Raw milk - too much variables in protein/fat ratio daily?

[CheeseForLife]

Good day,

I've been getting milks from local farmers directly, all were good but only recently seeing milks coming in daily with obvious different in yield.

I observe the curd firmness and it's variable day to day - some day it's firm the very next day it's jiggly wobbly, with everything as precise as I can on my side. My guts feeling was that there were probably a bit too much variations in the milk composition.

I don't expect the cow to eat and drink the same daily but for milk farms as a whole, what is a reasonable expectation? Or anyone measure/test their milk daily to adjust the ingredients accordingly (if so, what's a good method to do it)?

Thank you and hope someone can shed some lights on this matter. I talked to the farmer but it was rather inconclusive, only information I had was that they do have different cow breeds and what they fed but no idea how the farm actually operated in details.

[Bantams]

There is no reason the milk should be variable from day to day - unless they are not bottling out of the bulk tank but from different individual cows. Or perhaps they are taking it out of the bulk tank without turning the agitator on for several minutes, in which case you would get mostly skim on those days.
You will see variation over the course of a year, especially with seasonal dairies (all calving in the spring so all cows go through the same lactation curve at the same time), and as the diet changes from season to season - hay to fresh pasture and back.
But you shouldn't see variation day to day.

Or are you purchasing from different farms each time? Do these farms have 1-2 cows or a whole herd?

[CheeseForLife]

There is no reason the milk should be variable from day to day - unless they are not bottling out of the bulk tank but from different individual cows. Or perhaps they are taking it out of the bulk tank without turning the agitator on for several minutes, in which case you would get mostly skim on those days.
You will see variation over the course of a year, especially with seasonal dairies (all calving in the spring so all cows go through the same lactation curve at the same time), and as the diet changes from season to season - hay to fresh pasture and back.
But you shouldn't see variation day to day.

Or are you purchasing from different farms each time? Do these farms have 1-2 cows or a whole herd?

Thanks for the quick response! That kinda confirmed my thoughts basically. I had a feeling that something isn't right about the milk and shouldn't vary that much daily, moreover it only seem to happen recently out of a sudden.

To answer your questions, I only got it from that one farm. What I got from my farmer is that they might deliver different mixture of milks from different cows (I assumed they're more of a middle size farm, I need to visit someday, definitely not just a couple of cows) but that still doesn't sound right - a farmer would try to produce consistent milk as possible instead of letting it out of the farm randomly. I suspect there's more than that.

I'm afraid if this is persisting I'll probably need to look else where. Sadly, when the milk is good, boy was it tasty.