Poultry Talk Ontario (pto.ca)

Lately, my 15 hens that are fully capable of laying have drastically reduced their production. They are almost 1.5 yrs old, and for the past few days, they have been laying 8, 6, and today 4 eggs. The only change is a temporary barnyard addition of a pig (just for this week), which they cannot see unless they are let out, and the pig is also outside in a pen. Could that be it?

How's your lighting . Days are getting shorter but yes also strange noises etc will throw them off .

Mine have cut down and are getting ready to moult. A pig might upset them enough to lower production.

Agree with both ross and KB, time to start adding light, 1.5 year old hens will take a longish break without some additional light and molt is slowly starting so a double whammy.

Yes, that can do it. Any odd noises and smells can throw them off, any change in routine. Even a change in what you wear to do chores...if you usually go out in the same thing and one day decide to wear a floppy hat, you can throw them off for days. Pigs nearby will definitely do it, chickens instinctively know that pigs are opportunistic hunters. Plus,, 'tis the season for molt and diminishing daylight as stated above. Don't give up and buy more layers, or else next April you'll be swimming in eggs. Which make dandy pig slop, btw :)

if you've checked all the regular (like mites, lice, etc etc) then it's probably light. mine are moulting like mad right now, feather explosions everywhere....tis the season as www mentioned!

Thanks everyone!
The hens are outside all day within an enclosure (unless we let them out for fresh grass and bugs); they go into their coop to lay or to sleep at night. Actually, the BSL's "milk the day" for all it's worth and do not go into their coop at night until it's almost dark. On Monday or Tuesday, when we did let the hens out, they did get upset when they saw the pig outside in the hard paddock.
The pig's hours are numbered today, as it has been in our barn temporarily (just this week) in preparation for a pig roast on Saturday.
Also, I do have 6 RSL's on order for the end of September because we need a greater supply of eggs. The 6 Frey's Special Dual Purpose hens that we have are not great layers.... perhaps their days are numbered.

Oh yes.... now that the hens are about 18 months old, I shouldn't be surprised if they do begin to moult.

we see you live in Westport, nice and local. Mmmmmmmm!

Pig is gone. All is back to normal. Everything is "tickety-boo".
EXCEPT.... if the hens would kindly divvy themselves between all of the laying boxes and NOT ALL lay their eggs in ONE box, all eggs would be intact without any broken ones! Grr! By the way, the one PREFERRED laying box is not always the SAME laying box. Maybe it's time to put the golf balls back into the nesting boxes.