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Neonatal calf diarrhea (NCD) is a major cause of morbidity, mortality and economic losses in the beef and dairy industries. This study was conducted to investigate the existence of enteric viruses in two Egyptian farms with a history of recurrent diarrhea. Fecal samples were collected from 25 diarrheic calves. RNA was extracted and tested by reverse transcription polymerase chain reaction (RT-PCR) for the presence of rotavirus, norovirus, astrovirus, torovirus, coronavirus and bovine viral diarrhea virus. Overall, 76 % (19/25) of samples tested positive for one or more viruses. Rota-, noro- and astroviruses were detected in 48 %, 24 % and 32 % of tested samples, respectively. About 37 % (7/19) of positive samples had two different viruses. One-month-old calves were the group most vulnerable to infections. Based on phylogenetic analysis, bovine rotaviruses were of genotypes G6 and G10, bovine noroviruses were in GIII.2, and bovine astroviruses were in the BAstV lineage 1. Astrovirus sequences showed a high level nucleotide sequence similarity with the Brazilian BAstV sequences available in GenBank. We believe this is the first report of bovine norovirus and bovine astrovirus circulating among calves in Egypt. Further epidemiological studies are recommended to investigate their presence on a wider scale, to predict their association with NCD, and to design appropriate diagnostic and control methods.

In spite of the intensive vaccination policy against the Marek's disease virus (MDV) in Egypt, the Egyptian poultry flocks are still suffering from several tumor and paralysis cases. To investigate if MDV is the possible cause, feather follicle and tumor samples were collected during 2011 from 30 vaccinated chicken flocks experiencing nervous signs, emaciation, and tumor lesions. The samples were screened by PCR amplification of the meq full-length gene. Only five of 30 flocks were positive for MDV. Additionally, we sequenced meq from five samples and gL and gC from three samples. A phylogenetic tree was constructed using the deduced amino acid sequences of the meq gene. The sequence analysis revealed that most of the studied sequences showed > or = 98% identity to the very virulent European ATE and C12/130 isolates and the very virulent Chinese LMS, YA, WS03, and GX070060 MDV isolates. The two glycoproteins, gL and gC, displayed high similarity to the classical MDV strains published in the database regardless of their virulence.

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Zinc nanoparticles showed a great potential as mineral feed supplements in animals than the conventional sources. However, this potential has not been applied in rabbit nutrition. Therefore, this study was designed to evaluate the effects of dietary nano-zinc oxide on the growth performance, serum biochemical, economic parameters and gene expression of interleukin-6 in growing rabbits. A total of 120 male, five-week-old New Zealand White (NZW) rabbits were randomly distributed into four equal groups. The control group (Z 0) was fed on a basal diet with zinc free premix; the other three experimental groups received the basal diet supplemented with 60 mg zinc oxide/kg diet (Z 1), 60 mg nano-zinc oxide/kg diet (Z 2) and 30 mg nano-zinc oxide/kg diet (Z 3), respectively. The results revealed that rabbits in the groups Z 2 and Z 3 had higher body weight, daily weight gain, daily feed intake, serum total protein, globulin, IgG and SOD when compared with those of groups Z 0 and Z 1 (P<0.001). In addition, growth hormone level was higher in Z 3 group than in the other groups, whereas no significant differences were recorded among the treated groups in respect to serum TSH concentration (P>0.05). Hepatic and serum zinc contents were high in Z 2 and Z 3 groups, but the copper contents were decreased. Rabbits of group Z 3 yielded the highest gross margin with the lowest expenses to produce 1 kg of live weight compared with the others. The production of IL6 in spleen was increased in Z 3 group than that in the other groups. Thus, it can be concluded that nano-zinc oxide at a concentration of 30 mg/kg diet may be used instead of the traditional zinc sources in rabbit diets.

| Supplementation of the herbal oils in poultry nutrition is considered an alternative and complementary approach to the conventional control viral strategies in poultry industry. Their use is associated with remarkable improvement in both bird performance and immunity. In the current study, one hundred twenty broiler chickens were allocated into four equal groups. Three groups (group B, C and D) were vaccinated with inactivated avian influenza and live LaSota vaccine and one group (group A) was left as a control non vaccinated group. Two groups, C and D, were orally treated with 0.005 and 0.01% Oregano essential oil (OEO) respectively. Oral supplementation with a higher dose exerts improvement in the bird performance parameters in the early period of bird life and up to 21 days of age. Positive regulation of both NDV and AIV-HI specific antibody titers was existed when the birds were supplemented with the oil together with both NDV and AI vaccination, especially in case of the higher dose. Study of the effect of the OEO on chicken interferon-alpha signalling pathway components post NDV vaccination using quantitative real-time PCR (qRT-PCR) revealed no obvious positive immunomodulatory effect on Myxovirus resistance 1 (Mx1) transcripts level except at 29 days of age. On the other hand, a dose dependent up-regulation in both IFN regulatory factor 7 (IRF-7) and interferon-alpha RNA levels was observed. Both doses of OEO could protect the birds from nervous manifestation resulting from challenge with vvNDV. In conclusion, oral supplementation with OEO has beneficial effects on bird performance as well as humoral and innate immune responses.

Kobuviruses are small non-enveloped RNA viruses that probably cause diarrhea in cattle and swine. Since its discovery in 2003, few studies have addressed bovine kobuvirus (BKoV; a species of Aichivirus B) infections. BKoV has been reported in Europe, Asia, and South America, suggesting a worldwide distribution. To investigate the presence of BKoV in Egypt, 36 fecal specimens from diarrheic calves in two different Egyptian provinces (Cairo and Sharkia) were screened by RT-PCR and 24 (66.7%) were found positive for BKoV. RNA from one of the positive samples (BKoV/Egy-1/KY407744) was subjected to next-generation sequencing to determine the complete BKoV genome sequence. When compared to the only recorded BKoV genome sequence (BKoV/U-1/AB084788), the studied strain showed 94 amino acid (aa) substitutions through its entire polyprotein (2463 aa), one nucleotide (nt) insertion and one nt deletion in the 2B gene and 4-nt deletions in the UTRs (2 each). Additionally, five VP1 and seven 3D sequences were obtained from other samples by using RT-PCR and Sanger sequencing. A discrepancy in the phylogenetic topography of VP1 and 3D was observed, where the Egyptian VP1 sequences were classified as a distinct cluster within the proposed lineage 1 (genotype A), which also contained strains from the UK, Brazil, and Japan. While, the 3D sequences from Cairo were related to those of Chinese strains unlike Sharkia ones that were more closer to Korean  strains. To the best of our knowledge, this is the first detection and genomic characterization of BKoV in Egypt or indeed Africa.

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