ABSTRACT
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.
ABSTRACT
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.
