Dairy Farm Cleaning Procedures: 7 Steps With Temperatures

Dairy farm cleaning procedures for milking equipment run in four cycles after every milking: a warm first rinse, a hot chlorinated alkaline wash, an acid rinse, and a sanitizer cycle just before the next milking. University of Wisconsin training material gives the usual targets: a first rinse at 100–130°F, a wash that starts at 160–170°F and ends near 110–120°F, and an acid rinse at pH 3.5 or lower (UW–Madison Milk Research and Instruction Lab, MilkTech cleaning cycles).

The equipment routine sits inside a wider plan: clean, dry teats at milking, clean housing, and biosecurity at the farm gate. This guide gives each step with its numbers, the somatic cell count (SCC) and bacteria limits that buyers test against in the US, Canada, the UK and the EU, and a calculator for the weekly cost of your own wash routine.

Why the cleaning routine matters

Milk leaves a film of fat, protein, sugar and minerals on every surface it touches. If that film stays, bacteria grow in it between milkings and get into the next batch of milk. A University of Idaho Extension guide on cleaning and sanitizing milking equipment names unclean equipment as a major cause of high bacteria counts and poor milk quality, and lists four controls for every wash: temperature, time, turbulence and detergent concentration.

Two numbers show whether the routine works:

• Bacteria count (standard plate count or individual bacteria count). This mostly reflects how clean the equipment is and how fast milk is cooled.
• Somatic cell count. This mostly reflects udder health and mastitis. Teat preparation and a clean, dry bed for the cows move it the most.

Buyers and regulators test both. A high count can mean a lower price, lost quality premiums or, if it stays high, a halt on milk pick-up.

Milk quality limits by market

Each market sets its own ceiling for raw cow milk. The table and chart below show the published limits.

Chart

Raw cow milk somatic cell count limits

thousand cells per mL, regulatory ceiling

Sources: the UK’s retained version of Regulation (EC) No 853/2004, Annex III, Section IX, which carries the same raw cow milk limits as the EU text; a University of Wisconsin paper by Pamela Ruegg on bulk tank somatic cell count monitoring for the US rule; and the Government of Saskatchewan milk and milk product testing guide for Canada. Your milk buyer may set tighter limits for premiums. Check your contract and your state or provincial dairy authority.

The same UK and EU annex also says milk must be cooled at once to 8°C or less with daily collection, or 6°C or less if collection is not daily. Fast cooling and clean equipment work together: a clean tank still lets bacteria grow if milk sits warm.

Dairy farm cleaning procedures at a glance

This table sums up the four equipment cycles and the three farm routines around them. Temperatures and times are the ranges given in the cited university guides. Your detergent label and your equipment dealer’s wash chart come first.

The chart below shows the temperature window for each cycle. The wash is the only cycle where the start and end both matter, because the solution cools as it moves through the line.

Chart

Temperature window for each cleaning cycle

°F, low and high end of the recommended range

Step 1: First rinse right after milking

Start the rinse as soon as the last unit comes off. Milk that dries on stainless steel or rubber is much harder to remove.

• Water temperature: warm, about 100–130°F (38–55°C), per the UW–Madison MilkTech guide. Water much hotter than this can bake protein onto surfaces; much colder water can leave fat behind.
• Do not recirculate. Send rinse water to drain after one pass. Keep rinsing until the water at the end of the system runs clear.
• Warm the system. The rinse also heats the pipes, so the wash that follows loses less heat.
• Rinse the bulk tank as soon as it is emptied, before the milk film dries.

The Idaho guide says a good rinse removes at least 95% of the milk residue, which leaves less soil for the detergent to handle.

Step 2: Hot chlorinated alkaline wash

The wash removes the fat and protein the rinse left behind. Chlorinated alkaline detergents contain sodium or potassium hydroxide to break down fat and protein, chlorine to help lift soil, and other agents that hold minerals in solution.

• Start hot: 160–170°F (70–77°C) at the start is the usual target.
• Stay hot enough: the wash should end at about 110°F (43°C), or 120°F (49°C) for hard-to-clean systems, per MilkTech. For hand-washed calf-feeding equipment, the Cornell University NYSCHAP cleaning protocols treat 120°F as the lowest temperature at any point in a wash. Below that, soil can settle back onto surfaces.
• Circulate long enough: 8–10 minutes is the MilkTech guide; the older Idaho guide gives 7–15 minutes, depending on the manufacturer.
• Turbulence: in pipelines, an air injector creates slugs of water that scrub the top of the line. A slow, full pipe does not clean well.
• Right strength: measure detergent by the label for your water hardness and water volume. Too little leaves soil. Too much wastes money and can harm rubber parts.

Never mix acid and alkaline products in the same tank. They cancel each other out, and some mixes with chlorine give off toxic gas. Follow the product label and local rules.

Step 3: Acid rinse

The acid rinse dissolves mineral deposits (milkstone) from hard water and milk, and leaves a low-pH surface where bacteria grow poorly until the next milking. Cornell’s guide to cleaning calf-feeding equipment explains why: the acid rinse lowers surface pH, and bacteria grow best near the neutral pH of milk.

• pH: 3.5 or lower, per MilkTech. If your water has silicates, the guide notes a pH below 5 to 6 may be enough. Check the label.
• Temperature: warm water, about 100–120°F (38–49°C). If you rinse at 68°F (20°C) or below, use a non-foaming acid.
• Watch for film: a white or blue-grey film on stainless steel often means the acid step is too weak or too short.

Some farms alternate acid and alkaline products, or run an acid wash on a set schedule. Your chemical supplier can tell you what fits your water test.

Step 4: Sanitize just before milking

Sanitizing kills bacteria that grew on surfaces during the hours since the last wash. Do it shortly before milking starts, not right after the wash.

• Strength: MilkTech gives about 200 ppm final chlorine for the pre-milking sanitizer cycle.
• Time: 3–4 minutes of circulation.
• Drain well: let the system drain fully so sanitizer does not mix with milk.
• Hand-clean what CIP misses: wash and sanitize small parts, such as gaskets, valves and bulk tank outlets, by hand.

Use only sanitizers that are approved for milk-contact surfaces in your country, at the label rate.

Get the wash system checked regularly

Ask your equipment dealer for a full wash check regularly (many dealers do this yearly): test water hardness and iron, record wash temperatures at the start and the end, check the air injector and slug speed, and confirm the detergent dose. Keep the readings, so a rising bacteria count can be traced to one cycle.

Step 5: Clean, dry teats at every milking

Equipment cleaning keeps bacteria counts down. Cow preparation keeps SCC down. Penn State Extension’s standard operating procedure for the milking facility sets out a routine every milker should follow the same way:

1. Pre-dip with a product that has research behind it. Cover at least three-quarters of each teat and leave it on for the time on the label.
2. Fore-strip 4–5 squirts from each teat into a strip cup. This lets you spot mastitis and removes the milk with the highest cell count. It takes about 10 seconds.
3. Wipe dry with one clean towel per cow, with a twisting motion that cleans the teat end.
4. Attach the unit 60–90 seconds after the first touch (at least 90 seconds for herds milked three times a day).
5. Post-dip as soon as the unit comes off. The teat end stays open for about 30 minutes after milking.

The University of New Hampshire Extension guide to correct milking procedures adds two points: wear disposable gloves, because bare hands spread bacteria between cows, and never strip onto the floor of a tie-stall barn, where cows will lie down. Do not machine-strip cows by weighing down the claw.

For tail clipping, belly hair and more cow-side habits, see our separate guide to dairy farming hygiene tips for milk quality.

What US herd data show

Herds that test with Dairy Herd Improvement (DHI) have cut cell counts over time. Council on Dairy Cattle Breeding (CDCB) data show the national average test-day herd SCC fell from 304,000 cells/mL in 1995 to 179,000 in 2021 (CDCB research report SCC23). A CDCB summary reported in Progressive Dairy (April 2025) put both 2023 and 2024 at 181,000 cells/mL.

The share of herd test days above 400,000 cells/mL, the EU and Canadian limit, fell from 27.2% in 1995 to 8.5% in 2021 in the same report.

Chart

US DHI herd somatic cell count

national average test-day herd SCC, thousand cells/mL, selected years

Step 6: Housing and parlor sanitation

Clean, dry cows come from clean, dry housing. Manure on teats is the main route for environmental mastitis bacteria.

• Parlor: hose down after each milking, and clean the walls, rails and floor so cows walk back on a clean surface.
• Stalls and beds: remove wet or soiled bedding daily and top up with dry bedding. Sand, sawdust and recycled manure solids all need regular raking.
• Alleys and yards: scrape at least as often as cows are milked, so they do not carry manure into the parlor.
• Feed areas: clear spilled and spoiled feed, which draws rodents and birds.
• Disinfect in the right order: remove dirt first, wash, rinse, then apply a disinfectant. Disinfectants work poorly on dirty surfaces.

Plan where the wash water goes. Parlor and wash water carry milk solids, chemicals and manure, and usually belong in the manure storage, not a ditch. Check your state or local water rules.

Step 7: Biosecurity and manure handling

Biosecurity keeps new disease off the farm, so you are not cleaning up after an outbreak.

• Visitors: keep a log, give them clean boots or covers, and keep them away from cows unless they must enter.
• Vehicles: keep milk trucks, feed trucks and dead-stock pick-up on fixed routes away from cow areas, and clean shared machinery before it comes back on the farm.
• New animals: isolate them and test them before they join the herd.
• Feed and water: buy from known suppliers and keep troughs clean.
• Staff: clean clothes for milking (also a UK and EU legal duty under Annex III), hand washing, and boot dips at key doors.
• Manure: store it where cows cannot reach it, and spread it under a nutrient plan. For ideas on cutting the farm’s footprint, see our post on sustainable dairy farming.

Your vet can help you write a herd biosecurity plan that fits your disease risks.

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Weekly wash cost calculator

Enter your own numbers to see what the four equipment cycles cost each week, and how that compares with a milk quality premium. The default values are examples only, chosen to land close to break-even. They are not benchmarks.

The calculator counts hot water, chemicals and labour for the rinse, wash, acid and sanitize cycles. It leaves out housing work, equipment depreciation and repairs.

Try the numbers for your own farm below.

Troubleshooting a high count

When a test comes back high, match the count to the likely cause before changing everything.

Chart

US herd test days above 400,000 cells/mL

% of DHI herd test days, selected years

Change one thing at a time and keep testing. If counts stay high, ask your milk buyer’s field staff or a dairy extension specialist to watch a full milking and wash.

Forage fields and the rest of the farm

Many dairy farms also grow their own feed: corn silage, hay and pasture. Clean milk starts in the parlor, but herd health also depends on steady forage quality from those fields.

Satellite crop maps can show which parts of a silage or pasture field are falling behind, so you can check them on foot before harvest. Farmonaut offers this kind of field monitoring. It does not measure milk quality or check your wash system; those stay with your milk tests and your equipment dealer.

Related pages on our site: farm-to-buyer traceability · vehicle and fleet records · farm carbon footprint tracking · managing many farm sites · web and mobile apps · satellite and weather API docs

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FAQ

What are the four steps of cleaning milking equipment?

First rinse with warm water right after milking, a hot chlorinated alkaline wash, an acid rinse, and a sanitizer cycle shortly before the next milking. UW–Madison’s MilkTech material lists these as the cycles most commonly used in the US.

How often should milking equipment be cleaned?

After every milking, with a sanitizer cycle before each milking. UK and EU rules say milk-contact surfaces must be cleaned after use, and milk transport tanks at least once a day.

What temperature should the wash water be?

Start the alkaline wash at about 160–170°F and keep it above about 110–120°F at the end. Your detergent label and your dealer’s wash chart take priority.

What is the legal somatic cell count limit?

750,000 cells/mL in the US, and 400,000 cells/mL in the UK, the EU and Canada. Many milk buyers pay premiums for counts well below these limits.

Why is my bacteria count high when the SCC is low?

A high bacteria count with a low SCC usually points to equipment cleaning or slow cooling rather than mastitis. Check wash temperatures, detergent dose, worn rubber parts and how fast the tank cools.

Do dairy farm cleaning procedures differ for robotic milking?

The same four cycles apply, but the robot runs its own wash program on a set schedule. Follow the maker’s program and still check temperatures and chemical use.