Poultry is a popular and widely consumed meat worldwide and it plays a very important role in global food production (Gul et al., 2016; Bist et al., 2024; Ashour et al., 2025). In Algeria, poultry occupy a prominent place in the national economy, contributing significantly to nutritional security (Cherifi and Abdelli, 2023), domestic poultry production has recently experienced a significant expansion thanks to various support policies launched by the government over the past twenty years.
       
On the other hand, several authors indicated that the poultry industry is constantly seeking to improve the health and productivity of chickens without the use of antibiotics to meet the growing demand for chicken products (Atay, 2023; Prakash et al., 2024; Ashour et al., 2025). Current research is attempting to replace chemical antibiotics with powders and extracts from medicinal and aromatic plants (Atay, 2023; Ashour et al., 2025). Because of their many beneficial health effects (Jin et al., 2020), including increased appetite and feed intake, improved digestive enzyme secretion, immune response activation (Rahimi et al., 2011; Jin et al., 2020), antibacterial properties (Sambasivaraju and Fazeel,  2016) and antioxidant activity (Jin et al., 2020), aromatic plants have been used to achieve modern intensive poultry production (Ghazanfari et al., 2015; Adam et al., 2020; Puvaca et al., 2022; Atay, 2023).
       
Specific compounds from aromatic medicinal plants could help improve feed utilization efficiency and offer economic benefits in broiler production (Jin et al., 2020; Atay, 2023).
       
The genus Thymus L. which has antibacterial, antifungal and anticoccidiotic properties attributed to thymol and carvacrol, is practically widespread around the Mediterranean (Zouari et al., 2012; Perrino and Wagensommer, 2022; Mahdi et al., 2022). In Algeria it is represented by 17 species and subspecies, three of which are endemic (Tamma et al., 2024). Thymus algeriensis is one of the three thymuses endemic to Algeria (Zouari et al., 2012). Indeed, several studies which have focused on the effects of different species belonging to the genus Thymus as feed additive on growth performance, carcass characteristics and certain blood parameters of broiler chickens (Adam et al., 2020; Sigolo et al., 2021). Nevertheless and according to the best of our knowledge, no study has been carried out on the effect of Thymus algeriensis on the aforementioned parameters.
               
In this context, the aim of this study is determining the impact of varying dosages of Thymus algeriensis powder on broiler zootechnical and haemato-biochemical properties.

Chickens and experimental models
 
The study was conducted from September to November 2024 at a farm in the El-Ogla region (province of Tebessa, Northeastern Algeria), characterized by a semi-arid climate with cold winters.
       
A total of 96 one day-old Cobb 500 broilers of different sexes were randomly divided into four feed treatment groups: One control group (T1) and three groups fed a basal diet supplemented with 1% (T2), 2% (T3) and finally 3% (T4), respectively.
       
Four replicates of six chicks each made up each experimental group. The chicks were reared for 48 days in hygienic circumstances with deep litter.
 
Diet and breeding
 
Three experimental diets (starter, grower and finisher) were used in this trial. They were developed to meet the daily requirements of broilers. The ingredients and chemical composition of the experimental diets are presented in (Table 1).


       
For the first 18 days of the trial, the chickens were fed a starter diet; after that, they were fed a grower diet for 18-35 days and finally, a finisher diet for the remaining weeks.  T. algeriensis was combined with the basal diets after being run through a 2 mm sieve hammer mill and placed in plastic bags with labels, at 0% (T1: as a without-supplement control), 1% (T2: 100 g Thyme powder plus 9,9 kg basal diet total of  10 kg), 2% (T3: 200 g Thyme powder plus 9,8 kg basal diet in a total 10 kg mixture) and 3% (T4: 300 g Thyme plus 9,7 kg basal diet in a total 10 kg mixture). Each time the preparation was repeated according to the phases of broiler rearing.
       
Simultaneously, a tiny amount of the unrefined T. algeriensis powder was kept for chemical analysis in a dark glass container that was labeled and hermetically sealed.
       
The chemical composition of T. algeriensis powder was identified at the agricultural sciences department of the University of Khenchela, Algeria.           
       
Dry matter (DM), organic matter (OM) and crude protein (CP) were determined according to the methods of AOAC, (1990). Due to the importance of lignin as an anti-nutritive value in poultry feed, acid detergent fibre (ADF), neutral detergent fibre (NDF) and acid detergent lignin (ADL) were analysed according to the method described by Van Soest et al., (1991), (Table 2).


       
In accordance with treatment levels and replicates, the birds were kept in an experimental aviary that was divided into 16 pens of identical size (1x1,2 m), using by plasterboard partitions. Following the density regulation of 10 chickens/m2, six hens were kept in each pen. sawdust were utilized as bedding and each pen had a feeder and waterer. Ad-libitum access to feed and water was provided to the chicks. For the first seven days, the ambient temperature was initially fixed at 32°C. It was progressively lowered until 24°C on day 21 and then maintained for the remaining investigation.
       
Chickens were vaccinated against Newcastle disease (7^th and 14^th day of age), infectious bronchitis (16th day of age) and infectious bursal disease (Gumboro).
 
Performance parameters
 
Weekly body weight increases for each pen were tracked during the rearing phase. Body weight gain (BWG) and feed conversion ratio (FCR) were also calculated. At the end of the experiment, three chickens from each treatment group were weighed. recorded and sacrificed following the Islamic manner. The edible giblets (heart and liver), thighs and fat were collected and weighed.
 
Blood sampling
 
Three chickens in each group had their blood samples collected.  Twelve chickens in all were selected at random for sampling and then labeled for additional treatment. Blood samples were kept in two different kinds of test tubes, with half of the samples being put in anticoagulant tubes (EDTA tubes) for the measurement of the white blood cell and the heterophil /lymphocyte ratio (H/L) (Shoukary et al., 2015).
 
Statistical analysis
 
Statistica and Microsoft Excel were used for statistical analysis.  The data was first analyzed using ANOVA.  Then, the mean values of the variables were compared using the Tukey test. Besides, all residual data were subjected to the normality test. 

Growth performance
 
In the Table 3 showsthat thyme powder supplementation, at different levels, had no significant effect (P<0.05) on body weight of birds at 7 day and 28 day. However, body weight at 48 day was significantly increased as diet was supplemented with 3% of thyme powder. Feed intake of thyme powder supplemented group T3 and T4 was significantly higher than those of other groups T1 and T2 for all the trial period except starter phase.


       
Dietary supplementation of Thyme powder (T3 and T4) raised significantly FCR (P<0.05)  when compared to the other groups (T1 and T2) among all trial period of broiler.In overall, thyme powder supplementation had comparable performances to control group. Except at 48 day of age where T4 showed a higher body weight, feed intake and average daily gain than T1. However, Deeb et al., (2024) found that a basal diet with thyme leaves powder added at 1, 2 or 3 g/kg of diet enhanced significantly body weight and feed intake of broiler chickens throughout study period of 38 days.
       
Besides, Mehboob  et al. (2025) reported that supplementation of broiler diets with the fed herb Urtica dioica as a feed additive at 2% improved significantly  the performance of broiler chickens (body weight and FCR).
       
Anti-nutritional factors may be the cause of these outcomes.  Additionally, these improvements may be attributed to the antibacterial and antioxidant properties of the thyme powder employed, which may enhance gut health and boost the absorption of nutrients by stimulating digestive enzymes (Du et al., 2016). Thyme increases the amount of feed consumed by enhancing absorption through intestinal villi and causing the release of digestive enzymes including chymotrypsin and amylase (Denli et al., 2004). On the other hand, more undesirable FCR was recorded for the group T4 compared to control group T1 (1,66 vs 1,59). Similarly, numerous authors (Ashour et al., 2025; Golshahi et al., 2025) have already reported that the addition of thyme for broiler raise significantly FCR. Other studies, such as Vlaicu et al., (2023), which investigated the effect of thyme oil addition on broiler production, also stated that a diet containing 0.05% thyme oil had a more favorable feed conversion ratio. These contradictions could be attributed to different thyme products (powder, oil or extracts), maturity of plant at harvest and storage conditions which affect chemical composition of plant (Brenes and Roura, 2010).
 
Carcass yield
 
In the Table 4 revealed how various level of thyme powder concentration on broiler’s diet affect different carcass traits. A significance decrease in carcass weight before evisceration was observed at 2% of thyme powder inclusion (P<0.05). However, this difference don’t persist till evisceration (P>0.05). It can be noted that the addition of 3% of thyme powder to broiler diet improved significantly thigh’s mean weight of broiler (P<0.05) compared to other treatments. Weights of the heart and thighs augmented considerably (P<0.05) for treated groups,  with the highest results recorded at 3% comparatively with the control. Whereas, no effects occurred of thyme powder inclusion (P>0.05)  for liver and abdominal fat weights.

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Our results were in line with those of Adam  et al. (2020), who found that different levels of thyme powder or essential oils of thyme had non-significant effect on weight of gastric tracts and their parts. Also, previous studies found that enriching broiler’s diet with 5 g/kg feed (Ibrahim et al., 2024) of thyme powder had not improved significantly carcass, liver, gizzard, heart and abdominal fat weight.  
       
Additionally, Ashour et al., (2025) found that supplementing 2 g/kg feed of thyme powder in broiler diet had no effect on liver, gizzard weight and thigh meat, while noting a decrease in heart weight compared to the control group.
       
Furthermore, Rathor  et al. (2025) revealed that chickens fed the diet with Ajwain (Trachyspermum ammi) seeds at 1.5% level recorded significantly (P<0.05) higher carcass weight, heart and liver weight compared to control group.
       
Incorporation of herbs and their products in the diets of poultry are known to stimulate and promote the effective use of feed nutrients which subsequently results in rapid body weight gain, higher production rates and improved performance (Vargas et al., 2022; Ajaykumar et al., 2024).
 
Blood analysis
 
The results of the Table 5 detail the effect of supple-mentation with different levels of thyme powder on the biochemical and haematological blood parameters of broilers. They showed that glucose and cholesterol concentrations were higher while birds were fed a finisher diet supplemented with 3% thyme powder compared to other groups.However, the concentrations of uric acids, creatinine and globulin were increased in both T2 and T3 groups, while albumin concentration increased for broiler of T3 only. Moreover, the percentage of red blood cells and platelets were higher in broiler of T3 comparatively with T2 and T4 groups. In addition, the percentage of lymphocyte, monocyte and granulocyte cells was higher in chickens fed a diet supplemented with 3% thyme powder (T4) in comparison with the other groups. Ali, (2014) found that supplementing broiler diets with 0,5%, 1% or 1,5% thyme leaf powder decreased cholesterol levels. On the other hand, our findings are in agreement with Larbaoui et al. (2024) concerning the amount of blood (Glucose), reporting the same value by the addition of 5% of olive pomace on the growth of broiler chickens.


       
The antioxidant properties of thyme seem to reduce the destructive oxidative effect of the toxin on the liver and reduce cholesterol, triglycerides and liver enzymes due to the inhibitory effect of these extracts on key enzymes.

Based on the results, it was shown that adding 3% T. algeriensis powder to broiler feed improved the broiler’s body weight, carcass weight and haemato-biochemical profile. Consequently, the improvement in the overall health and well-being of broilers may be a sign that this plant species can constitute a promising substitute to antibiotics as a growth booster.

The authors would like to express their sincere appreciation to all people who contribute for the realization of this work. Pedagogic laboratory of the biology department of Abbes Laghrour university of Khenchela. Staff technical of laboratory medical analysis of HATTABI Adel, in El-Ogla, Tebessa, Algeria.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.
 
Informed consent
 
All animal procedures for experiments were approved by the committee of experimental animal care and handling techniques were approved by the university of  animal care committee.

The authors declare that they have no competing interests.