Intra-vascular administration of particles to induce pulmonary hypertension, pulmonary hypertension syndrome, and ascites in poultry

A method of producing improved genetic breeding stocks in chickens, the method comprising:

• a) inducing pulmonary hypertension in chickens by occluding the pulmonary vasculature with particulate substances of a size about 8 to about 250 micrometers in diameter injected into veneous blood that carries the particles to the right cardiac ventricle pumping the blood containing the particles to the lungs, wherein the particles directly increase pulmonary vascular resistance by lodging in small blood vessels, the heart being forced to develop and maintain an elevated pressure in the pulmonary arteries to propel the reguisite cardiac output through vessels remaining unoccluded, chickens that are susceptible to pulmonary hypertension subsequently developing pulmonary hypertension syndrome, and
• b) separating susceptible chickens from the resistant chickens, the resistant chickens being useful as genetic breeding stock resistant to pulmonary hypertension.