Cattoli G.,viale dellUniversita 10 |
Fusaro A.,viale dellUniversita 10 |
Monne I.,viale dellUniversita 10 |
Coven F.,Bornova Veterinary Control and Research Institute |
And 9 more authors.
Vaccine | Year: 2011
Highly pathogenic avian influenza (HPAI) H5N1 (clade 2.2) was introduced into Egypt in early 2006. Despite the control measures taken, including mass vaccination of poultry, the virus rapidly spread among commercial and backyard flocks. Since the initial outbreaks, the virus in Egypt has evolved into a third order clade (clade 2.2.1) and diverged into antigenically and genetically distinct subclades. To better understand the dynamics of HPAI H5N1 evolution in countries that differ in vaccination policy, we undertook an in-depth analysis of those virus strains circulating in Egypt between 2006 and 2010, and compared countries where vaccination was adopted (Egypt and Indonesia) to those where it was not (Nigeria, Turkey and Thailand). This study incorporated 751 sequences (Egypt n=309, Indonesia n=149, Nigeria n=106, Turkey n=87, Thailand n=100) of the complete haemagglutinin (HA) open reading frame, the major antigenic determinant of influenza A virus. Our analysis revealed that two main Egyptian subclades (termed A and B) have co-circulated in domestic poultry since late 2007 and exhibit different profiles of positively selected codons and rates of nucleotide substitution. The mean evolutionary rate of subclade A H5N1 viruses was 4.07×10 -3 nucleotide substitutions per site, per year (HPD 95%, 3.23-4.91), whereas subclade B possessed a markedly higher substitution rate (8.87×10 -3; 95% HPD 7.0-10.72×10 -3) and a stronger signature of positive selection. Although the direct association between H5N1 vaccination and virus evolution is difficult to establish, we found evidence for a difference in the evolutionary dynamics of H5N1 viruses among countries where vaccination was or was not adopted. In particular, both evolutionary rates and the number of positively selected sites were higher in virus populations circulating in countries applying avian influenza vaccination for H5N1, compared to viruses circulating in countries which had never used vaccination. We therefore urge a greater consideration of the potential consequences of inadequate vaccination on viral evolution. © 2011 Elsevier Ltd. Source
Ergun S.,Canakkale Onsekiz Mart University |
Turk N.,Bornova Veterinary Control and Research Institute
Israeli Journal of Aquaculture - Bamidgeh | Year: 2012
The effects of dietary cumin (Cuminum cyminum) as a feed additive on growth performance and disease resistance of tilapia (Oreochromis mossambicus) were studied. Five isonitrogenous (37% crude protein) and isocaloric (18.6 kj/g) diets were formulated to contain 0% (control), 0.5%, 1.0%, 1.5%, or 2.0% cumin. Fifteen aquaria (80 l) were stocked with 15 fish (0.56±0.02 g), each, and fish were fed one of the five diets for 75 days. The cumin supplementation did not affect the feed conversion rate (FCR) or specific growth rate (SGR). Cumulative mortality was 60% in fish fed the 0% control diet and challenged with Streptococcus iniae. However, in fish fed the 1.0%, 1.5%, or 2.0% supplemented diets, mortality was only 10.42%, 31.25%, and 37.50%, respectively. In conclusion, a dietary cumin level of 1% provides the best survival rate for tilapia, O. mossambicus, without adversely affecting growth performance or feed utilization. © Israeli Journal of Aquaculture - Bamigdeh. Source
Boynukara B.,Yuzuncu Yil University |
Gulhan T.,Yuzuncu Yil University |
Adizel O.,Yuzuncu Yil University |
Ilhan Z.,Yuzuncu Yil University |
And 6 more authors.
Journal of Animal and Veterinary Advances | Year: 2011
In this study, feces samples collected during 37 months from February 2006 to March 2009 from 2013 animals consisting of 47 avian species covering irregular vagrant, transit migrant, winter visitor, migratory and native birds in the Van Lake Basin Turkey were tested by Real-Time PCR (RT-PCR) with respect to Avian Influenza (AI) type A virus M2 gene. Of them, 59 samples (2.9%) were found to be positive. RT-PCR positive samples were examined with the same method with respect to H5N1 and 4 samples (6.8%) were found to be positive. RT-PCR positive 59 samples were inoculated in Embryonated Chicken Egg (ECE) and AI type A virus was isolated from 12 samples (20.3%). Of the isolates, 3 were typed as H1N7, 2 as H7N9, 2 as H11N9 and 1 as H8N4 with Hemagglutination Inhibition (HI) and Neuraminidase Inhibition (NI) tests. About 4 isolates obtained from winter visitor Anas cylpeata which had been determined as H5N1 by RT-PCR and agarose gel electrophoresis, gave positive reaction by HI test both with HI and H5 antisera and all were typed as Nl by Nl-test. Feces samples found to be positive by RT-PCR belonged to avian species Anseriformes, Charadriiformes, Pas seriformes, Gruiformes and Phoenicopteriformes orders. The highest positivity was determined in winter visitor Anas acuta (37.1%) and Anas penelope (22.5%) ducks. Of the RT-PCR positive 59 samples, 43 (72.9%) were determined in the samples collected during winter and spring of 2006-2009. Positivity was determined at a rate of 35.2% in respect of AI type A by RT-PCR in different species sharing the same time and place. With this study, the presence of AI type A viruses in various wild birds in the Van Lake Basin was determined for the first time in Turkey. © Medwell Journals, 2011. Source
Kucukyilmaz K.,Erbeyli Poultry Research Institute |
Bozkurt M.,Erbeyli Poultry Research Institute |
Herken E.N.,Pamukkale University |
Cinar M.,Erbeyli Poultry Research Institute |
And 3 more authors.
Asian-Australasian Journal of Animal Sciences | Year: 2012
White (Lohmann LSL) and Brown (ATAK-S) laying hens, were reared under organic and conventional cage rearing systems, and the effects of the rearing system on performance parameters, egg production, egg characteristics, and immune response were investigated. For this purpose, a total of 832 laying hens of two commercial hybrids, i.e., 416 white (Lohmann LSL) and 416 Brown (ATAK-S) layers, were used. The experiment lasted between 23 and 70 wk of age. In this study, the white layers yielded more eggs as compared to the brown layers in both organic and conventional production systems. Egg weight exhibited a similar pattern to that of laying performance. However, the total hen-housed egg number for the white birds in the organic system was fewer than that of white birds in the conventional cage facility; conversely, a contradictory tendency was observed for the brown birds. Livability of the white layers in the organic system was remarkably lower (14%) than that of the brown line, whereas the white line survived better (3.42%) than their brown counterparts in conventional cages. The feed conversion ratio of the white hens was markedly inferior in the organic system as compared to that of the white hens in the conventional system, whereas relatively lower deterioration was reported in brown layers when reared in an organic system. The organic production system increased egg albumen height and the Haugh unit in eggs of the brown layers. The yolk color score of organic eggs was lower than that of conventional eggs for both brown and white hens. The egg yolk ratio of eggs from white layers was found to be higher in organic eggs as compared to those obtained in the conventional system. All organic eggs had heavier shells than those produced in the conventional system. Eggs from brown layers had more protein content than eggs from white layers. Neither housing systems nor genotype influenced egg yolk cholesterol concentration. When compared to conventional eggs, n-3 fatty acid content was lower in organic eggs, and the n-6:n-3 ratio was higher in organic eggs. In conclusion, two hen genotypes showed different responses in terms of performance and egg quality to two different rearing systems. A commercial white strain produced more eggs with higher egg quality as compared to a native brown strain. The brown strain was found to have adapted well to organic production conditions when survival and total egg number was taken into consideration. Source
Bozkurt M.,Poultry Research Institute |
Kucukyilmaz K.,Poultry Research Institute |
Catli A.U.,Poultry Research Institute |
Cinar M.,Poultry Research Institute |
And 2 more authors.
Poultry Science | Year: 2012
In total, 432 thirty-six-week-old laying hens were fed a basal diet supplemented with man-nan-oligosaccharide (MOS) or an essential oil mixture (EOM) from 36 to 51 wk of age. Hens were divided into 3 equal groups replicated 6 times with 24 hens per replicate. No significant difference was observed among the dietary treatments in terms of performance indices. Different from the dietary manipulation, high environmental temperatures negatively influenced all of the laying performance traits except the feed conversion ratio in association with the diminished feed consumption. The MOS, and particularly the EOM, tended to alleviate the deleterious effect of heat stress on BW gain. Mortality was higher in MOS-fed hens than with other treatments. A supplementation diet with MOS or EOM provided increments in eggshell weight (P < 0.01). Relative albumen weight was significantly decreased (P < 0.05) in response to EOM or MOS supplementation; however, this was not the case in the yolk weight rate. The MOS decreased albumen height and Haugh unit (P < 0.05). High environmental temperatures hampered entire egg quality characteristics except for the eggshell breaking strength and egg yolk weight. These results indicated that heat stress adversely affected both productive performance and egg quality. As for the results of this study, neither MOS nor EOM was efficacious in improving efficiency of egg production and stimulating humoral immune response in laying hens reared under moderate and hot climatic conditions. However, the ameliorative effect exerted by MOS and EOM on eggshell characteristics is conclusive. © 2012 Poultry Science Association Inc. Source