Who’s Your Chicken’s Baby Daddy? Semen Retention and Chicken Choice

IMG_0719When I first started raising chickens, I determined very quickly that I wanted “more”.  I loved the chicks, watching them develop: excited to see physical changes like feathers develop as they lost their chicken fluff, and witness innate behaviours emerge – like scratching and pecking.  Everything about it was amazing.  All miraculous.  And I was hooked.

Starting to read about chicken breeding led me down some strange paths, and I learned a lot.  The most important and basic, being semen retention.  Chicken and human reproduction is very different in this area.  A successfully mated hen will hold and can use that semen for up to 3 weeks, or at least, that seems to be the going consensus.  And it’s logical… if she’s going to hatch a clutch of fertilized eggs, and it takes a while to lay a clutch, she might want them all from the same father.  But what does that mean for the chicken breeder?

Simple.  If you have multiple heritage breeds of chickens running around free on your farm, and if you want to keep that strain a pure breed, you want to make darn sure that you pair up your desired hens and roosters of the same breed… only after your hens has been separated from all other roosters of different breeds from the last 3 weeks.  Easy right?

Oddly enough, there’s another part of the equation.  It turns out that the hens can select if they are going to keep the rooster’s semen in their reproductive system.  That’s right.  If they decide that’s not the rooster for them, they essentially, for lack of a better terminology, “poop it out”.  They are actively making choices as to who their baby daddy is going to be.  Which means the hens aren’t passive about what genetic traits are getting passed onto their offspring.  So if your thinking that by keeping a lot of hens and several roosters in a group would be good enough to encourage genetic diversity, you may want to think again.  As all those hens, might be choosing the same rooster as their offspring’s father.

And what characteristics would a hen be looking for?  The dominant rooster is the ladies pick according to T. Pizzari & T. R. Birkhead’s research “Female feral fowl eject sperm of subdominant males“.  Which would be logical.  He’s usually the biggest and meanest rooster at our farm, and takes protecting his ladies to a whole new level… usually by attacking the Chef and Shepherd, by running at our shins.  But, the dominant rooster also has other characteristics… like sassy mating dances and a certain clucking when he’s found a food source that he’d like to share with his gals.  Looking for the specific characteristics that make a rooster the top rooster?  Research by Favati A, Leimar O & Løvlie H.,  “Personality predicts social dominance in male domestic fowl“, explains. But what happens if you’re a hen, and that dominant male that all the other hens are swooning over, happens to be your brother?

Not to worry.  Again, hens have a backup plan for just that problem.  They don’t want a shallow gene pool for their babies either.  Somehow, they seem to recognize that if they are too close of a relation, they eject the semen.  Researchers Hanne LøvlieMark A. F. GillinghamKirsty WorleyTommaso PizzariDavid S. Richardson focused in on what could be the root cause of this, in their article “Cryptic female choice favours sperm from major histocompatibility complex-dissimilar males“, if you’re interested in that read.

What all this boils down to, is that chicken breeding, is a lot more then just a physical act.   Hens can choose what semen to keep, and therefore, what genetics are passed on to future generations.  If a hen doesn’t think a rooster is suitable, or too close in genetics, it’s her choice… and out goes the semen!  Chickens certainly aren’t so dumb, as people would think!

Sincerely,

The Shepherd

3 thoughts on “Who’s Your Chicken’s Baby Daddy? Semen Retention and Chicken Choice

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