Application of Minimally Invasive Oral Swab Samples for qPCR-Based Sexing in Neognathae Birds.

Birds are inherently social creatures that rely on pairing to enhance their well-being. Since many bird species lack obvious physical differences between females and males, sex identification is essential for ensuring their welfare. Additionally, early determination of the sexes of birds is crucial for their breeders, especially considering that most companion birds do not display clear sexual characteristics. Molecular genetic sexing has been demonstrated to be the most reliable method for determining the sexes of monomorphic birds. The objective of the present study was to demonstrate rapid, effective, and precise identification of sex in birds through quantitative real-time PCR (qPCR) using samples obtained via a minimally invasive technique (oral swabs). This qPCR method assesses variations in gene copy numbers within conserved Z-specific genes such as , , , , and , which are absent from the W chromosome. A total of 34 samples were included in this study from the following 17 bird species: domestic pigeon (), domestic chicken (), domestic goose (), domestic duck (), Mute swan (), Budgerigar (), Lovebird (), Cockatiel (), Red-rumped parrot (), Rose-ringed parakeet (), African grey parrot (), domestic Canary (), Goldfinch (), Gouldian Finch (), Red Siskin (), Australian Zebra Finch (), and Common buzzard (). The results proved the , , , , and genes can reveal the sexes in the birds tested.