It greatly varies, but somewhere around 20,000 pounds per year. Or put another way, about 65 pounds a day...about 9 gallons per day. With 1000 cows we are producing about a tractor trailer load of milk per day, 9000 gallons.
BUT...where a farm makes its money is not really based on quantity, but on quality. Since every gallon of milk is tested for bacteria, the lower the bacteria the higher the farm gets for a grade, and a better price. We are a Gold Star Dairy Farm because we go to great lengths to keep bacteria out of the milk. We use surgical grade iodine to clean our cows before milking...it is expensive, but keeps bacteria out of the milk. The same for cleaning the milking parlor, we use more bacterial cleaners and less water because water spreads bacteria, even though rinsing with water looks fresh and clean. There are other things, but rest assured, we put out quality milk...as we should because people deserve safe milk to drink...and we get paid a little more for consistently producing that milk.
The other bonus we get for our milk comes from protein. A lot of products like sports drinks and stuff have protein added, and while people think they come from fish, it actually comes from milk. The creameries have derived ways to break milk down into its separate elements. There is no such thing as "whole milk" any more. They break the milk down into butter fat, protein, water, etc and then put back those elements to give you skim milk, 1-1/2 per cent milk and whole milk (which has sugar added by the way). The highest payout for creameries right now is protein content so we, as farmers, get bonuses for that. In order to get that, we had to totally change how we farm.
Protein comes from young grass. Certain grass types are higher in protein then others, so we had to plant our fields into such grasses like alfalfa, clover, orchard grass and timothy. But these grasses have to be cut at boot stage, about every 21 days. When you are harvesting 700 acres of grass 5 times a year, you use a lot more diesel fuel to get the same tonnage of feed...better quality, but less yield. With the higher prices in fuel, it has been really expensive to keep up with the higher protein milk that keeps our milk prices high. To compete with fuel costs, we have had to go to bigger equipment. It costs more money up front, but we are using less fuel to do it.
If this seems crazy, its really not. Its like being a professional photographer, you can't get the higher quality photos that pay really well with a point and shoot camera...the consistency will not be there. So you go out a buy expensive camera gear, take better photos, and get more money for those better photos. Its the same with dairy farming...we are chasing an ever changing market.
This whole system got tossed on its head however when ethanol was mandated in fuel. We cannot get the protein levels we need solely from young grass and so we employ nutritionists (don't laugh, our cows are treated extremely well since they provide everything we have...pillows in their stalls and nutritionists to ensure they are heathy and comfortable because how comfortable a cow is changes how much milk they give) who compare our feed (corn and grass) and then add in soy meal and grain to get the right balance for high protein milk. Ever since the ethanol mandate, dairy farms have struggled because with more farmers in the mid-west raising corn for ethanol, grain prices have gone up. With less acres being planted into soy beans, and more into corn, it is simply supply and demand...high grain prices. Now add in the effects of the drought this summer in the mid-west and you have extremely high grain prices mixed with very low milk prices. That is why in the last 10 years Maine has gone from 400 dairy farms to 300 and a few dairy farmers committing suicide because they cant stand losing their family farms.
We have always had a family milk cow or two, but we started commercial dairy farming in 1910. For us, our legacy is sheep, and with them we go back to the Mayflower. Being a tailor by trade, my Great Grandfather 15 times removed was needed because clothes were woolen then and we get credit for being the oldest sheep farm in New England, being the first sheep shearing shed in New England, as well as moving to Maine in 1746 and clearing all this land in the 1830's so that we could raise sheep and keep the woolen mills in Camden, Biddeford and Winthrop in wool. We still have sheep, and that is my responsibility, but the high protein feed the dairy farm requires, has an affect on them as well. High protein makes their wool course, so it is practically useless...think itchy here. It does make them put on weight so since they get the same feed as the dairy farm, our sheep mainly provide for lamb on the national food chain and no longer produce wool.
One thing is for sure; farming today is not like it was in the 1970's!
PS: Moderators, I recognize that this is a photography site and not a farming forum, but it seems as if people are interested in how farms today operate. I assure you this is an exchange to explain some of farming today and won't be a habitual thing. I do thank you for your understanding, and latitude in this slight deviation from photography as the main topic of conversation. It is a pleasure to explain to others just how a half a percent of the US population can feed the other 99-1/2%. In other words, I am glad people are interested in where their food comes from. As a farm family who has provided food to this nation since before this nation was a nation, it is my family's greatest honor to put quality food on the national food chain for you. Thank you for buying McDonald Milkshakes, Cabot Cheese, sports drinks, ice cream and pizza...