Ayurveda texts and modern research back the following facts:

Winter Cherry (Ashvagandha) is a libido enhancer that is known to increase sperm count.

Elephant Creeper (Vriddhadaru) is a potent tonic that has been used for centuries in Ayurveda to cure male sexual disorders like impotence.

Dosage:

Administer a dosage of 0.5g to each bird for 10 days. The dosage needs be repeated every month.