Study Notes for Milking Management Quiz
12 Golden Rules for Milking Cows
Before Milking:
Monitor udder health: Regularly review udder health and milk quality
information from various sources (dairy plant, testing organizations,
vet clinics, on-farm tests). Establish benchmarks for each cow and
the herd.
Milking order: Milk first-calf heifers first, then fresh cows, then the
main herd. Milk sick cows last. Wash and sanitize the milking system
after milking sick cows.
Foremilk cows: Remove and examine a few squirts of foremilk from
each teat. This stimulates milk letdown, and allows for early
detection of abnormal milk.
Clean teats and teat ends: Clean and dry each teat with approved
materials and single-service towels before attaching the milking unit.
Ensure proper laundering and drying of cloth towels if used.
During Milking:
Check Milking System: Use appropriate vacuum level and pulsation
settings for the farm. Check vacuum level at the start of each
milking.
Attach milking cluster at appropriate time: Attach within 60-90
seconds of teat preparation. Minimize air entry during attachment.
Ensure proper cluster balance.
Avoid overmilking: Remove the milking unit when the udder is
empty. Use manual observation or automatic systems (ACR) with
flow sensors to detect low flow.
Ensure proper removal of cluster: Shut off vacuum (manually or
automatically) and allow claw vacuum to decline fully before
removing the unit. Avoid squeezing the udder and pulling down on
the unit.
After Milking:
Sanitize teats: Sanitize each teat immediately after unit removal with
an approved post-milking teat dip or spray.
Clean milking equipment: Clean all external surfaces of the milking
system after each use. Rinse and clean all system components with
appropriate products at the proper temperature. Allow the system to
drain dry. Sanitize the system before the next milking if required.
Properly cool milk: Ensure proper cooling temperatures are reached
during and after milking.
Monitor milk quality, equipment, and data: Regularly review milk
quality, composition, milking center performance, and historical
data. Replace liners and rubber goods according to
recommendations. Have the milking system serviced regularly.
[1/30, 8:12 PM] Onilaja Ogunsanwo: Study Notes for Milking
Management Quiz
Milking Management Module in Bullet Point Form
Milking Management
Lactation: Continuous secretion and storage of milk in the udder.
Stored in alveolar cells and ducts.
Secretion is continuous for ~12 hours at a constant rate.
Causes gradual increase in internal udder pressure.
Milking Goals:
Fast, efficient, and complete milk removal.
High quantity and quality of milk.
Maintain good udder health and cow longevity.
Milk Ejection Reflex (Let-Down):
Neuro-hormonal, short-term effect.
Inhibited by pain or fear.
Stimulated by good husbandry practices (natural/conditioned).
Conditioned by feeding, milking machine sounds, udder prep.
Alveoli and milk ducts contract, forcing milk to udder sinus.
~10% of milk remains as residual milk.
Milking Intervals:
Residual milk (10-20%) has higher fat content.
Unequal milking intervals cause larger milk fat carryover and
seemingly faster secretion rate in evening milking.
12-hour intervals ideal, especially for high producers.
With uneven intervals, milk high producers first in AM and last in PM.
Milking Frequency:
Increased frequency increases lactation yield (10-15% on average).
Largest increases in heifers.
No effect on milk composition (fat and SNF).
3x/day milking most beneficial if done throughout lactation.
Frequent milk removal clears inhibiting substances that initiate drying
off.
Incomplete Milking:
Form 1: Excessive residual milk due to poor stimulation, inhibition
(fright, upset), or slow milk removal.
Form 2: Some available milk remains in the udder. Modern machines
remove ~95% without stripping.
Milking Routines:
Aim for minimal residual milk.
Reflects good stockmanship.
Residual milk is inversely proportional to conditioned stimuli strength.
Cows are creatures of habit; changes should be gradual and calm.
Avoid frightening or upsetting circumstances.
Increased residual milk reduces fat content in that milking, but the
fat is recovered in the next milking.
Consistent routine with strong, effective stimuli is essential.
Milk Removal Methods:
Suckling
Hand milking
Machine milking
Hand Milking:
Labor-intensive, low capital investment.
Requires cleanliness for hygienic milk.
Slower extraction rate than machines.
Used in small herds.
Milk with full hand (lock and squeeze), avoid stripping with thumb
and finger.
Milk rear quarters first.
Use hooded bucket.
Each cow's milking time should not exceed 15 minutes.
Machine Milking:
Uses vacuum/suction (constant) and pulsation (intermittent).
Systems: Bucket and pipeline.
Components: Vacuum source, pulsator, milking unit.
Other components: Interceptor, sanitary trap, vacuum gauge,
regulator, stall cock, pipelines, receiver/recorder jars.
Vacuum Source:
High-speed pump with revolving rotor in a metallic cylinder.
Rotor has vanes, placed eccentrically.
Driven by electric motor with drive belt.
Oil reservoir lubricates vanes.
Efficiency affected by lubrication, belt tension, voltage.
Vacuum measurement:
Systems operate at 50 kPa or 44 kPa.
1 mmHg = 0.133 kPa; 1 inHg = 3.386 kPa
100 kPa = absolute vacuum; 0 kPa = atmospheric pressure.
Pulsation:
Allows atmospheric pressure into pulsation chamber (between shell
and inflation).
Positive pressure: Liner collapses (resting/massage phase).
Negative pressure: Liner opens (milking phase).
Pulsation rate: Cycles per minute (40-80, minimum 40).
Pulsation ratio: Milking phase length : massage phase length (1:1 to
2.5:1). Wider ratio = faster milking, potentially higher strip yield.
Milk flow rate depends on: Pressure differential (vacuum level, udder
pressure), teat orifice size, sphincter muscle strength.
Simultaneous pulsation: All four chambers in the same phase (4x0).
Alternating pulsation: Two chambers resting, two milking (2x2).
Ratios >1:1 require simultaneous pulsation.
Milking Unit: Recorder jar/bucket, teat cups/liners, claw, vacuum
valve, short/long milk/pulsation lines.
Milking Machine Efficiency:
Correct vacuum (50 kPa).
Liner design: fast milk removal, minimal air
admission/slippage/falling off.
Cluster weight/design: 1.5-3.5kg ideal. Weight distribution important.
Recorder jar height: below or at udder level.
Maintenance: follow instructions, check oil, belt tension (12mm play
max), interceptor, sanitary trap, rubber wear, vacuum level (max 2
kPa variation), air leaks, pulsator sound.
Machine Misuse:
Milking without stimulation.
Delayed milking after stimulation.
Overmilking.
Improper cluster removal.
Results: Mammary damage, abnormal milk, mastitis.
Machine Misuse and Mastitis:
Liner organisms transfer to teats (check/change inflations).
Milk transfer from other cows (sanitize after each cow).
Teat end damage due to incorrect vacuum/pulsation or improper
cluster removal.
Teat end impact (air entry, squawking): aerosol droplets spread
microbes.
Mastitis Prevention with Machines:
Maintain vacuum levels.
Proper cluster attachment/removal.
Dry teats before attaching cluster.
Proper cluster fit.
Low-slip liners.
Correct pulsation.
Attention to "squawking."
Regular testing and maintenance.
Milk Hygiene:
Milk is sterile in a healthy udder.
Contamination occurs during/after milking.
Milk supports microbial growth (bacteria, yeast, mold).
Rapid growth at high temperatures causes spoilage.
Contamination sources: Udder infection, dirty teats/udders,
contaminated hands/cloths/equipment.
Udder Infection:
Prevention is crucial.
Keep udders and teats clean.
Exclude milk from clinical mastitis cases.
Use mastitis control routines.
Most mastitis is subclinical (>50,000/ml bacteria).
Clinical mastitis: millions/ml bacteria.
Good husbandry can keep counts <50,000/ml.
Milking Routine Details:
Bring cows in 2 hours before milking.
Ensure calm, rested, watered cows.
Feed consistently (before or during).
Wash udders with clean water.
Check foremilk.
Sanitize teats/udder with appropriate solution (in warm water)
Dry teats/udder with single-use towels.
Apply clusters properly.
Complete milking in 8-9 mins.
Turn off vacuum before cluster removal.
Dip teats immediately after.
Milking Personnel:
Experienced, disciplined, punctual, even-tempered.
Profile: Punctual, disciplined, agile, good husbandry skills,
even-mannered, healthy (lung/bronchial), local, quick-thinking,
good hygiene.
Annual requirements: TB check, physical/medical exam, food
handler's permit.
Ongoing training: New technologies, management advances.
Milking activity prerequisites: Clean hands/person, short nails, clean
clothes, sterilized equipment.
Drying Off the Cow
Dry Period:
Recommended: ~60 days prior to calving.
Allows mammary gland involution (necessary for regeneration of
secretory cells).
60 days offers no advantage.
<45 days can lead to incomplete involution and decreased
subsequent milk production.
Drying Off Methods:
Abrupt cessation of milking.
Skip every other milking, then stop completely.
Gradually decrease milking frequency (1x/day, 1x/2 days, 1x/4
days, then stop).
Method of drying off doesn't significantly impact mastitis incidence
(though abrupt cessation may be slightly better, especially with
average quality forage).
Reducing nutrient intake pre-drying off decreases milk secretion and
speeds up involution.
At Final Milking:
Strip the cow completely to remove milk.
Infuse each quarter with a dry cow treatment (DCT) or dry cow
therapy.
Dry Cow Treatment (DCT):
Intramammary infusion containing long-acting antibiotic.
Functions:
Treats existing infections.
Prevents new infections during the dry period.
Remains in udder at effective concentrations for 20-70 days
(depending on product).
Prolonged presence and formulation aid tissue penetration and treat
deep infections.
Directly and indirectly protects against new infections (physical teat
canal sealing).
Doesn't protect against environmental bacteria introduced during
unclean administration.
Internal Teat Sealants (ITS):
Can be administered in addition to DCT.
Functions:
Protects uninfected quarters during dry period and at calving.
Extends DCT protection.
Contains bismuth subnitrate (non-antibiotic, inert material) creating a
physical barrier in teat and teat canal.
Doesn't kill existing bacteria, so not suitable for infected cows (high
SCC) alone.
Unclean administration can introduce environmental bacteria and
cause mastitis.
Dry Cow Nutrition:
Well-conditioned cows: Maintain body weight on average quality
forage alone.
Over-conditioned cows: Avoid overfeeding to prevent Fat Cow
Syndrome (milk fever, ketosis, infertility, mastitis, metritis).
Under-conditioned cows: Feed to restore body weight. More
economical to gain weight in late lactation.
Calcium: Avoid overfeeding calcium in dry cow ration. Increases
milk fever risk. Withhold legumes and reduce daily calcium intake to
<100g.
Lead Feeding:
Two weeks before calving: Gradually add 2.36-4.5 kg grain (16-20%
CP, >75% TDN) along with anionic salts to prevent milk fever. This is
known as transition cow feeding.
Stimulates ruminal microbes that degrade grain, preparing the cow
for higher grain intake during lactation.
Dairy Cattle Lactation Curve & Dry Period:
Lactation Length: Ideally around 305 days. Some may reach 365.
Curve Phases: Early lactation (rapid increase), mid-lactation (peak),
late lactation (gradual decline).
Peak Milk Production: Occurs within the first 80-100 days.
VWP (Voluntary Waiting Period): Not explicitly defined in the notes,
but appears to represent the time between calving and breeding.
Dry Period: ~60 days before next calving. Allows mammary gland
involution.
Persistency: Refers to the rate of decline in milk production during
late lactation. A slower decline is desirable.
Calving Interval: Ideally one year.
Physiological States and Breeding:
Open Days: The time a cow is not pregnant (ideally 100 days or less).
Interpregnancy Period: Calculated as VWP + days open + gestation
length (~60d).
Physiological States: Open, breeding, pregnancy (1st, 2nd, 3rd
trimester), dry, open + lactating.
Detailed Lactation Phases (over 12 months):
Phase 1 (Far Off): Dry period, late gestation. Focus on body condition
and fetal growth.
Phase 2 (Close Up): Preparing for calving, transition cow feeding
begins (~2 weeks before calving).
Phase 3 (Fresh): Just after calving, peak milk production rapidly
approaches.
Phase 4 (Peak Milk): Highest milk production achieved. Feed intake
increases.
Phase 5 (Peak DMI): Peak Dry Matter Intake achieved. Body weight is
recovering after calving. Milk production starts to decline.
Phase 6 (Peak Tail End): Milk production continues to decrease.
Additional Notes:
Body Condition Score (BCS) is lowest around calving and gradually
increases through lactation and the dry period.
Dry Matter Intake (DMI) mirrors the lactation curve, peaking after
milk production and then declining.
Body weight decreases in early lactation (negative energy balance)
and recovers throughout lactation and dry period.
Two weeks before expected calving date, lead feeding starts
(2.36-4.5 kg grain, 16-20% Crude Protein, >75% Total Digestible
Nutrients) along with anionic salts to prevent milk fever. This diet
supports rumen microbe adaptation and prepares the cow for higher
grain intake during lactation.
Conception ideally occurs around 100-105 days after calving.
Breeding and pregnancy overlap with lactation. Interpregnancy
period is calculated as VWP + days open + gestation length. Dry
period is approximately 60 days before next calving.
Abbreviations:
EL: Early Lactation
ML: Mid Lactation
LL: Late Lactation
DP: Dry Period
DMI: Dry Matter Intake
BCS: Body Condition Score
VWP: Voluntary Waiting Period (Inferred)
IPP: Interpregnancy Period (Inferred)