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Volume 16 (2); June 2026

Physiological, Histopathological, and Molecular Characterizations of Escherichia coli Infection in Commercial Laying Hens in Basrah Governorate, Iraq

Research Paper

Physiological, Histopathological, and Molecular Characterizations of Escherichia coli Infection in Commercial Laying Hens in Basrah Governorate, Iraq

Abbas SS, Ali RAA, Saood AI, Seger WM, Najem HA, Khaleefah IA, and Abdulrasol MA.

J. World Poult. Res. 16(2): 157-167, 2026; pii: S2322455X2600015-16

DOI: https://dx.doi.org/10.36380/jwpr.2026.15

ABSTRACT: Colibacillosis represents one of the most important bacterial diseases affecting poultry production, particularly in commercial laying hens, where it leads to marked economic losses. The present study aimed to evaluate the physiological, histopathological, and molecular characteristics of Escherichia coli (E. coli) infection in commercial laying hens in Basrah Governorate, Iraq. A total of 250 laying hens aged 35 weeks with clinical signs and postmortem lesions of colibacillosis were examined. Bacterial isolation was performed using conventional culture methods, followed by molecular confirmation using PCR targeting the 16S rRNA gene. Blood samples were collected for hematological analysis, and tissue samples from the liver and oviduct were processed for histopathological examination. The results showed a clear decrease in red blood cell (RBC) count, white blood cell (WBC) count, hemoglobin (Hb), and hematocrit (Hct) values in infected hens compared with healthy controls. In contrast, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were significantly increased in infected hens compared with healthy controls. Histopathological findings showed severe pathological alterations in the liver and oviduct, including vascular congestion, inflammatory cell infiltration, vacuolation, hemorrhage, and necrosis. Molecular analysis confirmed the presence of E. coli through successful amplification of the 16S rRNA gene. The findings of the current study suggest that E. coli infection induces marked physiological and tissue-level alterations in laying hens, which may adversely affect their health and productivity, highlighting the need for effective control measures on poultry farms.
Keywords: Colibacillosis, Hematological parameters, Liver, Oviduct, PCR, 16S rRNA

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Effects of Bacillus amyloliquefaciens and phytase Administration on Growth Performance and Organ Weights in Broiler Chickens During the Hot-Humid Season

Research Paper

Effects of Bacillus amyloliquefaciens and phytase Administration on Growth Performance and Organ Weights in Broiler Chickens During the Hot-Humid Season

Zakari FO, Okoro P, Agweche OS, Idoga ES, Oladipo OO, Jonathan KB, Adaji OG, Emennaa P, Sati N, Uchendu C, and Aluwong T.

J. World Poult. Res. 16(2): 168-180, 2026; pii: S2322455X2600016-16

DOI: https://dx.doi.org/10.36380/jwpr.2026.16

ABSTRACT: In tropical regions, heat stress reduces broiler chicken productivity, highlighting the need for developing alternative growth promoters to replace antibiotics. The present study aimed to evaluate the effects of dietary phytase (Axtra® Phytase) and the probiotic Bacillus amyloliquefaciens (B. amyloliquefaciens) on the growth performance and feed intake in broiler chickens during the hot-humid season in Jos, Plateau State, Nigeria. A total of 180 broiler chickens, 15 days old, were randomly allocated to four experimental groups. Each group consisted of 45 chickens with three replicates per group and 15 chickens per replicate. The dietary groups included a control group fed the basal diet without additives (Ctrl), a probiotic group supplemented with B. amyloliquefaciens at 1 × 10⁹ CFU/kg (Prob), a phytase group supplemented with Axtra® Phytase enzyme at 200 FTU/kg (Phy), and a combined group that received probiotic and phytase (Phy + Prob). The broiler chickens experienced challenging environmental conditions throughout the study, with average measurements of 29.00 ± 0.40°C for dry-bulb temperature, 68 ± 1.54% for relative humidity, and 27.99 ± 0.50°C for the temperature-humidity index. All these factors were higher than the optimal range for broiler thermal comfort. The live weight, weight gain, feed intake, organ weight, and feed conversion ratio were assessed. On day 42, live and organ weights in the treated groups were significantly higher than those in Ctrl. All supplemented groups indicated increased weight gain. Feed intake was higher in the Ctrl and Prob groups compared to the Phy and Phy + Prob groups. These findings indicated that supplementation with phytase, alone or in combination with B. amyloliquefaciens, improved growth performance, feed efficiency, and organ development while modulating feed intake during heat stress. The present results demonstrated that B. amyloliquefaciens, phytase, or their combination enhanced growth performance, organ weights, feed efficiency, and overall productivity in broiler chickens subjected to heat stress during the hot-humid season in Nigeria. The current results supported the use of phytase and B. amyloliquefaciens in tropical poultry production.
Keywords: Bacillus amyloliquefaciens, Broiler chicken, Feed intake, Growth performance, Hot-humid season, Phytase

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Characterizations of Virulence, Serogroups, and Phylogenetic Groups of Avian Pathogenic Escherichia coli in West Java, Indonesia

Research Paper

Characterizations of Virulence, Serogroups, and Phylogenetic Groups of Avian Pathogenic Escherichia coli in West Java, Indonesia

Widyasaria D, Kurnia RS, Nugroho CMH, Putra MA, Setiyaningsih S, and Indrawati A.

J. World Poult. Res. 16(2): 181-194, 2026; pii: S2322455X2600017-16

DOI: https://dx.doi.org/10.36380/jwpr.2026.17

ABSTRACT: Colibacillosis is an infectious disease in poultry caused by avian pathogenic Escherichia coli (APEC), which can invade the host through the intestinal or respiratory tract and subsequently lead to systemic infection mediated by various virulence factors. The current study aimed to characterize the 15 Escherichia coli (E. coli) isolates obtained from colibacillosis-affected commercial layer farms (n=10) in West Java, Indonesia, between 2016 and 2020. Molecular identification and characterization were performed using Polymerase Chain Reaction (PCR) targeting uspA gene, four O-serogroups (O1, O2, O18, and O78), 11 virulence-associated genes, and phylogenetic markers, with appropriate positive and negative controls included in each assay. All isolates were confirmed as E. coli by uspA amplification. The most prevalent virulence gene was fimC in 87% (13/15), which was detected across multiple phylogenetic groups, including B1, B2, A/C, and D/E, followed by ibeB and traT (73%, 11/15 each), iucD and iroN (67%, 10/15 each), papC and vat (33%, 5/15 each), ibeA (13%, 2/15), and iss (7%, 1/15). Serogroup analysis identified three isolates as O1, two as O18, and one as O78, while the majority of isolates (9/15) were not assignable to the tested serogroups. Phylogenetic analysis classified the isolates into group A (1/15), B1 (2/15), B2 (5/15), F (3/15), A/C (2/15), D/E (1/15), and one unclassified group (1/15), with phylogenetic group B2 harboring the highest number of virulence-associated genes. The findings of the current study demonstrated substantial genetic diversity among APEC isolates circulating in West Java, Indonesia.
Keywords: Colibacillosis, Escherichia coli, Phylogenetic group, Virulence gene, Zoonotic disease

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Effects of Arugula Leaves Extract on Blood Biochemical Parameters in Broiler Chickens

Research Paper

Effects of Arugula Leaves Extract on Blood Biochemical Parameters in Broiler Chickens

Mohammed EM, Lehmood BA, and Al-Thuwaini TM.

J. World Poult. Res. 16(2): 195-203, 2026; pii: S2322455X2600018-16

DOI: https://dx.doi.org/10.36380/jwpr.2026.18

ABSTRACT: Arugula leaves contain abundant flavonoids, glycosides, and other bioactive substances, along with essential minerals such as calcium and potassium, which are commonly used as medicinal herbs in Iraq. The bioactive substances present in arugula leaves can positively influence the biochemical parameters in broiler chickens. The present study aimed to examine the effects of the cold-water extract of arugula leaves (Eruca sativa) on the blood biochemical parameters of broiler chickens when added to drinking water. One hundred forty-four broiler chickens with an initial weight of 44 g were randomly allocated to four treatment groups and reared for 35 days. Each treatment contained 36 chickens, with three replications of 12 chickens each. The first treatment group served as the control and did not receive any additional supplements (T1). In the second treatment group, arugula leaf extract was provided in drinking water at a concentration of 50 mg/ml per liter (T2), in the third treatment group, the concentration of arugula leaf extract was 100 mg/ml per liter (T3), and in the fourth treatment group, the concentration of arugula leaf extract was 150 mg/ml per liter (T4). Broiler chickens supplemented with arugula leaf extract indicated a significant reduction in serum levels of glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), thyroid hormones, urea, and creatinine compared to the control group. There was a significant increase in red blood cell count, hemoglobin, and packed cell volume in T3 compared to the control group. Additionally, the serum levels of total protein, albumin, and globulin were significantly elevated compared to those in T1. Group T3 demonstrated a significant increase in the concentration of high-density lipoprotein (HDL) and a significant decrease in the concentrations of triglycerides, cholesterol, low-density lipoprotein, and very low-density lipoprotein compared to the control group. The present findings indicated that administering 100 mg/ml of arugula leaf extract improved blood parameters, including liver enzyme activity, thyroid hormone levels, serum proteins (albumin, globulin, and total protein), and HDL concentrations in broiler chickens.
Keywords: Arugula, Broiler chicken, Liver enzyme, Lipoprotein, Thyroid hormone

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Morphometric Characterization of Local Guinea Fowl (Numida meleagris) Populations in Northern Ivory Coast

Research Paper

Morphometric Characterization of Local Guinea Fowl (Numida meleagris) Populations in Northern Ivory Coast

Yeo WI, N’dri AL, N’zi KAM, and Konan YKN.

J. World Poult. Res. 16(2): 204-214, 2026; pii: S2322455X2600019-16

DOI: https://dx.doi.org/10.36380/jwpr.2026.19

ABSTRACT: Guinea fowl production plays a key role in rural poultry systems in sub-Saharan Africa, contributing to food security and adaptation to harsh environmental conditions. The present study aimed to evaluate the morphometric variability of 479 local guinea fowl (Numida meleagris) reared under traditional free-range systems in six Northern regions of the Ivory Coast. Guinea fowl were aged at least six months, with an estimated mean age of approximately 7-8 months. Eight quantitative traits, including body weight, breast angle, breast circumference, wingspan, body length, drumstick length, tarsus length, and tarsus diameter, were measured according to FAO guidelines. Body weight (22%) and breast angle (20%) showed the highest variability, whereas morphometric traits such as breast circumference, wingspan, body length, drumstick length, tarsus length, and tarsus diameter generally exhibited low dispersion. Region significantly influenced all traits. Guinea fowl from Kabadougou and Poro exhibited superior morphometric performance, while those from Bounkani and Tchologo recorded lower measurements. Sexual dimorphism favoring females was observed for most traits, particularly body weight. Multivariate analyses identified three distinct morphological clusters. The greatest Mahalanobis distance (24.15) separated clusters with the highest and lowest growth potential. Wingspan, breast circumference, body weight, and tarsus length were the most discriminating traits. In conclusion, wingspan, breast circumference, body weight, and tarsus length were the most significant discriminating morphometric characteristics. The most notable production potential was observed in the cluster characterized by higher values of these traits, indicating superior growth and body conformation, which is favorable for breeding and conservation programs.
Keywords: Guinea fowl, Morphometric trait, Phenotypic characterization, Poultry

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Effects of Capsicum chinense Phytogenic Additive on Growth Performance and Breast Muscle Pigmentation in Broiler Chickens

Research Paper

Effects of Capsicum chinense Phytogenic Additive on Growth Performance and Breast Muscle Pigmentation in Broiler Chickens

Jaimes LJ, Torres A, Salgado L, and Alzate Y.

J. World Poult. Res. 16(2): 215-223, 2026; pii: S2322455X2600020-16

DOI: https://dx.doi.org/10.36380/jwpr.2026.20

ABSTRACT: The widespread use of antibiotic growth promoters (AGPs) in poultry production has contributed to the emergence of antimicrobial resistance, increasing the need for effective natural alternatives. The bioactive phenolic alkaloid present in Capsicum species has demonstrated antimicrobial, antioxidant, and digestive-stimulating properties. The present study aimed to evaluate the effects of a phytogenic additive derived from Capsicum chinense (oleoresin) on growth performance, survival rate, and breast muscle pigmentation in broiler chickens. A total of 2,400 one-day-old male broiler chickens with an initial body weight of 35.4 ± 0.43 grams were randomly allocated to 48 pens (50 chickens per pen) and assigned to four dietary treatment groups with 12 replicates each. The treatments included a basal balanced feed (BF) supplemented with 60 ppm of zinc bacitracin (T0). The second group received the BF with 300 g of capsicum chinense additives (ACC) per ton of feed (T300), the third group received the BF with 600 g of ACC per ton of feed (T600), and the fourth group received the BF with 1000 g of ACC per ton of feed (T1000). Growth performance parameters, including live weight (LW), average weight gain (AWG), feed intake, feed conversion ratio (FCR), and survival rate, were evaluated over a 42-day production period. At slaughter on day 42, breast skin pigmentation was evaluated using instrumental colorimetry based on the CIE Lab* system. The supplementation of Capsicum chinense significantly improved LW, AWG, and FCR during the first 21 days of age, with the best performance observed in Group T300 compared to the control group. Feed intake and survival rate were not significantly affected by the dietary treatments, although Group T600 experienced a lower survival rate. The current results indicated no significant differences in colorimetric parameters among dietary treatments, although Group T300 exhibited the highest redness (a*) values. The present findings indicated that supplementation with 300 g/ton of Capsicum chinense can improve growth performance in broiler chickens at 21 days of age, comparable to that of the group that received antibiotic growth promoters, without adversely affecting carcass pigmentation.
Keywords: Antibiotic, Efficiency, Feed intake, Phytogenic compound

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Molecular Characterization and Evaluation of Field Fowl Adenovirus Isolates in Specific Pathogen Free Chicken Embryonated Eggs

Research Paper

Molecular Characterization and Evaluation of Field Fowl Adenovirus Isolates in Specific Pathogen Free Chicken Embryonated Eggs

Ibrahim SHS, Sohaimi NM, Bejo MH, Omar AR, Mazlan M, Farzad MA, and Clifford UC.

J. World Poult. Res. 16(1): 224-241, 2026; pii: S2322455X2600021-16

DOI: https://dx.doi.org/10.36380/jwpr.2026.21

ABSTRACT: Fowl adenoviruses (FAdVs) pose a substantial economic threat to global poultry production due to outbreaks of inclusion body hepatitis (IBH) and gizzard erosion. The present study aimed to characterize four Malaysian FAdV serotype 8b isolates (UPM2101, UPM2102, UPM2103, and UPM2401) through sequence analysis of the hexon and fiber genes to identify unique variations, while concurrently assessing viral infectivity via propagation in specific pathogen free (SPF) chicken embryonated eggs. The four FAdV field isolates were obtained from commercial broiler chickens in Malaysia presenting classical lesions. Isolates UPM2101, UPM2102, and UPM2103 were collected from farms in Johore in 2021, whereas UPM2401 was collected from Kedah in 2024. UPM2101, UPM2103, and UPM2401 originated from swollen, pale, and friable livers with petechial hemorrhages, whereas UPM2102 was isolated from a gizzard erosion case. Polymerase chain reaction (PCR) amplification confirmed the presence of FAdV in all samples. Sequence analysis revealed high nucleotide identity among the isolates. In the hexon gene, a nucleotide insertion at position 33 in UPM2101 and a substitution (C→T) at position 428 in UPM2401 resulted in non-synonymous amino acid changes. UPM2101 exhibited multiple amino acid substitutions at positions 225–234 with an additional glutamine at position 235, whereas UPM2401 showed a single substitution (A93T). In the fiber gene, nucleotide substitutions and a deletion were observed in the knob region, resulting in amino acid changes including S149T and R150A in UPM2103 and R150S in UPM2401. Phylogenetic analysis classified all isolates within serotype 8b, forming a closely related cluster. Propagation in embryonated eggs demonstrated efficient viral replication, with UPM2101 exhibiting earlier embryonic mortality than UPM2401, indicating potential differences in virulence. The findings of the current study indicated that the Malaysian FAdV serotype 8b field isolates are closely related yet exhibit distinct molecular variations that may influence viral replication efficiency and infectivity in embryonated eggs.
Keywords: Fiber gene, Hexon gene, Inclusion body hepatitis, Infectivity, Serotype 8b, Substitution, Virulence