Drakes not putting on weight but roosters are?

[Hadynt]

Hi all,

We have hatched out a number of ducks(at the moment cherry valley a kind of Pekin duck) and have now slaughtered the drakes @20weeks. I was expecting them to dress out to be a few kilos - they looked huge! However once they were slaughtered and dressed they only came to 1.1kg.

They were fed on crumb then duck and goose grower mix and since 16weeks they have been in the mixed flock with half and half layers and duck and goose growers.

What have I done wrong to get these low weights as we will raise some more in the future?

I've just weighed(live) and our jersey giant roosters are putting on weight in line with where they should be but worried the khaki Campbell's we have will do the same as the cherry valleys. How can I make sure the ducks put on weight? They are always first to feed so don't know what I can do

 

[Quatie]

Do you have pictures of the ducks before you slaughtered?

I wonder if you got a different breed that looks white. Pekins are not the only white breed of duck. Because that is a huge weight difference. My guess would be they were not Pekin at all.