Isolation and molecular characterization of infectious bursal disease virus circulating in western and central India.

Background: Infectious bursal disease (IBD) caused substantial economic loss in central and western India during 2020 and 2021. Aims: The study was conducted to characterize IBD virus (IBDV) from field outbreaks. Methods: The study was conducted on 360 samples from 42 poultry flocks. The samples were subjected to histopathology and molecular detection, followed by phylogenetic typing of the partial VP2 gene. Results: The mortality ranged from 15.25 to 60.18%. The necropsy showed hemorrhages on thigh muscles, mottled spleen, swelling of kidneys and bursae with hemorrhages, and cheesy exudate. Histopathology revealed extensive necrosis and depletion of follicular lymphoid cells within the cortex and medulla, along with widespread hemorrhages, edema, and cystic cavities in the bursa. The field isolates showed cytopathic effects in the seventh passage. The cytopathic effects included swelling, rounding, granulation of cytoplasm around the nucleus, fragmentation of the infected cells, and detachment. The reverse transcription-polymerase chain reaction amplified 664 bp partial VP2 gene. The phylogenetic analysis identified 19 field isolates as very virulent IBDVs (vvIBDVs) and three as classical strains. Conclusion: The results indicated that different vvIBDV strains are involved in disease outbreaks in central and western India.

Performance of broiler chicken on dietary supplementation of protected organic acids blend.

1. The fatty acid coated organic acids blend was evaluated for its potential as a growth promoter.2. A six-week experiment was conducted following a completely randomised design. One-day old broiler chicks (n = 384) were randomly divided into four dietary groups (eight replicates per group). Diet treatments were an unsupplemented basal diet or containing 0.3, 0.6 and 1 g/kg of a coated organic acid blend. Birds were evaluated for growth performance, carcass traits, immune-competence, total viable count and gut villus height.3. The broiler chickens fed with 1 g/kg organic acids blend showed significantly higher body weight gain with improved feed conversion ratio and lower mortality than those fed the basal diet.4. The carcass traits vis. eviscerated yield, dressing percentage, breast yield and relative weight of giblets, were significantly better in the group fed with 1 g/kg coated organic acids blend with reduction in abdominal fat.5. Significantly higher cell-mediated, humoral immune responses and villi height with higher lymphoid organ weight (bursa and thymus) and a significant decrease in the total viable count were recorded in birds fed 1 g/kg organic acids blend.6. The results indicated that dietary inclusion of coated organic acids blend (1 g/kg) improved growth performance, carcass traits, immunity, and gut health in broiler chicken and reduced total viable count and abdominal fat, indicating its potential role as a promising growth promoter in poultry.

Brucellosis in migratory sheep flock from Maharashtra, India.

Brucellosis is a zoonotic disease worldwide distributed and having the economic as well as public health importance. The prevalence of brucellosis among sheep flock having history of abortions was studied. A total of 229 samples comprising of 157 blood and 72 clinical samples (vaginal swabs) were collected from 157 animals. Clinical samples were processed for the isolation of Brucella melitensis. Serum samples (n = 157) were tested by Rose Bengal plate test (RBPT) and i-ELISA. A total of 68 (43.31%) and 104 (66.24%) samples were positive by RBPT and ELISA, respectively. Brucella isolates (n = 2) were recovered from clinical samples. Both isolates demonstrated amplification for bcsp 31 and IS711 genes. On AMOS PCR, both the isolates amplified at 731 bp, i.e., belongs to B. melitensis species. The incidence of B. melitensis in a migratory flock warns the thorough testing and culling of Brucella-infected sheep from the flock on a continuous basis; otherwise, such incidence will be routine and poor farmers will be at a loss.

Comparative investigations of infectious runting and stunting syndrome in vaccinated breeder chicks by inactivated reovirus and chicks from non-vaccinated breeders.

Reoviruses are important pathogens responsible for poor growth performance and silent losses in the poultry industry. They are associated with many disease and syndromes such as malabsorption (runting and stunting syndrome), respiratory diseases and immunosuppression. Broiler birds are most susceptible to viral infections during the early post hatching period. Therefore, the transfer of maternal immunity to embryonated eggs is proved to be a primary means of protection from viral infections. In the present investigation, growth performance and pathology in breeder vaccinated and non-vaccinated chicks were studied after a challenge with the homologous malabsorption strain of the reovirus. Improvements in growth performance (mean live body weight, feed conversion ratio, broiler performance efficiency index, and protein efficiency index) in breeder vaccinated chicks were compared with non-vaccinated breeder chicks. The non vaccinated chicks showed various signs and lesions indicative of the reoviral malabsorption syndrome (MAS), whereas the vaccinated chicks showed very minimal alterations, demonstrating that the vaccination of breeders with homologous strains of the reovirus is profitable, and can help to increase the performance of broiler birds.