scholarly journals Classical and Variant Avian Infectious Bronchitis Virus Strains

EDIS ◽  
1969 ◽  
Vol 2003 (16) ◽  
Author(s):  
Gary D. Butcher ◽  
David P. Shapiro ◽  
Richard D. Miles

Infectious bronchitis (IB) is an acute and highly contagious respiratory disease of chickens. The disease is characterized by respiratory signs including gasping, coughing, sneezing, tracheal râles, and nasal discharge. In young chickens, severe respiratory distress may occur. In layers, respiratory distress, decrease in egg production, and loss of internal egg quality and egg shell quality are reported. Some strains of the virus cause severe kidney damage and may be associated with high mortality. This document is VM127, one of a series of the Veterinary Medicine-Large Animal Clinical Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date May 1, 2002. VM127/PS039: Infectious Bronchitis Virus: Classical and Variant Strains (ufl.edu)  

2009 ◽  
Vol 49 (2) ◽  
pp. 162 ◽  
Author(s):  
K. K. Chousalkar ◽  
J. R. Roberts

The effects of two Australian strains of infectious bronchitis virus (IBV-T and N1/88) on the internal and external quality of eggs were studied in unvaccinated Isa Brown hens in full lay. Overall, there was no decline in egg production in either of the infected groups. However, there were some long-lasting negative effects on the egg internal quality of T-infected hens. Negative effects on internal quality in the N1/88-infected group were relatively short term. Yolk colour score was lower only in T-infected hens. Egg shell quality was affected only in terms of loss of egg shell colour. IBV infection resulted in paler egg shells in both the infected groups. Paler egg shells may not be regarded well by consumers. The egg shape index was lower in both infected groups.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 897
Author(s):  
Marianne Hammershøj ◽  
Gitte Hald Kristiansen ◽  
Sanna Steenfeldt

Egg laying genotypes have been selected for generations due to their high yield and egg quality, resulting in efficient feed utilization and low body weight; hence, they are not suitable for meat production. This imposes an issue for the male layer chicks, which are killed at one day old. Because of ethical and food waste concerns, the search for suitable dual-purpose genotypes in order to avoid euthanasia of male day-old chicks has intensified. The aim of the present study is to evaluate potential dual-purpose genotypes for their egg quality compared to a representative egg laying genotype. Three dual-purpose genotypes with divergent characteristics were evaluated: genotype A represented an experimental crossbreed based on a broiler type male and an egg layer female, genotype B was a pure breed, and genotype C was a crossbreed of a layer type. These were compared to a control genotype D, which was an egg layer. Eggs were collected six times during the period of 21–54 weeks of hen age, i.e., a total of 1080 shell eggs were analyzed. Examined parameters were weights of egg, shell, yolk, and albumen, by calculating their relative proportions. Shell quality was assessed by shell strength, shell stiffness, and shell thickness. Yolk quality was determined as yolk color and inclusions of blood and meat spots, and albumen quality was evaluated in terms of pH and dry matter (DM) content. The egg layer genotype produced the smallest eggs with least blood and meat spot inclusions compared to that produced by the three dual-purpose genotypes. Shell quality was superior for the layer genotype. However, the experimental genotype A laid eggs of comparable shell quality, albumen DM, and yolk weight, but also with the darkest and most red-yellow colored yolk. The two other dual-purpose genotypes produced eggs of low-medium quality. In conclusion, the genotype A could serve as dual-purpose genotype from an egg quality perspective.


2019 ◽  
Vol 39 (10) ◽  
pp. 830-836 ◽  
Author(s):  
Ana Paula G. Mortari ◽  
Bruna P. Amaral ◽  
Pablo S.B. De Oliveira ◽  
Evelyn K. Dotto ◽  
Mariana M. Flores ◽  
...  

ABSTRACT: Equid alphaherpesvirus 1 (EHV-1) is an important pathogen of horses, associated with respiratory, neurological disease and abortions. As vaccination is not always effective, anti-herpetic therapy may represent an alternative to prevent the losses caused by the infection. We herein investigated the activity of ganciclovir (GCV), an anti-herpetic human drug, in rabbits experimentally infected with EHV-1. Thirty-days-old New Zealand rabbits were allocated in three groups (6 animals each) and submitted to different treatments: G1 (non-infected controls), G2 (inoculated with EHV-1) - 107 TCID50 intranasally - IN) and G3 (inoculated IN with EHV-1 and treated with GCV - 5mg/kg/day for 7 days) and monitored thereafter. All animals of G2 developed systemic signs (moderate to severe apathy, anorexia), ocular discharge and respiratory signs (serous to mucopurulent nasal discharge), including mild to severe respiratory distress. Viremia was detected in all rabbits of G2 for up to 11 days (mean duration = 6.5 days). One animal died after severe respiratory distress and neurological signs (bruxism, opistotonus). In addition, these animals gained less weight than the control (G1) and GCV-treated rabbits (G3) from days 4 to 14pi (p<0.05). The clinical score of rabbits of G2 was statistically higher than the other groups from days 3 to 6pi (p<0.05), demonstrating a more severe disease. In contrast, G3 rabbits did not present systemic signs, presented only a mild and transient nasal secretion and gained more weight than G2 animals (p<0.05). In addition, viremia was detected in only 3 rabbits and was transient (average of 2.3 days). Thus, administration of GCV to rabbits inoculated IN with EHV-1 resulted in an important attenuation of the clinical disease as demonstrated by full prevention of systemic signs, maintenance of weight gain and by drastic reduction in viremia and in the magnitude of respiratory signs. These results are promising towards further testing of GCV as a potential drug for anti-herpetic therapy in horses.


2018 ◽  
Vol 98 (4) ◽  
pp. 619-630 ◽  
Author(s):  
D. Kumar ◽  
C. Raginski ◽  
K. Schwean-Lardner ◽  
H.L. Classen

Ideally balanced dietary protein is critical for laying hen egg production and feed efficiency, but also affects other important characteristics. This research was designed to study the nonegg production and feed intake response of Lohmann-LSL Lite hens to 550, 625, 700, 775, and 850 mg d−1 of amino acid balanced digestible lysine (Dlys) from 27 to 66 wk of age. Data collection included hen weight (HW), feather scoring, tissue weights, egg specific gravity, egg component weights, and excreta nitrogen (N) content. The experiment was a completely randomized design and level of significance was fixed at P ≤ 0.05. Hen weight (quadratic, Q), pectoralis muscle (absolute, % – Q), and abdominal fat (absolute – linear, L; % – Q) increased with increasing Dlys intake. Although gastrointestinal segment weights and lengths were affected by Dlys intake, interpretation of results was confounded by other aspects of diet composition. Hen feather score (L) and excreta N content (Q) increased, and egg shell quality (L) decreased with increasing Dlys intake. Absolute egg component weights increased with Dlys intake, but effects on proportional weights were Q and relatively minor. In conclusion, balanced Dlys intake affected a variety of practical nonproduction characteristics in laying hens.


2019 ◽  
Vol 59 (8) ◽  
pp. 1553 ◽  
Author(s):  
S. S. Diarra ◽  
I. Wamekeni ◽  
A. Vunagilee ◽  
H. Lavaka ◽  
T. Finau

The effects of peeling and limestone flour level on the utilisation of Alocasia macrorrhiza corm meal (ACM) by laying hens were investigated. Maize-based diets with two concentrations of limestone flour (40 and 60 g/kg) and diets containing 200 g peeled and unpeeled ACM meal/kg with the same levels of limestone flour were fed to five replicate pens containing 10 20-week-old Shaver brown pullets (1635 ± 148 g), each for 105 days. Results showed no interaction or main effects of ACM or limestone concentration on feed intake, egg weight, egg mass, feed conversion efficiency, egg shape index, surface area and Haugh unit (P &gt; 0.05). Feeding whole ACM with 40 g limestone/kg diet reduced hen-day production and shell thickness (P &lt; 0.05) but this was overcome by increasing limestone concentration to 60 g/kg diet. Peeled ACM with both concentrations of limestone flour maintained laying performance and egg quality. We concluded that feeding 200 g whole ACM depresses egg production and shell quality in laying hens, but increasing dietary limestone concentration overcomes this adverse effect. The concentration of limestone flour in the diet has no effect on laying performance. Higher inclusion levels of ACM, calcium source and level that will maintain laying performance and reduce feed cost need to be investigated.


Author(s):  
Rafaella Rossetto ◽  
Maurício Barreta ◽  
Marcos José Migliorini ◽  
Fabíula Pecher ◽  
Lenílson Fonseca Roza ◽  
...  

SUMMARY Birds show poor utilization of phytic phosphorus in their diets because of the lack of endogenous enzymes to digest phosphorus and make it bioavailable. Therefore, the objective of this study was to evaluate phytase supplementation in the diets of laying quails. Eighty quails were used in a completely randomized experimental design with five treatments and four replicates of four birds each. The treatments were as follows: 0.35% Pd; 0.20% Pd; 0.20% Pd + 500FTUs of phytase; 0.09% Pd; 0.09% Pd + 500 FTUs of phytase. The birds were housed in metallic batteries during a trial period of 21 days, for evaluation of egg production, egg weight, feed intake and feed conversion. After being collected, the eggs were sent to the nutrition laboratory of the department of zootechnics of the CEO/Udesc, where analyses of albumin, yolk and shell quality were performed. The results were subjected to analysis of variance, and the differences between the averages were compared using the Tukey test at 5% of significance. No differences (P> 0.05) were observed in terms of performance and egg quality parameters. We conclude that the inclusion of phytase in the diet of laying quails can be accomplished without compromising the performance and quality of the eggs. Additionally, 0.09% of 22 disponible phosphorus can be used to grant adequate performance for 21 days.


Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2991
Author(s):  
Isabelle Ruhnke ◽  
Yeasmin Akter ◽  
Terence Zimazile Sibanda ◽  
Aaron J. Cowieson ◽  
Stuart Wilkinson ◽  
...  

Laying hens require substantial quantities of calcium (Ca) to maintain egg production. However, maintaining recommended dietary Ca through inclusion of limestone may impede nutrient digestibility, including that of other minerals. It was hypothesized that providing a separate source of dietary Ca in the form of limestone grit would preserve Ca intake of hens offered diets containing suboptimal Ca concentrations. Furthermore, the impact of dietary phytase at a “superdosing” inclusion rate on the voluntary consumption of limestone grit was evaluated. One hundred and forty-four laying hens (19 weeks of age) were assigned to one of six dietary treatments in a 3 × 2 factorial arrangement comprising three dietary Ca concentrations (40, 30, and 20 g/kg) and ±dietary phytase (3500 FYT/kg diet) on an ad libitum basis for six weeks. Limestone grit (3.4 ± 1.0 mm) was provided to all hens ad libitum. Hens offered diets containing phytase consumed significantly less limestone grit p = 0.024). Egg weight, rate of lay, and egg mass were unaffected by dietary treatment (p > 0.05). Egg shell weight % (p < 0.001), shell thickness (p < 0.001), and shell breaking strength (p < 0.01) decreased in line with dietary Ca levels. In summary, dietary superdosing with phytase reduced the consumption of a separate limestone source in individually housed, early lay ISA Brown hens. Egg shell quality variables but not egg production worsened in line with lower dietary Ca levels.


Author(s):  
Sachin Subedi ◽  
Sulove Koirala ◽  
Lilong Chai

Coronaviruses are positive sense RNA virus belonging to the Coronaviridae family, which are further subdivided into four genera: Alpha, Beta, Gamma, and Delta Coronaviruses. Infectious bronchitis virus and SARS-CoV belong to Beta Coronaviridae family. Infectious bronchitis virus causes respiratory and nephritic signs that includes tracheal rales, urate crystals, lethargy and nasal discharge. In livestock and pets, the Coronavirus infection causes mostly gastrointestinal lesions, which may be prevented through vaccination and biosecurity. Recent infections of SARS-CoV-2 (also known as COVID-19) on farm and pet animals were summarized in this study. Besides, zoo animals were reported with infections in some countries/regions. Although the damage of COVID-19 has not been reported as serious as highly pathogenic avian influenza (HPAI) and African Swine Fever (ASF) on farm animals so far, the transmission mechanism of COVID-19 among group animals/farms and its long-term impacts are still not clear. The impact of Coronavirus on animals and potential prevention strategies, such as vaccine development and farm biosecurity measures, were discussed. Prior to the development of the effective vaccine, the biosecurity measures (e.g., conventional disinfection strategies and innovated technologies) may play roles in preventing potential spread of diseases/viruses.


1959 ◽  
Vol 39 (2) ◽  
pp. 176-181 ◽  
Author(s):  
T. M. MacIntyre ◽  
J. R. Aitken

Diets varying in protein content from 10.9 to 16.7 per cent were fed over a 336-day laying period to hens in both floor pens and individual laying cages. All rations were approximately iso-caloric, the mean productive energy value being 825 Calories per pound. Each ration was fed to 200–240 hens in four floor pens and to 90–96 hens in individual cages.A crude protein level of 13 per cent of the diet proved adequate for egg production, but egg weights and body weights were improved when the dietary protein was increased. Egg shell quality was highest on low protein diets. Interior egg quality was not affected by the protein level in the diet.On comparable diets, birds in individual laying cages laid fewer eggs and consumed less feed than birds in floor pens. Caged birds were heavier in body weight and laid heavier eggs with thicker shells than their counterparts in floor pens. The criteria employed in the measurement of interior egg quality showed no differences between the cage and pen environments, nor did there appear to be any differences in protein requirements between the two environments.


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