Serious side effects can occur. 1  If you have any of these side effects, call your doctor right away or call 9-1-1: 2  Unusual bruising or bleeding. 3  Loss of appetite. 4  Abdominal pain. 5  Yellowing of the eyes or skin (jaundice) 6  Dark-colored urine. 7  Fever with sweating, confusion, racing heart, and muscle stiffness. 8  Extreme weakness.
Generally domestic ducks start to lay around 21 to 26 weeks of age. Although ducks will lay anywhere they can be trained to lay in low nest boxes especially if you place some pot eggs in the box. Plenty of straw which is changed frequently will help to keep the eggs clean once they start to lay. As they approach 20 weeks I would put some pot eggs in a low nest box or place a big pile of straw in the corner of the hut with some pot eggs in. My ducks started laying at 20 weeks old. I have found that my khaki campbell ducks generally lay their eggs early morning which means that it is not difficult to collect the eggs as they usually lay them in the hut before they are let out to free range for the day. I hope this helps.
Laying hens vary in size and how long they lay through their lives. Generally, they begin laying around 18 weeks of age, but sometimes it will take longer for them to get started. They reach their peak production when they're about a year or 2 old, laying fewer eggs as they age.