Journal of World's Poultry Research

556-564

Authors: Moustafa S. Abou El-Fetouh

In this study infectious bursal disease (IBD) vaccinations were evaluated against very virulent IBD (vvIBDV) challenge and were compared. A total of 120-day-old white Leghorn SPF chickens were divided into 6 groups (each was 20 birds). Two groups were vaccinated on either day 1 with an immune-complex vaccine. The second groups were vaccinated at days 9 and 14 of age using intermediate and intermediate plus IBD vaccines, respectively the balance groups are controls. All vaccines were administered according to the manufacturer's instructions. The challenge was conducted on the 16 days of age using 105 EID50 /0.1 ml of a vvIBDV strain via the oculonasal route. The antibody immune response was monitored in all groups at 14, 21, 28, and 35 days of age. The performance, bursal gross lesions, challenge virus detection, and bursal histopathology were evaluated in vaccinated non challenged and vaccinated challenged birds at days 21 and 28 of age. All vaccinated groups were protected against the vvIBDV challenge compared to 40% mortality in the challenge control group. Both the immune-complex and live attenuated IBD vaccine groups showed similar bursa body weight (BB) ratios compared to the negative control group. The immune-complex vaccinated groups antibody titers were significantly higher except on 28th day of age. Upon challenge, the intermediate/intermediate plus vaccinated challenged group showed higher antibody titers at 21 and 35th with the challenge virus detection and quantification on day 28. The immune-complex vaccinated challenged group developed milder bursal histopathology signs but no differences between the 2 vaccine programs were seen. It can be understandable, the use of either immune-complex vaccine at day-old or early vaccination with intermediate followed by intermediate plus live attenuated IBD vaccines induced protective antibody titers and protect chickens against an early vvIBDV challenge. The suggested schedules need further evaluation in commercial broilers with maternal derived IBD antibodies to simulate field conditions.

571-579

Authors: Wafaa A. Abd El-Ghany

Due to the hazardous use of antimicrobials in poultry production sector, development of drug resistance have become a worldwide problem. Therefore, using biotic or natural products, such as phytobiotics (phytogenics or botanicals) have received a great attention as antibiotic substitutes. The use of phytobiotics or their constituents have been considered as a relatively new class of natural herbs that gained popularity and acceptability among poultry farmers. The incorporation of several types of phytobiotic additives in poultry feed have proved their ability to enhance the productive performance of broilers as well as layers. Moreover, phytbiotics presented great efficacy in counteracting intestinal pathogenic microorganism while maintaining the population of normal inhabitant beneficial microflora. Immunostimulatory effect on both humoral and cellular immunity as well as antioxidant properties were recorded as characters of phytobiotics. Therefore, this review article aimed to give a spotlight on the uses of different types of phytobiotics as poultry dietary additives to improve the productive parameters, reduce the pathogenic intestinal bacteria, and potentiate the immune response, especially after vaccination processes.

587-598

Authors: Nevien M. Sabry

In avian, the prolactin hormone triggers and regulates ovarian follicle development. This study aims to detect the Prolactin (PRL) gene polymorphisms (exons 1and5) in four Egyptian duck breeds, namely Campbell, Moulard, Muscovy, and Pekin using PCR-RFLP technique and sequence analysis. It also investigated the association of this gene with egg production, egg weight, and body weight. The present results revealed that PRL gene exon 1 and part of intron 1 showed two alleles A and B (polymorphic) in each of Campbell and Moulard, however, Muscovy and Pekin had only one allele (monomorphic). The allele A was more dominant with frequencies of 0.70, 0.60, and 1.00, compared to the allele B (0.30, 0.40, and 0.00) for Campbell, Moulard, and Muscovy, respectively. For Pekin, the allele B only appeared with the frequency of 1.0. Ducks with the high frequency of allele A were superior at egg weight, compared to others. Furthermore, for PRL gene exon 5, there were two alleles G and C (polymorphic) in Campbell, Moulard, and Muscovy, however, Pekin had only one allele (monomorphic). The allele G was more dominant (0.15, 0.74, 0.0, and 0.84) than the allele C (0.85, 0.26, 1.0, and 0.15) for Campbell, Moulard, Pekin, and Muscovy, respectively. Ducks having a high frequency of allele C were superior at egg production. Furthermore, there were many single nucleotide polymorphisms (SNPs) in the sequences in all breeds. The utmost ones exist at the restriction sites of XbaI enzyme for the amplified fragment, in the promotor, exon 1 and intron 1 (T378C in intron 1), and DraI enzyme for that in exon 5 (A5871G in exon 5).

615-622

Authors: Zakia Sheila Faradilla

Coccidiosis is the main problem in poultry diseases. It is caused by the parasite Eimeria tenella, which induce the immune response of leukocyte. Anticoccidial drugs are administered in the poultry feed to control coccidiosis. However, taking medication for a long time can lead to resistance. Recent studies have indicated that Virgin Coconut Oil (VCO) has some benefits, including anti-inflammatory effects. The present research aimed to identify the effect of VCO at the different doses in improving the various leukocyte counts of chickens infected with E. tenella. Male chickens were divided into five groups (T0, T1, T2, T3, and T4) and treated for 28 days. T0 was neither infected with E. tenella nor get treatment, T1 was only infected with E. tenella, T2 was treated with 5 ml/kg VCO feed and had E. tenella infection, T3 was treated with 10 ml/kg VCO feed and had E. tenella infection, and T4 was treated 20ml/kg VCO feed and had E. tenella infection. Differential leukocyte was counted with a blood cell counter. The data obtained were analyzed using ANOVA and Duncan’s Multiple Range Test. The results indicated that a dose of 10 ml/kg feed and 20ml/kg feed of VCO could improve the differential leukocyte counts of chickens infected with E. tenella by maintaining the counts of basophil, eosinophil, heterophil, monocyte, and lymphocyte in the normal range. The present study concluded that VCO by a dose of more than 10 ml/kg would improve the differential leukocyte counts of chickens infected with E. tenella.

631-642

Authors: Sherif Mohamed Shawky

The present study was designed to evaluate the impacts of daily dietssupplemented with Amphora coffeaeformis and Star anise on growth performance and immunity of Cobb broiler chickens. Amphora coffeaeformis is considered a potent free radical scavenger due to the presence of β-carotene and fucoxanthin, which are used widely as food additives. Star Anise has a natural antioxidant, which can also be used for the chemo-prevention of disease occurring due to oxidative deterioration. A total of 270 broiler chickens were divided into three groups, each with three replicates of 30 birds. The control group (G1) was given the basal diet, the Amphora group (G2) received Amphora in a dose of 1g/Kg in the ration, and the Star anise group (G3) received Star anise in a dose of 2g/Kg in the ration. The results indicated that Amphora and Star anise significantly improved the final body weight, weight gain, and feed conversion ratio, total white blood cells count, phagocytic activity percentage, phagocytosis index in plasma, IgM, IgG, and A/G ratio in serum. In addition, Amphora and Star anise significantly increased mRNA expression of hepatic growth hormone gene, insulin-like growth factor-1 (IGF-1) genes (IGF1), and mRNA expression of splenic interferon-gamma (INF-γ) and Interleukin 12 (IL-12p35) genes from broiler chickens, compared to the control group. In conclusion, the use of fed additives, such as Amphora coffeaeformisand Star anise in the diet of broiler chickens for 35 days was sufficient to improve broiler growth performance and could modulate their immunity.

649-661

Authors: Nahed Yehia

Infectious Bronchitis Virus (IBV) is a severe infectious disease affecting chickens and causing serious economic loss. Although several studies have been conducted to characterize HVRs-S1 (Hyper-Variable Regions of Spike 1 gene) in Egypt, few of which aimed to characterize the major structural protein genes. In the present study, the genetic characterization of the major structural protein genes was carried out in 10 isolates selected from six governorates in 2019. Phylogenetically, the S1 gene was clustered into genotype GI-23 (variant II), with seven viruses that were clustered into Egy/Var II occurring in two subgroups (I, II) when aligned with previously isolated Egyptian strains. It had a specific character of 40 Amino Acids (AA) mutations except for IBV/EG/CV32/2019, which had 50 AA mutations, specifically in HVRs regions (HVRI, II, and III). The other three strains were clustered into Egy Var I with 17 AA mutations except IBV/EG/F859/ 2019, which had 15 AA mutations, compared to IBV/CU/4/2014 reference strain. The examined isolates had an additional glycosylation site at position 280 and one was missing at position 139 with the exception of two strains that only had an additional one, compared to IBV/CU/4/2014. The viruses in this study differed genetically from various vaccine seeds in the range of 69-83%. The Nucleocapsid, genetically characterized in the group of variant II (Egy/Var II) and the glycoprotein membrane genes genetically characterized in the variant group in a new sub-group with 11 and 9 AA mutations, respectively. The recombination event was only detected in the S1 gene in two isolates of IBV/EG/CV32/2019 and IBV/EG/F859/2019 from D274 and QX, respectively. In this regard, it is important to conduct continuous surveillance, pathogenicity study, and vaccine efficacy evaluation.