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Identification of infectious bursal disease virus with atypical VP2 amino acid profile in Latvia
2017
Introduction: Infectious bursal disease virus (IBDV) is a causative agent of immunosuppressive disorder resulting in significant losses to the world poultry industry. This study describes the molecular characterisation of an atypical IBDV from a field outbreak that occurred in vaccinated chicken flocks in Latvia in 2011.Material and Methods: Ten bursae of Fabricius from each flock were collected for laboratory examination. Virus isolation was performed in embryonated eggs and CEF culture. The RT-PCR aimed at hypervariable domain of VP2 gene combined with sequencing was performed for detection and identification of IBDV.Results: The molecular examinations confirmed the IBDV infection. The analysis of the amino acid sequence revealed that the strain possessed four amino acids at VP2 protein (222A, 256I, 294I, and 299S), indicating a genetic relatedness to a very virulent IBDV. However, some unique or rare amino acid substitutions (219L, 220F, 254D, 279N, and 280T) were also detected.Conclusion: The obtained results demonstrate the occurrence of IBDV with a high mutation rate within the hypervariable domain of VP2 peptide, and highlight the necessity of implementation of IBDV surveillance in Eastern European poultry industry to determine whether this strain is an exception or a new wave of IBDV with new genetic features emerged in the field.
Показать больше [+] Меньше [-]Pharmacokinetics and egg residues after oral administration of a single dose of meloxicam in domestic chickens (Gallus domesticus)
2017
Souza, Marcy J. | Bergman, Joan B. | White, Molly S. | Gordon, Kristen I. | Gerhardt, Lillian E. | Cox, Sherry K.
OBJECTIVE To determine the pharmacokinetics of meloxicam in domestic hens and duration and quantity of drug residues in their eggs following PO administration of a single dose (1 mg of meloxicam/kg). ANIMALS 8 healthy adult White Leghorn hens. PROCEDURES Hens were administered 1 mg of meloxicam/kg PO once. A blood sample was collected immediately before and at intervals up to 48 hours after drug administration. The hens' eggs were collected for 3 weeks after drug administration. Samples of the hens' plasma, egg whites (albumen), and egg yolks were analyzed by high-performance liquid chromatography. RESULTS The half-life, maximum concentration, and time to maximum concentration of meloxicam in plasma samples were 2.8 hours, 7.21 μg/mL, and 2 hours, respectively. Following meloxicam administration, the drug was not detected after 4 days in egg whites and after 8 days in egg yolks. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that meloxicam administered at a dose of 1 mg/kg PO in chickens appears to maintain plasma concentrations equivalent to those reported to be therapeutic for humans for 12 hours. The egg residue data may be used to aid establishment of appropriate drug withdrawal time recommendations.
Показать больше [+] Меньше [-]Evaluation of the effects of a 4.7-mg deslorelin acetate implant on egg laying in cockatiels (Nymphicus hollandicus)
2017
Summa, Noemie M. | Sanchez-Migallon Guzman, David | Wils-Plotz, Emma L. | Riedl, Nerisa E. | Kass, Philip H. | Hawkins, Michelle G.
OBJECTIVE To evaluate effects of administration of a 4.7-mg deslorelin acetate implant on egg laying in healthy cockatiels (Nymphicus hollandicus). ANIMALS 52 cockatiels. PROCEDURES 26 breeding pairs (a female and its respective male in each pair) were selected on the basis of their history of egg laying. Female birds were sedated and received a 4.7-mg deslorelin acetate implant (n = 13) or placebo implant (13) in the subcutaneous tissues between the scapulae. Male and female birds of each breeding pair were placed in separate but adjacent cages. Birds were exposed to 16 hours of light and 8 hours of darkness. A nest box was placed in cages of female birds to stimulate reproductive activity. Egg production and quality were monitored daily for 365 days. RESULTS Deslorelin acetate implants significantly suppressed egg laying in cockatiels, compared with effects for the placebo implants. Eleven of 13 placeboimplanted birds laid eggs between 12 and 42 days after implantation. None of the deslorelin-implanted birds laid eggs within 180 days after implantation, and only 5 of 13 deslorelin-implanted birds laid an egg during the study period (first egg laid between 192 and 230 days after implantation). No differences in egg quality or number of eggs per clutch were observed between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE Insertion of a 4.7-mg deslorelin acetate implant suppressed egg laying in healthy cockatiels for at least 180 days. Studies are necessary to evaluate effects of a deslorelin acetate implant in other avian species or in association with reproductive disorders.
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