FIRST MEAL, BIG DEAL
Absorption of antibodies from colostrum significantly affects the lifetime profitability of the new-born heifer calf. A systematic protocol for colostrum management can be simple, does not require large investment but will ensure that every new-born calf is better prepared for the inevitable early challenge of disease.
Colostrum is the most important meal in the calf’s life.
A calf is born without antibodies so the nutrients and antibodies in quality colostrum are essential to prevent disease and are vital for rapid growth of the new-born. Reduced incidence of diarrhoea and respiratory disease as a result of feeding adequate quantities of high-quality colostrum as soon as possible after birth set a solid foundation for heifer calves to achieve their genetic ability. Trials have shown a direct connection between optimized colostrum management and milk yield.
Table 1 shows the estimated financial gain from optimizing colostrum management taken from four different sources. The financial gain calculated varies from one source to another due to the different parameters applied. However, all sources predict a significant financial gain from optimized colostrum management.
The calculations in Campos 2015 are based on the measured increase in milk yield in the first and second lactations of the cows, corrected for the lactation number. This results in a relatively higher estimate (EUR 243 per cow per year) compared with the other sources.
Large variation in colostrum antibody content. A planned colostrum strategy lays the foundation to produce strong milking cows with a high milk yield. One of the challenges in practice is the wide variation in the antibody content of the colostrum between cows. This has been demonstrated both in Danish studies and abroad. The variation in colostrum quality between cows can be caused one or combination of multiple factors, including genetics, numbers of lactations, the interval from calving to milking, feeding and management in the dry period.
It is not possible to predict antibodies in colostrum
The antibody content of colostrum cannot be predicted — even based on the cow’s lactation number. Statistically, there is a greater chance that older cows produce milk with a high content of antibodies. However, in practice some heifers produce high-quality colostrum and some older cows can produce low-quality colostrum. Similarly, the consistency or colour of the colostrum is not an accurate guide to colostrum quality.
This means that if the colostrum is given directly from the cow to the calf without testing, the level of antibodies received will be random and determined by chance.
A refractometer measures the content of milk solids, which is accepted as a reasonable estimate of the antibody content of the colostrum.
Determine the herd’s individual cut-off limit
The threshold of Brix 22 (corresponding to an antibody content of over 50 g/L) in the colostrum is often cited but should be ignored.
Instead, the aim should be to implement a colostrum strategy that uses the best possible colostrum available in the individual herd.
To do this, an individual cut off limit (Brix value) should be established for the herd, based on the average and variation in the antibody content in colostrum among the herd's own cows. This ensures the best possible start for all the new-born calves in the herd.
At the same time, efforts should be made to raise the level of the herd's colostrum quality, so the cut-off threshold can be raised as much as possible – for example through focus on the feed and management of dry cows, and milking the cow as soon as possible after calving.
The more antibodies the better
In the discussion about colostrum quality and threshold values, it is important to remember that the traditional threshold of Brix 22 is based on studies from the 1980s and 90s, carried out in the conditions and with the targets for dairy milk yield which prevailed at that time (Gay 1983, NAHMS 1994). The results of these studies showed a reduced frequency of disease and mortality among calves with a blood antibody content of over 10 g/L. Newer studies have shown a beneficial effect from raising the bar and aiming for a higher antibody concentration in the calf's blood (Urie et al., 2018).
Cost of rearing heifers
The financial gain is to be considered in the light of the minimal financial investment required to optimize colostrum management in a herd. Out of the total costs in the rearing period, of about EUR 1,400 per heifer (Clausen 2014), the investment in colostrum management amounts to only about 0.5% (Figure 4).
Colostrum freezing and the coloQuick system
Establishment of a colostrum bank by freezing the colostrum is essential and necessary to provide high quality colostrum to all new-born calves in a herd. The coloQuick system includes freezing colostrum in individual bags, laid flat in the freezer to decrease the time for freezing and thawing. Rapid freezing and thawing reduce the risk of bacterial growth.
The coloQuick system provides a quick, easy-to-use, uniform, and careful thawing process with strict temperature regulation, ensuring the preservation of immune components in the colostrum.
The concentration of immunoglobulins decreases at temperatures above 60°C  and therefore the heating of colostrum must be well-controlled to maintain colostrum quality.
The effects of freezing on colostrum components
Nutrients and immunoglobulins in colostrum are preserved despite freezing, and no difference in serum IgG concentrations has been observed in calves fed fresh versus frozen colostrum. Bioactive substances in colostrum includes a variety of cytokines and growth factors. A study on human milk shows that freezing of colostrum for 6 months did not decrease the concentration of selected bioactive components.
Advantages of freezing colostrum
The advantages of a systematic approach to colostrum management in the herd, including freezing of high-quality colostrum, by far exceed the possible disadvantages. The high value in providing all calves with a sufficient volume of colostrum with high IgG concentration quickly after birth, is recognized by a decrease in calf morbidity and mortality as well as an increase in herd productivity [12, 13].
Colostrum, and particularly unrefrigerated colostrum, is an excellent growth medium for bacteria. Most bacteria rely on binary fission and exhibit exponential growth under optimal conditions. The bacteria inhabiting colostrum cleave every 15-30 minutes resulting in a doubling of the bacterial population every 20 minutes.
The increased bacteria in colostrum has multiple negative connotations for calf health.
Antibody absorption is reduced by bacteria occupying and destroying antigen binding sites in the calf’s intestine.
Bacteria bind to antibodies in the intestine and thus hinder the antibodies from being absorbed into the calf’s bloodstream (Corley et al. 1977, James et al. 1981, Staley and Bush 1985).
Apart from affecting the absorption of antibodies, a high bacterial count in colostrum increase the risk of disease among calves through transfer of specific pathogenic bacteria.
In addition, bacteria break down the nutrients in the colostrum, decreasing the colostrum nutritional value.