The Importance of Colostrum for Calves

Limin Kung, Jr., Ph.D.
Ruminant Nutrition & Microbiology Laboratory 

Raising healthy calves with minimal mortality is crucial in a successful dairying program.  The period between calving and weaning is the most crucial period in the animal's life.  Often, mortality may be as high as 15 to 20 % on any given farm.  Good dairymen should not be satisfied until calf losses are below 5 %.  Costs for quality weaned replacement heifers may be as high as $200 while bred heifers ready to calve average $1300.  In addition, calf raising is time consuming and carries potentially high medical bills. 

 A major management tool for reducing health problems in calves is the feeding of the dam's colostrum.  It is high in energy, protein, vitamins (especially vitamins A, D, E and B₁₂) and minerals (Table 1).  

Table 1.  Composition of colostrum compared to milk. 

Item	Colostrum – Day 1	Colostrum – Day 3	Milk
Total solids, %	21.0	13.0	12.9
Fat, %	6.3	4.3	4.0
Total protein, %	11.4	4.1	4.0
Lactose, %	3.3	4.7	5.0
Total minerals, %	1.03	.81	.74
Immunoglobulins, %	5.1	1.0	.09
Vitamin A, ug/100ml	240	74	34
Vitamin E, ug/g fat	80	31	15
Vitamin B12, ug/100 ml	4.9	2.4	.6

From Otterby, JDS 61:1033. 

Colostrum also contains proteins and peptides that have potent biological activity.  Most importantly, colostrum contains high levels of immunoglobulins, which transfers passive immunity to the calf and enables it to fight off infections.  The immunoglobulin, IgG1 accounts for about 80% of the total immunoglobulins.  The remainder is comprised of IgG2, IgM and IgA.  Immunoglobulin concentration in colostrum is highest in the first milking  (Table 1) and decreases to 50-70% at the second milking, to 30 to 50% by third milking and is nil by the fourth milking.  If the cow must be milked prior to calving, be sure to save the first colostrum for the calf.  To ensure optimal transfer of passive immunity from dam to calf, 2 quarts of first-colostrum must be fed to the calf within the first 2 to 4 hr of life followed by a second feeding within 12 hr.  Immunoglobulins are absorbed via a process called pinocytosis where by specialized cells in lower small intestine.  However, with age, these cells are replaced by basal nuclei incapable of pinocytosis.  This process is known as "gut closure" and it begins as rapidly as 12 hr after birth if no colostrum is fed.  When gut closure is complete, immunoglobulins cannot be absorbed.  Calf mortality increases as the interval between birth and ingesting colostrum increases.  An example of this is shown in Table 2.  The immunoglobulins are also absorbed selectively for varying times.  For example, IgG can be absorbed for about 27 hr, IgA for about 22 hr and IgM for about 16 hr.  In order to help protect degradation of immunoglobulins in the digestive tract, colostrum also contains trypsin inhibitors.  IgG levels have been used as a standard and titers of at least 10 g/L are needed for good passive transfer.  Besides being highly nutritious, colostrum also provides a local protective function at the intestinal lining.  Studies have shown that E. coli are absorbed through the intestine in calves that are not fed colostrum. 

Table 2.  Effect of interval from birth to colostrum feeding and calf mortality. 

How Soon Colostrum Was Fed	% Died, 0-14 days	% Died, Total
< 6 hours	7.6	16.3
6 – 12 hours	10.4	20.8

(From Oxender et al.  JAVMA)  

Colostrum is also a good source of minerals for calves.  Relative to dietary mineral requirements for calves, colostrum provides adequate amounts of Ca, P, Mg, Na, K, and Zn but is marginal in Fe, Cu and Mn.  Calves also have low liver stores of Fe and low levels of Fe can lead to anemia and adversely affect calf growth.  Several studies have shown improved growth when newborn calves were given oral or injectable Fe supplements.  A recent study showed that blood levels of Fe are extremely low in first calves from first calf heifers probably because transfer of Fe across the placenta is low in first calf heifers.  Thus, supplementing newborn calves with Fe is especially critical in calves from fist calf heifers.  Supplementation with Cu or Mn has been ineffective in enhancing growth probably because the calf has adequate liver stores of these two minerals. 

In general, milk from older cows with long dry periods contains more immunoglobulins than milk from younger cows.  If pooled colostrum is fed, obtain it from older herd cows rather than from heifers or purchased cows.  For unknown reasons, absorption of immunoglobulins is increased when calves stay with the dam for the first 2 to 4 feedings. 

A cow may provide 100 to 150 lbs. of colostrum, sufficient to feed their calves for 3 to 4 weeks if managed properly.  Direct savings in feed costs on a colostrum system compared to milk replacer is about $10 per calf.  Colostrum can be diluted and used as major source of milk for young calves with the only possible limitations being storage space and labor.  Freezing preserves nutritive value but requires a freezer and thawing time.  Other alternatives include fermenting or chemical treatment (propionic acid or formalin).  Michigan studies showed that calves fed frozen colostrum out performed those fed whole milk or replacer. 

Fermenting colostrum requires good management.  Fermentation causes a degradation of lactose and proteins so that calves fed fermented colostrum do not gain as rapidly as calves fed frozen colostrum or whole milk. 

To ferment colostrum:

1. Use only good colostrum that contains no blood
2. Store in covered plastic container
3. Pool colostrum
4. Store between 40 and 70 F, if ambient temperature is too cold the colostrum will not ferment
5. Stir once a day and, before feeding, check for mold (discard if moldy)
6. Use within 1 month

Other methods for storing colostrum:

1.  1% propionic acid.  Add 1 cup/6 gallons colostrum, 1 pt/100 lbs. colostrum; stir daily.
2.  .1% formalin (37% formaldehyde) 1.5 oz/100 lb. colostrum
3.  .5% sodium benzoate .5 lb/100 lb. colostrum 

After feeding fresh colostrum for 3 days, it should be diluted with water (2 parts colostrum: 1 part water) because of the high solids content and can be fed for up to 3 weeks before switching to a commercial replacer.  Using hot water often speeds the thawing process if using frozen colostrum.  Stools will be slightly loose for calves fed diluted colostrum but it is not detrimental diarrhea. 

If the calf is left with the dam be sure that her udder is washed and clean.  Suckling on a manure-covered teat will increase the chance of health problems for calves.