Dairy Farm

In a follow-up to last week's trip to see corn being harvested, we went yesterday to witness the next step in the food production chain: a dairy farm. Really this post should have pictures; I didn't have a camera with me, but hopefully I can get some pictures from some of the other participants. If I do I will be sure to post some. The tour was really fascinating (Thanks Dave!) We pulled up outside and walked past a big milk tanker truck; a hose connected the truck to the milk silo inside the building. This truck will take the milk from the dairy here in Utah to a milk processing plant in Idaho. Inside the building, we saw the big holding tanks, about 30 feet high, full of milk. This dairy has cows being milked (80 at a time) around the clock, so the milk trucks are always coming and going to transport the milk. We got to watch the entire milk collection process. First the cows walk single file into the milking bay and turn so they are lined up in stalls (the do this on their own--they've obviously had lots of practice). Two or three dairy workers then go down the line cleaning the udders and hooking up the milking machines. There is a meter at each station that shows how many pounds of milk each cow gives. The ones we saw seemed to be averaging 25-30 lbs at one milking. Each cow is milked three times per day. When the milk stops flowing the suction machine automatically pulls up and off the udder. Dairy workers then go through spraying the udders with a disinfectant. Once one group of cows has been milked the gate in front of each stall opens; those cows move out and a new group comes marching in, as they line up the dairy workers hose down the floor. The milk is collected through tubes that lead to milk pipelines downstairs. These pipelines lead to the chiller, where milk is rapidly cooled to refrigerator temperatures; if I understood correctly the chiller is a basic heat exchange structure where tubes of milk move past tubes of a coolant (Propylene glycol I think). The process seems to be pretty efficient--the milk pipes going into the chiller were very warm (body temperature) and coming out they were cold. From there the milk goes into the silo-shaped storage tanks. Their temperature is constantly monitored. Every time a tank is emptied it is cleaned out with hot water (180 degrees F).
The whole process was fascinating. The dairy had a definite factory-production-line feel. The cows did look healthy and the process seemed clean. I'm not sure I like thinking about this long production chain (through the dairy, trucked cross country, through the processing plant...) that my milk goes through before I drink it...It certainly made a fantastic field trip adventure for the kids!