to significant economic losses due to reduced feed efficiency and increased mortality (Mathis et al., 2024) [17] . The cellular immune response of chickens to Eimeria spp. invasion, which causes cecal coccidiosis, generates reactive oxidative species (ROS) (Ogwiji et al., 2024) [22] . Coccidiosis is often considered a disease of poor management (Ali et al., 2014; Bachaya et al., 2015) [5,7] , with an estimated US$ 20 million in annual economic losses recorded in India (Bera et al., 2010) [8] . Antimicrobial growth promoters (AGPs) are subtherapeutic doses of antibiotics that have been widely used in animal production to enhance feed efficiency, growth performance, and intestinal health (Mehdi et al., 2018) [18] . However, rising concerns about antimicrobial resistance and consumer demand for antibiotic-free poultry products have led many countries to ban or restrict the use of AGPs. Eimeria parasites undergo intracellular development in the gut, directly impairing the intestinal mucosa and affecting overall bird health (Lee et al., 2023) [16] . As an alternative, dietary supplementation with nucleotide-rich yeast extract at a 0.5% level has been shown to improve growth performance, including live body weight, weight gain, feed intake, and feed conversion ratio in broilers (Tembhurne, 2020) [28] . The recent shift toward reducing AGPs in poultry diets has increased the industry's focus on finding viable alternatives. In this context, phytogenic feed additives (PFAs) are being explored for their potential to enhance gut health and improve overall performance (Murugesan et al., 2015) [20] . Considering these factors, the present study was conducted to evaluate the effects of different feed additives on Eimeria colonization, intestinal health, and production parameters in broiler chickens.

Materials and Methods

Experimental Design

The present study was carried out in the Department of Veterinary Parasitology and Poultry Research and Training Centre, Nagpur Veterinary College, Nagpur. For the experiment, day-old broiler chicks were procured and randomly divided into nine treatments, each treatment made of three replicate pens, and each pen was comprised of 10 chicks. All chicks were provided with similar management and environmental conditions and reared on floor pen with rice husk as bedding material. The birds of all the nine treatments were fed with standard commercial broiler ration without any coccidiostat in feed (pre-starter, starter & finisher ration). Proper vaccination, bio-security and sanitization were maintained in all the pens to prevent any infection during experimental period. All the experimental birds were kept under constant observation during the entire period of study. A total of 270, day old chicks of either sex were divided into nine treatments with each one duplicate pen. The cleaned and disinfected surfaces were contaminated with sporulated oocysts equivalent to 4.0 x10 5 /m 2 . Then the floor was covered as usual with rice husk.

Methodology

Source of Eimeria spp. Oocyst Eimeria oocysts were collected from natural outbreaks, speciated, and subjected to sporulation. The required dilution was made and used for the challenge study.

The groups of birds and dosages given to them were as follows:

Experimental Groups

Lesion Scoring and Sample Collection

Three birds from each replicate were sacrificed on the 28th and 42 nd day of age. Intestines were observed, and lesion scoring was performed as per Johnson and Reid (1970) [15] .

Oocyst Per Gram (OPG)/Oocyst Shedding

Fecal content from all groups was collected on days 14, 21, 28, 35, and 42. Oocyst count was performed using Stoll's method and expressed as OPG (Haug et al., 2006) [14] .

Weekly Performance

Weekly body weight and feed consumption were recorded, and cumulative feed conversion ratios (FCR) were calculated. Mortality was also recorded.

Microbiological Count

One gram of fecal material was collected aseptically from six birds per group at the time of sacrifice on the 42 nd day.

Enumeration of E. coli and Clostridium spp. per gram of feces was performed.

Statistical Analysis

Data were analyzed statistically using standard procedures.

Results

Pathology Gross Pathology

Gross observations made on intestines in experimental broilers of different treatment groups (A-I) at Day 28 and Day 42 are presented in Fig. 1. At Day 28, the control group revealed ballooning of intestines along with hemorrhages in the caeca (lesion score 3). Other treatment groups exhibited mild ballooning of intestines. Milder lesions were noted in caeca of Groups C and G (lesion score 1). At Day 42, the intestine from the control group revealed enlargement and ballooning of caeca with hemorrhages (lesion score 2). Groups C, D, F, G, and H also showed mild enlargement and ballooning of caeca with hemorrhages (lesion score 2). Histopathology Histopathological analysis (Fig. 2) revealed severe villous disruption, crypt necrosis, and inflammatory infiltration in the duodenum, jejunum, ileum, and cecum of the control group. Treated groups exhibited moderate to mild lesions. By Day 28, moderate lesions were observed in the duodenum of Groups C, F, G, and H, while Groups D and E displayed milder changes. By Day 42, lesion severity decreased across all treatment groups, with Group E showing the mildest changes in the cecum.

Body Weight and Growth Performance

There were no significant differences (p>0.05) in body weight on Day 0. However, significant differences (p<0.001) were observed from Day 7 onwards. By Day 42, Group D had the highest body weight (2459.67±2.60 g), followed by Groups G and F. Group I recorded the lowest body weight (2000.67±1.20 g), indicating that Groups D, G, and E were effective in promoting weight gain.

Feed Consumption and Feed Conversion Ratio (FCR)

Feed intake varied among groups. [11] and Tsiouris et al. (2021) [29] . Body weight gains in Groups D, G, and E suggest that bioactive compounds or herbal additives have a potential role in promoting growth, likely through improved feed utilization and antimicrobial activity. These results correspond with previous findings by Rivera-Mendez et al. (2017) [27] , Habibi et al. (2016) [13] , Ajaykumar et al. (2024) [1] , and El-Ashram & Abdelhafez (2020) [9] , who reported enhanced growth with herbal supplements such as ginger, cinnamon, thyme, and star anise. Although feed intake was highest in the control group, it did not translate into better body weight, unlike Groups E and G, which demonstrated improved FCR. The efficient feed conversion in these groups aligns with Valenzuela-Grijalva et al. (2017) [31] , highlighting the influence of phytochemicals on production efficiency. However, similar to Vilienė et al. (2024) [32] , our results indicate that herbal additives, although promising, may not fully match the efficacy of synthetic coccidiostats in terms of final weight gain. Oocyst shedding patterns show the immediate efficacy of salinomycin and the delayed yet effective response of herbal treatments. This delayed response is possibly due to gradual immune modulation, as seen in studies by Alanazi et al. (2023) [3] , indicating a timedependent therapeutic effect of herbal additives like Ficus religiosa. The control of microbial load, particularly in Groups B, E, and F, points to antimicrobial potential of treatments. These results are consistent with findings by Ofima (2023) [21] , El-Ashram & Abdelhafez (2020) [9] , and support the idea that gut microbiota modulation contributes to better disease resistance and nutrient absorption. Additionally, the role of disinfectants in suppressing E. tenella sporulation (Rajendran & Fatima, 2023; You, 2014) [25, 33] further emphasizes the importance of integrated control strategies in coccidiosis management.

Conclusion

The findings suggest that different treatments significantly influenced gut health, body weight, feed efficiency, and oocyst shedding in broilers affected by coccidiosis. Group D exhibited the best overall weight gain, while Group E demonstrated the best feed conversion efficiency and reduced oocyst shedding over time. Group B showed the strongest anticoccidial effects, with nearly complete suppression of oocyst shedding. In terms of microbial balance, Groups B, E, and F controlled bacterial load effectively, which may contribute to improved gut health. The results highlight that strategic supplementation with anticoccidial and growth-promoting agents can mitigate the effects of coccidiosis, improve growth performance, and enhance feed efficiency in broilers.

Acknowledgement

AcknowledgmentsThe author(s) express gratitude to the Dean, Nagpur Veterinary College, Nagpur for providing necessary facilities to carry out the current study. Disclosure StatementNo potential conflict of interest was reported by the author(s).

References

1. Ajaykumar R, Harishankar K, Shri Rangasami SR, Saravanakumar V, Yazhini G, Rajanbabu V, et al. Growth performance, quantitative analysis, and economics of broiler chickens as influenced by herbal dietary additives as alternative growth boosters. Indian Journal of Animal Research. 2024;58(7):1139-1147. https://doi.org/10.18805/IJAR.B-5326
2. Akhtar M, Tariq AF, Awais MM, Iqbal Z, Muhammad F, Shahid M, et al. Studies on wheat bran Arabinoxylan for its immunostimulatory and protective effects against avian coccidiosis. Carbohydrate Polymers. 2012;90:333-339.
3. Alanazi HH, Elasbali AM, Alanazi MK, El Azab EF. Medicinal herbs: Promising immunomodulators for the treatment of infectious diseases. Molecules. 2023;28:8045.
4. Al-Ghamdi ES. Use of ginger and cinnamon oils mixture as a natural alternative to antibiotics in quail feed. Rendiconti Fisici dell'Accademia dei Lincei. 2022;33:843-849. https://doi.org/10.1007/s12210-02201106-4
5. Ali H, Naqvi F, Tariq N. Prevalence of coccidiosis and its association with risk factors in poultry of Quetta, Pakistan. Asian Journal of Applied Sciences. 2014;2:554-558.
6. Aviagen. Ross 308 AP: Ross Broiler Management Handbook; 1118-AVNR-032. Aviagen Group, Huntsville, AL, USA; 2018:80-105.
7. Bachaya HA, Abbas RZ, Raza MA, Iqbal Z, Rehman TU, Baber W, et al. Existence of coccidiosis and associated risk factors in broiler chickens in Southern Punjab, Pakistan. Pakistan Veterinary Journal. 2015;35:81-84.
8. Bera AK, Bhattacharya D, Pan D, Dhara A, Kumar S, Das S. Evaluation of economic losses due to coccidiosis in the poultry industry in India. Agricultural Economics Research Review. 2010;23:91-96.
9. El-Ashram S, Abdelhafez GA. Effects of phytogenic supplementation on productive performance of broiler chickens. Journal of Applied Poultry Research. 2020;29(4):852-862. https://doi.org/10.1016/j.japr.2020.07.005
10. Fathima S, Al Hakeem WG, Shanmugasundaram R, Selvaraj RK. Necrotic enteritis in broiler chickens: A review on the pathogen, pathogenesis, and prevention. Microorganisms. 2022;10(10):1958. https://doi.org/10.3390/microorganisms10101958
11. Gieryńska M, Szulc-Dąbrowska L, Struzik J, Mielcarska MB, Gregorczyk-Zboroch KP. Integrity of the intestinal barrier: The involvement of epithelial cells and microbiota-A mutual relationship. Animals. 2022;12(2):145. https://doi.org/10.3390/ani12020145
12. Graham D, Petrone-Garcia VM, Hernandez-Velasco X, Coles ME, Juarez-Estrada MA, Latorre JD, et al. Assessing the effects of a mixed Eimeria spp. challenge on performance, intestinal integrity, and the gut microbiome of broiler chickens. Frontiers in Veterinary Science. 2023;10:1224647. https://doi.org/10.3389/fvets.2023.1224647
13. Habibi H, Firouzi S, Nili H, Razavi M, Asadi SL, Daneshi S. Anticoccidial effects of herbal extracts on Eimeria tenella infection in broiler chickens: in vitro and in vivo study. Journal of Parasitic Diseases. 2016;40:401-407.
14. Haug A, Williams R, Larsen S. Counting coccidial oocysts in chicken faeces: A comparative study of a standard McMaster technique and a new rapid method. Veterinary Parasitology. 2006;136(3-4):233-242. https://doi.org/10.1016/j.vetpar.2005.11.024
15. Johnson J, Reid WM. Anticoccidial drugs: Lesion scoring techniques in battery and floor-pen experiments with chickens. Experimental Parasitology. 1970;28(1):30-36. https://doi.org/10.1016/0014-4894(70)90063-9
16. Lee Y, Park I, Lillehoj HS. Oral administration of chicken NK-lysin or recombinant chicken IL-7 improves vaccine efficacy of Eimeria tenella elongation factor-1α (EF-1α) against coccidiosis in commercial broiler chickens. Poultry Science. 2023;102:102611. https://doi.org/10.1016/j.psj.2023.102611
17. Mathis GF, Lumpkins B, Cervantes HM, Fitz-Coy SH, Jenkins MC, Jones MK, et al. Coccidiosis in poultry: Disease mechanisms, control strategies, and future directions. Poultry Science. 2024;104663. https://doi.org/10.1016/j.psj.2024.104663
18. Mehdi Y, Létourneau-Montminy MP, Gaucher ML, Chorfi Y, Suresh G, Rouissi T, et al. Use of antibiotics in broiler production: Global impacts and alternatives. Animal Nutrition. 2018;4(2):170-178.
19. Mottet A, Tempio G. Global poultry production: Current state and future outlook and challenges. World Poultry Science Journal. 2017;73:245-256. https://doi.org/10.1017/S0043933917000071
20. Murugesan GR, Syed B, Haldar S, Pender C. Phytogenic feed additives as an alternative to antibiotic growth promoters in broiler chickens. Frontiers in Veterinary Science. 2015;2:21. https://doi.org/10.3389/fvets.2015.00021
21. Ofima SJ. Fecal microbial evaluation of Gallus domesticus supplemented with Allium cepa. 2023. https://doi.org/10.13140/RG.2.2.35883.62245
22. Ogwiji M, Jatau ID, Natala AJ, Mohany M, Al-Rejaie SS, Zhu M. Effect of prebiotic, probiotic, and synbiotic products on oxidative status, performance, and parasitological parameters of broiler chickens induced with cecal coccidiosis. Journal of Applied Poultry Research. 2024;33(4):100472. https://doi.org/10.1016/j.japr.2024.100472
23. Pajić M, Aleksić N, Vejnović B, Polaček V, Novakov N, Ostojić-Andrić D, et al. Influence of anticoccidials on oxidative stress, production performance and faecal oocyst counts in broiler chickens infected with Eimeria species. Kafkas Üniversitesi Veteriner Fakültesi Dergisi. 2019;25(3):379-385.
24. Qaid M, Al-Mufarrej S, Azzam M, Al-Garadi MA. Anticoccidial effectivity of a traditional medicinal plant, Cinnamomum verum, in broiler chickens infected with Eimeria tenella. Poultry Science. 2020;100:Article 101071. https://doi.org/10.1016/j.psj.2020.11.071 International Journal of Advanced Biochemistry Research https://www.biochemjournal.com
25. Rajendran RM, Fatima SN. Effect of phenolic disinfectant on sporulation inhibition of Eimeria tenella for prevention of coccidiosis. Journal of Applied Biology & Biotechnology. 2023;11(6):228-232. https://doi.org/10.7324/JABB.2023.135101
26. Ramezani F, Shekarabi SPH, Mehrgan MS, Foroudi F, Islami HR. Supplementation of Siberian sturgeon (Acipenser baerii) diet with barberry (Berberis vulgaris) fruit extract: Growth performance, hematobiochemical parameters, digestive enzyme activity, and growth-related gene expression. Aquaculture. 2021;540:736750.
27. Rivera-Méndez C, Plascencia A, Torrentera N, Zinn RA. Effect of level and source of supplemental tannin on growth performance of steers during the late finishing phase. Journal of Applied Animal Research. 2017;45(1):199-203. https://doi.org/10.1080/09712119.2016.1141771
28. Tembhurne PB, Borkar SD, Bonde SW, Kadam MM, Khose KK, Patil DV, et al. Effects of graded level of nucleotide-rich yeast extract supplementation in diets on growth performance and economics of broilers. Journal of Entomology and Zoology Studies. 2020;8(4):1335-1338.
29. Tsiouris V, Giannenas I, Bonos E, Papadopoulos E, Stylianaki I, Sidiropoulou E, et al. Efficacy of a dietary polyherbal formula on the performance and gut health in broiler chicks after experimental infection with Eimeria spp. Pathogens. 2021;10:524.
30. Ullah MI, Akhtar M, Awais MM, Anwar MI, Khaliq K. Evaluation of immunostimulatory and immunotherapeutic effects of tropical mushroom (Lentinus edodes) against eimeriasis in chicken. Tropical Animal Health and Production. 2018;50:97104.
31. Valenzuela-Grijalva NV, Pinelli-Saavedra A, MuhliaAlmazán A, Domínguez-Díaz D, González-Ríos H. Dietary inclusion effects of phytochemicals as growth promoters in animal production. Journal of Animal Science and Technology. 2017;59(1):1-17. https://doi.org/10.1186/s40781-017-0133-9
32. Vilienė V, Murawska D, Gesek M, Matusevičius P, Miknienė Z, Nutautaitė M. Evaluation of herbal anticoccidials on growth performance in experimentally infected broiler chickens. Agriculture. 2024;14(12):2261. https://doi.org/10.3390/agriculture14122261
33. You MJ. Suppression of Eimeria tenella sporulation by disinfectants. Korean Journal of Parasitology. 2014;52(4):435-438. https://doi.org/10.3347/kjp.2014.52.4.435