Results of Duck Breeder Flock Culling

Originally posted by John Metzer on Wed, Aug 11, 2010 @ 12:37 PM

Last week we went through our Rouen, Cayuga, White Crested and Fawn and White Runner breeder flocks.  Each female was picked up and the distance between her pelvic bones was estimated.  This technique was shown in our last blog: Determining Which of Your Ducks Is Laying. I want to share the results with you.
The Fawn and White Runner flock had 405 females in it that were at 33% egg production (this means we were getting an average 33 eggs a day for every 100 females).  We put a fence down the middle of the pen, one side for the "keepers" and one side for the cull birds. After checking each female, we had 175 females in the "keep" flock and 230 females in the cull flock.  The next day the females in the "keep" flock layed 112 eggs which is a rate of 64%.  The females in the group that we will not keep laid 6 eggs which is a rate of 3%!

So by checking each female, we removed 57% of our feed bill and only lost 5% of our eggs!  As there are now fewer females in the pen, we will also use less shavings.  Of course we were able to remove some of the males, too.  As far as we know, there is no way to visually determine the fertility of a male but you can cull out any males that are less thrifty than the others, have bad legs or appear to have been picked on by other birds.
The results for the other flocks was just as impressive:

Cayuga start 49%, after culling: keep flock 66%, cull flock 7%

White Crested start 35%, after culling: keep flock 69%, cull flock 1%

Rouen start 43%, after culling: keep flock 66%, cull flock 7%

Mallard start 30%. after culling: keep flock 63%, cull flock 0%

Of all the breeds, the Mallards were the easiest to differentiate layers from nonlayers.  As you can see, over half the females were  removed and there were no eggs in the cull flock pen the next morning.

The picture shows the keep and cull flocks of Fawn and White Runners.  As you can see, there is very little difference in appearance in the two flocks.  You have to pick up each bird and check it.  It is basically a comparison with other birds of the same breed so if you have never done it before, check 10-15 birds and note the difference among them.  Then start over and remove those birds in which their pelvic bones are stiffer and closer together than the others.

In our next blog we will be addressing how to use the feed formulation program on our website. http://www.metzerfarms.com/FeedConversion.cfm.  Many times you cannot find feed with the correct level of protein.  This program will show you how much to mix of two different feeds to achieve the protein (or other nutrient) level you want to achieve.
Thank you! Enjoy your ducks and geese!