Garlic (Allium sativum), fenugreek (Trigonella foenum-graecum) and coriander (Coriandrum sativum): performance, nutrient digestibility and blood metabolites in broilers

ABSTRACT The effects of the inclusion of a selected herbal mixture consisting of fenugreek, garlic and coriander (FGC) in different levels of growth performance, digestibility of nutrients and blood biochemicals in broiler chickens (Cobb 500) were studied in a 42-day experiment on 360 broilers, which were grouped into 4 treatments. The dietary treatments consisted of a basal diet (control) and the same diet with the addition of FGC at rates of 1%, 2%, and 3%. The results showed that the treatment groups exhibited a significantly lower feed intake (P < .01) than the control group. However, significantly (P < .05) higher weight gain was recorded in birds fed with a 1% and 3% mixture of FGC. Significantly (P < .05) higher digestibility of nutrients was found in birds fed with a 1% herbal mixture. The results showed that the blood cholesterol profile was significantly (P < .05) lower in birds fed with a 1% mixture of herbs. In conclusion, an improvement in performance, nutrient digestion and lipid profile was observed in broilers when the herbal mixture of fenugreek, garlic and coriander was added to their diet at the rate of 3%, However, blood lipid profile was better when in response to 1% mixture.


Introduction
Antibiotics have been utilized in poultry rations as feed supplements to enhance both growth performance and feed efficiency (Khan et al. 2012a).Other compounds, such as organic acids, probiotics, prebiotics, natural herbs and spices (Khan and Naz 2013;Tufail et al. 2019;Hafeez et al. 2020aHafeez et al. , 2020b;;Alshelmani et al. 2021), have now received considerable attention primarily because in 2006, the European Union prohibited the utilization of antibiotics as additives in animal diets (Abudabos et al. 2018;Israr et al. 2021;Khan et al. 2021;Kairalla et al. 2022aKairalla et al. , 2022bKairalla et al. , 2023)).Feed additives are non-nutritive natural substances incorporated into the base diet in small quantities to enhance the quality of feed and derived animal products and boost animal health and performance (Khan et al. 2012c(Khan et al. , 2012d)).Additionally, feed supplements stimulate intake, nutrient utilization and the growth of animals by influencing immune function and stress resistance (Alzawqari et al. 2016;Kairalla et al. 2022a).Studies have indicated that phytobiotics could serve as antibiotic substitutes for broilers, resulting in the reduction of mortality and improvement in growth performance, with no compromise on environmental or consumer well-being (Dhama et al. 2014).Phytogenic feed supplements can function as a substitute for antibiotics.Studies have indicated that herbal plants and their components may be beneficial in enhancing carcass yield and feed efficiency (Abudabos et al. 2016;Haq et al. 2020).The essential chemical compounds found in spices, herbs and essential oils may enhance blood circulation, stimulate digestive secretions, combat pathogens and bolster the immune system of birds (Ali et al. 2019).
Fenugreek (Trigonella foenum-graecum) is one of Asia's most extensively cultivated plants.Its seeds are utilized in culinary preparations.Fenugreek stimulates feed intake and appetite, with positive effects on the health and performance of poultry.The consumption of fenugreek leads to enhanced enzyme secretion, stimulation of the immune system and facilitation of antioxidant activity (Balasubramanian et al. 2016).Fenugreek seeds are notably rich in total carbohydrates, fat, protein and macro-and micro-mammals (Khorshidian et al., 2016).When chicks were supplemented with a diet containing 1% fenugreek seeds, an improvement in body weight, along with a decrease in total protein, serum cholesterol, calcium and albumin was reported (Mamoun et al. 2014).
Garlic (Allium sativum), as a supplement in broiler feed, improved growth and decreased the rate of mortality (Khan et al. 2012b).The inclusion of garlic as a supplement in poultry feed improves feed conversion efficiency (Ali et al. 2019).It was reported that garlic contains important alkaloids such as allin, sulphuric compounds, diallyl sulphide, allyl disulphide and allicin which are bioactive components, having antihypertensive, antimicrobial and anti-oxidative properties (Khan et al. 2012b).Demir et al. (2008) concluded that garlic can potentially be used as a growth promoter in swine and poultry.Pagrut et al. (2018) conducted a study to assess the influence of incorporating garlic (0.5 kg/ton) into diets as a substitute for antibiotics on the productive performance of broilers and reported the highest live weight compared to the other treated groups.The findings suggest that including garlic in the diet could be a cost-effective and efficient method for producing broilers.Issa and Abo Omar (2012) reported that broilers fed with garlic resulted in improved performance and lipid profile in broilers.
No study has hitherto reported on the cumulative effects of fenugreek, garlic and coriander (FGC) at varying levels on the performance, nutrient digestibility and blood biochemical profile in broilers.Thus, the aim of this study was to assess the impact of FGC supplementation at different levels on the performance, nutrient digestibility and blood biochemical profile in broilers.

Feed additives
Dried seeds of fenugreek and coriander and bulbs of garlic were purchased from the market.Seeds of each plant were taken in equal quantity, milled and mixed at the level of 1%, 2% and 3% in the ratio of a broiler.Before mixing, the seeds were well dried in an oven at 70°C.

Experimental design, animal and diet
A total of 360 one-day-old broiler (Cobb 500) chicks were obtained from the commercial market.Birds were distributed into four groups, where every group consisted of six replicates.Birds were reared under an open-sided system where average temperature and humidity were 28.5 ± 1.5°C and 63.55 ± 2.33%, respectively.Proper ventilation and light were made available.The total time of the trial was six weeks.One group was kept as a control (FGC-0) and was fed with basic feed without any additives.Group FGC-1), FGC-2) and FGC-3) were fed with a basic feed-supplemented herbal mixture at 1%, 2% and 3%, respectively.Dietary ingredients and their composition are presented in Table 1 while the analysed nutrients of the herbal plants are given in Table 2.

Data collection and sampling procedure
During 42 days of the experiment, feed offered and refused quantity was measured to find out the feed intake of birds followed by weight gain on a weekly basis.The obtained data were utilized to calculate the feed conversion ratio (FCR) of each group.

Determination of apparent total digestibility
Total tract digestibility of nutrients was determined by mixing chromic oxide (Cr 2 O 3 ; 0.5 g/kg) in each of the experimental diets as an inert marker.On day 35 of age, four birds per treatment were segregated in separate cages.The digestibility experiment consisted of a four-day acclimation phase succeeded by a  three-day data collection period.Excreta were collected 4 times daily from each replicate and stored at −20°C.Duplicate samples of both feed and excreta were subjected to analysis for dry matter (DM), crude protein (CP), crude fat (CF), ash and nitrogen-free extract (NFE) using the methodology outlined by Shuib et al..For the determination of phosphorous, a spectrophotometer was used while an atomic absorption spectrophotometer was used to find chromium and calcium.

Analysis of blood metabolites
On day 42, blood samples were obtained from two birds per replicate to measure various parameters, including serum total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, triglycerides (TG), total low-density lipoprotein (LDL) cholesterol, protein and glucose.These measurements were conducted using a chemistry analyser (a spectrophotometer was used as mentioned before) along with commercial kits provided by Zhongsheng Biochemical Company, Beijing, China.

Statistical analysis
The data were subjected to analysis using one-way analysis of variance through the General Linear Model (GLM) procedure of SAS software (2001).Statistical significance was determined at a probability threshold of P < .05.

Growth performance
The findings in response to the effect of phytogenic feed mixture on feed intake are given in Table 3.The results indicated that it was significantly (P < .01)lower in birds fed with the FGC mixture at the level of 3% during the first (135.21g) and second weeks (260.32 g) compared to the control.
During the fourth week, significantly (P < .01)lower feed intake was recorded in birds in groups supplemented with the FGC mixture at the rate of 2 (613.18g) and 3% (623.43 g).At the finisher level and overall period, feed intake was significantly (P < .01)lower in the treatment groups than the control.The effect of the photogenic feed mixture on body weight is given in Table 4.The results showed that weight gain in birds did not change significantly (P > .05)during the first three weeks of the study.Weight gain was significantly (P < .05)higher in birds fed with the FGC mixture at the rate of 1% (417.12 g) than the birds fed the mixture at the rate of 2% (292.9 g).At the end of the study, significantly (P < .05)higher weight gain was recorded in birds fed with 1% (1795.77g) and 3% (1701.12g) mixture and the control (1720.22g) than birds supplemented with a 2% (1561.00g) FGC mixture.
The effect of the phytogenic feed mixture on FCR is given in Table 5.It was significantly (P < .05)higher in birds supplemented with a 3% FGC (1.29) mixture than the rest of the groups.Similarly, significantly (P < .05)lower FCR was recorded in birds fed with a 1% (1.87) mixture of herbs than the control at the end of the study.

Nutrient digestibility
Table 6 presents the impact of the FGC mixture on the apparent total digestibility of nutrients in broilers during the finisher phase.Significantly (P < .05)higher digestibility of CP, CF and NFE was found in birds fed with a 1% FGC mixture.

Blood metabolites
Table 7 displays the influence of the FGC mixture on blood parameters in broilers during the finisher phase.The results showed that serum TG and TC were significantly (P < .05)lower in birds fed with a 1% mixture of herbs, while LDL decreased significantly (P < .05) in a 3% FGC mixture.The other parameters remained non-significant.

Discussion
There is a growing interest in exploring alternatives to conventional feed additives in poultry diets.The primary objective is to ensure the production of safe and high-quality food.Phytogenics present a promising solution in this regard and warrant serious consideration as alternative feed additives.Phytogenics are natural chemical compounds with therapeutic properties that help regulate and sustain normal physiological functions, thereby promoting the health of the host organism.In the current study, feed intake decreased significantly with increasing levels of the FGC mixture.However, weight gain increased in birds at the level of 1% and decreased at higher levels suggesting negative effects on birds.Mixed findings have been published in the literature regarding the effects of garlic, coriander and fenugreek effects on feed intake and weight gain in broilers (Saeid and AL-Nasry 2010;Awadein et al. 2010;Yatoo et al. 2012;Patel et al. 2014).To date, the combined effects of these herbs have not been reported; therefore, a conclusion is difficult to draw.We observed that the best production performance was observed when FGC was added into the feed at the level of 1%.Increasing the level of the FGC reduced the performance of broilers.The reduced feed intake in the higher doses (2% and 3%) may be due to the pungent smell of the herbal mixture.The increased feed intake in 1% FGC may be due to the effect of active substances in the herbal products available at optimum levels which have useful effects on birds (Khan et al. 2012a;Wahab et al. 2019).
The non-significant FCR might have come as a result of reduced feed intake in the treatment groups and largely unchanged body weight (Paraskeuas et al. 2017).
In the present study, significantly higher CP, CF and NFE were found when the FGC mixture was added at the dose level of 1%.Interestingly, the digestibility of nutrients was decreased when the FGC mixture was added to the diet at higher levels.In addition, the growth performance could be considered in line with alternation in feed intake and body weight change.Similar inclusion level-dependent effects have been reported using different phytogenic feed additives (Paraskeuas et al. 2017).Increment in phytogenic-mediated nutrient digestibility may be due to phytogenic activities to enhance digestion (Khan et al. 2012b).The herbal mixture improves the digestibility of nutrients through several factors, such as increasing enzyme secretion, alterations of intestinal microbiota and enhancement of intestinal wall in broilers (Khan et al. 2012c).The improvement of growth in broilers fed with a herbal mixture could be partly explained in light of the improvement in the digestibility of dry matter.
In the present study, TG, TC and LDL cholesterol decreased significantly in birds fed with a 1% FGC mixture.There is no published report on the effect of the FGC mixture on blood cholesterol in broilers.Similar findings have been reported in response to FGC in broilers fed individually (Abdalla et al. 2011;Issa and Abo Omar 2012;Saleh et al. 2014).Herbal products exhibit antioxidant properties, leading to reduced lipid peroxidation and subsequently, an improved blood profile (Khan et al. 2012a).Furthermore, these products may have hypo-lipidemic and hypo-cholesterolaemic properties.Additionally, it is possible that these feed additives inhibit the Acetyl CoA synthetase enzyme, which plays a role in the biosynthesis of fatty acids (Khan et al. 2012d).

Conclusions
An improvement in performance, nutrient digestion and lipid profile was observed in broilers when the herbal mixture of fenugreek, garlic and coriander was added to their diet at the rate of 3%.

Ethical statement
This study has been approved by the departmental committee on ethics and animal welfare at the University of Agriculture, Peshawar (12/PS/2020).

Table 2 .
Approximate level of basic ingredients of fenugreek, garlic and coriander (per 100 g each).

Table 3 .
Effect of the dietary mixture of FGC on feed intake (g) of broilers.

Table 4 .
Effect of the dietary mixture of FGC on weight gain (g) of broilers.Means in the same row with different superscripts are significantly different (P < .05).

Table 5 .
Effect of dietary supplementation of FGC on feed conversion ratio of broilers.

Table 6 .
Effect of dietary supplementation of FGC on apparent total digestibility (%) of nutrients in broilers at the finisher phase.
Note: Means presented in the same row with different superscripts are significantly different at (P < .05).

Table 7 .
Effect of feed additive of FGC on blood parameters in broilers at the finisher phase.Means presented in the same row with different superscripts are significantly different (P < .05).