Aim: The present study was designed for the detection of the most prevalent respiratory infections in chicken flocks and clarifying their interaction and impact on flock health. Materials and Methods: A total of 359 serum samples were collected from 55 backyard chickens and tested using commercial enzyme-linked immunosorbent assay kits to determine the seroprevalence of Newcastle disease virus (NDV), infectious bronchitis virus (IBV), influenza type A, Mycoplasma gallisepticum (MG), and Mycoplasma synoviae (MS). Molecular prevalence of NDV, IBV, low pathogenic avian influenza virus (LPAIV) H9N2, MG, and MS was carried out on swab, and tissue samples collected from 55 backyard flocks and 11 commercial broiler flocks suffered from respiratory infections using polymerase chain reaction (PCR) and reverse transcription-PCR. Results: Seroprevalence of NDV, IBV, Influenza type A virus, MG, and MS in chicken backyard flocks was 56.4%, 50.9%, 12.7%, 14.5%, and 3.6%, respectively. Specific antibodies against one or more respiratory viruses and mycoplasma were detected in 36.4% of backyard flocks, indicating concurrent viral infections. The molecular survey showed that 90.9% of chicken backyard flocks were infected with common respiratory viruses (NDV, IBV, and LPAIV H9N2) while 81.8% of commercial broiler flocks were infected. The molecular prevalence rate of NDV, IBV, and LPAIV H9N2 was 46.97%, 56.1%, and 19.7% in backyard flocks, respectively. Combined viral and bacterial infection represented 40% and 63.6% of the respiratory infections, resulting in enhanced pathogenicity and increased mortalities of up to 87.5% and 27.8% in backyard and commercial flocks, respectively. Mixed infection of IBV, LPAIV H9N2, and/or Escherichia coli is the most prevalent mixed infection in broiler flocks, inducing severe clinical outcomes. Avian pathogenic E. coli was, respectively, isolated from 40% of backyard flocks and 81.82% of broiler flocks. Staphylococcus aureus was isolated from three backyard chicken flocks mixed with other respiratory pathogens with elevated mortality. Mixed infection of E. coli and MG reported in 9.1% of broiler flock. MG was detected in 14.5% of backyard flocks and 9.1% of broiler flocks while MS was detected only in 3.6% of backyard chickens mixed with E. coli, and other viruses. Conclusion: Our results confirm that mixed infections are more commonly prevalent and associated with dramatic exacerbation in clinical outcomes than a single infection. Bidirectional synergistic interaction between these concurrently interacted respiratory pathogens explains the severe clinical impact and high mortality rate. The high prevalence of IBV (either as a single or combined infection) with LPAIV H9N2 and/or E. coli, in spite of intensive use of commercial vaccines, increases the need for revising vaccination programs and the application of standard biosecurity measures. Backyard chickens impose a great risk and threaten commercial flocks due to the high prevalence of viral respiratory pathogens.

The study evaluated the influence of dietary supplementation with nano-encapsulated cumin oil, B. subtilis, or a combination of both to mitigate the impacts of heat stress on the performance and health of growing rabbits. In the feeding trial, a total of eighty-four growing New Zealand White (35 days, 781.3 ± 1.8 g average body weight) were randomly distributed in a completely randomized design into four groups; each had 21 rabbits arranged in 7 replicates (3 rabbits each). The experiment lasted 42 days (35 days to 77 days). Growing rabbits received a basal diet (first group, CON) without additives, while the other groups were supplemented with nano-encapsulated cumin oil (NECO, 200 mg/kg), B. subtilis (BS, 500 mg/kg), or both (BSNO, 500 mg BS plus 200 mg/kg NECO). Adding BSNO significantly enhanced body weight gain, carcass weight, and feed conversion ratio and reduced mortality rate (p < 0.05). Additionally, the BSNO enhanced digestive system performance by increasing the secretion of trypsin enzymes, as well as nutrient digestibility, especially for protein and fiber (p < 0.05). Supplementing BSNO enhanced oxidative stability and immunity via higher levels of superoxide dismutase (SOD), IgA, IgG, triiodothyronine (T3), thyroxine (T4) and lower malondialdehyde (MDA) levels (p < 0.05), indicating a better ability to adapt to stress. During the examination of gut health, pathogenic bacteria counts decreased, as well as down-regulation of interleukin-6 (IL-6) gene expression and up-regulation of cationic amino acid transporter-1 (CAT-1), interleukin-10 (IL-10), and mucin-2 (MUC-2) gene expression (p < 0.05), supporting gut integrity. This study highlights the potential of mixing nano-encapsulated cumin oil and B. subtilis in growing rabbits’ diets as an effective strategy to counteract the negative effects of heat stress caused by high ambient temperatures.

This study investigates the nutritional effects of a thyme meal and B. subtilis mixture on growth performance, immune function, antioxidant capacity, gene expression, and gut microbiota in heat-stressed rabbits. One hundred and twenty male New Zealand White rabbits were divided into four dietary treatments (five replicates/group). The rabbits in the first group were fed a basal diet, while the other three groups were fed a basal diet containing B. subtilis, thyme meal, and their mixture, respectively. The B. subtilis and thyme meal mixture increases the heat-stressed rabbits’ body weight gain and carcass weight, and enhances nutrient digestibility and the feed conversion ratio. Supplementing the CBT mixture improved the lipid profile and liver and kidney function via decreasing plasma triglycerides, cholesterol, LDL, creatinine, urea, and AST levels, while increasing total protein and albumin levels. Furthermore, the CBT mixture enhanced the immune response and oxidative stability by increasing IgA and IgG levels, GPx enzyme activity, and SOD, while decreasing plasma MDA content. Adding the CBT mixture enhanced gut health by reducing pathogens and inflammation, as well as increasing volatile fatty acid levels and the expression of CAT-1, MUC-2, and SGLT-1 genes. The combination of a thyme meal and B. subtilis enhanced growth, immune function, antioxidant capacity, gut microbiota modification, and the expression of gut health nutrient absorption-related genes in heat-stressed rabbits.

Inclusion body hepatitis (IBH) is an infectious viral disease caused by fowl aviadenoviruses (FAdVs) leading to a significant economic losses in broilers in Saudi Arabia and worldwide. In this study, the FAdVs causing IBH were identified using the polymerase chain reaction (PCR) with primers directing the hexon gene. For a detailed molecular characterization, the complete open reading frames (ORFs) of hexon and fiber 2 genes were amplified and sequenced. The generated sequences were aligned and analyzed with certain FAdV reference strains. Five FAdV-D were detected had an average percentage of identity of approximately 96.80%. The detailed molecular analysis of the hyper-variable regions (HVRs) in the hexon loop 1 region revealed several amino acid substitutions that might alter the antigenicity as shown by an antigenic index analysis. The comparison of the genomic sequences of the fiber genes confirmed a 17‒amino acid deletion in the shafts of three investigated strains isolated during 2017-18. Several amino acid substitutions were reported in the fiber gene knob and tail regions. Based on fiber gene sequence analysis, the average percentage of identity of the investigated strains and certain FAdV-D reference strains was 94.24%. The frequent isolation and identification of FAdV-Ds in IBH clinical cases with an average genetic diversity of 56.10% when compared with reference strains of FAdV-C emphasize that current preventive measures should be reviewed and that a new homologous vaccine may be needed. Keywords: IBH, Hexon gene, Fiber gene, Phylogenetic analysis, Fowl aviadenoviruses

Molecular and microbiological approaches were used to investigate the common circulating pathogens in pigeon flocks. Sixty-nine flocks were investigated for viral, bacterial and parasitic infection evidence, including the histories, clinical signs and lesions. We reported that the seroprevalences of Newcastle disease viruses (NDVs), Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) were 50.57%, 7.25% and 8.69%. respectively; no avian influenza virus (AIV)‒specific antibodies were detected. NDVs and pigeon paramyxoviruses (PPVs) were detected in 40.57% and 15.9%, respectively, of the pigeons. Multiple diseases were the predominant finding, with 60.87% of diseased flocks harboring multifactorial infections of viral, bacterial and parasitic pathogens. Concurrent viral and bacterial infections were reported in 15.94%, and viral and parasitic coinfections were found in 20.29%. Mixed infections of NDV with bacterial and parasitic diseases were detected in 21.74%. Bacterial and mycotic pathogens were detected in 22/69 (31.88%) and 5/69 (7.25%), respectively. Salmonella spp. were only detected in 3/69 (4.35%) of diseased flocks. Parasitic diseases were the most prevalent infections, either as a single infection or concurrently with others. Parasites including Cestoda spp., Ascaris spp., Eimeria spp., Trichomonas gallinae and external parasites(Menopon gallinae, Pseudolynchia canariensis) were reported in 12/69 (17.39%), 10/69 (10.49%), 10/69 (10.49%), 18/69 (26.1%) and 3/69 (4.35%), respectively. We concluded that pigeon flocks harbor many pathogens that may threaten the health of animals and humans; they are serious amplifiers and reservoir hosts of disease and, ultimately, may be serious biological hazards to the intensive poultry production sector and community. Pigeon vaccines should be developed. Strict biosecurity measures should be applied to protect pigeons and commercial poultry flocks. Key words: Pigeon, diseases, PCR, isolation and identification, Saudi Arabia

This study aimed to investigate the effects of supplementing with an essential oil blend and ascorbic acid on performance, semen characteristics, antioxidant status, gut microbiota, immunity, and gene expression in heat-stressed male rabbits. One hundred and forty male New Zealand White rabbits, aged 6 months, were randomly distributed into four dietary groups: the control group receiving basal feed (CON), the group receiving an essential oil blend (EOB, 200 mg/kg), the group receiving ascorbic acid (ASA, 1000 mg/kg), and the group receiving an essential oil blend and ascorbic acid (MAO). The experimental period lasted for eight weeks. The MAO mixture supported rabbits’ tolerance to heat stress by enhancing stress markers, as demonstrated by decreased glucose and HSP70 and increased triiodothyronine (T3). In addition, increased body weight, carcass weight, and nutrient digestibility, but reduced mortality rate, were observed in rabbits fed the MAO mixture. Additionally, semen density and volume, as well as sperm progressive motility and normality, were enhanced in rabbits fed the MAO mixture. Furthermore, MAO mixture supplementation decreases plasma cholesterol, triglycerides, AST, urea, and creatinine levels, while raising HDL and total protein levels. Adding MAO mixture contributed to an increase in plasma SOD and GPx levels, as well as seminal fluid TAC and GSH levels. Additionally, the incorporation of MAO increases IgA, IgG, and IL-10 levels while decreasing IL-6 and TNF-α levels. Adding the MAO mixture reduced C. perfringens and E. coli, as well as increased the expression of the MUC-2, CAT-1, and CLDN-1 genes. Combining an essential oil blend and ascorbic acid may contribute to improvements in performance, semen quality, immune response, antioxidant capacity, and gut health in heat-stressed male rabbits.