Influence of dietary garlic powder on growth efficiency, cut-up yields, and meat quality attributes in broilers

Introduction

Poultry production is one of the fastest-growing sectors of animal agriculture and plays an important role in meeting the increasing demand for affordable, high-quality animal protein. The expansion of poultry production has been driven by population growth, urbanization, increasing purchasing power and changing dietary preferences (Mottet and Tempio, 2017; FAO, 2025) [13,17] . Broiler chickens are particularly important because of their rapid growth rate, short production cycle and efficient utilization of dietary nutrients. However, intensive broiler production and genetic selection for rapid growth can increase the susceptibility of birds to metabolic, environmental and oxidative stresses, which may adversely affect intestinal health, nutrient utilization, growth performance and meat quality (Sugiharto, 2016; El-Saadony et al., 2024) [12,27] . Historically, antibiotic growth promoters (AGPs) were widely incorporated into poultry diets to improve growth performance and feed efficiency. Their beneficial effects were primarily associated with suppression of undesirable intestinal microorganisms and improvement of the overall gastrointestinal environment (Castanon, 2007) [8] . However, prolonged and extensive use of antibiotics in animal production has raised serious concerns regarding antimicrobial resistance, alteration of intestinal microbial populations and potential risks to food safety and public health (Abd El-Hack et al., 2025) [3] . These concerns have stimulated increasing research interest in natural and sustainable alternatives to antibiotic growth promoters. Among the available alternatives, phytogenic feed additives have attracted considerable attention because of their diverse biological activities and potential to support animal health and productivity (Puvača et al., 2013; Valenzuela-Grijalva et al., 2017) [23,28] . Phytogenic feed additives comprise plant-derived materials such as herbs, spices, essential oils and plant extracts containing a wide variety of biologically active secondary metabolites. Their potential beneficial effects in poultry include antimicrobial, antioxidant, digestive-stimulatory, immunomodulatory and metabolic activities. The use of such natural feed additives has therefore gained importance in modern poultry nutrition, particularly in the context of reducing reliance on conventional antibiotic growth promoters. Among the different phytogenic materials evaluated in poultry diets, garlic (Allium sativum L.) has received considerable scientific attention because of its rich phytochemical composition and multiple biological properties (Shang et al., 2019) [26] . Garlic (Allium sativum L.) is an important culinary and medicinal plant belonging to the family Amaryllidaceae. The bulb contains several biologically active organosulfur compounds, including alliin, allicin, ajoene, diallyl disulfide, diallyl trisulfide and S-allylcysteine, along with phenolic compounds and flavonoids (Amagase, 2006; Shang et al., 2019) [4,26] . The characteristic biological activity of garlic is largely associated with its organosulfur compounds. When garlic tissue is mechanically disrupted, the enzyme alliinase converts alliin into allicin, a highly reactive sulfur-containing compound that contributes substantially to the antimicrobial and biological activity of garlic (Borlinghaus et al., 2014) [7] . The biological properties of garlic provide several possible mechanisms through which it may influence poultry performance. Garlic-derived compounds have demonstrated antimicrobial activity against a range of microorganisms and may help regulate the gastrointestinal microbial environment (Ankri and Mirelman, 1999) [5] . Garlic and its bioactive constituents may also stimulate digestive processes and influence the activity of digestive enzymes, potentially contributing to improved nutrient digestion and utilization (Platel and Srinivasan, 2004 [21] . In addition, the antioxidant properties of garlic may contribute to protection against oxidative stress by influencing endogenous antioxidant defence mechanisms such as superoxide dismutase, catalase and glutathione peroxidase (El-Saadony, 2024) [12] . These combined properties make garlic a promising phytogenic feed additive for improving the productive efficiency and physiological status of broiler chickens. Growth performance and feed efficiency are among the most important indicators used to assess the nutritional and economic value of a feed additive in broiler production. Dietary garlic supplementation has been investigated for its potential effects on body weight gain, feed intake and feed conversion efficiency. Previous studies have reported improvements in broiler performance following garlic supplementation, although the magnitude of response has varied according to inclusion level, duration of feeding, basal diet and experimental conditions (Puvača et al., 2013) [23] . Garlic supplementation may improve feed utilization through a combination of antimicrobial, digestive-stimulatory and antioxidant effects, thereby supporting efficient nutrient utilization and tissue growth. The effect of garlic supplementation may also extend beyond growth performance to carcass characteristics and meat quality. Carcass yield and the distribution of commercially important cuts are economically important traits in broiler production. Dietary phytogenic additives have been reported to influence carcass characteristics and meat quality through their effects on nutrient metabolism, antioxidant status and nutrient partitioning (Demir et al., 2003; Lewis et al., 2003; Orlowski et al., 2018) [11,16,20] . Garlic supplementation has therefore been investigated as a potential nutritional strategy for improving carcass yield and maintaining desirable meatquality characteristics. The proximate composition of broiler meat is another important consideration when evaluating dietary interventions. Moisture, dry matter, crude protein, crude fat and ash determine the nutritional composition and overall quality of poultry meat. Dietary supplementation with phytogenic additives may influence nutrient deposition and lipid metabolism, potentially affecting the chemical composition of muscle tissue (Orlowski et al., 2018) [20] . Garlic, in particular, has been associated with alterations in lipid metabolism, including effects on cholesterol and fatty acid biosynthesis (Qureshi et al., 1983; Chowdhury et al., 2002) [10,24] . Consequently, determination of the proximate composition of meat provides useful information regarding whether dietary garlic supplementation influences the nutritional characteristics of the final poultry product. Meat quality is not determined solely by chemical composition and carcass yield; sensory characteristics are also important for consumer acceptance. Attributes such as colour, flavour, tenderness, texture, juiciness and overall acceptability determine the eating quality of poultry meat. The antioxidant properties of garlic may help protect meat against oxidative deterioration, while its phytochemical constituents may influence certain organoleptic characteristics (Onibi et al., 2009) [19] . Previous investigations have reported that dietary garlic supplementation can influence meat quality and sensory characteristics, although responses may depend on the level and duration of supplementation (Onibi et al., 2009; Orlowski et al., 2018; Puvača et al., 2013) [19,20,23] . Despite the considerable research conducted on garlic as a phytogenic feed additive, the reported effects on broiler performance and meat quality are not completely consistent. Differences in garlic variety, processing method, dietary inclusion level, basal diet, broiler strain, environmental conditions and experimental duration may contribute to variation among studies. Furthermore, many studies have focused on individual response variables, whereas simultaneous assessment of growth performance, feed conversion efficiency, proximate meat composition, carcass characteristics and sensory quality provides a more comprehensive evaluation of the practical usefulness of garlic powder in broiler nutrition. Therefore, further controlled studies are warranted to evaluate the effects of dietary garlic powder supplementation across different aspects of broiler production and product quality. The present study was undertaken to investigate the effect of supplementation of garlic (Allium sativum) powder on growth performance and carcass quality of broilers, with particular emphasis on weekly growth performance, feed conversion efficiency, proximate chemical composition of meat, carcass and commercial cut-up characteristics, edible organ yields and sensory attributes.

Materials and Methods

Experimental Design, Birds, and Diets

A 42-day feeding trial was conducted using day-old commercial broiler chicks (Gallus domesticus) randomly allocated to five dietary treatment groups (𝑇 0 , 𝑇 1 , 𝑇 2 , 𝑇 3 ,and 𝑇 4 ) under a Completely Randomized Design (CRD) with uniform brooding, deep-litter housing, and standard vaccination management. Clean, shade-and oven-dried (50 ∘ C) garlic (Allium sativum L.) bulbs were ground (1.0 mm sieve) and incorporated into standard isocaloric and isonitrogenous starter (0-3 weeks) and finisher (4-6 weeks) basal mash diets:  𝑇 0 (Control): Basal diet without garlic powder.  𝑇 1 to 𝑇 4: Basal diet supplemented with graded levels of garlic powder.

Feed and potable water were provided ad libitum throughout the 6-week experimental period.

Growth Performance and Feed Efficiency

Individual live body weight and pen feed intake were recorded weekly (weeks 1 to 6) in the morning before feeding. Body weight gain (BWG), feed intake (FI), and Feed Conversion Ratio (FCR) were calculated weekly as:

Results and discussion

Growth Performance and Feed Conversion Efficiency

The average weekly body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) of commercial broilers under different dietary treatments over the 6-week experimental period are presented in Table 1. During the starter phase (Weeks 1 to 3), dietary supplementation of garlic powder exerted no statistically significant effect (𝑝 > 0.05) on weekly body weight gain, feed intake, or feed conversion ratio among the experimental groups. This initial lack of differentiation is consistent with findings reported by Sugiharto (2016) [27] and Windisch et al.

(2008) [29] , who noted that the immature gastrointestinal tract of young chicks relies primarily on highly digestible nutrients in basal prestarter/starter rations, rendering phytobiotic stimulation less pronounced during early brooding.

In contrast, a highly significant treatment effect (𝑝 < 0.01) The substantial improvement in growth performance and feed efficiency observed in group 𝑇 3 can be attributed to the multifunctional properties of garlic's bioactive organosulfur constituents, principally allicin (Borlinghaus et al., 2014) [7] . Allicin enhances the secretion of endogenous digestive enzymes including pancreatic amylase, lipase, trypsin, and intestinal disaccharidases thereby improving the hydrolysis and absorption of dietary nutrients (Platel & Srinivasan, 2004) [21] . Furthermore, garlic exhibits potent broad-spectrum antibacterial activity against enteric pathogens (such as Escherichia coli and Clostridium perfringens) while preserving beneficial Lactobacillus populations, thereby promoting greater villus height, improved mucosal architecture, and enhanced intestinal absorptive surface area (Ankri & Mirelman, 1999; Abd El-Ghany et al., 2024; Yitbarek et al., 2015) [2,5,30] . Similar improvements in finisher body weight gain and feed conversion efficiency resulting from dietary garlic powder have been documented by Issa [2,15,23] . Khirodkar et al. (2026) [23] reported that dietary garlic powder supplementation improved growth performance and feed efficiency in broiler chickens. Supplementation with 1.5% garlic powder resulted in the highest final body weight, greater body weight gain, lower feed intake, and improved feed conversion ratio. The authors suggested that these beneficial effects may be associated with improved nutrient utilization, gut health, and metabolic efficiency. The study concluded that garlic powder at 1.5% could serve as a promising natural phytogenic feed additive for improving broiler productivity.

Carcass Traits, Cut-Up Yields, and Edible Organs

The relative yields of commercial cut-up parts and edible giblets, expressed as a percentage of pre-slaughter live body weight, are summarized in Table 2. Similarly, giblet yields comprising liver (3.52% to 3.62%), gizzard (1.69% to 1.77%), and heart (0.44% to 0.58%) showed no statistical variation (𝑝 > 0.05). The lack of significant variation in relative cut percentages indicates that dietary garlic powder stimulated proportionate allometric body growth. Because birds in the supplemented groups (specifically 𝑇 3 ) achieved higher absolute live body weights, the absolute yield (𝑔) of prime commercial cuts scaled up proportionally without inducing anatomical imbalances (Demir et al., 2003; Lewis et al., 2003) [11,16] . Furthermore, the stable liver and heart percentages confirm that garlic supplementation at the tested dosages did not cause visceral hypertrophy, hepatic lipid overload, or physiological toxicity (Saghi et al., 2022; Puvača et al., 2023) [22,25] . These observations agree with Onibi et al. (2009) [19] and Orlowski et al. (2018) [20] , who demonstrated that phytogenic feed additives support overall carcass development while maintaining consistent cut-up yields.

Proximate Chemical Composition of Meat

The proximate chemical composition of broiler meat under different dietary treatments is presented in Table 3. No statistically significant variations (𝑝 > 0.05) were observed across dietary treatments for moisture (69.50% to 72.50%), dry matter (26.00% to 27.38%), crude protein (17.00% to 18.89%), crude fat (3.00% to 3.13%), or total ash (0.98% to 1.05%). All proximate values remained within normal physiological ranges for commercial broiler meat. These findings indicate that dietary garlic powder supplementation did not alter the fundamental nutritional composition of the meat. The stability in crude protein and lipid concentrations indicates that the superior live weight gain achieved in group 𝑇 3 represented true skeletal muscle protein accretion rather than excessive fluid retention or intramuscular adipose deposition (Orlowski et al., 2018) [20] . Garlic's organosulfur compounds are known to inhibit key hepatic lipogenic enzymes, such as 3-hydroxy-3-methylglutarylcoenzyme A (HMG-CoA) reductase, acetyl-CoA carboxylase, and fatty acid synthase, which suppresses excessive visceral lipid accumulation while maintaining normal cellular lipid architecture (Qureshi et al., 1983; Chowdhury et al., 2002) [10,24] . These results are in accordance with the findings of Choi et al. (2010) and Valenzuela-Grijalva et al. (2017) [28] , who reported that dietary phytogenics do not adversely modify the proximate chemical composition of broiler muscle.

Sensory and Organoleptic Characteristics

The sensory evaluation scores of cooked broiler meat evaluated on a standard 9-point Hedonic scale are presented in Table 4. Sensory analysis revealed no significant differences (𝑝 > 0.05) among treatments for colour (scores ranging from 7.37 to 7.67) and flavour (scores ranging from 7.26 to 7.39). This indicates that dietary garlic powder did not impart an undesirable odor, pungent aftertaste, or visual discoloration to the cooked meat product, preserving standard consumer appeal. However, dietary supplementation had a significant positive effect (𝑝 < 0.05) on texture, juiciness, and overall acceptability. Meat from groups 𝑇 2 (8.01) and 𝑇 4 (7.97) exhibited significantly superior texture (tenderness) scores compared to the control group 𝑇 0 (7.39) and 𝑇 3 (7.48). Meat from group 𝑇 4 recorded the highest juiciness score (8.25), differing significantly (𝑝 < 0.05) from all other treatments. Consequently, overall acceptability was significantly higher in 𝑇 4 (8.24) and 𝑇 2 (8.14) relative to 𝑇 0 (7.39), with all garlicsupplemented groups (𝑇 1 -𝑇 4 ) receiving superior scores over the control. The improvements in meat tenderness, juiciness, and consumer acceptability can be linked to the antioxidant protection provided by the phenolic compounds and organosulfur molecules in garlic (El-Saadony, 2024; Shang et al., 2019) [12,26] . During post-mortem storage and thermal preparation, freeradical-mediated lipid oxidation compromises cell membrane integrity, leading to drip loss, moisture release, and myofibrillar toughening (El-Saadony et al., 2024) [12] . Garlic's antioxidant properties help mitigate post-mortem lipid peroxidation, improving water-holding capacity (WHC) and retaining bound intracellular moisture, which enhances meat tenderness and juiciness (Onibi et al., 2009; Orlowski et al., 2018) [19,20] . These findings are consistent with Puvača et al. (2023) [22] , who reported elevated sensory acceptance and improved eating quality in meat from broilers fed phytogenic supplements.

Conclusion

Based on the findings of the present investigation, dietary supplementation with garlic (Allium sativum L.) powder serves as an effective, natural, non-residual phytogenic feed additive in commercial broiler production. Supplementation exerted a highly significant positive effect on growth performance and feed efficiency during the finisher phase (weeks 4 to 6), with treatment group 𝑇 3 consistently achieving the highest weekly body weight gain, lower feed intake, and superior feed conversion ratio (FCR). Carcass evaluation demonstrated that dietary garlic powder supported balanced, allometric growth, maintaining uniform relative proportions across all commercial cut-up parts (breast, thigh, drumstick, wing, back, neck) and edible giblets (liver, gizzard, heart) without inducing physiological or visceral abnormalities. Furthermore, the proximate chemical composition of broiler meat including moisture, dry matter, crude protein, crude fat, and total ash remained stable across all groups, confirming that the accelerated growth represented genuine lean muscle accretion rather than excessive lipid deposition. In addition, garlic supplementation significantly enhanced cooked meat sensory attributes, with groups 𝑇 4 and 𝑇 2 scoring highest for tenderness (texture), juiciness, and overall consumer acceptability without altering natural meat colour or flavour. In conclusion, dietary garlic powder supplementation particularly at the level evaluated in 𝑇 3 for maximum growth efficiency and 𝑇 4 for optimal organoleptic appeal can be safely recommended as a sustainable nutritional strategy to optimize broiler performance and meat eating quality.

References

1. Abd El-Ghany Al-Garadi MA, Al-Ajeeli MN, Al-Baadani HH. Influence of dietary garlic powder supplementation on growth performance, carcass traits, and blood parameters in broiler chickens. Veterinary Sciences. 2021;8(9):184.
2. Abd El-Ghany WA. Applications of organic acids in poultry production: an updated and comprehensive review. Agriculture. 2024;14(10):1756. DOI:10.3390/agriculture14101756.
3. Abd El-Hack ME, Aldhalmi AK, Abu-Hiamed HA, Almarkhan WD, Alharbi NA, Alhassani WE, et al. Antibiotic alternatives to produce organic poultry meat as a safe food source and the impact of its consumption on human health-a review. Annals of Animal Science. 2025;25(3):815-828.
4. Amagase H. Clarifying the real bioactive constituents of garlic. The Journal of Nutrition. 2006;136(3):716S-725S.
5. Ankri S, Mirelman D. Antimicrobial properties of allicin from garlic. Microbes and Infection. 1999;1(2):125-129.
6. AOAC. Official Methods of Analysis. 20th ed. Washington, DC: Association of Official Analytical Chemists; 2016.
7. Borlinghaus J, Albrecht F, Gruhlke MC, Nwachukwu ID, Slusarenko AJ. Allicin: chemistry and biological properties. Molecules. 2014;19(8):12591-12618.
8. Castanon JIR. History of the use of antibiotic as growth promoters in European poultry feeds. Poultry Science. 2007;86(11):2466-2471.
9. Choi IH, Park WY, Kim YJ. Effects of dietary garlic powder and α-tocopherol supplementation on performance, serum cholesterol levels, and meat quality of chicken. Poultry Science. 2010;89(8):1724-1731.
10. Chowdhury SR, Chowdhury SD, Smith TK. Effects of dietary garlic on cholesterol metabolism in laying hens. Poultry Science. 2002;81(12):1856-1862.
11. Demir E, Sarica S, Ozcan MA, Suicmez M. The use of natural feed additives as alternatives for an antibiotic growth promoter in broiler diets. British Poultry Science. 2003;44(S1):44-45.
12. El-Saadony MT, Saad AM, Korma SA, Salem HM, Abd El-Mageed TA, Alkafaas SS, et al. Garlic bioactive substances and their therapeutic applications for improving human health: a comprehensive review. Front Immunol. 2024;15:1277074. DOI:10.3389/fimmu.2024.1277074.
13. FAO. World food and agriculture-statistical yearbook 2025. Rome: Food and Agriculture Organization; 2025.
14. Frančič T, Voljč M, Salobir J, Rezar V. Use of herbs and spices and their extracts in animal nutrition. Acta Agriculturae Slovenica. 2009;94(2):95-102.
15. Issa KJ, Omar JA. Effect of garlic powder on performance and lipid profile of broilers. Open Journal of Animal Sciences. 2012;2(2):62.
16. Lewis MR, Rose SP, Mackenzie AM, Tucker LA. Effects of dietary inclusion of plant extracts on the growth performance of male broiler chickens. British Poultry Science. 2003;44(S1):43-44.
17. Mottet A, Tempio G. Global poultry production: current state and future outlook and challenges. World's Poultry Science Journal. 2017;73(2):245-256.
18. Khirodkar NG, Shende RB, Kumar P, Athira VS, Chugh P, Bhosale TR. Effect of dietary garlic (Allium sativum) powder supplementation on growth performance of broiler chickens. Int J Vet Sci Anim Husbandry. 2026;11(7):416422. DOI:10.22271/veterinary.2026.v11.i7f.3666.
19. Onibi GE, Adebisi OE, Fajemisin AN, Adetunji AV. Response of broiler chickens in terms of performance and meat quality to garlic (Allium sativum) supplementation. African Journal of Agricultural Research. 2009;4(5):511517.
20. Orlowski S, Flees J, Greene ES, Ashley D, Lee SO, Yang FL, et al. Effects of phytogenic additives on meat quality traits in broiler chickens. J Anim Sci. 2018;96(9):37573767. DOI:10.1093/jas/sky238.
21. Platel K, Srinivasan K. Digestive stimulant action of spices: a myth or reality? Indian Journal of Medical Research. 2004;119(5):167.
22. Puvača N, Roljević Nikolić S, Lika E, Shtylla Kika T, Giannenas I, Nikolova N, et al. Effect of the nettle essential oil (Urtica dioica L.) on the performance and carcass quality traits in broiler chickens. Journal of the Hellenic Veterinary Medical Society. 2023;74(2):57815788.
23. Puvača N, Stanaćev V, Glamočić D, Lević J, Perić L, Milić D. Beneficial effects of phytoadditives in broiler nutrition. World's Poultry Science Journal. 2013;69(1):27-34.
24. Qureshi AA, Abuirmeileh N, Din ZZ, Elson CE, Burger WC. Inhibition of cholesterol and fatty acid biosynthesis in liver enzymes and chicken hepatocytes by polar fractions of garlic. Lipids. 1983;18(5):343-348.
25. Saghi R, Zarghi H. The effect of different levels of garlic powder on performance, carcass efficiency and serum metabolites of Japanese quail. Research Journal of Livestock Science. 2022;34(133):31-44.
26. Shang A, Cao SY, Xu XY, Gan RY, Tang GY, Corke H, et al. Bioactive compounds and biological functions of garlic (Allium sativum L.). Foods. 2019;8(7):246.
27. Sugiharto S. Role of nutraceuticals in gut health and growth performance of poultry. Journal of the Saudi Society of Agricultural Sciences. 2016;15(2):99-111.
28. Valenzuela-Grijalva NV, Pinelli-Saavedra A, MuhliaAlmazan 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):8.
29. Windisch W, Schedle K, Plitzner C, Kroismayr A. Use of phytogenic products as feed additives for swine and poultry. Journal of Animal Science. 2008;86(Suppl 14):E140-E148.
30. Yitbarek MB. Phytogenics as feed additives in poultry production: a review. International Journal of Extensive Research. 2015;3(1):49-60.