Evaluation of Herbal Anticoccidials on Growth Performance in Experimentally Infected Broiler Chickens

Abstract

Avian diseases, especially coccidiosis, represent a significant threat to poultry production, demanding research into the use of herbal supplements in birds’ diets. So, the aim of this study was to assess the efficacy of selected herbal components in mitigating coccidiosis in broilers and to examine their overall impact on the productivity traits of broilers. A 35-day feeding trial was conducted with 1200 male ROSS 308 broiler chickens in two poultry facilities, one non-infected, using either usual coccidiostats (UC⁻) or 500 g/t herbal additive (consisting of Holarrhena antidysenterica, Ficus religiosa, Berberis aristata, Allium sativum, Embelia ribes, and Azadirachta indica; HA⁻) and the other intentionally exposed to Eimeria via drinking water at 7 days old, with corresponding control and experimental groups (UC⁺ and HA⁺). Dietary interventions significantly influenced broiler chicken body weight (BW) and average daily gain (ADG) throughout the trial, notably on day 21, with UC⁺ treatment yielding the highest values. Herbal supplements did not affect the feed conversion ratio (FCR) or liveability. Under infection, litter dry matter (DM) content differences were notable on days 14 and 21, favouring herbal additive treatments (HA⁻ and HA⁺). Herbal supplements also impacted Eimeria presence in the duodenum and jejunum on day 21, with notable differences between treatments. Despite several limitations, the study reveals that herbal additions may effectively manage Eimeria infection and enhance litter quality in broiler production, since control treatments demonstrated improved development and anatomy.

1. Introduction

Avian diseases represent a significant risk factor for maintaining optimal meat production levels, with coccidiosis emerging as a particularly costly affliction within the poultry meat production sector. The considerable expenses associated with prevention and treatment coupled with economic losses stemming from diminished bird productivity underscore the financial impact of this disease [1,2]. Specifically, the pathogenicity of seven Eimeria species, localised within distinct regions of the broiler digestive tract, contributes to the observed reductions in meat production [3]. Notably, Eimeria species such as E. tenella, E. necatrix, E. acervulina, and E. maxima are identified as primary causative agents of coccidiosis, each inducing a spectrum of clinical signs that further complicate the assessment of disease impact [4,5].

Microbial infectious diseases exert adverse impacts on chicken production through colonisation of the avian digestive system, resulting in deleterious consequences on final body weight, gut health, and meat quality in broilers [6,7,8]. In the poultry industry, various chemical anticoccidials are employed as a preventive measure against avian coccidiosis. However, the utilisation of such preparations necessitates a withdrawal period of 3–7 days before slaughter to mitigate the presence of remaining drug residues in the carcass. An additional consideration is that antibiotics effectively suppress and inhibit microorganisms until the emergence of antibiotic-resistant bacteria [9,10]. So, the emergence of drug-resistant Eimeria strains coupled with escalating consumer demand for organic products underscores the imperative to explore novel natural substances as alternatives to preventing coccidiosis in poultry [11]. Phytochemicals represent a viable option, comprising plant-derived compounds encompassing a diverse array of substances, including herbs, spices, botanicals, oleoresins, and essential oils, employed in broiler production [12,13,14,15,16]. In contrast to antibiotics, herbal supplements offer the advantage of posing no residual risk to final animal production. Noteworthy benefits encompass increased animal weight, improved feed conversion ratio, anti-inflammatory, antioxidant, antibacterial, and antimicrobial actions, and disease prevention [17,18,19,20,21].

In general, the therapeutic benefits of many plants are mostly due to their bioactive components. Holarrhena antidysenterica is recognised for its indole alkaloids, specifically conessine and ehrenbergine, which have anti-diarrhoeal properties [22]. Similarly, Ficus religiosa, which is high in flavonoids and tannins like quercetin and kaempferol, has strong antioxidant and anti-inflammatory properties [23]. Berberis aristata is differentiated by its principal alkaloid, berberine, which has substantial antibacterial and anti-inflammatory qualities, making it suitable for use in traditional medicine [24]. Allium sativum (garlic) contains a high concentration of sulphur-containing chemicals, including allicin and ajoene, which have been linked to cardiovascular health benefits and antibacterial activity [25]. Embelin, a phenolic molecule found in Embelia ribes, has been related to anti-inflammatory properties, underlining its medicinal potential [26]. Finally, Azadirachta indica (neem) is known for its varied triterpenoids, including azadirachtin and nimbidin, which have a variety of therapeutic benefits, notably in the treatment of infections and inflammation [27]. Collectively, these plants demonstrate the importance of bioactive chemicals in both traditional and modern medical practises, requiring more investigation and validation of their therapeutic uses. Altogether, plants such as Azadirachta indica, Holarrhena antidysenterica, Barberis aristata, Embelia ribes, Acorus calamus, Artemisia annua, and Artemisia absinthium have demonstrated potent anticoccidial effects [28]. Tsiouris et al. [29] observed that broiler chickens infected with Eimeria spp. and administered a phytogenic formula based on plants including Holarrhena antidysenterica, Berberis aristata, Syzygium aromaticum, Polygonum aviculare, and Allium sativum exhibited a reduction in the deleterious effects of eimeriosis on broilers, manifesting a coccidiostatic impact on E. tenella, E. maxima, and E. acervuline. Notably, this effect paralleled that of salinomycin, a recognised anticoccidial agent. Moreover, the investigated multi-herbal mixture demonstrated positive effects on gut microbiota and gut morphology. Furthermore, Ficus religiosa, known for its medicinal properties, including immunopotential, antidiabetic, anti-inflammatory, antibacterial, and anti-diarrhoeal effects [30], when incorporated as aqueous and ethanol extracts in the diet of broiler chickens, exhibited immunostimulating and growth-promoting effects, conferring protection against coccidiosis [31].

Prior investigations highlight the significant potential for employing individual or synergistic herbal preparations in the dietary regimen of broiler chickens. However, the composition, chemical constituents, and additives of individual plant components vary based on factors such as structure, growing conditions, harvesting time, and geographical location. Consequently, the diverse herbal preparations utilised in animal feed may exhibit disparate effects and efficacy. This study aims to assess the prophylactic efficacy of selected herbal components (Holarrhena antidysenterica, Ficus religiosa, Berberis aristata, Allium sativum, Embelia ribes, and Azadirachta indica) in mitigating coccidiosis in broilers (experimentally infected with Eimeria spp. (E. cervulina HP, E. maxima CP, E. maxima MFP, E. mitis HP, E. tenella) and non-infective), along with an examination of the overall impact of these components on the productivity traits of the broilers.

2. Materials and Methods

2.1. Animals and Feeding

A feeding trial was conducted utilising 1-day-old male broiler chickens of the ROSS 308 line combination. A total of 1200 broiler chickens were involved in the study, encompassing a growth period from 1 to 35 days. At the initiation of the feeding trial, the broilers were randomly allocated to four distinct dietary treatments (Figure 1). The birds were individually housed in pens with wood shaving litter on the floors, comprising 6 pens per treatment and 50 birds per pen. The stocking density for all groups adhered to the stipulations of Council Directive 2007/43/EC, ensuring it did not exceed 33 kg/m². The temperature and lighting regimen adhered to the guidelines stipulated by Aviagen [32]. Broiler chickens were housed in two distinct poultry facilities based in Lithuania, one designated as non-infected, including a control group with chemical-based coccidiostats (1:1 narasin and nicarbazin; Elanco US, Inc., Greenfield, IN, USA; UC⁻) and an experimental group with a herbal additive to replace chemical-based ones (HA⁻). The other facility was intentionally exposed to Eimeria through drinking water at 7 days of age, with corresponding control (UC⁺) and experimental (HA⁺) treatments (Figure 1). To expose Eimeria to broiler chickens, each 0.004 mL dose (n = 6000 doses for 1200 broiler chickens) of vaccine contained the following number of sporulated oocysts derived from five pre-attenuated coccidia lines as follows:

• E. ecervulina HP 500–650 oocyst;
• E. maxima CP 200–260 oocyst;
• E. maxima MFP 100–130 oocyst;
• E. mitis HP 1000–1300 oocyst;
• E. tenella HP 500–650 oocyst.

The broilers had ad libitum access to pelleted feed diets, including pre-starter (1–10 days of age), starter (11–24 days of age), grower (25–30 days of age), and finisher (31–35 days of age) formulations. Pellet sizes used in the recent study were chosen based on the broilers’ age and developmental stage. Newly hatched chicks were given a starter crumble of 1–2 mm to facilitate simple intake and digestion. As they developed, we switched to a grower pellet of 3–3.5 mm, which met industry specifications for the Ross 308 lineage [32].

Figure 1. Dietary treatments in the feeding trial.

Figure 1. Dietary treatments in the feeding trial.

The composition and nutrient content of the feed ingredients are detailed in

Table 1. The composition and nutrient content of feed ingredients during the pre-starter (1–10 days of age), starter (11–24 days of age), grower (25–30 days of age), and finisher (31–35 days of age) periods.

	Period
Ingredient (%) 1,2,3	Pre-Starter	Starter	Grower	Finisher
Soybean meal	37.84	34.12	26.99	22.26
Wheat	28.72	27.07	26.63	28.48
Maize	25.00	25.00	25.00	20.00
Triticale	-	5.00	10.00	15.00
Rapeseed cake	-	-	2.00	4.00
Vegetable oil	3.58	4.67	5.60	6.53
Limestone	1.55	1.38	1.23	1.21
Monocalcium phosphate	1.28	0.98	0.72	0.65
Lysine sulphate	0.45	0.31	0.38	0.44
Methionine	0.40	0.34	0.31	0.29
Sodium chloride	0.19	0.19	0.19	0.18
Sodium sulphate	0.15	0.15	0.15	0.17
Threonine	0.15	0.10	0.11	0.11
Guar gum	0.15	0.15	0.15	0.20
Mycotoxin binder	0.10	0.10	0.10	0.10
Mineral premix	0.10	0.10	0.10	0.10
Vitamin premix	0.24	0.24	0.24	0.23
Nutrient absorption enhancer	0.05	0.05	0.05	0.05
Coccidiostats (chemical-based on UC− and UC+; herbal origin on HA− and HA+)	0.05	0.05	0.05	-
Calculated analysis, % (unless stated otherwise)
ME (MJ/kg)	12.57	12.99	13.42	13.66
Crude protein	23.00	21.50	19.50	18.50
Crude fat	5.57	6.65	7.69	8.63
Crude fibre	2.62	2.55	2.64	2.78
Crude ash	6.75	6.10	5.48	5.25
Calcium	0.97	0.85	0.75	0.73
Phosphorus	0.70	0.62	0.55	0.53
Sodium	0.16	0.16	0.16	0.16
Magnesium	0.18	0.17	0.16	0.16
Potassium	1.03	0.97	0.86	0.80
Chlorine	0.17	0.17	0.17	0.17
Lysine	1.42	1.26	1.15	1.10
Methionine	0.71	0.63	0.58	0.55
Methionine + Cysteine	1.06	0.96	0.90	0.85
Tryptophan	0.29	0.27	0.24	0.23

Note: ¹ mineral premix (per kilogramme of feed): Fe, 20.00 mg; Mn, 120.00 mg; Zn, 110.00 mg; Cu, 16.00 mg; I, 1.25 mg; Se, 0.30 mg. ² Vitamin premix (per kilogramme of feed): vitamin A, 11.995.20 U; vitamin D₃, 4998.00 U; vitamin E, 100.00 mg; vitamin K₃, 3.50 mg; vitamin B₁, 2.50 mg; vitamin B₂, 8.00 mg; vitamin B₆, 5.00 mg; vitamin B₁₂, 29.98 mg. ³ Calculated values are according to meeting the nutrient and energy requirements for Ross 308 broiler chickens [32].

. The herbal origin supplement was utilised in powder form (Life Circle Nutrition AG, Wangen, Switzerland), comprising plant fibre with the following nutritional values: crude fibre 22.8%, crude protein 5.1%, crude fat 1.9%, crude ash 7.3%, salt 0.02%, lysine 0.4%, and methionine 0.1%.

2.2. Growth and Slaughter Performance

We recorded the broiler chickens’ body weight (BW) on the first day of their age, at one-week intervals, and then at two-week intervals until they reached five weeks of age. Throughout the feeding trial, the following parameters were assessed: ADG for the periods of 1–10, 11–21, and 22–35 days of age; average daily feed intake (ADFI), FCR, and liveability for the entire trial period. Additionally, we determined the DM content of the litter at 14, 21, and 35 days of age by drying it at 105 °C until we achieved a constant weight (n = 6 samples/treatment; centre and corners of the pen).

After the 35-day feeding trial concluded, we randomly selected 80 birds, 20 for each treatment, overnight fasted them, and then euthanised them at a commercial slaughterhouse using the recommended procedures for experimental animal euthanasia, as detailed by Close et al. [33]. After the cooling process, the carcasses underwent dissection for further analysis.

2.3. Litter Oocyst Analysis

We collected litter samples (n = 6 samples/treatment) in sterile containers for oocyst determination, recording the date, sampling location (centre and corners of the pen), and age of the broilers on the farm. We assessed the oocyst concentration using a standard McMaster technique [4] by employing the flotation of 2 g of protozoan oocysts diluted in 60 mL of hypertonic sodium chloride solution to determine their number. We used the McMaster helminth egg counting method to prepare and count the oocysts for analysis.

2.4. Lesion Scores

We euthanised 10 chickens per treatment through CO₂ inhalation to assess intestinal Eimeria species lesion scores on days 14, 21, and 28 of age. Day 14 marks the first peak of oocyst spreading and early lesion development, day 21 presents the most noticeable lesions, and day 28 allows for the assessment of recovery and long-term consequences, all of which align with the Eimeria infection patterns in broilers. Furthermore, we selected multiple intestinal areas for lesion evaluation because mixed Eimeria species simultaneously infect different segments of the intestine. The same evaluator employed a consistent scoring approach, as outlined by Johnson and Reid [34], for all selected birds. The evaluator graded lesions from various sections of the intestine on a scale from 0 (no gross lesions) to 4 (most severe lesions).

2.5. Statistical Analysis

The results were statistically analysed using STATISTICA version 13.3 software (TIBCO Software Inc., Palo Alto, CA, USA, 2017). The normality or non-normality of the distribution was determined by the Shapiro–Wilk test. The pen served as the experimental unit for evaluating growth performance (n = 6; 6 pens/treatment and 50 birds/pen), determining oocysts and the DM content of litter samples (n = 6; 6 samples/treatment), while individual birds were used for the slaughter evaluation (n = 20 birds/treatment). The collected data underwent processing through the chi-squared test (lesion scores) or one-way ANOVA for comparisons between groups. The results are presented as means with the standard error of the mean (±SEM). The statistical significance of differences between group means was estimated using Duncan’s multiple range test at p ≤ 0.05.

3. Results

3.1. Growth Performance

The growth performance indices, such as BW and ADG, of broiler chickens are delineated in

Table 2. The impact of herbal origin additives on the BW and ADG of broiler chickens.

Item 1 (g)	Period 2	Group 3,4,5				SEM 6	p-Value
		UC−	UC+	HA−	HA+
BW
	1 d	48.88	48.87	48.87	48.88	0.02	0.997
	10 d	317.04 a	358.19 b	261.69 c	319.28 a	7.68	0.000
	21 d	1125.50 a	1117.31 a	972.26 b	1018.26 c	14.62	0.000
	35 d	2660.92 a	2615.65 ab	2507.60 c	2543.17 bc	17.99	0.004
ADG
	1–10 d	34.33 a	39.77 b	29.77 c	33.63 a	0.85	0.000
	11–21 d	73.90 a	67.19 ab	61.38 b	68.11 ab	1.60	0.038
	22–35 d	107.13 a	100.40 ab	95.25 b	107.14 a	1.85	0.048

Note: ¹ BW, body weight; ADG, average daily gain; ² d, day; ³ UC⁻, control without infection with usual coccidiostat; UC⁺, control experimentally infected with usual coccidiostat; HA⁻, experimental without infection with herbal origin additive; HA⁺, experimentally infected with herbal origin additive. ⁴ The means with different superscript letters (a–c) in a row differ significantly (p < 0.05). ⁵ Means with ab and bc superscript letters in a row did not have significant differences between groups (p > 0.05). ⁶ SEM, standard error of the means.

. The BW of chickens randomly assigned to groups on the day the experiment began did not differ (p = 0.997). The BW of broiler chickens across all trial periods reveals that birds subjected to the HA⁻ treatment exhibited the lowest BW across all age periods under investigation on the 10th, 21st, and 35th days (p-value, respectively; p < 0.000, p < 0.000, p = 0.004). A more detailed examination during the 10th day of life indicates that the BW of birds under UC⁻ and HA⁺ treatments was relatively similar (p > 0.05). However, it is noteworthy that broilers under the UC⁺ treatment achieved the highest BW compared to the remaining treatments (358.19 g; p < 0.05). On the 21st day of life of the birds, similarly to the 10th day, the lowest BW was observed in the birds from the HA⁻ group (p < 0.05). The BW of the birds from the UC⁺ and UC⁻ groups was similar (p > 0.05). Furthermore, the final BW at the 35th day for UC⁻ broiler chickens was significantly higher by 153.32 and 117.75 g when compared to birds subjected to HA⁻ and HA⁺ treatments, respectively (p < 0.05).

Dietary interventions had a significant impact on ADG across all growth periods investigated (Table 2, at 1–10-, 11–21-, and 22–35-day-period p-value, respectively; p < 0.000, p = 0.038, p = 0.048). The ADG of broiler chickens was discovered to be the highest under the UC⁺ treatment (39.77 g) and the lowest under the HA⁻ treatment (29.77 g) during the experiment’s 1–10-day period (p < 0.05). Analysing the 11–21-day trial period, the ADG value was determined to be the highest in the UC⁻ treatment (73.90 g) and the lowest in HA⁻ (61.38 g; p < 0.05). In the remaining UC⁻, UC⁺, and HA⁺ treatments of chickens, ADG values were relatively similar (73.9 g, 67.19 g, and 68.11 g, respectively; p > 0.05). At the end of the trial period (22–35 days), the highest and almost identical ADG values were discovered under UC⁻ and HA⁺ (107.13 g and 107.14 g, respectively; p > 0.05), while compared to the mentioned treatments, the lowest ADG was found in HA⁻ (95.25 g; p < 0.05).

There was no effect of the experimental factor on the ADFI (p = 0.358), FCR (p = 0.553), and liveability (p = 0.982) of broiler chickens (

Table 3. The impact of herbal origin additives on the ADFI, FCR, and liveability of broiler chickens.

Item 1	Period 2	Treatments 3				SEM 4	p-Value
		UC−	UC+	HA−	HA+
ADFI (g)	1–35 d	87.47	88.46	84.96	86.97	1.03	0.358
FCR (kg/kg)		1.60	1.64	1.48	1.51	0.04	0.717
Liveability (%)		99.56	99.61	99.55	99.50	0.09	0.982

Note: ¹ ADFI, average daily feed intake; FCR, feed conversion ratio. ² d, day; ³ UC⁻, control without infection with usual coccidiostat; UC⁺, control experimentally infected with usual coccidiostat; HA⁻, experimental without infection with herbal origin additive; HA⁺, experimentally infected with herbal origin additive; ⁴ SEM, standard error of the means.

).

3.2. Slaughter Performance

The findings from the slaughter performance analysis are detailed in

Table 4. The impact of herbal origin additives on the slaughter performance of broiler chickens.

Item (% of BW) 1	Treatments 2				SEM 3	p-Value
	UC−	UC+	HA−	HA+
Carcass without feathers, head, and legs, with viscera	80.28	80.63	79.43	82.81	1.00	0.738
Fully eviscerated carcass, without viscera	67.86	68.62	68.21	68.18	0.91	0.994
Thigh muscle (with bone)	12.14	12.41	12.13	11.74	0.26	0.879
Drumstick (with bone)	8.28	7.23	7.40	7.28	0.21	0.253
Thigh muscle (without bone)	10.49	10.18	10.38	9.56	0.23	0.586
Drumstick (without bone)	6.24	5.12	5.70	5.43	0.16	0.060
Total breast fillet	24.74	22.48	24.29	24.40	0.43	0.217
Outer breast fillet	20.61	18.50	20.35	20.44	0.40	0.199
Inner breast fillet	4.15	3.80	3.93	3.81	0.13	0.789

Note: ¹ BW, body weight; ² UC⁻, control without infection with usual coccidiostat; UC⁺, control experimentally infected with usual coccidiostat; HA⁻, experimental without infection with herbal origin additive; HA⁺, experimentally infected with herbal origin additive. ³ SEM, standard error of the means.

. No effect of the experiential factor on the analysed broiler chicken slaughter quality traits was found. Due to the lack of evidence of the factor’s influence on the value of the analysed features, comparing the means from the groups was not justified.

3.3. Litter Dry Matter and Oocyst Count

No effect of the herbal origin additive on the DM of litter (%) was found on day 14 and 21 of the experiment (

Table 5. The impact of herbal origin additives on the DM content and oocyst count in the broiler chicken litter.

Item 1	Age 2	Treatments 3,4				SEM 5	p-Value
		UC−	UC+	HA−	HA+
DM of litter (%)	14 d	76.91	82.92	86.85	86.20	1.77	0.172
	21 d	75.81	78.62	76.64	76.49	0.62	0.451
	35 d	68.71 a	76.84 b	66.97 a	77.10 b	1.15	0.001
Oocyst (g/l)	14 d	0.00 a	120.80 b	173.00 c	245.60 d	21.76	0.000
	21 d	0.00 a	90.00 b	82.20 b	107.60 c	9.71	0.000
	28 d	2.80 a	12.40 b	7.20 c	8.80 d	0.82	0.000

Note: ¹ DM, dry matter; ² d, day; ³ UC⁻, control without infection with usual coccidiostat; UC⁺, control experimentally infected with usual coccidiostat; HA⁻, experimental without infection with herbal origin additive; HA⁺, experimentally infected with herbal origin additive. ⁴ The means with different superscript letters (a–d) in a row differ significantly (p < 0.05). ⁵ SEM, standard error of the means.

, p-value = 0.172 and p-value = 0.451, respectively). The effect of the factor on DM was found only on day 35 (p = 0.001). At day 35, the DM of litter value in the UC⁻ and HA⁻ groups was similar (UC⁻ 68.71% and 66.97%, p > 0.05) but lower compared to values in the UC⁺ and HA⁺ groups (p < 0.05).

Table 5 shows that herbal origin additives significantly affected the number of Eimeria oocysts in litter samples (p < 0.000). However, on the 14th day of rearing, no oocysts were found in the litter of chickens under UC⁻ treatment, whereas the highest concentration was observed under HA⁺ (p < 0.05). On the 21st day of age, we observed a similar trend. By the 28th day, oocysts were detected under all treatments, with the highest concentration observed in UC⁺ (p < 0.05).

3.4. Lesion Scores

Table 6. The impact of herbal origin additives on the lesion scores in the alimentary system of broiler chickens.

Period 1	14 d				21 d				28 d
Treatment 2	UC−	UC+	HA−	HA+	UC−	UC+	HA−	HA+	UC−	UC+	HA−	HA+
Item 3
Duodenum (with E. acervuline)	0	0	0	0	2	0	3	0	2	2	4	2
p-value	0.438				0.045 *				0.372
p-value UC−/UC+					0.083
p-value UC−/HA−					0.604
p-value UC−/HA+					0.083
p-value HA−/HA+					0.030 *
Jejunum (with E. maxima)	1	3	2	2	3	5	4	11	7	8	6	13
p-value	0.268				0.048 *				0.049 *
p-value UC−/UC+					0.481				0.121
p-value UC−/HA−					0.452				0.762
p-value UC−/HA+					0.009 *				0.003 *
p-value HA−/HA+					0.015 *				0.050 *
Cecum (with E. tenella)	0	1	0	0	0	1	0	0	1	2	1	3
p-value	0.415				0.415				0.466

Note: ¹ d, day; ² UC⁻, control without infection with usual coccidiostat; UC⁺, control experimentally infected with usual coccidiostat; HA⁻, experimental without infection with herbal origin additive; HA⁺, experimentally infected with herbal origin additive. ³ The means with superscript * in a row differ significantly (p < 0.05).

presents the intestinal lesion scores in experimental treatments at different stages of the feeding period. In the duodenum (with E. acervulina present), significant differences were observed among all treatments on the 21st day of life (p < 0.05). Within the same location and on the same day, differences were identified between treatments with herbal additives (HA⁻ and HA⁺; p = 0.030), with higher values noted in the HA⁻ treatment.

In the jejunum (with E. maxima present), significant differences were noted among all treatments on the 21st and 28th days of life (p < 0.05; Table 5). On the 21st day, we observed differences between treatments UC⁻ and HA⁺ (3 and 11 lesion points, respectively; p = 0.009) and between HA⁻ and HA⁺ (4 and 11 lesion points, respectively; p = 0.015). On the 28th day, the same treatments—UC⁻ and HA⁺ (7 and 13 lesion points, respectively; p = 0.003) and HA⁻ and HA⁺ (6 and 13 lesion points, respectively; p = 0.050)—established similar differences. The presence of E. tenella did not reveal any differences within the cecum.

4. Discussion

The integration of herbal additives, specifically Holarrhena antidysenterica, Ficus religiosa, Berberis aristata, Allium sativum, Embelia ribes, and Azadirachta indica, represents a promising strategy for mitigating the effects of coccidiosis in broiler chickens. Holarrhena antidysenterica is characterised by its anti-diarrhoeal and anti-inflammatory properties [35], which may enhance gastrointestinal health during coccidia infections. Similarly, Ficus religiosa is recognised for its antimicrobial and anti-inflammatory effects [36], potentially diminishing the inflammatory response associated with coccidiosis in the avian gastrointestinal tract. Berberis aristata, particularly its berberine component, has demonstrated efficacy against coccidial pathogens as an antimicrobial [37], further broadening the spectrum of herbal interventions. Allium sativum contributes to this therapeutic approach through its immune-modulating and antimicrobial properties [38], potentially enhancing the host’s immune defence while exerting direct coccidiacidal effects. Embelia ribes, recognised for its anthelmintic properties [39], enhances the multifaceted management of coccidiosis in broiler poultry. Furthermore, Azadirachta indica, with its extensive antimicrobial and immune-modulatory capabilities [40], plays a critical role in controlling coccidia proliferation and promoting host immune resilience. The synergistic effects of these herbal additives underscore a promising avenue for the development of alternative therapeutic strategies to combat coccidiosis in poultry farming, warranting further investigation into their combined efficacy and mechanisms of action.

4.1. Growth and Slaughter Performance

Plant-based feed additives, including various plant extracts, have been shown to exert diverse effects on non-infected chickens, potentially enhancing growth rates and optimising feed conversion efficiency [41,42,43]. Previous research indicates that certain herbal extracts displayed significantly lower efficacy in mitigating body weight loss and oocyst excretion compared to the herbal additive utilised in this study [44,45,46,47]. Investigations into dietary treatments reveal that Eimeria spp. infections markedly influence the growth performance of broiler chickens, with significant fluctuations in BW and ADG observed throughout different trial periods. Notably, broilers receiving the control treatment with conventional coccidiostats (under Eimeria spp. infection; UC⁺) consistently maintained higher BW, demonstrating the effectiveness of this dietary regimen in promoting growth under pathogenic conditions. Conversely, birds fed the herbal additive without Eimeria infection (HA⁻) showed persistently lower BW across all trial periods, indicating that this dietary intervention may not be optimal for supporting growth in the absence of coccidial challenge.

In addition to growth performance, the study explored the potential effects of herbal supplements on ADFI, FCR, and the overall liveability of broiler chickens. While no significant differences were observed across these indicators, the possibility that herbal supplements may confer health benefits and enhance overall performance cannot be discounted. Supporting this notion, Bozkurt et al. [45] found that the severity of coccidial challenges did not significantly affect liveability outcomes when using herbal-based additives containing oregano oil (Origanum spp.), Laurus nobilis, and Lavandula stoechas, suggesting the potential resilience of poultry towards these supplements, even in challenging conditions.

The disparities in growth performance between the control group and the herbal additive group without Eimeria infection underscore the critical need for further evaluation of the herbal blend’s efficacy. Moreover, components such as Allium sativum (garlic) and Azadirachta indica (neem) possess well-documented antimicrobial properties, which may modulate the gut microbiota and enhance nutrient absorption, thereby improving productivity [48]. Additionally, bioactive compounds in Berberis aristata, particularly berberine [49], have been implicated in influencing immune responses and enhancing growth metrics. Moreover, future research should focus on delineating the specific effects and interactions of these herbal additives to optimise their integration into poultry diets and improve overall production efficiency.

Regardless of Eimeria infection status, dietary treatments had a minimal impact on most slaughter indicators relative to total BW, with no statistically significant differences observed. However, the data suggest that dietary regimens may potentially influence muscle development, which is essential for meat quality. Furthermore, trends in the herbal additive group were consistent with overall growth performance, indicating a potential, albeit unquantified, effect of these additives. These findings underscore the need for further research to explore the underlying mechanisms involved.

4.2. Litter Dry Matter and Oocyst Count

The moisture content of litter in poultry housing facilities is critical for bird health and welfare. Excessive moisture levels exceeding 35% have been linked to adverse health outcomes such as pododermatitis, while excessively dry litter can elevate airborne dust levels, posing risks to avian respiratory health [50,51]. This study revealed that both treatments significantly influenced litter DM in the last period of the feeding trial. Overall, litter moisture increased with bird age, although this varied across treatments. In the UC⁻ and HA⁻ groups without Eimeria infection, DM decreased consistently with age. In contrast, the Eimeria-affected UC⁺ treatment exhibited differences in DM on day 14, with levels stabilising between days 21 and 35. Initially, herbal supplement treatments showed higher moisture levels on day 14, but by day 21 and onwards, DM levels equalised across all groups.

Recent research indicates that herbal origin additives, which are botanicals, can be employed to manipulate broiler chicken litter moisture, typically by reducing it. For instance, Berberis aristata, containing bioactive compounds like berberine with antimicrobial and anti-inflammatory properties, may enhance nutrient utilisation and digestion efficiency by modulating gut microbiota and reducing gastrointestinal inflammation, potentially leading to lower litter moisture [52].

Previous studies have demonstrated the antimicrobial and anti-tumour properties of natural herbal products by stimulating lymphocyte proliferation and eliminating pathogens [53]. In the context of coccidiosis, certain bioactive foods and probiotics have been recognised for their ability to confer protection against Eimeria infection by activating specific cellular and humoral immune responses [54,55]. Additionally, various herbal extracts and biomolecules have been reported to mitigate the detrimental effects of coccidian parasites on treated birds [56,57].

The life cycle of Eimeria includes both an exogenous phase and an endogenous phase. Sporozoites, the infective forms contained within sporulated oocysts, are encased in a resilient oocyst wall and subsequently expelled from the host via faeces [58,59]. As is well established, Eimeria oocysts serve as the primary etiological agent of coccidiosis, entering chickens through the ingestion of contaminated feed, water, and litter [60].

In the present study, broilers under control treatment without Eimeria infection (UC⁻) showed no oocysts in litter at 14 and 21 days of age, while the highest concentration was observed in Eimeria-infected broilers fed herbal additive-supplemented feed (HA⁺). A similar trend was noted on day 21. By day 28, osteocytes were present in all treatments, with UC⁺ exhibiting the highest concentration. Notably, oocyst concentrations decreased with age, particularly in broilers fed with herbal additive-supplemented feed. By day 28, both herbal origin additive treatments exhibited lower oocyst concentrations compared to the control group receiving conventional coccidiostats, highlighting the potential impact of the herbal additives.

Consistent with the findings of Mumtaz et al. [31], elevated oocyst levels were observed in the control group relative to chickens in the experimental groups administered extracts of Ficus religiosa. The reduced oocyst counts in the Ficus religiosa-supplemented groups of inoculated chickens may be associated with enhanced resistance mechanisms or immune efficacy, thereby mitigating the proliferation of Eimeria parasites within the host [61].

4.3. Lessions Scores

The evaluation of the therapeutic potential of herbal additives in poultry health necessitates understanding their effects on gut lesions and the underlying mechanisms involved. The analysis of lesion scores across different gut segments reveals varied outcomes, particularly in the duodenum, where the addition of herbal additives demonstrates positive effects. Specifically, on day 21, the group supplemented with herbal additives and subjected to the Eimeria challenge (HA⁺) exhibited no detectable lesions, indicating a beneficial impact of the herbal supplementation. This finding contrasts with the study conducted by Ghafouri et al. [56], which reported less favourable outcomes in the duodenum following supplementation with Echinacea purpurea and Glycyrrhiza glabra compared to toltrazuril treatment or challenged untreated groups. Conversely, Tsiouris et al. [23] provide more optimistic results, suggesting a pronounced positive effect of herbal components on lesion scores in the duodenum. According to these authors, herbal supplementation resulted in lower lesion scores, similar to the effects of salinomycin, when compared to groups challenged with coccidia.

The potential mechanisms by which herbal additives exert their protective effects may include the modulation of immune responses, the enhancement of gut microbiota balance, and the reduction in intestinal inflammation. Herbal components can stimulate immune cell proliferation and activity, leading to a more robust defence against coccidial infections [62]. Additionally, some herbal extracts possess antimicrobial properties, which may help in controlling pathogenic bacterial populations, thereby promoting intestinal health [63]. Furthermore, the anti-inflammatory effects of certain bioactive compounds in herbs can decrease the severity of intestinal lesions by mitigating inflammatory responses triggered by Eimeria infection [64]. These discrepancies among study outcomes highlight the complexity of evaluating the efficacy of herbal supplements in mitigating gut lesions, as some studies report less favourable results while others demonstrate promising effects comparable to conventional treatments.

The effectiveness of herbal supplementation on gut lesions in broiler chickens remains a topic of considerable debate, with varying results reported in recent studies. In research focused on the jejunum, no positive impact associated with herbal supplementation was observed, as groups receiving herbal additives and subjected to the Eimeria challenge exhibited the highest lesion scores compared to other treatments. However, Tsiouris et al. [23] reported contrary findings, observing beneficial effects on lesion scores in both the jejunum and ileum. Their study demonstrated significant differences between the herbal addition group and the coccidia-challenged group, with notably lower lesion scores in the former (0.5 and 1.7, respectively).

Similarly, El-Khtam et al. [65] found favourable outcomes with the supplementation of turmeric (Curcuma longa) and garlic (Allium sativum), reporting reduced intestinal lesions, especially with garlic supplementation. Furthermore, Kim et al. [66] noted positive effects of turmeric addition, with fewer jejunal lesion scores compared to E. maxima-infected groups lacking turmeric supplementation. Additionally, Mumtaz et al. [31] investigated aqueous and ethanolic extracts of Ficus religiosa and discovered positive effects on intestinal lesion scores, particularly at doses of 200 mg/kg for the aqueous extract and 300 mg/kg for the ethanolic extract. Collectively, these findings indicate that the efficacy of herbal supplementation in mitigating gut lesions may vary based on the specific herbal components, dosages used, and experimental conditions, highlighting the need for further research to optimise these interventions in poultry health management.

5. Conclusions

In conclusion, the study highlights the significant effects of dietary treatments on broiler performance and the management of Eimeria infections. While conventional coccidiostats demonstrated superior growth metrics, such as BW and ADG, herbal additives presented beneficial anatomical characteristics and effectively reduced Eimeria oocyst concentrations over time. These findings suggest that despite some limitations in growth performance, herbal additives may offer an alternative strategy for improving litter quality and enhancing disease management in poultry production. Future research should explore optimising the use of herbal additives to maximise their potential benefits while maintaining production efficiency.