lecture 8

• the most important part of the milk process is the cow
• dairy systems differ by region and certain weather conditions
• dairy systems differ by resource availability/access; includes pasture availability, feed ability, labor, and capital
• in the U.S., machines are available to milk cows instead of hand milking; no need for labor
• different dairy systems: pasture system, dry lot, bedded pack, and free stall
• pasture systems: found in New Zealand, Virginia, and Mississippi; cows get most feed from grass; exposed to weather; takes a long time to go get cows; rotational system is best to prevent overgrazing
• dry lots: found in southwest US, in dry climates; exposed to weather; does not work in extreme cold
• bedded pack system: found in southeast US, sawdust is used as compost, requires maintenance and conditions for fermentation, no such thing as a "dry lot" in the south
• free stall system: very popular, found everywhere, can be closed up during cold weather, variable bedding types (sand, rubber mat, water bed, mattress), concrete with flush or scrape system, cows are free to walk around, could have traditional or robot parlor
• environment and housing set up determine parlor type; how far do cows travel to get to parlor, how many times a day, how far is feed and water from parlor
• robot system needs to be close and easy access to cows
• tie stall (housing/parlor combo): found in colder climates, older style, smaller farms, found in northeast (PA, NY, Canada), cows stay tied in their stall (no free movement), milk system moves on a rail and comes to the cows
• benefits of a tie stall system: ability to monitor feed, water, and health individually (dry matter intake)
• tie stalls are not as common
• most parlor types have a "pit", except the tie stall system
• if a pit is present, you would be standing on the same level as the cow, bending over to attach the unit
• the pit system is less efficient than pit parlor; slower to move cows in and out, give grain to motivate cows to go in head locks
• the most popular parlor type is herringbone
• herringbone parlor: most popular in US, cows stand at an angle, milking unit is attached from the side, has a swing bar to hold up the unit under the cow, cows can exit in a line or rapid exit system (influences milking time efficiency)
• parallel parlor: cows are side by side, straight/no angle like the herringbone, takes some learning from the cows, units are attached from behind the cow not the side, rapid exit system
• tandom style parlor: krauss dairy in wooster, cows stand in a line, front to back, can let cows in and out individually, don't have to wait for the whole side to finish milking, takes up more space (can't milk as many cows, not very efficient or common)
• rotary/carousel parlor: cows get on and off while rotary is moving, takes some learning, milkers stand outside ring and prep cows and put on units or can be robotic system, cows are signaled to get off carousel when done (bells, chain, something that makes noise or touches them)
• the rotary/carousel parlor is very efficient and is growing more and more popular
• cows must be smart in a carousel/parlor system
• swing parlors: typically there is a unit for every cow, have half the number of units, cows on both sides, milking cluster swings to each side of the parlor, slows down efficiency, more common in New Zealand
• robotic/AMS parlor: automated milking system, no labor needed, more common in the Netherlands and small dairies in Eastern US, needs specific housing set up, need one machine per 60-70 cows, large investment cost, maintenance is important, not completely hands off (still need people, rely on technology to alert you to sick cows)
• milk flow: milk cluster, milk line, milk receiver jar, filter, plate cooler, bulk tank
• milking system has phases: air and vacuum (mimics nursing)
• starts at milk claw: milk is collected from udder through milk claw, goes through technology system, goes through milk line, goes into collection jar (until full), measures how much milk the cow produced
• milk line/receiver jar: milk travels through milk line to receiver jar, slope of parlor is important for milk to move by gravity, as receiver jar gets full, milk pump will send milk to the bulk tank
• filter/plate cooler: milk travels through filter to remove debris, manure; must be changed every milking; milk goes through plate cooler to quickly bring milk to refrigeration temperature, milk goes into bulk tank
• bulk tank: agitator, keeps milk cold, milk gets picked up every day or every other day depending on the size, every tank load gets sampled for testing (SCC, bacteria counts, antibiotics)
• vacuum regulator: regulates vacuum at the cow teat end
• reserve tank: vacuum comes from here to pulsators, tank of reserve air to keep vacuum high enough when a unit gets kicked off, otherwise all units would fall off
• vacuum pump: provides vacuum, holds unit on udder, can be variable or constant
• it is important to keep a balance between air and vacuum
• the vacuum line is the pulsator
• the milking chamber has a liner, shell, and claw
• pulsation occurs through a combination of vacuum and atmospheric air
• pulsation contains the massage phase and the milk phase