Here's my dirty little secret---- I clean the poultry barn twice a day, and all of the poop, shavings, spilled food, moulted feathers, etc. get swept up or scraped and dumped into a couple of big buckets. When the buckets are full, I take them out to the garden beds and dump them out and spread them out over the ground. Within 2 or 3 months, it is rich dark soil. I keep it moist and the earthworms and other critters macroscopic and microscopic feast on it and break it down quickly.
In the winter, it takes longer because the soil organisms are not around, but it makes a great mulch. And come spring it breaks down fast.
The poop NEVER stinks, either. Never have had a problem with odors.
If you make a compost pile, rather than just directly applying it to the garden, it does take longer. The more contact the manure-bedding mix has with the ground, the quicker it decomposes if there is enough moisture..