I can remember my mother explaining it to me. She did so in reaction to a Christmas pageant in which the innkeeper was denigrated for forcing poor pregnant Mary to sleep in a stable, and use a feed trough for the crib. My mother explained that the innkeeper was actually being nice, because the stable was likely to be one of the warmer places available, because the body heat of the animals would warm things up. And my father the veterinarian chimed in that this was one of the reasons farm cats hang out in the barn. Trust a cat to find comfort.
Plus the lyrics to another Christmas carol -
“I”, said the cow, all shaggy and red,
“I gave him my manger to make him his bed.”
When I was a little kid, we lived on a place that had a really old classic barn. There was an opening from the hayloft to throw hay down into the mangers for the cows (if we had them). Never used a different word for a simple hay feeding thing. A “trough” would be for higher grade food and made of better quality. Not so rough and full of holes. And also a lot messier. Harder to clean out in order to put a newborn in.
Nowadays, one might hear “manger” to describe a hay feeding system where the hay is behind rails and barely accessible to the livestock. They would tug on the hay from the bottom to pull it out to eat it. Very tall and really hard to get a baby in and out of.
In modern usage a manger is different from a trough, and it’s a relatively common word in the horse world, synonymous with “hay rack”. It’s for forage, like hay, plant stalks, etc, and its open or slatted so that the animals pull bits out from the sides as well as the top (sometimes it’s set high so that hay can only be pulled from the sides). Horses usually have a manger for their hay, and a feed tub for their grain. Since the animals pull the feed out, they don’t (usually) drool into it or spit back half chewed bits like when they eat grains from a trough. mangers are usually the cleanest, softest spot you’e going to find in a barn, and much favored by feline residents.
But speaking of troughs, since it looks like “though” I thought it it sounded like “trow” for ages. Same for “slough”. (troff and sluff, for those playing at home).
Back in the Nineties, before the explosion of cigarette taxes in NY, a certain Greenwich Village newsstand, run by Arabs, as it appeared to me, put up a little hand-written poster advertising cigarettes for “$2 per manger”.
I know what it is, probably because it was explained to me in context of nativity scenes when I was child, but I don’t believe in my entire life I have ever read or heard the word used except in the context of nativity scenes/Christmas references. And I grew up in the rural Midwest among farms (although not a farm family). If it’s used at all in modern times, it may be very regional or jargon of a very small subset of farming.
I knew what a manger was, even if I never heard the word used outside of the context of the nativity. I’d been around cattle farmers, and it was obviously a feed trough thing.
However, I had never been around sheep farmers, and certainly I had never been around shepherds.
So, you know the part in Silent Night where “shepherds quake at the sight”? I just thought quaking was something…shepherds did. Maybe it was a noise they made to comfort the sheep. You know, like cowboy songs.
I’m pretty sure I was an adult before it finally dawned on me…quake…earthquake. Oh, they were scared. They were trembling!