Composite Cellular Defense Stratagem in the Respiratory System of Kuttanad Ducks (Anas platyrhynchos domesticus) - Quantification of Free Respiratory Macrophages (FRM's) in Post-hatch Period

Macrophages are extremely diffused cells, morphologically present in different forms and numbers in the tissue of body defending animals from pathogenic microorganisms and injurious particulate matter. Present study was aimed to quantify free surface respiratory macrophages (FRM's) in Kuttanad ducks (Anas platyrhynchos domesticus). Seventy eight female Kuttanad ducks were procured and reared upto 24 weeks of age. Samples were collected randomly from six birds at fortnightly intervals by respiratory lavage using sterile pre-warmed (40°C) phosphate buffered saline (PBS). Cells were harvested following centrifugation, and stained with trypan blue. The macrophages obtained in the lavage were roughly circular with eccentric nucleus. The quantification of spherical nuclei of surface macrophages indicated an increase in their number with age and were highest in 24^th weeks-old ducks.