Less coded than practical.

Newly hatched poultry don’t always have any characteristics than can easily tell the sexes apart. Some particular breeds might have sex linked traits that are manifested and visible when a chick has hatched but its not universal.

Also, Chickens have Hens (female) and Roosters (male). Horses have Mares (female) and Stallion (male). Cows have Heifer (female) and Bull (male). There’s also nouns for newborns and prepuberty and castrated. I’d imagine that the specific names for things aren’t necessary to teach to city folk who aren’t expected to ever work around animals

As far as cultures that heavily relied on horses, mares tend to fight each other less while the stallions (and geldings sometimes depending on when they were castrated) can be incredibly dangerous when fighting each other for their position in the herd and when there are mares in heat.

Cant forget to mention that male horses don’t have hands to properly wash their penii and sheathes which can get incredibly nasty, to the point of causing urinary tract infections, smegma that becomes the size and hardness of rocks, to just getting rocks and plant material stuck inside. So trying to ride a horse that has gravel constantly grinding against the head of their penis until you take the time to personally hand wash that horse’s junk and remove all the unpleasant objects hiding in its sheath isn’t the safest or most desirable thing when you can just ride a mare instead.