Some turkey farmers are concerned there may be an over-supply of birds this Christmas with social gatherings potentially much smaller than usual.
With UK coronavirus infections rising at present, potential restrictions on meeting up are unclear.
But thousands more turkey chicks, known as "poults", are being reared for Christmas meals.
And some producers are betting on travel restrictions keeping more people at home over the festive period.
One south Wales farm, which normally rears 70,000 turkeys a year, told Radio 4's Farming Today it has already cut its numbers by 20%.
Nick Davis from Usk Vale Poultry is concerned the birds will be too big for the numbers at the dinner table.
The turkeys were ordered in the spring when the outlook for a "normal" Christmas seemed clearer.
He said: "In May, when we canvassed our main core of customers, who are retail butchers, they were having a boom time.
"[They] were saying nothing is going to change, because everything's buoyant, and we want the same numbers as last year. But that was easy for them to say."
"We have to decide what size people want and you can't even tell me today what size that might be."
He said the farm has "a bit of flexibility".
"We can play around with rations a bit, and we can process [slaughter them] a week or 10 days earlier, so we can reduce the size to a certain extent, but not by massive percentages".
New rules from Monday mean people will be banned from meeting more than six people socially indoors or outdoors.
It is not yet clear how long the new "rule of six" will be in place, although Health Secretary Matt Hancock told Radio 4's Today programme he hoped it would be lifted before Christmas.
Similar rules are being introduced in Scotland and Wales.
According to data from the Department for Environment, Food and Rural Affairs (Defra), the number of turkey chicks being reared in the first six months of 2020 increased compared to the same period last year.
Between January and June 2020, there were 6.2 million poults on farms, compared to 6.1 million in the same period in 2019.
Despite worries by some farmers about an over-supply of turkey, some producers are more optimistic, believing more families will be at home this Christmas should travel restrictions remain in place.
Neil Cooksey, commercial director for Bernard Matthews, said that could be good news for turkey producers, with in-home consumption of the meat expected to increase.
"The eating out-of-home occasion and holiday market is going to be much smaller, and our view is they will convert into retail sales. People want turkey on their plates at Christmas and that's never going to change.
"Do I see purchases and orders going up this year? Yes I do," he said.
However smaller producers remain nervous about demand for the larger birds they are rearing.
Mr Davis said "The run up to Christmas is not a fun time for a turkey farmer at the best of times, but this year we really are on tenterhooks.
"It's going to be a lucky turkey producer that gets this Christmas right, rather than a clever one".