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What is colostrum vs breast milk?

Both colostrum and breast milk are natural substances produced by a mother to feed her newborn baby. However, colostrum and breast milk have some key differences.

Colostrum is the first milk produced after giving birth. It is thick and yellowish/clear in color. Colostrum is only produced during the first few days after giving birth, before mature breast milk comes in. It contains high concentrations of nutrients and antibodies to provide nutrients and passive immunity to the newborn.

Breast milk is the mature milk that is produced after colostrum. It is thinner and whitish in color. Breast milk contains the perfect balance of proteins, fat, carbohydrates, vitamins, and minerals needed for a growing infant. It also contains antibodies, living cells, enzymes, and hormones that all contribute to infant health and development.

The key differences between colostrum and mature breast milk lie in the concentration and composition of nutrients, antibodies, and other bioactive components. Understanding the unique roles of colostrum versus breast milk can help mothers know what to expect in terms of breastfeeding nutrition in the first few days and weeks after giving birth.

Nutrient Composition

Colostrum and breast milk have different nutrient compositions:


– Colostrum is higher in concentration of protein compared to mature breast milk. Colostrum contains around 2-5x more protein than mature breast milk.

– The high protein content in colostrum helps stimulate growth and development in the newborn. It provides amino acids for building muscle, organs, enzymes, antibodies and more.

– Mature breast milk contains lower levels of protein (0.9-1.2g per 100ml) which meets the needs of the growing infant.


– Colostrum contains medium chain fatty acids which are easily absorbed into the bloodstream to provide quick energy. However, the overall fat content is lower than mature breast milk.

– Breast milk has a higher fat content than colostrum. It provides around 50% of an infant’s energy needs from fat. The high fat content aids in the development of the brain, nerves and eyes.


– Colostrum contains the milk sugar lactose like breast milk, but at a lower concentration.

– Breast milk provides around 40% of an infant’s energy needs from lactose which also promotes growth of healthy gut bacteria.

Vitamins & Minerals

– Colostrum contains at least 2-3x higher concentrations of many vitamins and minerals, including vitamin A, vitamin B12, vitamin E, selenium, and zinc.

– Breast milk contains lower concentrations overall but adequate amounts to meet an infant’s nutritional needs.

Here is a table comparing the nutrient composition of colostrum and breast milk:

Nutrient Colostrum Breast Milk
Protein 2-5x higher 0.9-1.2g per 100ml
Fat Medium chain fatty acids ~50% of energy needs
Carbs (lactose) Lower concentration ~40% of energy needs
Vitamins & Minerals 2-3x higher Adequate amounts

Immunologic Factors

One of the key functions of colostrum is providing passive immunity to the newborn. Colostrum contains much higher concentrations of protective compounds compared to mature breast milk.


– Colostrum contains high levels of secretory IgA antibodies that protect against pathogens by neutralizing viruses and bacteria.

– Levels of IgA and other antibodies are significantly lower in mature breast milk, but still provide antibody protection.


– Colostrum contains billions of white blood cells and other immune factors that can kill pathogens directly.

– Breast milk contains some leukocytes, but at lower concentrations than colostrum.


– Lactoferrin is an antimicrobial and anti-inflammatory protein found in high amounts in colostrum.

– Lactoferrin levels decrease as breast milk matures.


– Colostrum contains some oligosaccharides which act as prebiotics for healthy gut bacteria.

– However, mature breast milk contains significantly higher levels of oligosaccharides to promote the infant gut microbiome.

Here is a comparison of the immunologic factors:

Immune Factor Colostrum Breast Milk
Antibodies (IgA) Very high levels Lower levels
Leukocytes Billions present Some present
Lactoferrin High levels Levels decrease
Oligosaccharides Some present Higher levels

Hormones & Growth Factors

Colostrum and breast milk also differ in their hormone and growth factor content:

– Colostrum is rich in growth factors like insulin, IGF-1, TGF-beta, and EGF which stimulate development of the intestinal tract and immune system. Levels decrease as breast milk matures.

– Breast milk contains some growth factors but lower amounts than colostrum. However, it contains higher amounts of hormones like leptin, ghrelin, and adiponectin that regulate appetite in infants.

– The unique profile of hormones in breast milk protects against obesity later in life by influencing infant hunger and satiety signals.

– In summary, colostrum provides a concentrated dose of growth factors for early development while breast milk contains hormones for ongoing appetite regulation.

Volume Produced

The volumes of colostrum and breast milk produced also differ:

– Colostrum is only produced in small volumes in the first few days after giving birth, ranging from around 10-100ml per day.

– After the milk comes in around 2-5 days postpartum, volumes sharply increase to around 400-1200ml per day.

– Colostrum provides concentrated nutrition and immune factors in a small volume that is perfect for the newborn stomach capacity.

– Higher volumes of breast milk are then produced to align with the infant’s increasing nutritional demands during growth and development.

Here is a table comparing the volumes:

Colostrum Breast Milk
Volume Range 10-100 ml/day 400-1200 ml/day

How Long It’s Produced

– Colostrum is only produced for the first 2-5 days after giving birth before mature milk comes in.

– Breast milk can be produced as long as a mother breastfeeds her infant, which can be up to 2 years or longer.

– The composition of breast milk continues changing slightly to meet the infant’s needs over time. But it maintains the adequate balance of nutrients, antibodies, and other protective components.

Color and Consistency

There are visual differences between colostrum and mature breast milk:

– Colostrum is thick and sticky with a yellow, golden, or clear color.

– Mature breast milk is thinner and more white or bluish in color. The fat content can cause it to look bluish-white or white.

– Colostrum’s thick, sticky texture helps it adhere and coat the lining of an infant’s mouth and digestive tract.

– Breast milk has a thinner, more watery consistency that allows it to flow easily during breastfeeding.

Benefits for the Infant

Both colostrum and breast milk have unique benefits tailored to an infant’s needs:

Benefits of Colostrum

– Clears meconium from newborn intestines

– Provides concentrated nutrition for quick energy

– Contains antibodies and leukocytes for passive immunity

– Growth factors stimulate development of the gut

– Bioactive compounds like lactoferrin have antimicrobial effects

– Thick consistency coats and protects digestive tract

Benefits of Breast Milk

– Perfectly balanced nutrition for growth and development

– Ongoing source of antibodies to fight infections

– Contains prebiotics to establish healthy gut flora

– Metabolic hormones influence infant hunger and satiety

– Promotes bonding and emotional attachment

– Reduces risk of diseases like diarrhea, allergies, and obesity

Pumping and Storage

Collecting and storing colostrum is different than for mature breast milk:

– Colostrum can be hand expressed and collected before giving birth since only small amounts are produced.

– It should be frozen in small volumes like syringes since production is limited.

– Colostrum can be stored frozen for 12 months. It can be thawed and given to newborns who need additional immune protection.

– For breast milk, mothers pump and store milk as needed based on baby’s feeding requirements and her milk supply.

– Breast milk can be stored in bottles, bags or containers. It can be refrigerated for 4 days or frozen for up to 6 months.

Signs of Quality

There are visual cues mothers can look for to identify quality colostrum vs breast milk:

High Quality Colostrum

– Thick, sticky, and opaque yellow/gold color

– Coats surfaces instead of separating into layers

– Looks like melted vanilla ice cream

High Quality Breast Milk

– Creamy white or bluish-white color

– mainly opaque with thin translucent layer

– pleasant or mild odor


Colostrum and breast milk have some differences in taste:

– Colostrum often has a salty taste, similar to blood plasma which makes sense since it contains high levels of protein and antibodies.

– Breast milk tends to have a sweeter, more agreeable taste than colostrum. The higher lactose content contributes to breast milk’s sweeter taste.

– Infants generally show signs of preferring the taste of mature breast milk to colostrum, possibly because of its sweeter flavor.

– However, colostrum provides them with the nutrients and immune factors essential in those early days. Over time, infants will adapt to the changing flavors of breast milk as the composition changes.

Common Concerns

There are some common concerns that mothers may have regarding colostrum and breast milk:

Colostrum Concerns

– Not producing enough – But even small amounts provide concentrated nutrition and antibodies for baby’s needs.

– Unusual color – Normal colors can range from yellow to clear. As long as it’s thick and opaque, the color is likely normal.

– Worried baby is hungry – Babies have a tiny stomach capacity at birth and colostrum meets their needs.

Breast Milk Concerns

– Insufficient supply – Keep nursing on demand and stay hydrated to increase supply. Certain foods, herbs, and medication can also help increase milk production.

– Needing to supplement – Supplementary feedings may be recommended if growth needs aren’t being met. The goal should be increasing breast milk supply so supplementation is temporary.

– Safety of medications/illness – Discuss any medications or illnesses with your doctor to identify any breastfeeding risks or precautions needed.

Increasing Low Supply

If mothers are concerned about low colostrum or breast milk supply, there are various methods that may help increase production:

– Breastfeed as often as possible, allowing infant to fully drain the breasts. This signals your body to produce more milk.

– Stay hydrated by drinking water, milk, soups and other fluids. Dehydration can decrease supply.

– Get adequate rest and relaxation. Stress inhibits let-down reflex and milk production.

– Certain foods like oatmeal, leafy greens, and garlic can help boost supply.

– Herbal supplements like fenugreek, blessed thistle, and fennel may also help some mothers.

– Medications like domperidone and galactagogues are sometimes prescribed when other methods don’t work. But discuss with your doctor first.

– Seek help from a lactation consultant who can assess feeding issues and advise about increasing low supply.


While colostrum and mature breast milk have distinct differences in nutrient content, immune factors, and volumes produced, they both provide perfect nutrition tailored to the specific needs of infants at each stage of development in the first days, weeks and months of life. Colostrum gives an immunity boost and growth factors for rapid development right after birth. Breast milk takes over as the ongoing source of nutrition, antibodies, and other components supporting growth and establishing long-term health. Understand the role of each helps mothers know what to expect and how to maximize the benefits of breastfeeding their newborns.