The current study was designed to investigate the impacts of heat stress (HS) on performance parameters of broiler chicken reared at different stocking densities, also study assessed the effects of anti-stress (vitamin) supplementation in the mitigation of different levels of stress. A total of 720 7th-day-old Cobb ® chicks were randomly distributed into 18 groups, (two replicates within each group). The experiment with a factorial arrangement of treatments (3x3x2), 3 levels of stocking densities (RSD: 10 chicks/m2, MSD: 14 chicks/m2, and HSD: 18 chicks/m2), 2 levels of vitamin supplementation (0 mg/l and combination of 250 mg/l ascorbic acid plus 0.5 ml/l Vit E + Se) and three temperatures (Thermoneutral temperature (TN), sudden chronic heat stress exposure (CHS) and gradual chronic heat stress exposure). Broilers were kept either under thermoneutral conditions (24 ± 1 ºC) during the whole life period or slowly introduced to CHS from 7th to 21st d of age and kept at high temperature thereafter and the third chamber had chicks that were exposed to CHS (32 ± 2 ºC for 8 h/day) during the period from 21st: 42nd day of age. Chicks were reared on a deep litter system and had free access to feed and water. Performance parameters (FI, BW, BWG, and FCR) were determined on the 42nd day of age. The results showed HSD had adverse effects on the growth performance of broilers reared under thermoneutral or CHS conditions where the differences between densities were significant (P<0.05) under TN and sudden CHS conditions and insignificant in case of gradual CHS exposure conditions for most of the performance parameters. Vitamins supplementation had improved growth performance (BW and FCR) of broilers kept under MSD or HSD and exposed to thermoneutral or sudden CHS conditions as compared to corresponding not supplemented birds. While it was effective in combating the adverse effects of gradual HS exposure in RSD and MSD kept broilers only. In addition, there was no significant difference between RSD not supplemented broilers and MSD-supplemented birds under TN conditions; concluding that broilers can be stocked at MSD under thermoneutral conditions if they were supplemented with vitamins.

Colibacillosis is a disease caused by avian pathogenic E. coli (APEC) and is one of the principle cause of morbidity and mortality in poultry worldwide which is represented by a complex syndrome characterized by multiple organ lesions. This study was carried out to determine phylogenetic grouping and virulenceassociated genes contained by E. coli isolates which is related in causing disease in chicken. E. coli isolates obtained from clinical cases of Veterinary ResearchInstitute were re-identified by conventional methods. Phylogenetic grouping of the isolates was determined by triplex polymerase chain reaction (PCR), and the presence of eight virulence genes were identified by multiplex PCR. A total of 125 E. coli isolates were subjected toanalysis of phylogenetic background and virulence associated genes profiling. Phylogenetic analysis demonstrated that most of the E. coli isolated from chicken in this study belonged to group B1 (36.0%),group D (28.0%), group A (27.2%) and group B2 (8.8%). Multiplex PCR analysis demonstrated that 96 (78.6%) of the E. coli isolates harbored at least one virulencegene, while 29 (23.3%) did not contain any virulence genes tested. The most prevalent virulence genes identified were iss (51.2%), followed by iucD (36.0%),tsh (32.8%), vat (16.0%), astA (13.6%), irp2 (11.2%), papC (9.6%) and the least is cva/cvi gene (0%). None of the isolates harbored more than four virulence genes.Each of phylogenetic groups presented with different combinations of virulence genes, with no specific combinations of virulence genes found to correlate withE. coli phylogroups. None of the E. coli isolates harbored more than four virulence genes, suggesting that E. coli isolates from chicken in this study appear to bederived from commensal strains and may relate to environmental predispose factors especially stress factors in the host to establish infection.

Data over a period of eleven years was analysed for Infectious Bursal Disease (IBD) virus isolated from chicken samples submit ted to the Regional Veterinary Laboratory at Bukit Tengah, Malaysia (RVLBT) for diagnosis. A total of 247 suspect IBD cases were tested by Virology Section, RVLBT between years of 2006 to 2016. IBD virus has been isolated by using Agar Gel Precipitation Test (AGPT), a bursal homogenate which has been used as an antigen against a known positive antiserum. About 27 cases (11%) from a total of 247 suspect cases in chickens were positive for the presence of IBD. The rate of IBD may be influenced by age of chickens with an increase in the possibility of IBD occurring in chicken older than 3 weeks. Apart from that, both broiler and local chickens are highly susceptible to this disease. Therefore, awareness on the existing IBD cases indicates the importance of strict management procedures, proper management programmes, vaccination and immunisation for chickens in Malaysia.

A serious infection in avian species can be caused by Clostridium perfringens (C. perfringens). Because of the harmful consequences that antibiotics have on public health, reducing their usage in the animal industry is a major global concern. As an alternative to antibiotics, nanoparticles (NPs) have been used more and more recently to target bacteria. Zinc oxide (ZnO), one of these NPs, exhibited antibacterial activity even at low concentrations. Consequently, at 14 days, 75-day-old Cobb broiler chicks were separated into 5 equal groups (15 birds each divided into triplicate, 5 bird per replicate). The groups were calssified as G1, G2, G3, G4 & G5. G1 was infected with C. perfringens type A; G2 was infected & given zinc oxide nanoparticles (ZONPs); G3 was infected with C. perfringens & given doxycycline as an antibiotic; G4 received ZONPs continuously for 35 days; & G5 was the negative control. For two successive days, 4×108 colony forming units (CFU) of C. perfringens type A/mL/bird were given orally to birds in infected groups. ZONPs in the treatment groups received a total dose of 150 µg/bird. Bird performance is measured for 35 days, & data is gathered on body weight (BW), feed conversion (FC), feed conversion rate (FCR), clinical signs score, & mortalities. Moreover, immune organ indices & the microbial loads in the caecum & intestine were assessed. Remarkably, BW improvements (P < 0.05) were noted in ZONPs treated group & ZONPs / C. perfringens infected group, in contrast to those in G1. Compared to G1, treatment with ZONPs lowered the colonization of C. perfringens in the caeca & intestine, lessened the severity of clinical symptoms, & decreased mortality. Thymus, bursa, & spleen relative weights varied considerably (P < 0.05) between treatment groups. When ZONPs were administered alone or in conjunction with infection, the spleen’s relative weight was considerably (P < 0.05) larger in treated birds than in control & antibiotic-treated birds. In conclusion, ZONPs positively affect the BW & FCR, improve the relative weight of immune organs, & can decrease the C. perfringens count in the intestine, positively impacting performance, general health, & gut health integrity. However, ZONPs also reduce the population of gut microbes. On the other hand, birds that received antibiotic treatment showed adverse effects on a few metrics. Therefore, more investigation into the use of ZONPs in broiler diets and their safety for the health of humans and avian species is still advised.

The experimental protocol aimed to assess the influence of nucleotides and/or β-glucan on the production performance, growth-related gene expression in the broiler chickens’ liver tissue, intestinal histomorphology, and some biochemical parameters. One hundred forty-four newly hatched chicks were categorized into four groups based on the supplements: a control group, a group supplemented with nucleotides (200 mg/kg diet), a group with β-glucan (1 g/kg diet), and a group with both nucleotides and β-glucan. The study's findings showed that, when compared to the control group, all dietary supplemented groups showed a substantial (P < 0.05) improvement in production parameters without having a negative impact on the general health of broilers. Additionally, the treatments positively impacted the expression of some genes associated with growth performance in the broiler chickens’ liver tissue, such as the insulin-like growth factor 1 (IGF-1) and growth hormone receptor (GHR). The supplemented groups also demonstrated a significant (P < 0.05) enhancement in intestinal histomorphology, characterized by increased villi length, crypt depth, and goblet cell number. Furthermore, dietary supplementation of nucleotides and/or β-glucan led to a significant (P < 0.05) elevation in total protein and albumin levels, with no significant effect on globulin, AST, and ALT. The conclusion can be drawn that adding nucleotides along with β-glucan to the diet led to enhancements in growth performance, the expression of genes related to growth (GHR and IGF-1), intestinal histomorphology, and certain biochemical parameters (specifically total protein and albumin).

Aflatoxins are one of the most dangerous toxic residues in various foods including poultry. This study was conducted to assess the reducing effect of gamma radiation on the levels of aflatoxin B1 in poultry meat, skin, and liver. To this end, a total of 80 poultry samples including meat, skin, and liver were surveyed for the incidence of aflatoxins, where only positive samples (27 samples of muscle, skin, and liver; 9 samples each) were selected for testing the effect of treatment by gamma radiation. The levels of aflatoxins were estimated in the examined samples using High Performance Liquid Chromatography (HPLC) whereas positive samples were exposed to 0 kGy, 5 kGy, or 10 kGy, and the differences in aflatoxin contents before and after exposure were calculated. The obtained results clarified that radiation achieved reduction rates in aflatoxin B1 level in muscle samples with a mean value 99.259±0.741, and 100.00±0.00% when treated with 5 kGy and 10 kGy, respectively. Whereas in skin samples, 98.676±1.324 and 100.00±0.00 % when treated 5 kGy and 10 kGy, respectively. While in liver samples, reduction rates accounted for 84.312±7.406 and 88.249±10.882 were obtained when treated with 5 kGy and 10 kGy, respectively. In conclusion, the exposure of poultry meat, skin, and liver to gamma radiation (5kGy or 10 kGy) has a significant reducing effect (p<0.05) in aflatoxins B1. The results were discussed from the hygienic point of view and compared with the national and international standards to assess their reliability for consumption.

Campylobacter is the most common bacterial cause of gastroenteritis globally. A total of 182 fully identified strains of Campylobacter species (42 C. coli and 140 C. jejuni) collected from 6 broiler farms were subjected to studying the antimicrobial resistance pattern and molecular typing of virulence (cadF, ctdA, dnaJ waaC,iam, and fla) and antimicrobial resistance genes (blaOXA-61, gyrA, tetA, tetO, and IR) with sequencing of gyrA region of one strain of fluroquinolones resistant C. coli and C. jejuni. The identified isolates were highly resistant to erythromycin and sulfamethoxazole-trimethoprim. Furthermore, both meropenem and imipenem were effective against the recovered isolates. The tested C. jejuni and C. coli strains had 100%, 83.3%, and 83.3% prevalence of cadF, ctdA, and dnaJ virulence genes, respectively, while waaC, iam, and fla genes couldn’t be detected. The blaOXA-61 resistance gene was found in all of the Campylobacter spp. examined. Furthermore, gyrA, tetA, tetO, and IR resistance genes were found in 100%, 83.3%, 83.3%, and 66.7% of the retrieved C. jejuni strains, respectively.  Likewise, resistance genes were found in 83.3%, 83.3%, 83.3%, and 66.7% of the retrieved C. coli strains, respectively. Approximately 58% (7/12) of the Campylobacter spp. recovered were MDR. Furthermore, 50% (3/6) of the C. jejuni strains recovered were MDR, while 66.7% (4/6) of the C. coli isolates recovered were MDR with MARI(0.22-0.55). For detection of mutations of the gyrA gene, the sequence data of two isolates (C. jejuni and C.coli) were analyzed against the reference sequence on the gene bank where the C. jejuni strain had six mutations, while the C. coli strain had twenty-three. The current findings suggest that MDR Campylobacter strains in poultry may be able to transmit highly virulent Campylobacter as a foodborne pathogen.

The aim of this experiment was to investigate the impacts of dietary supplementation of extracted oregano essential oils on the physical, chemical properties of meat and the carcass properties of broilers, 180 one day old chicks (Ross 308)  arranged into3 dietary groups with 3 replicates (20 birds for each replicate). The experimental groups as follows: Group 1 (G1) control (basal diet), Group 2 (G2) included basal diet + 300 μl of oregano plant extract per kg of diet,  Group 3 (G3) contained basal diet + 600 µl of oregano plant extract for kg of diet. The period of experiment was 35 days. Results revealed that the % of dressed weight as well as % weight of breast was significantly (P ˂0.05) increased in groups which feeding with essential oil of oregano compared to a control diet. In contrast, there were no significant (P ˃ 0.05) influences of essential oils of oregano on (heart, liver, kidney, spleen, pancreas, gizzard) relative weights and intestinal length. However, supplemented groups with oregano essential oils showed a significant decrease in % of pH, TVN and TBA, as well as a significant (P ˂ 0.05) reductions in % of cooking loss, % of drip loss and shear force of the pectoral muscles when compared to the group feeding control diet. A higher significant increase in WHC was found in the group supplemented with 600 μl of OEO compared to the 300µl OEO and control group. OEO had non-significant influence on breast meat color (a, b, l) compared to the group feeding control diet. In conclusion, the supplementation of essential oils of oregano plant extract can improve carcass quality, physical and chemical meat quality of broiler chickens.

This work compared the antibacterial activity and in vivo effects of nitazoxanide and tylosin against infected broilers with antibiotic resistant Clostridium perfringens field strain to control necrotic enteritis disease. Both in vitro and in vivo assessment studies were used. Firstly, C. perfringens was isolated with a total rate of 46% from liver and intestine samples of diseased broilers. By using PCR molecular typing all tested isolates were type A (produced only alpha-toxin (cpa virulence gene)) and included Bla and tetK (resistant genes). Using antibiotic sensitivity test they showed multi-drugs resistance against amoxiclave, tetracycline, gentamicin, clindamycin, sulphamethoxazole-trimethoprim and cefoxitin. Minimal inhibitory and bactericidal concentrations (μg/ml) were 0.4 and 12 for nitazoxanide and 0.7 and 49 for tylosin respectively. Then, a total of 90 one-day-old-chicks were divided into 6 groups; G1: negative-control, G2: infected-control, G3: non-infected (nitazoxanide 15.4 mg/kg body weight), G4: non-infected (tylosin 20 mg/kg body weight), G5: infected-nitazoxanide (15.4 mg/kg), and G6: infected-tylosin (20 mg/kg). Treatments lasted for 5 days in drinking water. No adverse effects on liver or kidney parameters were recorded in non-infected treated groups. Both treatments overcome the infection signs, C. perfringens count and revealed a significant improvement in most of inflammatory and biochemical parameters to their normal levels especially, G5 reflected a significant increase in total protein, albumin, globulin while reduced alanine and aspartate aminotransferase and gamma-glutamyl transferase activities, C-reactive protein, uric acid, and creatinine levels than G2. Finally, nitazoxanide revealed a significant anti-clostridial activity as tylosin for the control of necrotic enteritis in broilers.

This study was conducted to investigate the effects of the sources and levels of dietary copper supplementation on broiler chickens. A 37-day feeding trial was accomplished using 192 one-day-old unsexed Arbor Acres broiler chicks which were randomly allocated into four groups with different strategies of copper supplementation. The first group was the negative control and fed on diets containing copper-free mineral-vitamin broiler premix. Diets of the second group were supplemented with copper sulfate (Cu2SO4) at the level of 7.5 mg/kg. The third and fourth groups were fed on diets supplemented with copper nanoparticles (Cu-NPs) at the levels of 7.5 mg/kg and 3.75 mg/kg, respectively. Growth performance, carcass characteristics, copper concentrations, serum antioxidant bio-markers and mRNA of metallothionein and ceruloplasmin were evaluated. Results of growth performance showed that Cu-NPs significantly (P ≤ 0.05) increased body weight gain and feed utilization compared to an equal quantity of Cu2SO4. No adverse effect on growth performance occurred when Cu-NPs were supplemented at half of the level of Cu2SO4. Dressing and thigh yields were significantly (P ≤ 0.05) increased in birds in the fourth group. Total antioxidant capacity, malondialdehyde level and transcription of ceruloplasmin were not significantly affected by the tested copper sources or levels. The superoxide dismutase enzyme activity and transcription of metallothionein were significantly (P ≤ 0.05) increased by the replacement of Cu2SO4 with the same quantity of Cu-NPs. Our findings suggested that Cu-NPs could be a superior dietary supplement of copper in broiler chickens’ diets over Cu2SO4, with possibility of quantity reduction.