They comsume about taka 1 worth of feed everyday. 3oo duck=300 taka every day. They will start laying eggs when they are 5 month old. Meaning 30*5=150 days. 150*300=45000 taka in total. They will survive aother 150 days while laying eggs. Therefore another 45000 taka for their feed. Total 90000 taka for the feed. Now they will layin one egg per day. So 300 eggs per day. 300*150=45000 eggs. 45000*3=135000 taka. 135000-90000=45000 as profit. Cut 10 month labor, electricity, water, mortality, accidents with 2000 taka and you have only 25000 in 10 months. that's will 300 birds. if we increase more bird the profit will be more. a rough calculation is with 1000 bird ther'll be 30000 tak profit per month.