Growth promoting effects of clove powder and eugenol in broilers

Introduction

The poultry industry plays a vital role in global food security by providing affordable and high quality animal protein through its meat and eggs [1] . In India, poultry production has rapidly evolved from a backyard sector to an organized commercial sector, contributing primarily to the national economy [2] . According to FAOSTAT 2024, egg production of poultry in India has increased at an annual rate of 8.9%, with per capita poultry meat consumption rising from 3.23 to 7.10 kg between 2020 and 2022. For many years, low-dose antibiotics have been used as antibiotic growth promoters (AGPs) to improve feed efficiency, disease resistance and growth performance in poultry [3] . However, their extensive and indiscriminate use has accelerated the emergence of antimicrobial resistance (AMR), now a serious danger to public health and food safety [4] . It is estimated that by the year 2050, AMR related deaths may reach 10 million annually if preventive measures are not taken [5] . Consequently, there is a shift toward identifying natural, safe and viable alternatives to AGPs [6] . Phytogenic feed additives like herbs, spices, essential oils and plant extracts, have gained significant attention as promising alternatives to antibiotics in poultry nutrition [7] . These plantderived compounds possess antimicrobial, antioxidant and immunomodulatory properties that can enhance feed utilization, gut health and overall performance [8] . Among various phytogenics, clove (Syzygium aromaticum), a spice from the Myrtaceae family, is known for its bioactive components like eugenol. Eugenol constitutes up to 95% of its essential oil [9] . Clove and eugenol exhibit potent antimicrobial, antioxidant, antiinflammatory and digestive stimulant activities [10] . Several studies suggest that eugenol improves digestive activity, nutrient absorption, promotes growth and feed efficiency in broilers [11] . Therefore, the present study was designed to evaluate the growth promoting effects of clove powder and eugenol in broiler chickens to identify potential natural alternatives to antibiotic growth promoters for sustainable poultry production.

Materials and Methods

Experimental Birds, Feeding, Housing and Management

The experimental design was reviewed and approved by the Institutional Animal Ethics Committee of the College of Veterinary Science and Animal Husbandry, KU, Anand (India) and was undertaken as per the guidelines of the CCSEA, Government of India, New Delhi. The experiment was carried out at Poultry research station of the college at Anand. The experiment was conducted on day-old Ven-cobb broiler chicks from a single hatch. A deep litter system was used for the rearing of chicks with a well-ventilated brooder house using standard management and health care practices and monitored daily for any abnormal clinical signs and mortality if any. According to the age of the birds, all the birds received broiler feed according to the age of birds i.e., 1-7 days (pre-starter), 8-21 days (starter) and 22-42 days (finisher) during the entire experimental period. Clove powder and eugenol at the different doses mixed with basal feed to make different treatment feeds. Throughout the experiment, all birds had ad libitum access to clean, fresh, cool drinking water to keep the bird stress free. The birds were protected against various diseases by vaccination.

Experimental Design

The experiment was conducted on 144, day-old ven-cobb broiler chicks. The chicks were randomly allocated to six experimental groups, each consisting of four replicates and each replicate consisting of six chicks. The chicks of group-I served as a control group and was given basal diet without administration of any treatments. Chicks of group-II were given standard antibiotic avilamycin @ 15 ppm in feed. Chicks of group-III were given clove powder @ 5 g/kg in feed. Chicks of group-IV were given clove powder @ 10 g/kg in feed. Chicks of group-V and VI were given eugenol @ 150 and 300 mg/kg in feed, respectively. The study was conducted for 42 days. The treatment details for growth promoting effects are given in Table 1.

Growth Performance Parameters

Various parameters were taken like weekly body weight, body weight gain, feed consumption and feed conversion ratio (FCR). Mortality was recorded daily and expressed as a percentage. At day 42, eight birds from each treatment were randomly selected, fasted for 6 h (with water ad libitum) before slaughter and slaughtered for carcass trait evaluation. Carcass characteristics, including pre-slaughter weight, dressed weight and weight of organs like liver, heart and gizzard (giblet) were recorded. Dressing and Giblet percentage were calculated.

Statistical Analysis

One-way analysis of variance (ANOVA) and completely randomized design was used to compare the means of various parameters by using IBM SPSS software (version 25.0). Significant differences (p < 0.05) between different experimental groups were analysed by Duncan's multiple range test. All the data were presented as Mean ± S.E.

Results and Discussion Body Weight and Body Weight Gain

The weekly Body Weight (BW) and Body Weight Gain (BWG) values as Mean + S.E. are given in Table 2 and3, respectively. During the initial weeks, body weights did not differ significantly among birds supplemented with different treatments and the control group (Group I). At the 4 th week, body weight of all treatment groups was non-significant as compared to control group I. During the 5 th week, birds supplemented with clove powder at 5 g/kg (Group III) and the antibiotic growth promoter (Group II) showed significantly high body weights as compared to the control group, whereas birds in Groups IV and VI had intermediate but nonsignificant increases. At 6 th week, the birds of Groups II, III, V and VI were showed significantly higher body weights as compared to the control group. Overall body weight gain at the 6 th week of age was significantly higher in birds supplemented with clove powder at both 5 g/kg feed (Groups III), eugenol at 150 and 300 mg/kg feed (Groups V and VI) and the standard antibiotic growth promoter (Group II) compared to the control group (Group I). Additionally, the total body weight gain over the 6-week period in birds supplemented with clove powder and eugenol (Groups III, V and VI) was comparable to that of the standard antibiotic avilamycin treated group II. These results suggest that both clove powder at lower dose and eugenol at both doses effectively promote growth performance in broilers, similar to conventional antibiotic growth promoters. Body weight and body weight gain recorded in the of present study were in accordance with the findings of Marcincak et al. (2011) [12] who reported improved body weight of broiler by inclusion of clove (1%) in the feed and agrimony extracts (0.2%) into water as compared to birds of control group [12] . Similarly, Al-Mufarrej et al. (2019) [13] reported improvement in body weight and body weight gain in 1% and 2% clove powder supplemented group of birds as compared to birds of control group [13] . Olayemi et al. (2020) [14] determined the final body weight and weight gain at finisher phase was significantly higher in birds fed with clove powder (1%) in feed as compared to birds of control group [14] . Elbaz et al. (2022) [15] observed that broilers fed 100 mg/kg and 200 mg/kg clove essential oil had significantly higher weight gain (P < 0.05) than control birds [15] .

Feed Consumption and Feed Conversion Ratio

The Mean ± S.E. values of FC and FCR for all the experimental groups are depicted in Table 4 and5, respectively. Birds supplemented with clove powder at 5 g/kg feed (Group III), eugenol at both 150 mg/kg (Group V) and 300 mg/kg feed (Group VI) and the standard antibiotic treated birds (Group II) showed no significant alteration in feed consumption as compared to the control group I at 6 th week of age. Total feed consumption at the 6 th week period was significantly lower in birds supplemented with clove powder at 10 g/kg feed (Group IV) as compared to the control group (Group I). These results indicate that supplementation with higher doses of clove powder may reduce feed intake without adversely affecting growth performance. The feed conversion ratio (FCR) did not differ significantly among the experimental groups up to the 4 th week of age. However, at the 5 th week, FCR was significantly reduced in birds supplemented with clove powder at both 5 and 10 g/kg feed (Groups III and IV) and eugenol at 150 mg/kg feed (Group V), as well as in birds given the standard antibiotic growth promoter (Group II) as compared to the control group (Group I). At the sixth week, FCR was significantly decreased in birds supplemented with clove powder (5 and 10 g/kg feed), eugenol (150 and 300 mg/kg feed) and the standard antibiotic treated group II as compared to the control group I. Moreover, the FCR values in all supplemented groups (III, IV, V and VI) were comparable to that of the antibiotic treated group (II). These findings suggest that both clove powder and eugenol effectively improve feed efficiency in broilers, comparable to antibiotic growth promoters. The results of present study were in agreement with the findings of Othman et al. (2022) [16] who reported a significant reduction in daily feed consumption in broilers supplemented with clove bud powder at higher inclusion levels compared with the control group [16] . Hussein et al. (2023) [17] observed significantly lower feed intake in broilers receiving an essential-oil mixture containing clove (measured values were lower than control), indicating that clove-containing blends can depress voluntary intake at certain levels [17] . Parmar et al. (2024) [18] reported significantly improved feed conversion ratio in birds supplemented with clove oil (400 and 800 mg/kg feed) as compared to birds of control group [18] . Kholy et al. (2021) reported the feed conversion ratio was significantly lower in post hatch birds treated (In-ovo injection of clove extract 0.1 ml/egg) as compared to birds of control group [19] . Arif et al. (2022) [20] who observed that significantly improved in feed conversion ratio in birds treated with clove powder (0.5%) in feed as compared to birds of control group [20] .

Carcass Characteristics and Mortality

The Mean ± S.E. values of various Carcass Characteristics in all experimental groups are given in Table 6. Pre-slaughter weight was significantly higher in birds supplemented with eugenol (150 mg/kg feed) as compared to the control group I. Additionally, the pre-slaughter weight of birds receiving clove powder and eugenol (groups III, IV, V and VI) was comparable to that of birds supplemented with the antibiotic (group II). Dressed weight increased significantly in birds supplemented with eugenol (150 mg/kg feed) as compared to the control group I. The dressed weights in low and high dose of clove and eugenol at high dose supplemented groups were similar to those of birds supplemented with the standard antibiotic treated group II. Dressing percentage and giblet percentage of birds treated with clove powder and eugenol at low and high doses (group III, IV, V and VI) exhibits no significant alteration as compared to control group I. Heart weight was significantly increased in birds supplemented with eugenol at 150 mg/kg feed as compared to the control group. However, liver weight of birds supplemented with clove powder and eugenol at both doses did not differ significantly among the various experimental groups. Findings of the present study were in accordance with the results of Essien et al. (2024) [21] reported that clove powder at several inclusion levels (0, 100, 200, 300 g) and found a progressive increase in dressing percentage from ~85.29% at control to ~87.64% at the highest clove powder level, but internal organ weights (heart, liver, gizzard) remained relatively stable (heart% ~0.43-0.45) across treatments [21] . Marcincak et al. (2011) [12] who reported improved dressing percentage in broiler birds supplemented with clove (1%) in the feed and agrimony extract (0.2%) into water as compared to birds of control group [12] . Arif et al. (2022) [20] observed no significant difference in liver heart and gizzard weight in birds supplemented with clove powder (0.5%) in feed as compared to birds of control group [20] . The livability (%) of birds in all experimental groups (Groups I to VI) was 100%. No mortality was observed in birds supplemented with clove powder (5 and 10 g/kg feed) and eugenol (150 and 300 mg/kg feed), indicating that dietary inclusion of clove powder and eugenol at the given doses had no any adverse effects in broiler birds.

Conclusion

Results of present study revealed that the supplementation of broiler diet with clove powder at 5 g/kg or eugenol at 150 mg/kg daily once for 42 days significantly improved body weight gain and feed conversion ratio in broiler birds. No mortality or adverse effects were recorded in any treatment groups at given dosage, confirming the safety of these feed additives.

Acknowledgement

AcknowledgementsThe authors are grateful to the Principal, College of Veterinary Science and Animal Husbundry, Kamdhenu University, Anand, and Research Scientist and Head and all the staff members of Poultry Research Station, Anand for provided the facilities for this research work.

References

1. The Editors of Encyclopaedia Britannica. Argon. Encyclopaedia Britannica. 2020 Jul. Available from: https://www.britannica.com/science/argon
2. Agricultural and Processed Food Products Export Development Authority (APEDA), Ministry of Commerce and Industry, Government of India. Poultry products. 2021. https://apeda.gov.in/apedawebsite/SubHead_Products/Po ultry_Products.htm
3. Aarestrup FM. The livestock reservoir for antimicrobial resistance: a personal view on changing patterns of risks, effects of interventions and the way forward. Philosophical Transactions of the Royal Society B: Biological Sciences. 2015;370(1670):20140085.
4. Liu YY, Wang Y, Walsh TR, Yi LX, Zhang R, Spencer J, Doi Y, Tian G, Dong B, Huang X, Yu LF. Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: a microbiological and molecular biological study. The Lancet Infectious Diseases. 2016;16(2):161-168.
5. World Health Organization. Antimicrobial resistance: global report on surveillance. Geneva: World Health Organization; 2014.
6. Nguyen NT, Nguyen HM, Nguyen CV, Nguyen TV, Nguyen MT, Thai HQ, Ho MH, Thwaites G, Ngo HT, Baker S, Carrique-Mas J. Use of colistin and other critical antimicrobials on pig and chicken farms in southern Vietnam and its association with resistance in commensal Escherichia coli bacteria. Applied and Environmental Microbiology. 2016;82(13):3727-3735.
7. Toghyani M, Mosavi SK, Modaresi M, Landy N. Evaluation of kefir as a potential probiotic on growth performance, serum biochemistry and immune responses in broiler chicks. Animal Nutrition. 2015;1(4):305-309.
8. Mohammadi Gheisar M, Kim IH. Phytobiotics in poultry and swine nutrition: a review. Italian Journal of Animal Science. 2018;17(1):92-99.
9. Tsagareli MG, Merrill AW, Tsiklauri N, Carstens MI, Nozadze I, Gurtskaia G, Abzianidze E, Carstens EE. Some effects of mustard oil and cinnamaldehyde on spinal neuronal responses to cutaneous stimuli in male rats. Bulletin of the Georgian National Academy of Sciences. 2012;6(3):12-20.
10. Marchese A, Arciola CR, Barbieri R, Silva AS, Nabavi SF, Tsetegho Sokeng AJ, Izadi M, Jafari NJ, Suntar I, Daglia M, Nabavi SM. Update on monoterpenes as antimicrobial agents: a particular focus on p-cymene. Materials. 2017;10(8):947.
11. Borazjanizadeh M, Eslami M, Bojarpour M, Chaji M, Fayazi J. The effect of clove and oregano on economic value of broiler. Journal of Animal and Veterinary Advances. 2011;10(2):169-173.
12. Marcincak S, Cabadaj R, Popelka P. The effect of clove and agrimony extracts on broiler performance and meat quality. Acta Veterinaria Brno. 2011;80(1):61-67.
13. Al-Mufarrej SI, Al-Baadani HH, Fazea EH. Effect of level of inclusion of clove (Syzygium aromaticum) powder in the diet on growth and histological changes in the intestines and livers of broiler chickens. South African Journal of Animal Science. 2019;49(1):166-175.
14. Olayemi WA, Adeyemi KD, Sola-Ojo FE, Akanji AM. Growth performance, carcass characteristics, and oxidative stability of broiler chickens fed diets supplemented with clove powder (Syzygium aromaticum). Poultry Science Journal. 2020;8(2):159168.
15. Elbaz AM, Ashmawy ES, Farahat MA, Ali SA, Amin SA, Thabet HA, Gad GG. Effect of different levels of clove essential oil on the growth performance, lipid metabolism, immunity, and intestinal microbial structure of broiler chickens. Egyptian Journal of Nutrition and Feeds. 2022;25(3):361-368.
16. Othman SM, Naser KM, Kanoun AH, Salim AA, Sherif BM, Asheg AA. Effect of adding clove buds powder in feed on performance and jejunum morphology in broiler chickens. Open Veterinary Journal. 2022;12(6):995-999.
17. Hussein MA, El-Tarabany MS, Al-Shammari KI, Abdelnour SA. Effect of dietary supplementation with essential oil mixtures containing clove on performance, nutrient digestibility, and feed intake of broilers. Animal Bioscience. 2023;36(2):183-191.
18. Parmar BB, Patel KM, Sadariya KA, Bhavsar SK. Evaluation of immunomodulatory activities of clove powder in broiler. Journal of Phytopharmacology. 2024;13(3):242-248.
19. Oladokun S, MacIsaac J, Rathgeber B, Adewole D. Essential oil delivery route: effect on broiler chicken's growth performance, blood biochemistry, intestinal morphology, immune, and antioxidant status. Animals. 2021;11(12):3386.
20. Arif A, Hussain J, Khan SA, Ullah S. Dietary inclusion of clove (Syzygium aromaticum) powder enhances growth performance and feed efficiency in broiler chickens. Pakistan Journal of Zoology. 2022;54(3):14111418.
21. Essien CA, Sam IM, Okon UM, Ebong MO. Evaluation of clove powder as a feed additive on the performance, carcass traits, and internal organ weights of broiler chickens. AKSU Journal of Agriculture and Food Sciences. 2024;8(1):85-95.