Hay, stalls, water trough or bucket, food trough, pens, seed, grain, blue salt lick, curry comb, tools (shovel, pitchfork, broom) feed buckets, flies, spiders, spider webs, dust, rusty nails, pen gates, horse hair pinched in cracked boards/stall rails, manure, feathers, dirty straw, clean straw, bales of hay, loft, ladder, lighting on pull string, mice, animals, horse blankets, tack, brush, split door or double door, glassless windows with shutters, mud, grime
The rustle of hay, creaking boards, stamping, thumps, whinnies, squeaks, grunts and other animal-specific vocals, huffing breath, snorting, rubbing noises as animals scratch against posts or rails, the clatter of grain spilling into a trough, the scrape of a shovel against the rough floorboards while mucking out the barn, hay bales thumping to the floor, the shush/papery rustle of clean straw being spread in a stall, the chomp and crunch of an apple treat, chewing noises, cows lowing, the swish of a tail, the squeak of a gate, a latch being set into place, the slosh of water, the clink of tack, the flutter of a horse blanket as it's shaken out, humans talking or clucking with their tongue at the animals
straw (clean and dirty), urine, manure, salt, animals, hay (dusty & slightly sweet-smelling), grain (dusty & earthy)
Dust & chaff in the air, spit
Prickly hay and straw, chaff sticking to the neck, getting into your shirt, rough boards, sweat trickling down your face, sides and back, a band of heat where your hat sits, swiping dust and chaff from clothes and hair, pulling on heavy work gloves, the dry & hairy tickle of horse lips nibbling up a treat of apple, carrot, sugar cubes, etc, the warmth of animals pressing against you for attention, horsehide, robe burn from hoisting square hay bales with no gloves, heavy boots against the rough floor, the jarring vibration of dragging a square-shaped shovel across the floor to collect and dispose of soiled straw and manure, the pain of being kicked by an injured or frightened animal, slivers, scratching a bristly chin, patting a flank, holding up a hoof to check or clip it, moving a curry comb slowly over the curve of a horse's back or side, running a hand through the mane, pulling doors and gates shut, throwing catches, climbing ladders & tossing down hay with a pitchfork
--The words you choose can convey atmosphere and mood.
Dara woke from her nap, wide-awake with the vague remembrance of an unpleasant dream. Her skin itched from a dozen hay pricks; the strong smell of animal assaulted her nose. As her eyes grew accustomed to the dark, she made out rough wooden stalls with milk pails stacked against the wall. She pushed away a rusty pitchfork and decided to be more careful next time she fell asleep in the barn.
Dara woke from her nap, wide-awake with the vague remembrance of a pleasant dream. The hay was soft, almost bouyant, beneath her; the comforting smell of horses drifted on the lazy air. As her eyes grew accustomed to the dark, she made out smooth wooden stalls and shining milk pails stacked against the wall. She stretched like a cat and smiled; she should sleep in the barn more often.
--Similes and metaphors create strong imagery when used sparingly.
Example 1: (Simile)
I stepped into Uncle Amos' barn and the unholy stench of manure and filthy straw almost knocked my boots off. It was like entering a free standing public toilet in the height of summer...one that had gone weeks without being emptied.
Example 2: (Metaphor)
After a few inquisitive nuzzles at Andrea's pockets to make sure all the carrots pilfered from the garden were gone, Old Sam rested his chin on her bare shoulder. The bristles under his muzzle were sparse, an old broom sweeping at her shoulder, tickling her skin.